Impact of Vertical Facial Patterns and Oral Habits on Microbial Colonization in Children and Adolescents: A Cross-Sectional Study

Impact of Vertical Facial Patterns and Oral Habits on Microbial Colonization in Children and Adolescents: A Cross-Sectional Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Impact of Vertical Facial Patterns and Oral Habits on Microbial Colonization in Children and Adolescents: A Cross-Sectional Study Saliha Akçay Köprücü, Saadettin Kayıpmaz, İlknur Tosun, Ömer S. Sezgin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8062768/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 11 Mar, 2026 Read the published version in BMC Pediatrics → Version 1 posted 12 You are reading this latest preprint version Abstract Background The oral commissures represent a unique anatomical interface where intra- and extra-oral environments converge. This study aimed to investigate the association between vertical facial patterns and microbial colonisation at the oral commissures in children and adolescents. Methods A total of 150 healthy participants aged 8–18 years were equally divided into low-, norm-, and high-angle groups according to their cephalometric GoGn/SN values. Swab samples from both commissures were cultured for Candida species and Gram-positive bacteria. Commissural wetness, intra-oral pH, and oral habits were also recorded. Group differences were analysed using chi-square and ANOVA tests with effect sizes (α = 0.05). Results Vertical facial morphology showed a significant association with bacterial colonisation (p = 0.001). Gram-positive bacilli were absent in low-angle but frequent in norm- and high-angle individuals. Candida carriage (12.0%) showed no significant association with facial pattern (p = 0.103). Mouth breathing was significantly more prevalent in high-angle participants (p = 0.038), while lip-licking habits showed no intergroup difference. Conclusion Increased vertical facial dimension was strongly related to bacterial, but not fungal, colonisation at the oral commissures. Craniofacial morphology may therefore influence the local microbial ecology and should be considered a potential risk modifier in paediatric patients presenting with recurrent angular lesions. Trial registration: Not applicable. Candida Gram-positive bacteria Vertical dimension Child Adolescent Figures Figure 1 INTRODUCTION Vertical facial morphology may influence several local physiological and microbial conditions within the oral environment. Individuals with increased vertical dimensions often exhibit altered perioral muscle tone, lip competence, and salivary flow, which can modify surface moisture and pH at the mouth corners. 1-4 The oral commissures, located at the intersection of intra- and extra-oral regions, represent a dynamic microenvironment affected by facial structure, saliva flow, and oral habits. Imbalances in this area can lead to microbial accumulation and inflammatory changes. 5-7 Among the microorganisms inhabiting the commissural region, Candida species and Gram-positive bacteria are the most frequently detected. Candida albicans is a commensal yeast that can become opportunistic under local or systemic disturbances, whereas Gram-positive cocci and bacilli are part of the resident flora that may increase under altered moisture or pH. 6,8-9 Previous studies have mostly focused on elderly or denture-wearing populations, where loss of vertical dimension was considered a risk factor for angular cheilitis. 6,9-11 However, little is known about whether vertical facial patterns in children and adolescents—who exhibit active growth and no prosthetic alterations—affect local microbial colonization at the oral commissures. In children and adolescents, additional local factors such as mouth breathing and lip-licking habits may play an important role in shaping the microbial ecology of the perioral region. Indeed, recent studies have shown that mouth breathing not only is associated with skeletal and facial vertical changes (for example, increased mandibular plane angles) but also corresponds to distinct alterations in oral microbial communities, including enrichments of opportunistic bacterial species and changes in salivary protein composition. 12-13 These oral habits are also known to be more prevalent in certain vertical facial patterns, such as high-angle skeletal configurations, and may therefore serve as indirect risk modifiers for colonization. Despite these potential links, evidence regarding the interaction between vertical facial patterns, oral habits, and oral microbial colonization in children and adolescents remains scarce. Therefore, the aim of this study was to evaluate the relationship between vertical facial morphology, oral habits, and microbial colonization at the oral commissures in children and adolescents. We hypothesized that distinct vertical growth patterns could be associated with specific microbial profiles and that oral habits may influence this relationship. To our knowledge, this is the first study to highlight the oral commissures as a clinically relevant site reflecting both functional and microbial interactions in growing individuals. MATERİALS AND METHODS Ethical Approval This study was reviewed and approved by the Scientific Research Ethics Committee of Karadeniz Technical University, Faculty of Dentistry (Approval No: 2015/89). All procedures were conducted in accordance with the Declaration of Helsinki, and written informed consent was obtained from all participants and their parents or legal guardians. Study Design and Sample Selection This cross-sectional study included 150 caries-free children and adolescents (66 males, 84 females; mean age = 13.4 years; range 8–18 years) who attended the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Karadeniz Technical University. Eligibility criteria were the absence of systemic disease, no history of tobacco or alcohol use, no previous orthodontic treatment, and no craniofacial anomalies. Participants were equally distributed among low-, norm-, and high-angle groups to enable balanced comparisons across vertical facial patterns. The study followed the STROBE checklist for cross-sectional studies. 14 Assessment of Vertical Facial Dimension Lateral cephalometric radiographs were obtained with a Kodak 9000C Dental System (Carestream Health, Rochester, NY, USA) using 80 kVp, 10 mA, and 0.5 s exposure, with a 24 × 30 cm field of view and a magnification factor of 1.15. Vertical facial pattern was defined by the GoGn/SN angle and classified as low-angle (36°). Each category included 50 patients (n=50 per group). Oral Habits Assessment Breathing pattern and lip-licking habit information were obtained by self-report from children and their parents and recorded as either present or absent. Oral pH Measurement Intraoral pH was measured using MColorpHast indicator strips (Merck, Darmstadt, Germany). Strips were placed intraorally for 2 minutes, then compared with the manufacturer’s color chart. Angular Wetness Measurement Angular wetness was assessed with modified Schirmer strips folded in an L shape. The shorter arm (5 mm) was positioned at the mouth corner for 3 minutes, and the wetted length (mm) recorded as the wetness value. Collection and Culturing of Swab Samples All samples were collected between 9:00 and 11:00 AM to minimize diurnal variations. Using sterile cotton swabs, both commissures were sampled by gentle contact for ≥ 5 seconds. Each swab was transferred to Stuart transport medium (FIRATMED, Türkiye) and immediately inoculated on Sabouraud dextrose agar (SDA) in duplicate Petri dishes, incubated 30–35 °C for 7 days. Colonies were microscopically examined; yeast-like forms underwent the germ-tube test (positive = C. albicans ), while negative samples were classified as non-albicans Candida using API 20 C AUX (bioMérieux, France). Statistical Analysis All analyses were performed in SPSS v26.0 (IBM Corp., Armonk, NY, USA). Sample adequacy (N = 150; n = 50 per group) was verified using G*Power 3.1.9.7 for one-way ANOVA (effect size 0.30, α = 0.05, power = 0.91). Normality of continuous variables (age, wetness, pH) was verified with Kolmogorov–Smirnov and |skewness|, |kurtosis| < 1.5; hence parametric tests were applied. Means ± SD and frequencies (%) summarized data. Group differences for continuous variables were tested with one-way ANOVA and Duncan post-hoc comparisons. Categorical associations (e.g., vertical pattern vs microbial type, oral habit) used Pearson χ² and Fisher’s exact test (where expected frequencies < 5). Correlations among continuous variables used Pearson r. Two-tailed