Middle Mesial Canals Prevalence percentage and Its Configuration type Among Some Egyptian Population by CBCT

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Rokaya, Wael Hussein Kamel, Khalid S Hassan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1455902/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: An untreated root canal is one of the main causes of failure in endodontics. The aims of this study were to detect the middle mesial canals (MMCs) prevalence in mandibular 1 st molars, its configuration type, and its percentage of incidence with age by Cone-Beam Computed Tomography (CBCT) analysis. Methods: CBCT scan of 1650 patients were observed between January 2021 to February 2022 were collected using the CBCT imaging system from the database of the department of oral radiology, faculty of dental medicine, Al-Azhar university - Assiut branch. CBCT scan images were analyzed by Sidexis software. CBCT images were examined to detect the following: (1) The percentage of incidence frequency of the MMCs, (2) MMCs classification, and (3) Frequency of occurrence of MMCs according to age. Results: The incidence frequency percentage of the presence of MMCs among the Egyptian population was 10.79 % (208/1926) with no statistically significant due to gender, While MMCs configuration types showed 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy and only 6.7% (14/208) showed independent MMCs with separate orifices and apical foramen. lastly the incidence frequency percentage of the presence of MMCs decreases with age. Conclusions: The MMCs prevalence in mandibular 1 st molars among some Egyptian population was 10.79 %, and CBCT scan is helpful way to detect the presence of MMCs. middle mesial canals Cone-Beam Computed Tomography and Configuration type Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Background: The successful of endodontic treatment requires to find and detect all root canal for further removal of all debris, and bacteria for good sealing of all canals. On other hand the dentist should be fulfillment of the internal anatomy of the teeth and its variations [ 1 ]. Abnormal root canal morphology maybe contributes to the root canal failure because of lack of knowledge of all root canal anatomy variation. The success of endodontic treatment necessitates chemo mechanical preparation for all root canal spaces. Complete chemo mechanical preparation for lateral canals, ramifications, and intercanal communications is very important to facilitate healing of the periapical tissues [ 2 ]. Mandibular molars are one of the teeth with abnormal root canal morphology. High incidence of internal morphology variation as Cshaped canals, isthmus, and its mesial root may possess mor than two canals [ 3 , 4 ]. The existence of a third canal was discovered by De Pablo in the mesial root of lower 1st molars. After that Pomeranz et al. classified this third canal to three types: independent, confluent, and fin. After that this canal was named “middle mesial canal”, and “accessory mesial canal”. More studies were held to detect this canal by different ways, and its incidence rate ranges from 0.26 to 46.15% [ 5 ]. Magnification has enhanced the ability to detect canals that could not usually be observed by clinical inspection alone [ 6 ]. This has increased the number of published case reports showing unsuccessful endodontic treatment because Accessory Mesial Canals are not always visible without the aid of magnification [ 7 ]. In vivo studies utilizing radiograph, CBCT, MICRO CT, guided troughing, and use of CBCT has been used for evaluating middle mesial canals in North America, South America, Europe, and South Asia. The Presence of the middle mesial canal in the range of 4–28% is recorded. An in vivo study was done in mandibular first molars with the utilization of ultrasonic tips and endodontic explorer under a Dental Operating Microscope in the north Indian population. 28.3% of the negotiable middle mesial canal has been reported in the study [ 1 ]. In recent years CBCT was devolved and become widely used due to its low radiation dose with high image resolution, three-dimensional reconstruction more than apical film or panoramic images [ 8 , 9 ]. On other hand CBCT was used in different studies to detect the presence of MMCs reliable clinical imaging data[ 10 , 11 ]. So, this study aims to determine the percentage of incidence frequency of the middle mesial canals (MMCs) of mandibular 1st molars, Its configuration type, and its percentage of incidence with age among some Egyptian population by CBCT scan. Methods: The study design of this study research was passed on Yang et al design [5]. Samples selection This study was approved by the Medical Ethics Committee of the Faculty of Dental Medicine, Al Azhar University, Assuit, which granted approval for the research with number (AUAREC20200315-11). The procedures were carried out in conformity with applicable laws and regulations. All patients provided signed consent forms after being given written information. Patients required radiographic examination of CBCT as part of their dental treatment. The images were taken as part of the routine examination, diagnosis, and treatment planning of patients that included those suffering facial trauma who required oral surgery, orthodontic treatment or who needed implant treatment. With the informed consent of the patients. CBCT was used to scan the mandibular region of the patient to obtain a continuous image of the mandibular 1 st molar and its periodontal tissue. CBCT scan of 1650 patients were observed between January 2021 to February 2022 were collected using the CBCT imaging system from the database of the department of oral radiology, faculty of dental medicine, Al-Azhar university - Assiut branch. All images were included in the study and further analysis according to the following inclusion criteria: Age between 20 and 60 