p < 0.05 was considered significant. RESULTS Microbiological Findings Microbiological analysis showed that Gram-positive cocci were the most prevalent isolates, found in 84 of 150 participants (56.0%). Other findings included no microbial growth in 23 (15.3%), Candida species in 18 (12.0%), Gram-positive bacilli in 18 (12.0%), and combined Gram-positive cocci + bacilli in 7 (4.7%) (Table 1). Overall, Gram-positive cocci represented the dominant flora at the oral commissures of healthy children and adolescents. A significant association was observed between vertical facial morphology and microbial outcomes (p = 0.001) (Table 2). Post-hoc analysis indicated that the low-angle group had a higher rate of no microbial growth (65.2%) compared with other groups, whereas all Gram-positive bacilli isolates occurred in norm-angle (66.7%) and high-angle (33.3%) individuals. This distribution demonstrates that increased vertical dimension correlates with a more complex bacterial profile at the oral commissures. One-way ANOVA revealed significant differences in vertical dimension degrees across microbial categories (p = 0.005) (Table 3). Participants with Candida (35.9 ± 6.8), Gram-positive bacilli (33.2 ± 3.7), Gram-positive cocci (30.8 ± 9.3), or cocci + bacilli (34.7 ± 5.8) had higher GoGn/SN angles than those with no microbial growth (26.8 ± 6.6). Candida carriage showed no significant association with vertical facial pattern (p = 0.103). Similarly, no significant differences were found for cocci or cocci + bacilli combinations (all p > 0.05). These results confirm that vertical skeletal morphology is significantly associated with bacterial—but not fungal—colonization at the oral commissures. In addition, no significant sex-related differences were observed in any of the microbiological outcomes (all p > 0.05). Angular Wetness and Oral pH Mean angular wetness was 9.5 ± 5.0 mm and mean intraoral pH = 7.3 ± 0.3 (Table 1). Both variables showed no significant intergroup differences (p > 0.05). Correlation analysis indicated that age correlated negatively with wetness (r = –0.369, p = 0.001), while wetness (r = 0.171, p = 0.036) and pH (r = 0.183, p = 0.025) correlated positively with vertical dimension degrees. Thus, higher vertical dimensions were associated with slightly higher moisture and pH, whereas increasing age reduced wetness. In addition, there were no significant sex-related differences in the physiological parameters, including pH and angular wetness (all p > 0.05). Mouth Breathing Mouth breathing was reported by 22.0% (n = 33). Its association with vertical morphology was significant (p = 0.038) (Table 2). The habit was most frequent in high-angle participants (51.5%) versus norm-angle (27.3%) and low-angle (21.2%) groups, suggesting that increased vertical dimension relates to greater mouth-breathing prevalence. Although the association between mouth breathing and microbiological category did not reach significance (p = 0.078), descriptive data showed that Gram-positive cocci were most common among mouth breathers (57.6%), followed by Candida (21.2%). Lip-Licking Lip-licking was reported in 12.7% (n = 19). No significant association was found between vertical morphology and lip-licking (p = 0.075) (Table 2). Gram-positive cocci predominated among these individuals (68.4%), but the relationship was not statistically significant (p = 0.432). DISCUSSION This study demonstrates that vertical skeletal morphology is significantly associated with bacterial—but not fungal—colonization at the oral commissures in children and adolescents. The absence of Gram-positive bacilli in low-angle individuals, contrasted with their presence in norm- and high-angle groups, indicates that craniofacial structure is a determinant of the perioral ecological niche. To our knowledge, this association has not previously been documented in paediatric populations. The prevalence of Candida carriage (12.0%) in this cohort is lower than the 20–40% range commonly reported for children. 15,16 This difference likely reflects the localized sampling site (oral commissures only) and the inclusion of caries-free, systemically healthy participants. Prior studies have used pooled intraoral samples from multiple sites, resulting in higher isolation rates. Importantly, colonization does not imply infection; Candida species often exist as commensals. 17 In contrast, Gram-positive bacilli were closely linked to increased vertical dimension. These organisms were found exclusively in norm- and high-angle individuals, supporting the idea that skeletal morphology can shape the local microbial environment. Such a relationship extends previous research that largely emphasized fungal species by highlighting how anatomical structure may condition bacterial colonization patterns. 18 Recent evidence suggests that mouth breathing may influence the composition of the oral microbiota. Marincak Vrankova et al. reported a higher relative abundance of Solobacterium in mouth-breathing children compared with nasal breathers, indicating a potential microbial shift associated with altered breathing patterns. 19 In our study, however, no significant microbial differences were detected between breathing types. The increased occurrence of Gram-positive bacilli in the high-angle group might indirectly reflect a higher prevalence of mouth breathing within this craniofacial pattern. Nonetheless, subtle microbial alterations related to oral respiration may not have been fully captured, as the breathing pattern was determined based on self-reported information rather than objective evaluation. Previous microbiome studies have shown that the oral cavity harbors hundreds of bacterial species, primarily from the phyla Firmicutes , Bacteroidetes , Proteobacteria , Actinobacteria , Spirochaetes , and Fusobacteria 20 In healthy individuals, Streptococcus salivarius represents the predominant commensal organism on the tongue surface, whereas its reduction and the increased abundance of anaerobes such as Solobacterium moorei , Atopobium parvulum , and Fusobacterium periodonticum have been associated with halitosis and dysbiotic oral conditions. 21 These findings support the concept that changes in oral environment—such as those potentially occurring in high-angle, mouth-breathing individuals—may favor a microbial shift toward species with greater pathogenic potential. Mouth breathing was more frequent in high-angle individuals, consistent with earlier studies associating this habit with increased mandibular plane angles and maxillary constriction. 22,23 Although not statistically significant, mouth breathers showed a tendency toward higher bacterial diversity, possibly related to airflow and mucosal dehydration. The present results support early identification and management of airway dysfunction as part of paediatric dental assessment. Lip-licking behaviour was not significantly related to vertical morphology but showed mild directional trends. Repetitive lip licking can increase moisture and epithelial irritation, promoting colonization potential. 24 Larger samples may clarify whether such habits indirectly modulate the commissural microbiota. Neither fungal nor bacterial colonization was significantly associated with oral habits, suggesting that structural morphology exerts a stronger, more consistent influence than transient behavioural factors. These findings are consistent with contemporary reviews describing the paediatric oral microbiome as multifactorial yet heavily influenced by host anatomy. 1,2,7 The mechanism underlying the relationship between increased vertical dimension and bacterial colonization may involve multiple pathways. First, high-angle individuals typically exhibit reduced lip seal competence and altered perioral muscle function, potentially creating a more humid microenvironment favorable for bacterial growth. 25 Second, the association with mouth breathing—observed more frequently in our high-angle group (51.5%)—may contribute through chronic mucosal dehydration and altered local immunity. 12 Third, biomechanical factors such as increased tissue tension at the commissures in vertically excessive faces may affect epithelial barrier integrity. However, the finding that pH and wetness did not differ significantly between groups suggests that unmeasured variables—such as salivary protein composition, local cytokine profiles, or epithelial turnover rates—may play important roles. 26 Further research using molecular and immunological approaches is needed to elucidate these pathways. Limitations and Future Directions This study has several limitations that should be considered when interpreting the results. Although equal group sizes were used to ensure statistical balance, this stratification does not reflect the natural prevalence of vertical facial patterns in the general paediatric population, which may limit the generalizability of the findings. Furthermore, culture-based identification restricted taxonomic resolution; molecular techniques such as 16S rRNA sequencing would provide broader microbial detection and species-level characterization. Additional variables—including nutritional status, salivary flow rate, and vitamin levels—were not evaluated, and single-time measurements of pH and wetness may not capture daily fluctuations. Future research should adopt multicentre and longitudinal designs integrating molecular bacteriome and mycobiome profiling, objective quantification of oral habits, and airway assessment. Such studies would help clarify the causal pathways linking craniofacial morphology to oral microbial ecology and identify potential clinical markers for early preventive intervention. CONCLUSION In this cross-sectional study of healthy children and adolescents, increased vertical facial dimension was significantly associated with Gram-positive bacilli colonization at the oral commissures, independent of Candida carriage. These findings suggest that craniofacial morphology may influence local bacterial ecology and warrant consideration in pediatric oral health assessment. Abbreviations ANOVA Analysis of Variance CFU Colony-Forming Unit FOV Field of View SPSS Statistical Package for the Social Sciences STROBE Strengthening the Reporting of Observational Studies in Epidemiology Declarations Ethics approval and consent to participate This study was reviewed and approved by the Scientific Research Ethics Committee of Karadeniz Technical University, Faculty of Medicine (Approval No: 2015/89). Written informed consent was obtained from all participants and their parents or legal guardians. Consent for publication Not applicable. Availability of data and materials All data generated or analysed during this study are included in the supplementary material files submitted with the manuscript. Competing Interests The authors declare that they have no competing interests. Funding No specific funding was received for this study. Authors’ contributions Conceptualisation: SAK, SK; Methodology: SAK, SK, ÖSS, İT; Data collection and analysis: SAK, İT; Writing – original draft: SAK; Writing – review and editing: SAK, İT, SK; All authors read and approved the final manuscript. Acknowledgements The authors also thank İstatistik Analiz Merkezi, Ankara, Türkiye, for their assistance with data processing. References Jørgensen MR. Pathophysiological microenvironments in oral candidiasis. APMIS. 2024;132(12):956–73. https://doi.org/10.1111/apm.13412 . AlHarbi SG, Almushayt AS, Bamashmous S, Abujamel TS, Bamashmous NO. The oral microbiome of children in health and disease: a literature review. Front Oral Health. 2024;5:1477004. https://doi.org/10.3389/froh.2024.1477004 . Paik CH, Lee MH, Park JH. Treatment strategies for vertical maxillary excess: cases with and without anterior open bite. Semin Orthod. 2024;30(5):648–72. https://doi.org/10.1053/j.sodo.2024.06.004 . Venugopal A, Manzano P, Ahmed F, Vaiid N, Bowman SJ. Gummy smiles: etiologies, diagnoses and formulating a clinically effective treatment protocol. Semin Orthod. 2024;30(5):482–501. https://doi.org/10.1053/j.sodo.2023.11.014 . Patil S, Rao RS, Majumdar B, Anil S. Clinical appearance of oral Candida infection and therapeutic strategies. Front Microbiol. 2015;6:1391. https://doi.org/10.3389/fmicb.2015.01391 . Cabras M, Gambino A, Broccoletti R, Lodi G, Arduino PG. Treatment of angular cheilitis. Oral Dis. 2020;26(6):1107–15. https://doi.org/10.1111/odi.13183 . Ramage G, Borghi E, Rodrigues CF, Kean R, Williams C, Lopez-Ribot JL. Our current clinical understanding of Candida biofilms: where are we two decades on? APMIS. 2023;131(11):636–53. https://doi.org/10.1111/apm.13310 . Epub 2023 Mar 29. Millsop JW, Fazel N. Oral candidiasis. Clin Dermatol. 2016;34(4):487–94. https://doi.org/10.1016/j.clindermatol.2016.02.022 . Park KK, Brodell RT, Helms SE. Angular cheilitis: local etiologies. Cutis. 2011;87(6):289–95. https://pubmed.ncbi.nlm.nih.gov/21838086 . Shang J, Li J. Risk factors for denture-related oral mucosal lesions. J Hard Tissue Biol. 2024;33(3):143–6. https://doi.org/10.2485/jhtb.33.143 . Mahdani FY, Jati GD, Febrine ET, Cahyaningrum KW, Radithia D, Wicaksono S. Knowledge of xerostomia and angular cheilitis in geriatric population among clinical dental students: an institutional cross-sectional study. J Int Soc Prev Community Dent. 2023;13(6):443–9. https://doi.org/10.4103/jispcd.JISPCD_91_23 . Fan C, Guo L, Gu H, Huo Y, Lin H. Alterations in oral–nasal–pharyngeal microbiota and salivary proteins in mouth-breathing children. Front Microbiol. 2020;11:575550. https://doi.org/10.3389/fmicb.2020.575550 . Mummolo S, Nota A, Caruso S, Quinzi V, Marchetti E, Marzo G. Salivary markers and microbial flora in mouth-breathing late adolescents. Biomed Res Int. 2018;2018:8687608. https://doi.org/10.1155/2018/8687608 . von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP, STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008;61(4):344–9. https://doi.org/10.1016/j.jclinepi.2007.11.008 . Kadir T, Uygun B, Akyüz S. Prevalence of Candida species in Turkish children: relationship between dietary intake and carriage. Arch Oral Biol. 2005;50(1):33–7. https://doi.org/10.1016/j.archoralbio.2004.07.004 . Pinto-Almazán R, Frías-De-León MG, Fuentes-Venado CE, Arenas R, González-Gutiérrez L, Chávez-Gutiérrez E, Torres-Paez OU, Martínez-Herrera E. Frequency of Candida spp. in the oral cavity of asymptomatic preschool Mexican children and its association with nutritional status. Child (Basel). 2022;9(10):1510. https://doi.org/10.3390/children9101510 . Vila T, Sultan AS, Montelongo-Jauregui D, Jabra-Rizk MA. Oral candidiasis: a disease of opportunity. J Fungi (Basel). 2020;6(1):15. https://doi.org/10.3390/jof6010015 . Ma T, Wu Z, Lin J, Shan C, Abasijiang A, Zhao J. Characterization of the oral and gut microbiome in children with obesity aged 3 to 5 years. Front Cell Infect Microbiol. 2023;13:1102650. https://doi.org/10.3389/fcimb.2023.1102650 . Marincak Vrankova Z, Brenerova P, Bodokyova L, Bohm J, Ruzicka F, Borilova Linhartova P. Tongue microbiota in relation to the breathing preference in children undergoing orthodontic treatment. BMC Oral Health. 2024;24(1):1259. https://doi.org/10.1186/s12903-024-05062-3 . Dewhirst FE, Chen T, Izard J, Paster BJ, Tanner AC, Yu WH, Lakshmanan A, Wade WG. The human oral microbiome. J Bacteriol. 2010;192(19):5002–17. https://doi.org/10.1128/JB.00542-10 . Kazor CE, Mitchell PM, Lee AM, Stokes LN, Loesche WJ, Dewhirst FE, Paster BJ. Diversity of bacterial populations on the tongue dorsa of patients with halitosis and healthy patients. J Clin Microbiol. 2003;41(2):558–63. https://doi.org/10.1128/JCM.41.2.558-563.2003 . Souki BQ, Pimenta GB, Souki MQ, Franco LP, Becker HMG, Pinto JA. Prevalence of malocclusion among mouth-breathing children: do expectations meet reality? Int J Pediatr Otorhinolaryngol. 2009;73(5):767–73. https://doi.org/10.1016/j.ijporl.2009.02.006 . Zhao Z, Zheng L, Huang X, Li C, Liu J, Hu Y. Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis. BMC Oral Health. 2021;21:108. https://doi.org/10.1186/s12903-021-01458-7 . Fonseca A, Jacob SE, Sindle A. Art of prevention: practical interventions in lip-licking dermatitis. Int J Womens Dermatol. 2020;6(5):377–80. https://doi.org/10.1016/j.ijwd.2020.06.001 . Drevensek M, Papić JS. The influence of respiration disturbances on the growth and development of the orofacial complex. Coll Antropol. 