years. Lower 1 st molars that had not been received root canal treatment. Lower 1 st molars without periapical disease. Lower 1 st molars exhibit absence of coronal or post and core restorations, which may obscure the imaging study. Exclusion criteria: Cases where physiological or pathological processes compromised the anatomy, and the original root canal morphology was not clear. Images with missing all mandibular molars. CBCT scanning: CBCT images were acquired using Orthophos S 3D extraoral imaging system (Dentsply Sirona) A scout view was acquired, and adjustments were made to ensure that all patients were correctly adjusted in the scanner according to light beam before acquisition. the Feld-Of-View size (FOV) of 8×8 cm, a peak voltage of 90 kV, a beam current of 16 mA and an exposure time of 14.s for a full arch. The voxel size was 160 μm×160 μm, and the minimum layer thickness was 0.16 mm. The detector resolution was 1024×1024 pixels, and the pixel size was 127 μm×127 μm. After acquisition, data were exported and transferred to Sidexis software (Sirona, DICOM viewer software, version 4.0.2, Germany) Serial axial, coronal, and sagittal CBCT images were thoroughly examined from the pulp orifice to the apex. All the images were assessed separately by two endodontists. In cases of disagreement, these two endodontists discussed the data until a consensus was reached. An oral radiologist provided guidance when necessary. CBCT was used to scan the mandibular region of the patient to obtain a continuous image of the mandibular 1 st molar and its periodontal tissue. Variables to be analysed in this study: 1) Incidence frequency of the MMCs present in lower 1 st molars (Figure 1). 2) Middle Mesial Canals classification (Figure 2) according to the classification of Pomeranz et al. [12]: a) Confluent either with the mesio buccal canal or with the mesio lingual canal, b ) Independent, and c ) Fin type (no separate orifice). 3) Frequency of occurrence of MM canals according to age. Statistical analysis: Categorical data were presented as frequencies (n) and percentages (%) and were analyzed utilizing Fisher’s exact test. Numerical data were explored for normality by checking the data distribution, calculating the mean and median values, and using Kolmogorov-Smirnov and Shapiro-Wilk tests. Data showed parametric distribution, so they were presented as mean and standard deviation (SD) values and were analyzed using one-way ANOVA test. The significance level was set at p ≤0.05 within all tests. Statistical analysis was performed with R statistical analysis software version 4.0.3 for windows ® Core Team (2020). Results: CBCT scan of 1650 patients were observed, and 1926 CBCT images of 1200 patients met the inclusion criteria, among which 208 CBCT images contained MMC. The incidence of MMCs in our experimental study was 10.79 % (208/1926) as illustrated in figure (3). Among them, there were 108 (51.9%) males and 100 (48.1%) females, and the difference was not statistically significant (P = 0.215). Moreover, there was no significant difference in the distribution of MMCs between the right and left side. These results are illustrated in figure (4). The results of this study concerning the frequency occurrence of MMCs in three age groups (group A: 50 years) revealed that group A exhibited a greater occurrence of MMCs (96/208) than group B (73/208) or C (39/208) but with significant deference where P = 0.002 as illustrated in figure (5). Our study results that concerning MMCs type was illustrated in figure (6), and it showed that 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy and only 6.7% (14/208) showed independent MMCs with separate orifices and apical foramen. Discussion: Racial and ethnic factors explained the presence of certain abnormalities as the prevalence of MMCs in the mesial root of lower molars that may occur at different rates in different parts of the world. On other hand the methods used to detect root canal abnormalities also plays a big role in detection the prevalence of MMCs [ 14 ]. CBCT image scans were used in our research study to visualize the root canal anatomy with low radiation dosage, and high resolution [ 15 ]. In vivo and vitro studies were reported the incidence of MMCs [ 6 , 16 – 22 ]. The detection of the increased incidence rates reported of accessory canals were done under magnification, moreover occurrence percentage of MMCs was reported as 46.2% [ 19 ]. In our study, the incidence frequency percentage of the presence of MMCs among the Egyptian population was 10.79% (208/1926) with no statistically significant due to gender, while the frequency of the prevalence of MMCs in the studies searched with different populations varied from (1%) to (46%) the variability in results can be attributed to several possible reasons such as ethnic population, sample size, study design and methods to detect the middle mesial canal. Our study is the 1st study about detecting the frequency percentage of the presence of MMCs among the Egyptian population dealing with large number of CBCT image scans. The differences in age groups of this study revealed high frequency of the prevalence of MMCs at the young age and decrease with ageing so it is easier to detect the MMCs in younger patients because they have less physiologic or pathologic pulp calcifications than older patients, these results agree with the previous studies reporting the effect of age on frequency of the prevalence of MMCs [ 14 , 16 , 17 , 20 – 22 ]. Similar results were reported by Sherwani et al., [ 2 ] who observed that there was a significant decrease in the incidence of MMCs with an increase in age in an Indian population. Deposition of secondary dentine within the canal at the cervical, middle, and apical thirds in the mesiodistal direction was explained by Hess [ 23 ] to be the cause of root canal variations that causes canal separation. At 30–40 