2005;29(1):221–5. Said HS, Suda W, Nakagome S, Chinen H, Oshima K, Kim S, Kimura R, Iraha A, Ishida H, Fujita J, Mano S, Morita H, Dohi T, Oota H, Hattori M. Dysbiosis of salivary microbiota in inflammatory bowel disease and its association with oral immunological biomarkers. DNA Res. 2014;21(1):15–25. https://doi.org/10.1093/dnares/dst037 . Tables Table 1 to 4 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Table2.docx Table3.docx SupplementaryTableFinal.docx Table4.docx Cite Share Download PDF Status: Published Journal Publication published 11 Mar, 2026 Read the published version in BMC Pediatrics → Version 1 posted Editorial decision: Revision requested 19 Jan, 2026 Reviews received at journal 03 Jan, 2026 Reviews received at journal 29 Dec, 2025 Reviewers agreed at journal 22 Dec, 2025 Reviewers agreed at journal 22 Dec, 2025 Reviewers agreed at journal 22 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviewers invited by journal 19 Dec, 2025 Editor assigned by journal 17 Dec, 2025 Editor invited by journal 20 Nov, 2025 Submission checks completed at journal 19 Nov, 2025 First submitted to journal 19 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8062768","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":563208087,"identity":"8ef5db25-a310-4a31-a9d6-0f1e983a4485","order_by":0,"name":"Saliha Akçay Köprücü","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYDCCAyCiQCKBgYENxLIBYsbGA3i1HAMRBnAtaSAtDcRoYYBpOYywGhfgu9/A/OGHgUUef/uxxA8/287brW0/DLSlxiYalxbJYwxskj0GEsUSZ9IOS/a23U7ediYRqOVYWm4DDi0GQC0MPAYSQGXpbQy8QC1mB4BsxobD+LQwf/wD1DL//PM2xr9t55LNzj8kqIVBGmTLhhtpx5h52w7Ymd0gYIvkscQ2aRmglo03niVLy5xLTjC7AbQlAY9f+A4fPvzxTUVd4rzzaYYf35TZ2ZudT3/44EONDU4toIhDYrMxJIK5CTiVY4A/DPbEKx4Fo2AUjIKRAgCe0Ga4cYm6agAAAABJRU5ErkJggg==","orcid":"","institution":"Karadeniz Technical University","correspondingAuthor":true,"prefix":"","firstName":"Saliha","middleName":"Akçay","lastName":"Köprücü","suffix":""},{"id":563208088,"identity":"67b77c76-b253-4b8d-badf-b874ad7fa3d6","order_by":1,"name":"Saadettin Kayıpmaz","email":"","orcid":"","institution":"Karadeniz Technical University","correspondingAuthor":false,"prefix":"","firstName":"Saadettin","middleName":"","lastName":"Kayıpmaz","suffix":""},{"id":563208089,"identity":"75c7a42c-38fc-46ea-9f28-b89fe9230b32","order_by":2,"name":"İlknur Tosun","email":"","orcid":"","institution":"Karadeniz Technical University","correspondingAuthor":false,"prefix":"","firstName":"İlknur","middleName":"","lastName":"Tosun","suffix":""},{"id":563208090,"identity":"5b713357-63bf-4588-8380-18bcdb0a7241","order_by":3,"name":"Ömer S. Sezgin","email":"","orcid":"","institution":"Karadeniz Technical University","correspondingAuthor":false,"prefix":"","firstName":"Ömer","middleName":"S.","lastName":"Sezgin","suffix":""}],"badges":[],"createdAt":"2025-11-08 09:08:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8062768/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8062768/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12887-026-06732-7","type":"published","date":"2026-03-11T15:58:45+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":98771118,"identity":"7b07cfdf-8163-43e4-b406-ba41b206776b","added_by":"auto","created_at":"2025-12-22 10:40:11","extension":"tif","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7923622,"visible":true,"origin":"","legend":"","description":"","filename":"figure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/0e079f034fbdde6b81ae28b5.tif"},{"id":98771140,"identity":"5123fd24-9104-4379-a579-8b607559bf63","added_by":"auto","created_at":"2025-12-22 10:40:13","extension":"doc","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":114176,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.doc","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/d1db25e9524a083de38547ee.doc"},{"id":98771062,"identity":"a3b71df1-c3d6-40d1-9ed7-21900bef92c8","added_by":"auto","created_at":"2025-12-22 10:40:07","extension":"json","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5872,"visible":true,"origin":"","legend":"","description":"","filename":"5e39a36e89184fb6bce2477427333832.json","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/a7f04ba7f8a6c0170142f509.json"},{"id":98771048,"identity":"697a62a7-f8df-4daa-9f28-e79793fbc36f","added_by":"auto","created_at":"2025-12-22 10:40:05","extension":"docx","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":25369,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTableFinal.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/dd2759e67d6969da3e9f02e7.docx"},{"id":98771133,"identity":"f849015f-643c-4553-ab6d-ee832089845d","added_by":"auto","created_at":"2025-12-22 10:40:12","extension":"xml","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":107309,"visible":true,"origin":"","legend":"","description":"","filename":"5e39a36e89184fb6bce24774273338321enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/d241737c754afbfbfc3ee982.xml"},{"id":98771081,"identity":"e2bc2191-48f4-43a6-93ee-4106e6f12cda","added_by":"auto","created_at":"2025-12-22 10:40:09","extension":"tif","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7923622,"visible":true,"origin":"","legend":"","description":"","filename":"figure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/971ac99c28710b1a64879fbe.tif"},{"id":98771104,"identity":"6e6e1c6a-f153-4c10-9874-0f1db7aacdd4","added_by":"auto","created_at":"2025-12-22 10:40:11","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":23831,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/c78fc1bfe7ecc23d94644202.png"},{"id":98771128,"identity":"4d48bffe-d809-490f-9b04-ff58f967920c","added_by":"auto","created_at":"2025-12-22 10:40:12","extension":"xml","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":103095,"visible":true,"origin":"","legend":"","description":"","filename":"5e39a36e89184fb6bce24774273338321structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/669a477e9ec4bf003a6479a9.xml"},{"id":98771105,"identity":"509dbd56-4d43-4a8f-a003-abef5b3ebff4","added_by":"auto","created_at":"2025-12-22 10:40:11","extension":"html","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":118717,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/8702ef1ffe4fd811da8daa01.html"},{"id":98771075,"identity":"4d6d6b2a-3d06-4776-a41a-405587b2cb98","added_by":"auto","created_at":"2025-12-22 10:40:09","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":97753,"visible":true,"origin":"","legend":"\u003cp\u003ePrevalence of microbial isolates at the oral commissures by vertical facial dimension\u003c/p\u003e","description":"","filename":"figure121.png","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/3c837681229c2792209477b9.png"},{"id":104739975,"identity":"a8d323ed-34b3-40fc-b8db-100647dccdec","added_by":"auto","created_at":"2026-03-16 16:14:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":699437,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/57532bb1-11fb-497e-8335-76d71f0be0a7.pdf"},{"id":98771095,"identity":"ee28e1e1-a3b7-4b1d-a187-c59155bc04fb","added_by":"auto","created_at":"2025-12-22 10:40:10","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":13471,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/b9d738d71232ec4c498d2027.docx"},{"id":98780006,"identity":"30bfa3c8-d728-46f3-b06f-f270e7cc3b2e","added_by":"auto","created_at":"2025-12-22 12:30:58","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":14289,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/b3f29066ae5f12f29b29ab60.docx"},{"id":98771089,"identity":"eefd01cf-d724-488f-8123-ce426ed1e46a","added_by":"auto","created_at":"2025-12-22 10:40:10","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":14145,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/90431837e3132cfe7bf04625.docx"},{"id":98771132,"identity":"82c79fc3-f5f7-4736-bdd5-8a5d8eb459a2","added_by":"auto","created_at":"2025-12-22 10:40:12","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":25369,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTableFinal.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/4461f4a83db67791424e6718.docx"},{"id":98771094,"identity":"56d20b0d-ff96-4552-8892-aa9630ad6995","added_by":"auto","created_at":"2025-12-22 10:40:10","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":13219,"visible":true,"origin":"","legend":"","description":"","filename":"Table4.docx","url":"https://assets-eu.researchsquare.com/files/rs-8062768/v1/6c7801d4f8a261a29be8d806.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Vertical Facial Patterns and Oral Habits on Microbial Colonization in Children and Adolescents: A Cross-Sectional Study","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eVertical facial morphology may influence several local physiological and microbial conditions within the oral environment. Individuals with increased vertical dimensions often exhibit altered perioral muscle tone, lip competence, and salivary flow, which can modify surface moisture and pH at the mouth corners. \u003csup\u003e1-4\u0026nbsp;\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eThe oral commissures, located at the intersection of intra- and extra-oral regions, represent a dynamic microenvironment affected by facial structure, saliva flow, and oral habits. Imbalances in this area can lead to microbial accumulation and inflammatory changes. \u003csup\u003e5-7\u0026nbsp;\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eAmong the microorganisms inhabiting the commissural region, \u003cem\u003eCandida\u003c/em\u003e species and Gram-positive bacteria are the most frequently detected. \u003cem\u003eCandida albicans\u003c/em\u003e is a commensal yeast that can become opportunistic under local or systemic disturbances, whereas Gram-positive cocci and bacilli are part of the resident flora that may increase under altered moisture or pH. \u003csup\u003e6,8-9\u0026nbsp;\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003ePrevious studies have mostly focused on elderly or denture-wearing populations, where loss of vertical dimension was considered a risk factor for angular cheilitis. \u003csup\u003e6,9-11\u003c/sup\u003e However, little is known about whether vertical facial patterns in children and adolescents\u0026mdash;who exhibit active growth and no prosthetic alterations\u0026mdash;affect local microbial colonization at the oral commissures.\u003c/p\u003e\n\u003cp\u003eIn children and adolescents, additional local factors such as mouth breathing and lip-licking habits may play an important role in shaping the microbial ecology of the perioral region. Indeed, recent studies have shown that mouth breathing not only is associated with skeletal and facial vertical changes (for example, increased mandibular plane angles) but also corresponds to distinct alterations in oral microbial communities, including enrichments of opportunistic bacterial species and changes in salivary protein composition.\u003csup\u003e12-13\u003c/sup\u003e These oral habits are also known to be more prevalent in certain vertical facial patterns, such as high-angle skeletal configurations, and may therefore serve as indirect risk modifiers for colonization. Despite these potential links, evidence regarding the interaction between vertical facial patterns, oral habits, and oral microbial colonization in children and adolescents remains scarce.\u003c/p\u003e\n\u003cp\u003eTherefore, the aim of this study was to evaluate the relationship between vertical facial morphology, oral habits, and microbial colonization at the oral commissures in children and adolescents. We hypothesized that distinct vertical growth patterns could be associated with specific microbial profiles and that oral habits may influence this relationship. To our knowledge, this is the first study to highlight the oral commissures as a clinically relevant site reflecting both functional and microbial interactions in growing individuals.\u003c/p\u003e"},{"header":"MATERİALS AND METHODS","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was reviewed and approved by the Scientific Research Ethics Committee of Karadeniz Technical University, Faculty of Dentistry (Approval No: 2015/89). All procedures were conducted in accordance with the Declaration of Helsinki, and written informed consent was obtained from all participants and their parents or legal guardians.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Design and Sample Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis cross-sectional study included 150 caries-free children and adolescents (66 males, 84 females; mean age = 13.4 years; range 8\u0026ndash;18 years) who attended the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Karadeniz Technical University. Eligibility criteria were the absence of systemic disease, no history of tobacco or alcohol use, no previous orthodontic treatment, and no craniofacial anomalies. Participants were equally distributed among low-, norm-, and high-angle groups to enable balanced comparisons across vertical facial patterns. The study followed the STROBE checklist for cross-sectional studies.\u003csup\u003e14\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAssessment of Vertical Facial Dimension\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLateral cephalometric radiographs were obtained with a Kodak 9000C Dental System (Carestream Health, Rochester, NY, USA) using 80 kVp, 10 mA, and 0.5 s exposure, with a 24 \u0026times; 30 cm field of view and a magnification factor of 1.15. Vertical facial pattern was defined by the GoGn/SN angle and classified as low-angle (\u0026lt;26\u0026deg;), norm-angle (26\u0026ndash;36\u0026deg;), or high-angle (\u0026gt;36\u0026deg;). Each category included 50 patients (n=50 per group).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOral Habits Assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBreathing pattern and lip-licking habit information were obtained by self-report from children and their parents and recorded as either present or absent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOral pH Measurement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIntraoral pH was measured using MColorpHast indicator strips (Merck, Darmstadt, Germany). Strips were placed intraorally for 2 minutes, then compared with the manufacturer\u0026rsquo;s color chart.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAngular Wetness Measurement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAngular wetness was assessed with modified Schirmer strips folded in an L shape. The shorter arm (5 mm) was positioned at the mouth corner for 3 minutes, and the wetted length (mm) recorded as the wetness value.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCollection and Culturing of Swab Samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll samples were collected between 9:00 and 11:00 AM to minimize diurnal variations. Using sterile cotton swabs, both commissures were sampled by gentle contact for \u0026ge; 5 seconds. Each swab was transferred to Stuart transport medium (FIRATMED, T\u0026uuml;rkiye) and immediately inoculated on Sabouraud dextrose agar (SDA) in duplicate Petri dishes, incubated 30\u0026ndash;35 \u0026deg;C for 7 days. Colonies were microscopically examined; yeast-like forms underwent the germ-tube test (positive = \u003cem\u003eC. albicans\u003c/em\u003e), while negative samples were classified as non-albicans \u003cem\u003eCandida\u003c/em\u003e using API 20 C AUX (bioM\u0026eacute;rieux, France).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll analyses were performed in SPSS v26.0 (IBM Corp., Armonk, NY, USA). Sample adequacy (N = 150; n = 50 per group) was verified using G*Power 3.1.9.7 for one-way ANOVA (effect size 0.30, \u0026alpha; = 0.05, power = 0.91).\u003c/p\u003e\n\u003cp\u003eNormality of continuous variables (age, wetness, pH) was verified with Kolmogorov\u0026ndash;Smirnov and |skewness|, |kurtosis| \u0026lt; 1.5; hence parametric tests were applied. Means \u0026plusmn; SD and frequencies (%) summarized data.\u003c/p\u003e\n\u003cp\u003eGroup differences for continuous variables were tested with one-way ANOVA and Duncan post-hoc comparisons. Categorical associations (e.g., vertical pattern vs microbial type, oral habit) used Pearson \u0026chi;\u0026sup2; and Fisher\u0026rsquo;s exact test (where expected frequencies \u0026lt; 5). Correlations among continuous variables used Pearson r. Two-tailed p \u0026lt; 0.05 was considered significant.\u0026nbsp;\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e\u003cstrong\u003eMicrobiological Findings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMicrobiological analysis showed that Gram-positive cocci were the most prevalent isolates, found in 84 of 150 participants (56.0%). Other findings included no microbial growth in 23 (15.3%),\u0026nbsp;\u003cem\u003eCandida\u003c/em\u003e species in 18 (12.0%), Gram-positive bacilli in 18 (12.0%), and combined Gram-positive cocci + bacilli in 7 (4.7%) (Table 1).\u003cbr\u003e\u0026nbsp;Overall, Gram-positive cocci represented the dominant flora at the oral commissures of healthy children and adolescents.\u003c/p\u003e\n\u003cp\u003eA significant association was observed between vertical facial morphology and microbial outcomes (p = 0.001) (Table 2). Post-hoc analysis indicated that the low-angle group had a higher rate of no microbial growth (65.2%) compared with other groups, whereas all Gram-positive bacilli isolates occurred in norm-angle (66.7%) and high-angle (33.3%) individuals. This distribution demonstrates that increased vertical dimension correlates with a more complex bacterial profile at the oral commissures.\u003c/p\u003e\n\u003cp\u003eOne-way ANOVA revealed significant differences in vertical dimension degrees across microbial categories (p = 0.005) (Table 3). Participants with \u003cem\u003eCandida\u003c/em\u003e (35.9 \u0026plusmn; 6.8), Gram-positive bacilli (33.2 \u0026plusmn; 3.7), Gram-positive cocci (30.8 \u0026plusmn; 9.3), or cocci + bacilli (34.7 \u0026plusmn; 5.8) had higher GoGn/SN angles than those with no microbial growth (26.8 \u0026plusmn; 6.6).