years of age in lower first and second molars was confirmed that canal differentiation is completed at this range of age [ 24 ]. The most frequent canal configuration type among the Egyptian population was showed that 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy, and only 6.7% (14/208) independent MMCs with separate orifices and apical foramen. Our results are like other studies. These studies reported high percentage rate of confluent anatomy of MMCs [ 20 , 21 ]. On other side there was disagreement of our result to the result of KarapinarKazandag et al. [ 22 ] they reported that no incidence of independent or fin anatomy, and all MMCs have confluent anatomy. Conclusions: The MMCs prevalence in mandibular 1st molars among some Egyptian population was 10.79%, and CBCT scan is helpful way to detect the presence of MMCs. Abbreviations: MMCs: Middle Mesial Canals. CBCT: Cone-Beam Computed Tomography. Declarations: Acknowledgements Not applicable. Author contributions M.R: Contributed to data collection, data analysis, and original manuscript writing. W.K: Contributed to protocol/project development, data analysis, and original manuscript editing. K.H: Contributed to manuscript editing, and performed critical revisions, study data collection, revised manuscript editing. Funding No funding was obtained. Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Data cannot be deposited in a public repository since this research is not yet published. For that reason, and for data confidentiality data will be granted upon reasonable request. Ethics approval and consent to participate This study was approved by the Medical Ethics Committee of the Faculty of Dental Medicine, Al Azhar University, Assuit, which granted approval for the research with number (AUAREC20200315-11). A written informed consent signed was obtained from all participants and/or their legal guardians. All methods were carried out in accordance with relevant guidelines and regulations of Helsinki Declaration of the World Medical Association regarding using human participants. All the data used in this study were anonymized before its use. Consent for publication Not applicable. Competing interests The authors declare that there are no conflicts of interest regarding the publication of this paper. Author details * Associate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine Al-Azhar University. Assiut Branch, Egypt. ** Professor and Head of Endodontic Department, Faculty of oral and dental medicine, Future University (FUE) in Egypt. *** Professor of Oral Medicine &Periodontology, Dean College of Dentistry, Al-Azhar University. Assiut Branch, Egypt. References: Sajjan GS, Rajashekar Ch, Madhu Varma K, Kalyan Satish R, Rishitha T, Srikanth G. Prevalence of middle mesial canals and Isthmi in mandibular molars in a subpopulation of Andhra Pradesh: an in vivo investigation using CBCT. Int J Dent Mater 2021;3(1): 08–15. Sherwani OA, Kumar A, Tewari RK, Mishra SK, Andrabi SM, Alam S. Frequency of middle mesial canals in mandibular first molars in North Indian population - an in vivo study. Saudi Endod J 2016; 6:66–70. Arora A, Acharya SR, Sharma P. Endodontic treatment of a mandibular first molar with 8 canals: A case report. Restor Dent Endod 2015; 40:758. Huang RY, Cheng WC, Chen CJ, Lin CD, Lai TM, Shen EC, et al. Threedimensional analysis of the root morphology of mandibular first molars with distolingual roots. Int Endod J 2010; 43:47884. Yang Y, Wu B, Zeng J. et al. Classification and morphology of middle mesial canals of mandibular first molars in a southern Chinese subpopulation: a cone-beam computed tomographic study. BMC Oral Health2020; 20: 358. De Toubes KM, de Souza Côrtes MI, de Abreu Valadares MA, Fonseca LC, Nunes E, Silveira FF. Comparative analysis of accessory mesial canal identification in mandibular first molars by using four different diagnostic methods. J Endod. 2012;38 (4):436–41. Jacobsen EL, Dick K, Bodell R. Mandibular First Molars with Multiple Mesial Canals. 1994; 20 (12): 610–613. Scarfe WC, Levin MD, Gane D, Farman AG. Use of cone beam computed tomography in endodontics. Int J Dent. 2009. Kumar V, Gossett L, Blattner A, Iwasaki LR, Williams K, Nickel JC. Comparison between cone-beam computed tomography and intraoral digital radiography for assessment of tooth root lesions. Am J Orthod Dentofac Orthop. 2011;139: e 533 – 41. Patel S, Dawood A, Whaites E, Pitt Ford T. New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems. Int Endod J. 2009; 42:447–62. Shukla S, Chug A, Afrashtehfar KI. Role of cone beam computed tomographyn diagnosis and treatment planning in dentistry: an update. J Int Soc Prev Commun Dent. 2017;7: 125–36. Ballullaya SV, Vemuri S, Kumar PR. Variable permanent mandibular first molar: Review of literature. J Conserv Dent. 2013 Mar;16(2):99–110. Bansal R, Hegde S, Astekar M. Morphology, and prevalence of middle canals in the mandibular molars: A systematic review. J Oral Maxillofac Pathol 2018; 22:216–26. Hargreaves K.M., Berman. Pathways of the Pulp, Mosby Inc, St. Louis, MI, USA, 2016:11th Edition. Ni, N., Cao, S., Han, L. et al. Cone-beam computed tomography analysis of root canal morphology in mandibular first molars in a Chinese population: a clinical study. Evid.-based endod 3, 1 (2018). https://doi.org/10.1186/s41121-018-0015-8 . Gu L, Wei X, Ling J, Huang X. A microcomputed tomographic study of canal isthmuses in the mesial root of mandibular first molars in a Chinese population. J Endod 2009; 35:3536. 9. Pomeranz HH, Eidelman DL, Goldberg MG. Treatment considerations of the middle mesial canal of mandibular first and second molars. J Endod 1981; 7:5658. 10. Goel NK, Gill KS, Taneja JR. Study of root canals configuration in mandibular first permanent molar. J Indian Soc Pedod Prev Dent 1991; 8:124. Skidmore AE, Bjorndal AM. Root canal morphology of the human mandibular first molar. Oral Surg Oral Med Oral Pathol 1971; 32:77884. Azim AA, Deutsch AS, Solomon CS. Prevalence of middle mesial canals in mandibular molars after guided troughing under high magnification: An in vivo investigation. J Endod 2015; 41:1648. 