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCandida\u003c/em\u003e carriage showed no significant association with vertical facial pattern (p = 0.103). Similarly, no significant differences were found for cocci or cocci + bacilli combinations (all p \u0026gt; 0.05).\u003c/p\u003e\n\u003cp\u003eThese results confirm that vertical skeletal morphology is significantly associated with bacterial\u0026mdash;but not fungal\u0026mdash;colonization at the oral commissures. In addition, no significant sex-related differences were observed in any of the microbiological outcomes (all p \u0026gt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAngular Wetness and Oral pH\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMean angular wetness was 9.5 \u0026plusmn; 5.0 mm and mean intraoral pH = 7.3 \u0026plusmn; 0.3 (Table 1). Both variables showed no significant intergroup differences (p \u0026gt; 0.05). Correlation analysis indicated that age correlated negatively with wetness (r = \u0026ndash;0.369, p = 0.001), while wetness (r = 0.171, p = 0.036) and pH (r = 0.183, p = 0.025) correlated positively with vertical dimension degrees. Thus, higher vertical dimensions were associated with slightly higher moisture and pH, whereas increasing age reduced wetness. In addition, there were no significant sex-related differences in the physiological parameters, including pH and angular wetness (all p \u0026gt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMouth Breathing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMouth breathing was reported by 22.0% (n = 33). Its association with vertical morphology was significant (p = 0.038) (Table 2). The habit was most frequent in high-angle participants (51.5%) versus norm-angle (27.3%) and low-angle (21.2%) groups, suggesting that increased vertical dimension relates to greater mouth-breathing prevalence.\u003c/p\u003e\n\u003cp\u003eAlthough the association between mouth breathing and microbiological category did not reach significance (p = 0.078), descriptive data showed that Gram-positive cocci were most common among mouth breathers (57.6%), followed by \u003cem\u003eCandida\u003c/em\u003e (21.2%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLip-Licking\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLip-licking was reported in 12.7% (n = 19). No significant association was found between vertical morphology and lip-licking (p = 0.075) (Table 2). Gram-positive cocci predominated among these individuals (68.4%), but the relationship was not statistically significant (p = 0.432).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis study demonstrates that vertical skeletal morphology is significantly associated with bacterial\u0026mdash;but not fungal\u0026mdash;colonization at the oral commissures in children and adolescents. The absence of Gram-positive bacilli in low-angle individuals, contrasted with their presence in norm- and high-angle groups, indicates that craniofacial structure is a determinant of the perioral ecological niche. To our knowledge, this association has not previously been documented in paediatric populations.\u003c/p\u003e\n\u003cp\u003eThe prevalence of \u003cem\u003eCandida\u003c/em\u003e carriage (12.0%) in this cohort is lower than the 20\u0026ndash;40% range commonly reported for children. \u003csup\u003e15,16\u003c/sup\u003e This difference likely reflects the localized sampling site (oral commissures only) and the inclusion of caries-free, systemically healthy participants. Prior studies have used pooled intraoral samples from multiple sites, resulting in higher isolation rates. Importantly, colonization does not imply infection; \u003cem\u003eCandida\u003c/em\u003e species often exist as commensals.\u003csup\u003e17\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eIn contrast, Gram-positive bacilli were closely linked to increased vertical dimension. These organisms were found exclusively in norm- and high-angle individuals, supporting the idea that skeletal morphology can shape the local microbial environment. Such a relationship extends previous research that largely emphasized fungal species by highlighting how anatomical structure may condition bacterial colonization patterns.\u003csup\u003e18\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eRecent evidence suggests that mouth breathing may influence the composition of the oral microbiota. Marincak Vrankova et al. reported a higher relative abundance of \u003cem\u003eSolobacterium\u003c/em\u003e in mouth-breathing children compared with nasal breathers, indicating a potential microbial shift associated with altered breathing patterns. \u003csup\u003e19\u003c/sup\u003e In our study, however, no significant microbial differences were detected between breathing types. The increased occurrence of Gram-positive bacilli in the high-angle group might indirectly reflect a higher prevalence of mouth breathing within this craniofacial pattern. Nonetheless, subtle microbial alterations related to oral respiration may not have been fully captured, as the breathing pattern was determined based on self-reported information rather than objective evaluation.\u003c/p\u003e\n\u003cp\u003ePrevious microbiome studies have shown that the oral cavity harbors hundreds of bacterial species, primarily from the phyla \u003cem\u003eFirmicutes\u003c/em\u003e, \u003cem\u003eBacteroidetes\u003c/em\u003e, \u003cem\u003eProteobacteria\u003c/em\u003e, \u003cem\u003eActinobacteria\u003c/em\u003e, \u003cem\u003eSpirochaetes\u003c/em\u003e, and \u003cem\u003eFusobacteria\u0026nbsp;\u003c/em\u003e\u003csup\u003e20\u003c/sup\u003e In healthy individuals, \u003cem\u003eStreptococcus salivarius\u003c/em\u003e represents the predominant commensal organism on the tongue surface, whereas its reduction and the increased abundance of anaerobes such as \u003cem\u003eSolobacterium moorei\u003c/em\u003e, \u003cem\u003eAtopobium parvulum\u003c/em\u003e, and \u003cem\u003eFusobacterium periodonticum\u003c/em\u003e have been associated with halitosis and dysbiotic oral conditions. \u003csup\u003e21\u003c/sup\u003e These findings support the concept that changes in oral environment\u0026mdash;such as those potentially occurring in high-angle, mouth-breathing individuals\u0026mdash;may favor a microbial shift toward species with greater pathogenic potential.\u003c/p\u003e\n\u003cp\u003eMouth breathing was more frequent in high-angle individuals, consistent with earlier studies associating this habit with increased mandibular plane angles and maxillary constriction.\u003csup\u003e22,23\u003c/sup\u003e Although not statistically significant, mouth breathers showed a tendency toward higher bacterial diversity, possibly related to airflow and mucosal dehydration. The present results support early identification and management of airway dysfunction as part of paediatric dental assessment.\u003c/p\u003e\n\u003cp\u003eLip-licking behaviour was not significantly related to vertical morphology but showed mild directional trends. Repetitive lip licking can increase moisture and epithelial irritation, promoting colonization potential.\u003csup\u003e24\u003c/sup\u003e Larger samples may clarify whether such habits indirectly modulate the commissural microbiota.\u003c/p\u003e\n\u003cp\u003eNeither fungal nor bacterial colonization was significantly associated with oral habits, suggesting that structural morphology exerts a stronger, more consistent influence than transient behavioural factors. These findings are consistent with contemporary reviews describing the paediatric oral microbiome as multifactorial yet heavily influenced by host anatomy.\u003csup\u003e1,2,7\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eThe mechanism underlying the relationship between increased vertical dimension and bacterial colonization may involve multiple pathways. First, high-angle individuals typically exhibit reduced lip seal competence and altered perioral muscle function, potentially creating a more humid microenvironment favorable for bacterial growth. \u003csup\u003e25\u003c/sup\u003e Second, the association with mouth breathing\u0026mdash;observed more frequently in our high-angle group (51.5%)\u0026mdash;may contribute through chronic mucosal dehydration and altered local immunity. \u003csup\u003e12\u003c/sup\u003e Third, biomechanical factors such as increased tissue tension at the commissures in vertically excessive faces may affect epithelial barrier integrity. However, the finding that pH and wetness did not differ significantly between groups suggests that unmeasured variables\u0026mdash;such as salivary protein composition, local cytokine profiles, or epithelial turnover rates\u0026mdash;may play important roles. \u003csup\u003e26\u003c/sup\u003e Further research using molecular and immunological approaches is needed to elucidate these pathways.