15. Nosrat A, Deschenes RJ, Tordik PA, Hicks ML, Fouad AF. Middle mesial canals in mandibular molars: Incidence and related factors. J Endod 2015; 41:2832. 16. KarapinarKazandag M, Basrani BR, Friedman S. The operating microscope enhances detection and negotiation of accessory mesial canals in mandibular molars. J Endod 2010; 36:128994. Hess W. Formation of Root–Canals in Human Teeth I. J Nat Dent Assoc 1921; 8:704–34. Peiris HR, Pitakotuwage TN, Takahashi M, Sasaki K, Kanazawa E. Root canal morphology of mandibular permanent molars at different ages. Int Endod J 2008; 41:828–35. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-1455902","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":103224872,"identity":"a0f435ab-70f5-4658-84d7-689fe4edf302","order_by":0,"name":"Mohammed E. Rokaya","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIiWNgGAWjYHACZhAhx8DAA+YxNhCrxZh0LYkNRGvRnX34sMHPNrv0/v6zBz9XMNjIbjjAfPgFPi1m59KSE3vbknNnHDiXLHmGIc14wwG2NAu8Ws7wGB/gbWPObTjYYyDZwHA4ccMBHjMDQloO/m2rT5c/zGP8s4HhP1AL/zeCWpJ52w4nGBzjMQPacgBkC/MD/FrYko1lzh033HiGx8yywSDZeOZhNjN8OoBamA9Lvimrlpc7f8b4ZkOFnWzf8ebHH/DqAQFGNhgL5AlmBjYJgloY/qBymQnbMgpGwSgYBSMJAAD800vR5i5SgAAAAABJRU5ErkJggg==","orcid":"","institution":"Al Azhar University","correspondingAuthor":true,"prefix":"","firstName":"Mohammed","middleName":"E.","lastName":"Rokaya","suffix":""},{"id":103224873,"identity":"1d9e80d9-ea6a-4398-bd3c-e7a740c04012","order_by":1,"name":"Wael Hussein Kamel","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Wael","middleName":"Hussein","lastName":"Kamel","suffix":""},{"id":103224874,"identity":"3354b023-a30f-40dc-90bb-8381105b9123","order_by":2,"name":"Khalid S Hassan","email":"","orcid":"","institution":"Al Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Khalid","middleName":"S","lastName":"Hassan","suffix":""}],"badges":[],"createdAt":"2022-03-15 23:14:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1455902/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1455902/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":21121320,"identity":"a3b41f2d-c343-43a6-ac82-48843365ccc1","added_by":"auto","created_at":"2022-05-05 16:24:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":234347,"visible":true,"origin":"","legend":"\u003cp\u003eA photograph showing the presence of MMC in axial view in CBCT scan.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/9174462231cb1ccf3187dc2b.png"},{"id":21121324,"identity":"ebdba3a6-56da-4815-b4a7-b2a19b055b06","added_by":"auto","created_at":"2022-05-05 16:24:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":514821,"visible":true,"origin":"","legend":"\u003cp\u003eA diagram of Pomeranz et al. classification of middle mesial canal. (a) Independent b) Fin (c) Confluent with mesio buccal d) Confluent with mesio lingual[13].\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/48c6083c9f21588c6852a962.png"},{"id":21121325,"identity":"66c31913-3447-4295-8a5e-635069037460","added_by":"auto","created_at":"2022-05-05 16:24:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":121715,"visible":true,"origin":"","legend":"\u003cp\u003eA bar chart showing incidence frequency of the MMCs present in lower 1\u003csup\u003est\u003c/sup\u003e\u0026nbsp;molars.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/9af45cb2843a7525da6da633.png"},{"id":21121321,"identity":"875a2a18-e7d0-44d8-b1f3-54974f022837","added_by":"auto","created_at":"2022-05-05 16:24:04","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":118524,"visible":true,"origin":"","legend":"\u003cp\u003eA bar chart showing distribution of MMCs according to sex and right or left side.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/0065f31e46c3dedf56a7c38d.png"},{"id":21121954,"identity":"09ffdb8c-0f26-46b4-9815-ba08eb9b8ccd","added_by":"auto","created_at":"2022-05-05 16:29:04","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":103784,"visible":true,"origin":"","legend":"\u003cp\u003eA bar chart showing distribution the presence of MMCs according to age groups.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/b3a5d97b460eba2f7bc3ada8.png"},{"id":21121322,"identity":"f7a93a8c-93a4-46bb-9ee8-c7ce1c8a4f5a","added_by":"auto","created_at":"2022-05-05 16:24:04","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":100885,"visible":true,"origin":"","legend":"\u003cp\u003eA bar chart showing the percentage of MMCs types.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure6.png","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/f022c2beeac8fab90693fbe3.png"},{"id":26333501,"identity":"df92cc2d-6918-4c11-845d-172a474cbd64","added_by":"auto","created_at":"2022-09-12 10:59:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1234381,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1455902/v1/e85c5898-917d-434c-92b7-4476aef37e78.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Middle Mesial Canals Prevalence percentage and Its Configuration type Among Some Egyptian Population by CBCT","fulltext":[{"header":"Background:","content":"\u003cp\u003eThe successful of endodontic treatment requires to find and detect all root canal for further removal of all debris, and bacteria for good sealing of all canals. On other hand the dentist should be fulfillment of the internal anatomy of the teeth and its variations [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAbnormal root canal morphology maybe contributes to the root canal failure because of lack of knowledge of all root canal anatomy variation. The success of endodontic treatment necessitates chemo mechanical preparation for all root canal spaces. Complete chemo mechanical preparation for lateral canals, ramifications, and intercanal communications is very important to facilitate healing of the periapical tissues [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMandibular molars are one of the teeth with abnormal root canal morphology. High incidence of internal morphology variation as Cshaped canals, isthmus, and its mesial root may possess mor than two canals [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe existence of a third canal was discovered by De Pablo in the mesial root of lower 1st molars. After that Pomeranz et al. classified this third canal to three types: independent, confluent, and fin. After that this canal was named \u0026ldquo;middle mesial canal\u0026rdquo;, and \u0026ldquo;accessory mesial canal\u0026rdquo;. More studies were held to detect this canal by different ways, and its incidence rate ranges from 0.26 to 46.15% [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMagnification has enhanced the ability to detect canals that could not usually be observed by clinical inspection alone [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. This has increased the number of published case reports showing unsuccessful endodontic treatment because Accessory Mesial Canals are not always visible without the aid of magnification [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn vivo studies utilizing radiograph, CBCT, MICRO CT, guided troughing, and use of CBCT has been used for evaluating middle mesial canals in North America, South America, Europe, and South Asia. The Presence of the middle mesial canal in the range of 4\u0026ndash;28% is recorded. An in vivo study was done in mandibular first molars with the utilization of ultrasonic tips and endodontic explorer under a Dental Operating Microscope in the north Indian population. 28.3% of the negotiable middle mesial canal has been reported in the study [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn recent years CBCT was devolved and become widely used due to its low radiation dose with high image resolution, three-dimensional reconstruction more than apical film or panoramic images [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. On other hand CBCT was used in different studies to detect the presence of MMCs reliable clinical imaging data[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSo, this study aims to determine the percentage of incidence frequency of the middle mesial canals (MMCs) of mandibular 1st molars, Its configuration type, and its percentage of incidence with age among some Egyptian population by CBCT scan.\u003c/p\u003e"},{"header":"Methods:","content":"\u003cp\u003eThe study design of this study research was passed on \u003cstrong\u003eYang et al\u003c/strong\u003e design\u0026nbsp;[5].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSamples selection\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Medical Ethics Committee of the Faculty of Dental Medicine, Al Azhar University, Assuit, which granted approval for the research with number (AUAREC20200315-11). The procedures were carried out in conformity with applicable laws and regulations. All patients provided signed consent forms after being given written information.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePatients required radiographic examination of CBCT as part of their dental treatment. The images were taken as part of the routine examination, diagnosis, and treatment planning of patients that included those suffering facial trauma who required oral surgery, orthodontic treatment or who needed implant treatment. With the informed consent of the patients.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCBCT was used to scan the mandibular region of the patient to obtain a continuous image of the mandibular 1\u003csup\u003est\u003c/sup\u003e molar and its periodontal tissue.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;CBCT scan of 1650 patients were observed between January 2021 to February 2022 were collected using the CBCT imaging system from the database of the department of oral radiology, faculty of dental medicine, Al-Azhar university - Assiut branch.\u0026nbsp;All images were included in the study and further analysis according to the following inclusion criteria:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eAge between 20 and 60 years.\u003c/li\u003e\n \u003cli\u003eLower 1\u003csup\u003est\u003c/sup\u003e molars that had not been received root canal treatment.\u003c/li\u003e\n \u003cli\u003eLower 1\u003csup\u003est\u003c/sup\u003e molars without periapical disease.\u003c/li\u003e\n \u003cli\u003eLower 1\u003csup\u003est\u003c/sup\u003e molars exhibit absence of coronal or post and core restorations, which may obscure the imaging study.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion criteria:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eCases where physiological or pathological processes compromised the anatomy, and the original root canal morphology was not clear.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eImages with missing all mandibular molars.\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCBCT scanning:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCBCT images were acquired using Orthophos S 3D extraoral imaging system (Dentsply Sirona) A scout view was acquired, and adjustments were made to ensure that all patients were correctly adjusted in the scanner according to light beam before acquisition. the Feld-Of-View size (FOV) of 8\u0026times;8 cm, a peak voltage of 90 kV, a beam current of 16 mA and an exposure time of 14.s for a full arch. The voxel size was 160 \u0026mu;m\u0026times;160 \u0026mu;m, and the minimum layer thickness was 0.16 mm. The detector resolution was 1024\u0026times;1024 pixels, and the pixel size was 127 \u0026mu;m\u0026times;127 \u0026mu;m.