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations and Future Directions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study has several limitations that should be considered when interpreting the results. Although equal group sizes were used to ensure statistical balance, this stratification does not reflect the natural prevalence of vertical facial patterns in the general paediatric population, which may limit the generalizability of the findings. Furthermore, culture-based identification restricted taxonomic resolution; molecular techniques such as 16S rRNA sequencing would provide broader microbial detection and species-level characterization. Additional variables\u0026mdash;including nutritional status, salivary flow rate, and vitamin levels\u0026mdash;were not evaluated, and single-time measurements of pH and wetness may not capture daily fluctuations.\u003c/p\u003e\n\u003cp\u003eFuture research should adopt multicentre and longitudinal designs integrating molecular bacteriome and mycobiome profiling, objective quantification of oral habits, and airway assessment. Such studies would help clarify the causal pathways linking craniofacial morphology to oral microbial ecology and identify potential clinical markers for early preventive intervention.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eIn this cross-sectional study of healthy children and adolescents, increased vertical facial dimension was significantly associated with Gram-positive bacilli colonization at the oral commissures, independent of Candida carriage. These findings suggest that craniofacial morphology may influence local bacterial ecology and warrant consideration in pediatric oral health assessment.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANOVA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnalysis of Variance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCFU\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eColony-Forming Unit\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFOV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eField of View\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSPSS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStatistical Package for the Social Sciences\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSTROBE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStrengthening the Reporting of Observational Studies in Epidemiology\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was reviewed and approved by the Scientific Research Ethics Committee of Karadeniz Technical University, Faculty of Medicine (Approval No: 2015/89). Written informed consent was obtained from all participants and their parents or legal guardians.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analysed during this study are included in the supplementary material files submitted with the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo specific funding was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualisation: SAK, SK; Methodology: SAK, SK, \u0026Ouml;SS, İT; Data collection and analysis: SAK, İT; Writing \u0026ndash; original draft: SAK; Writing \u0026ndash; review and editing: SAK, İT, SK; All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors also thank İstatistik Analiz Merkezi, Ankara, T\u0026uuml;rkiye, for their assistance with data processing.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eJ\u0026oslash;rgensen MR. Pathophysiological microenvironments in oral candidiasis. APMIS. 2024;132(12):956\u0026ndash;73. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/apm.13412\u003c/span\u003e\u003cspan address=\"10.1111/apm.13412\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlHarbi SG, Almushayt AS, Bamashmous S, Abujamel TS, Bamashmous NO. The oral microbiome of children in health and disease: a literature review. Front Oral Health. 2024;5:1477004. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/froh.2024.1477004\u003c/span\u003e\u003cspan address=\"10.3389/froh.2024.1477004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaik CH, Lee MH, Park JH. Treatment strategies for vertical maxillary excess: cases with and without anterior open bite. Semin Orthod. 2024;30(5):648\u0026ndash;72. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1053/j.sodo.2024.06.004\u003c/span\u003e\u003cspan address=\"10.1053/j.sodo.2024.06.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVenugopal A, Manzano P, Ahmed F, Vaiid N, Bowman SJ. Gummy smiles: etiologies, diagnoses and formulating a clinically effective treatment protocol. Semin Orthod. 2024;30(5):482\u0026ndash;501. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1053/j.sodo.2023.11.014\u003c/span\u003e\u003cspan address=\"10.1053/j.sodo.2023.11.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatil S, Rao RS, Majumdar B, Anil S. Clinical appearance of oral Candida infection and therapeutic strategies. Front Microbiol. 2015;6:1391. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fmicb.2015.01391\u003c/span\u003e\u003cspan address=\"10.3389/fmicb.2015.01391\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCabras M, Gambino A, Broccoletti R, Lodi G, Arduino PG. Treatment of angular cheilitis. Oral Dis. 2020;26(6):1107\u0026ndash;15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/odi.13183\u003c/span\u003e\u003cspan address=\"10.1111/odi.13183\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRamage G, Borghi E, Rodrigues CF, Kean R, Williams C, Lopez-Ribot JL. Our current clinical understanding of \u003cem\u003eCandida\u003c/em\u003e biofilms: where are we two decades on? APMIS. 2023;131(11):636\u0026ndash;53. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/apm.13310\u003c/span\u003e\u003cspan address=\"10.1111/apm.13310\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2023 Mar 29.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMillsop JW, Fazel N. Oral candidiasis. Clin Dermatol. 2016;34(4):487\u0026ndash;94. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.clindermatol.2016.02.022\u003c/span\u003e\u003cspan address=\"10.1016/j.clindermatol.2016.02.022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark KK, Brodell RT, Helms SE. Angular cheilitis: local etiologies. Cutis. 2011;87(6):289\u0026ndash;95. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/21838086\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/21838086\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShang J, Li J. Risk factors for denture-related oral mucosal lesions. J Hard Tissue Biol. 2024;33(3):143\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2485/jhtb.33.143\u003c/span\u003e\u003cspan address=\"10.2485/jhtb.33.143\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahdani FY, Jati GD, Febrine ET, Cahyaningrum KW, Radithia D, Wicaksono S. Knowledge of xerostomia and angular cheilitis in geriatric population among clinical dental students: an institutional cross-sectional study. J Int Soc Prev Community Dent. 2023;13(6):443\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4103/jispcd.JISPCD_91_23\u003c/span\u003e\u003cspan address=\"10.4103/jispcd.JISPCD_91_23\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFan C, Guo L, Gu H, Huo Y, Lin H. Alterations in oral\u0026ndash;nasal\u0026ndash;pharyngeal microbiota and salivary proteins in mouth-breathing children. Front Microbiol. 2020;11:575550. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fmicb.2020.575550\u003c/span\u003e\u003cspan address=\"10.3389/fmicb.2020.575550\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMummolo S, Nota A, Caruso S, Quinzi V, Marchetti E, Marzo G. Salivary markers and microbial flora in mouth-breathing late adolescents. Biomed Res Int. 2018;2018:8687608. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/2018/8687608\u003c/span\u003e\u003cspan address=\"10.1155/2018/8687608\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evon Elm E, Altman DG, Egger M, Pocock SJ, G\u0026oslash;tzsche PC, Vandenbroucke JP, STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008;61(4):344\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jclinepi.2007.11.008\u003c/span\u003e\u003cspan address=\"10.1016/j.jclinepi.2007.11.008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKadir T, Uygun B, Aky\u0026uuml;z S. Prevalence of \u003cem\u003eCandida\u003c/em\u003e species in Turkish children: relationship between dietary intake and carriage. Arch Oral Biol. 2005;50(1):33\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.archoralbio.2004.07.004\u003c/span\u003e\u003cspan address=\"10.1016/j.archoralbio.2004.07.