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAfter acquisition, data were exported and transferred to Sidexis software (Sirona, DICOM viewer software, version 4.0.2, Germany) Serial axial, coronal, and sagittal CBCT images were thoroughly examined from the pulp orifice to the apex. All the images were assessed separately by two endodontists. In cases of disagreement, these two endodontists discussed the data until a consensus was reached. An oral radiologist provided guidance when necessary. CBCT was used to scan the mandibular region of the patient to obtain a continuous image of the mandibular 1\u003csup\u003est\u003c/sup\u003e molar and its periodontal tissue.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e\u003cu\u003eVariables to be analysed in this study:\u003c/u\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1) Incidence frequency of the MMCs present in lower 1\u003csup\u003est\u003c/sup\u003e molars (Figure 1).\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2) Middle Mesial Canals classification (Figure 2) according to the classification of Pomeranz et al. [12]:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ea) Confluent either with the mesio buccal canal or with the mesio lingual canal, \u003cstrong\u003eb\u003c/strong\u003e) Independent, and \u003cstrong\u003ec\u003c/strong\u003e) Fin type (no separate orifice).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3) Frequency of occurrence of MM canals according to age.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCategorical data were presented as frequencies (n) and percentages (%) and were analyzed utilizing Fisher\u0026rsquo;s exact test. Numerical data were explored for normality by checking the data distribution, calculating the mean and median values, and using Kolmogorov-Smirnov and Shapiro-Wilk tests. Data showed parametric distribution, so they were presented as mean and standard deviation (SD) values and were analyzed using one-way ANOVA test. The significance level was set at p \u0026le;0.05 within all tests. Statistical analysis was performed with R statistical analysis software version 4.0.3 for windows \u0026reg; Core Team (2020).\u003c/p\u003e"},{"header":"Results:","content":"\u003cp\u003eCBCT scan of 1650 patients were observed, and 1926 CBCT images of 1200 patients met the inclusion criteria, among which 208 CBCT images contained MMC. The incidence of MMCs in our experimental study was 10.79 % (208/1926) as illustrated in figure (3). Among them, there were 108 (51.9%) males and 100 (48.1%) females, and the difference was not statistically significant (P = 0.215). Moreover, there was no significant difference in the distribution of MMCs between the right and left side. These results are illustrated in figure (4).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The results of this study concerning the frequency occurrence of MMCs in three age groups (group A: \u0026lt; 30, group B: 30\u0026ndash;50, and group C \u0026gt; 50 years) revealed that group A exhibited a greater occurrence of MMCs (96/208) than group B (73/208) or C (39/208) but with significant deference where P = 0.002 as illustrated in figure (5).\u003c/p\u003e\n\u003cp\u003eOur study results that concerning MMCs type was illustrated in figure (6), and it showed that 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy and only 6.7% (14/208) showed independent MMCs with separate orifices and apical foramen.\u003c/p\u003e"},{"header":"Discussion:","content":"\u003cp\u003eRacial and ethnic factors explained the presence of certain abnormalities as the prevalence of MMCs in the mesial root of lower molars that may occur at different rates in different parts of the world. On other hand the methods used to detect root canal abnormalities also plays a big role in detection the prevalence of MMCs [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCBCT image scans were used in our research study to visualize the root canal anatomy with low radiation dosage, and high resolution [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn vivo and vitro studies were reported the incidence of MMCs [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan additionalcitationids=\"CR17 CR18 CR19 CR20 CR21\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The detection of the increased incidence rates reported of accessory canals were done under magnification, moreover occurrence percentage of MMCs was reported as 46.2% [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, the incidence frequency percentage of the presence of MMCs among the Egyptian population was 10.79% (208/1926) with no statistically significant due to gender, while the frequency of the prevalence of MMCs in the studies searched with different populations varied from (1%) to (46%) the variability in results can be attributed to several possible reasons such as ethnic population, sample size, study design and methods to detect the middle mesial canal.\u003c/p\u003e \u003cp\u003eOur study is the 1st study about detecting the frequency percentage of the presence of MMCs among the Egyptian population dealing with large number of CBCT image scans.\u003c/p\u003e \u003cp\u003eThe differences in age groups of this study revealed high frequency of the prevalence of MMCs at the young age and decrease with ageing so it is easier to detect the MMCs in younger patients because they have less physiologic or pathologic pulp calcifications than older patients, these results agree with the previous studies reporting the effect of age on frequency of the prevalence of MMCs [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Similar results were reported by Sherwani et al., [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] who observed that there was a significant decrease in the incidence of MMCs with an increase in age in an Indian population.