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePinto-Almaz\u0026aacute;n R, Fr\u0026iacute;as-De-Le\u0026oacute;n MG, Fuentes-Venado CE, Arenas R, Gonz\u0026aacute;lez-Guti\u0026eacute;rrez L, Ch\u0026aacute;vez-Guti\u0026eacute;rrez E, Torres-Paez OU, Mart\u0026iacute;nez-Herrera E. Frequency of \u003cem\u003eCandida\u003c/em\u003e spp. in the oral cavity of asymptomatic preschool Mexican children and its association with nutritional status. Child (Basel). 2022;9(10):1510. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/children9101510\u003c/span\u003e\u003cspan address=\"10.3390/children9101510\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVila T, Sultan AS, Montelongo-Jauregui D, Jabra-Rizk MA. Oral candidiasis: a disease of opportunity. J Fungi (Basel). 2020;6(1):15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/jof6010015\u003c/span\u003e\u003cspan address=\"10.3390/jof6010015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa T, Wu Z, Lin J, Shan C, Abasijiang A, Zhao J. Characterization of the oral and gut microbiome in children with obesity aged 3 to 5 years. Front Cell Infect Microbiol. 2023;13:1102650. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fcimb.2023.1102650\u003c/span\u003e\u003cspan address=\"10.3389/fcimb.2023.1102650\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarincak Vrankova Z, Brenerova P, Bodokyova L, Bohm J, Ruzicka F, Borilova Linhartova P. Tongue microbiota in relation to the breathing preference in children undergoing orthodontic treatment. BMC Oral Health. 2024;24(1):1259. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12903-024-05062-3\u003c/span\u003e\u003cspan address=\"10.1186/s12903-024-05062-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDewhirst FE, Chen T, Izard J, Paster BJ, Tanner AC, Yu WH, Lakshmanan A, Wade WG. The human oral microbiome. J Bacteriol. 2010;192(19):5002\u0026ndash;17. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1128/JB.00542-10\u003c/span\u003e\u003cspan address=\"10.1128/JB.00542-10\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKazor CE, Mitchell PM, Lee AM, Stokes LN, Loesche WJ, Dewhirst FE, Paster BJ. Diversity of bacterial populations on the tongue dorsa of patients with halitosis and healthy patients. J Clin Microbiol. 2003;41(2):558\u0026ndash;63. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1128/JCM.41.2.558-563.2003\u003c/span\u003e\u003cspan address=\"10.1128/JCM.41.2.558-563.2003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSouki BQ, Pimenta GB, Souki MQ, Franco LP, Becker HMG, Pinto JA. Prevalence of malocclusion among mouth-breathing children: do expectations meet reality? Int J Pediatr Otorhinolaryngol. 2009;73(5):767\u0026ndash;73. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijporl.2009.02.006\u003c/span\u003e\u003cspan address=\"10.1016/j.ijporl.2009.02.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao Z, Zheng L, Huang X, Li C, Liu J, Hu Y. Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis. BMC Oral Health. 2021;21:108. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12903-021-01458-7\u003c/span\u003e\u003cspan address=\"10.1186/s12903-021-01458-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFonseca A, Jacob SE, Sindle A. Art of prevention: practical interventions in lip-licking dermatitis. Int J Womens Dermatol. 2020;6(5):377\u0026ndash;80. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ijwd.2020.06.001\u003c/span\u003e\u003cspan address=\"10.1016/j.ijwd.2020.06.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDrevensek M, Papić JS. The influence of respiration disturbances on the growth and development of the orofacial complex. Coll Antropol. 2005;29(1):221\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaid HS, Suda W, Nakagome S, Chinen H, Oshima K, Kim S, Kimura R, Iraha A, Ishida H, Fujita J, Mano S, Morita H, Dohi T, Oota H, Hattori M. Dysbiosis of salivary microbiota in inflammatory bowel disease and its association with oral immunological biomarkers. DNA Res. 2014;21(1):15\u0026ndash;25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/dnares/dst037\u003c/span\u003e\u003cspan address=\"10.1093/dnares/dst037\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 to 4 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Candida, Gram-positive bacteria, Vertical dimension, Child, Adolescent","lastPublishedDoi":"10.21203/rs.3.rs-8062768/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8062768/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe oral commissures represent a unique anatomical interface where intra- and extra-oral environments converge. This study aimed to investigate the association between vertical facial patterns and microbial colonisation at the oral commissures in children and adolescents.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA total of 150 healthy participants aged 8\u0026ndash;18 years were equally divided into low-, norm-, and high-angle groups according to their cephalometric GoGn/SN values. Swab samples from both commissures were cultured for \u003cem\u003eCandida\u003c/em\u003e species and Gram-positive bacteria. Commissural wetness, intra-oral pH, and oral habits were also recorded. Group differences were analysed using chi-square and ANOVA tests with effect sizes (α\u0026thinsp;=\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eVertical facial morphology showed a significant association with bacterial colonisation (p\u0026thinsp;=\u0026thinsp;0.001). Gram-positive bacilli were absent in low-angle but frequent in norm- and high-angle individuals. \u003cem\u003eCandida\u003c/em\u003e carriage (12.0%) showed no significant association with facial pattern (p\u0026thinsp;=\u0026thinsp;0.103). Mouth breathing was significantly more prevalent in high-angle participants (p\u0026thinsp;=\u0026thinsp;0.038), while lip-licking habits showed no intergroup difference.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eIncreased vertical facial dimension was strongly related to bacterial, but not fungal, colonisation at the oral commissures. Craniofacial morphology may therefore influence the local microbial ecology and should be considered a potential risk modifier in paediatric patients presenting with recurrent angular lesions.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eNot applicable.\u003c/p\u003e","manuscriptTitle":"Impact of Vertical Facial Patterns and Oral Habits on Microbial Colonization in Children and Adolescents: A Cross-Sectional Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 10:39:01","doi":"10.21203/rs.3.rs-8062768/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-20T04:43:33+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-03T15:29:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-29T12:47:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"258038793080372803754775652351494853386","date":"2025-12-23T04:59:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"130296113005656039171499657549179559197","date":"2025-12-22T18:44:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"101202924111596447989199512627850587502","date":"2025-12-22T07:39:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"29073241357665189902178506660647510752","date":"2025-12-19T21:39:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-19T16:47:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-17T06:00:28+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-20T23:23:50+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-19T12:29:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2025-11-19T12:23:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6922b330-0c2a-4059-9744-180614d24101","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-16T16:09:07+00:00","versionOfRecord":{"articleIdentity":"rs-8062768","link":"https://doi.org/10.1186/s12887-026-06732-7","journal":{"identity":"bmc-pediatrics","isVorOnly":false,"title":"BMC Pediatrics"},"publishedOn":"2026-03-11 15:58:45","publishedOnDateReadable":"March 11th, 2026"},"versionCreatedAt":"2025-12-22 10:39:01","video":"","vorDoi":"10.1186/s12887-026-06732-7","vorDoiUrl":"https://doi.org/10.1186/s12887-026-06732-7","workflowStages":[]},"version":"v1","identity":"rs-8062768","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8062768","identity":"rs-8062768","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}