\u003c/p\u003e \u003cp\u003eDeposition of secondary dentine within the canal at the cervical, middle, and apical thirds in the mesiodistal direction was explained by Hess [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] to be the cause of root canal variations that causes canal separation. At 30\u0026ndash;40 years of age in lower first and second molars was confirmed that canal differentiation is completed at this range of age [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe most frequent canal configuration type among the Egyptian population was showed that 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy, and only 6.7% (14/208) independent MMCs with separate orifices and apical foramen.\u003c/p\u003e \u003cp\u003eOur results are like other studies. These studies reported high percentage rate of confluent anatomy of MMCs [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. On other side there was disagreement of our result to the result of KarapinarKazandag et al. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] they reported that no incidence of independent or fin anatomy, and all MMCs have confluent anatomy.\u003c/p\u003e"},{"header":"Conclusions:","content":"\u003cp\u003eThe MMCs prevalence in mandibular 1st molars among some Egyptian population was 10.79%, and CBCT scan is helpful way to detect the presence of MMCs.\u003c/p\u003e"},{"header":"Abbreviations:","content":"\u003cp\u003eMMCs: Middle Mesial Canals.\u003c/p\u003e\n\u003cp\u003eCBCT: Cone-Beam Computed Tomography.\u003c/p\u003e"},{"header":"Declarations:","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eM.R: Contributed to data collection, data analysis, and original manuscript writing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eW.K: Contributed to protocol/project development, data analysis, and original manuscript editing.\u003c/p\u003e\n\u003cp\u003eK.H: Contributed to manuscript editing, and performed critical revisions, study data collection, revised manuscript editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was obtained.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Data cannot be deposited in a public repository since this research is not yet published. For that reason, and for data confidentiality data will be granted upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Medical Ethics Committee of the Faculty of Dental Medicine, Al Azhar University, Assuit, which granted approval for the research with number (AUAREC20200315-11). A written informed consent signed was obtained from all participants and/or their legal guardians. \u0026nbsp;All methods were carried out in accordance with relevant guidelines and regulations of Helsinki Declaration of the World Medical Association regarding using human participants. All the data used in this study were anonymized before its use.\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\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there are no conflicts of interest regarding the publication of this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e*\u0026nbsp;\u003c/strong\u003eAssociate Professor of Endodontics, Endodontic Department, Faculty of Dental Medicine Al-Azhar University. Assiut Branch, Egypt.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e**\u0026nbsp;\u003c/strong\u003eProfessor and Head of Endodontic Department, Faculty of oral and dental medicine, Future University (FUE) in Egypt.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e***\u0026nbsp;\u003c/strong\u003eProfessor of Oral Medicine \u0026amp;Periodontology, Dean College of Dentistry, Al-Azhar University. Assiut Branch, Egypt.\u003c/p\u003e"},{"header":"References:","content":"\u003col\u003e\n \u003cli\u003e\u003cspan\u003eSajjan GS, Rajashekar Ch, Madhu Varma K, Kalyan Satish R, Rishitha T, Srikanth G. Prevalence of middle mesial canals and Isthmi in mandibular molars in a subpopulation of Andhra Pradesh: an \u003cem\u003ein vivo\u003c/em\u003e investigation using CBCT. Int J Dent Mater 2021;3(1): 08\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eSherwani OA, Kumar A, Tewari RK, Mishra SK, Andrabi SM, Alam S. Frequency of middle mesial canals in mandibular first molars in North Indian population - an in vivo study. Saudi Endod J 2016; 6:66\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eArora A, Acharya SR, Sharma P. Endodontic treatment of a mandibular first molar with 8 canals: A case report. Restor Dent Endod 2015; 40:758.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHuang RY, Cheng WC, Chen CJ, Lin CD, Lai TM, Shen EC, et al. Threedimensional analysis of the root morphology of mandibular first molars with distolingual roots. Int Endod J 2010; 43:47884.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eYang Y, Wu B, Zeng J. et al. Classification and morphology of middle mesial canals of mandibular first molars in a southern Chinese subpopulation: a cone-beam computed tomographic study. BMC Oral Health2020; 20: 358.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eDe Toubes KM, de Souza C\u0026ocirc;rtes MI, de Abreu Valadares MA, Fonseca LC, Nunes E, Silveira FF. Comparative analysis of accessory mesial canal identification in mandibular first molars by using four different diagnostic methods. J Endod. 2012;38 (4):436\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eJacobsen EL, Dick K, Bodell R. Mandibular First Molars with Multiple Mesial Canals. 1994; 20 (12): 610\u0026ndash;613.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eScarfe WC, Levin MD, Gane D, Farman AG. Use of cone beam computed tomography in endodontics. Int J Dent. 2009.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eKumar V, Gossett L, Blattner A, Iwasaki LR, Williams K, Nickel JC. Comparison between cone-beam computed tomography and intraoral digital radiography for assessment of tooth root lesions. Am J Orthod Dentofac Orthop. 2011;139: e 533 \u0026ndash; 41.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003ePatel S, Dawood A, Whaites E, Pitt Ford T. New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems. Int Endod J. 2009; 42:447\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eShukla S, Chug A, Afrashtehfar KI. Role of cone beam computed tomographyn diagnosis and treatment planning in dentistry: an update. J Int Soc Prev Commun Dent. 2017;7: 125\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eBallullaya SV, Vemuri S, Kumar PR. Variable permanent mandibular first molar: Review of literature. J Conserv Dent. 2013 Mar;16(2):99\u0026ndash;110.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eBansal R, Hegde S, Astekar M. Morphology, and prevalence of middle canals in the mandibular molars: A systematic review. J Oral Maxillofac Pathol 2018; 22:216\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHargreaves K.M., Berman. Pathways of the Pulp, Mosby Inc, St. Louis, MI, USA, 2016:11th Edition.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eNi, N., Cao, S., Han, L. et al. Cone-beam computed tomography analysis of root canal morphology in mandibular first molars in a Chinese population: a clinical study. Evid.-based endod 3, 1 (2018). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s41121-018-0015-8\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eGu L, Wei X, Ling J, Huang X. A microcomputed tomographic study of canal isthmuses in the mesial root of mandibular first molars in a Chinese population. J Endod 2009; 35:3536. 9.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003ePomeranz HH, Eidelman DL, Goldberg MG. Treatment considerations of the middle mesial canal of mandibular first and second molars. J Endod 1981; 7:5658. 10.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eGoel NK, Gill KS, Taneja JR. Study of root canals configuration in mandibular first permanent molar. J Indian Soc Pedod Prev Dent 1991; 8:124.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eSkidmore AE, Bjorndal AM. Root canal morphology of the human mandibular first molar. Oral Surg Oral Med Oral Pathol 1971; 32:77884.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eAzim AA, Deutsch AS, Solomon CS. Prevalence of middle mesial canals in mandibular molars after guided troughing under high magnification: An in vivo investigation. J Endod 2015; 41:1648. 15.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eNosrat A, Deschenes RJ, Tordik PA, Hicks ML, Fouad AF. Middle mesial canals in mandibular molars: Incidence and related factors. J Endod 2015; 41:2832. 16.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eKarapinarKazandag M, Basrani BR, Friedman S. The operating microscope enhances detection and negotiation of accessory mesial canals in mandibular molars. J Endod 2010; 36:128994.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eHess W. Formation of Root\u0026ndash;Canals in Human Teeth I. J Nat Dent Assoc 1921; 8:704\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003ePeiris HR, Pitakotuwage TN, Takahashi M, Sasaki K, Kanazawa E. Root\u0026nbsp;\u003c/span\u003e\u003cspan\u003ecanal morphology of mandibular permanent molars at different ages. Int Endod J 2008; 41:828\u0026ndash;35.\u003c/span\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"middle mesial canals, Cone-Beam Computed Tomography, and Configuration type","lastPublishedDoi":"10.21203/rs.3.rs-1455902/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1455902/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eAn untreated root canal is one of the main causes of failure in endodontics.\u003cstrong\u003e \u003c/strong\u003eThe aims of this study were\u003cstrong\u003e \u003c/strong\u003eto detect the middle mesial canals (MMCs) prevalence in mandibular 1\u003csup\u003est\u003c/sup\u003e molars, its configuration type, and its percentage of incidence with age by Cone-Beam Computed Tomography (CBCT)\u003cstrong\u003e \u003c/strong\u003eanalysis.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e CBCT scan of 1650 patients were observed between January 2021 to February 2022 were collected using the CBCT imaging system from the database of the department of oral radiology, faculty of dental medicine, Al-Azhar university - Assiut branch. CBCT scan images were analyzed by Sidexis software. CBCT images were examined to detect the following: (1) The percentage of incidence frequency of the MMCs, (2) MMCs classification, and (3) Frequency of occurrence of MMCs according to age.\u003cstrong\u003e \u003c/strong\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e The incidence frequency percentage of the presence of MMCs among the Egyptian population was 10.79 % (208/1926) with no statistically significant due to gender, While MMCs configuration types showed 77% (160/208) confluent anatomy merging with either the mesio buccal or mesio lingual canals, 16.3% (34/208) fin anatomy and only 6.7% (14/208) showed independent MMCs with separate orifices and apical foramen. lastly the incidence frequency percentage of the presence of MMCs decreases with age. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eThe MMCs prevalence in mandibular 1\u003csup\u003est\u003c/sup\u003e molars among some Egyptian population was 10.79 %, and CBCT scan is helpful way to detect the presence of MMCs.\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"Middle Mesial Canals Prevalence percentage and Its Configuration type Among Some Egyptian Population by CBCT","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-05-05 16:24:02","doi":"10.21203/rs.3.rs-1455902/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"79c0ad2f-210c-435a-aa35-ee603d707fe9","owner":[],"postedDate":"May 5th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-09-12T10:59:32+00:00","versionOfRecord":[],"versionCreatedAt":"2022-05-05 16:24:02","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1455902","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1455902","identity":"rs-1455902","version":["v1"]},"buildId":"J0_U0BvcaRcwD8yVFaRlm","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}