Radiographic Detection of an Extra Root in a Mandibular First Molar: A Case Report

Radiographic Detection of an Extra Root in a Mandibular First Molar: A Case Report | 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 Case Report Radiographic Detection of an Extra Root in a Mandibular First Molar: A Case Report Esma Deniz Barc This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9448209/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 Anatomical variations in the root morphology of mandibular molars can complicate endodontic treatment if not accurately identified. Although panoramic radiography is not considered a definitive modality for assessing root canal anatomy, it may provide valuable preliminary clues indicating complex root configurations. We report a case of an additional root detected in a mandibular first molar of a 40-year-old female patient during ongoing orthodontic treatment. A panoramic radiograph obtained on April 28, 2021, revealed an unusual distal root morphology suggestive of an anatomical variation. During treatment planning for root canal therapy, the presence of an additional root with an independent canal was clinically confirmed. This case emphasizes the importance of careful radiographic assessment of mandibular molars, particularly when panoramic imaging reveals subtle morphological irregularities. Early recognition of such variations may help prevent missed canals and improve endodontic outcomes. In conclusion, clinicians should remain vigilant for atypical root anatomy in mandibular molars and consider further diagnostic evaluation when conventional radiographs raise suspicion of complex root morphology. Dentistry Mandibular first molar Additional root Radix entomolaris Panoramic radiography Root canal morphology Figures Figure 1 Introductıon Anatomical variations in the root and root canal morphology of mandibular first molars represent a significant challenge in endodontic diagnosis and treatment planning. Although mandibular first molars are generally described as having two roots and three canals, numerous studies have demonstrated substantial variability in root number and canal configuration, which may adversely affect endodontic outcomes if not properly identified ( 1 , 2 ). Among these variations, the presence of an additional distolingual root—commonly referred to as radix entomolaris—has been widely reported and is considered clinically important due to the frequent presence of an independent root canal system ( 3 , 4 ). The prevalence of this anatomical variation has been shown to differ considerably among populations, as demonstrated by cone-beam computed tomography (CBCT)–based studies conducted in various ethnic groups ( 5 , 6 ). CBCT has been shown to provide superior accuracy in the assessment of complex root and root canal morphology and is regarded as the reference standard for three-dimensional evaluation ( 7 , 8 ). Nevertheless, panoramic radiography remains a commonly used initial imaging modality in routine dental practice because of its availability and lower radiation dose. Although panoramic imaging is limited in depicting detailed root canal anatomy, recent evidence suggests that careful evaluation may reveal subtle radiographic features indicative of additional roots in mandibular first molars ( 9 ). Failure to detect such anatomical variations before endodontic treatment may result in missed canals and compromised treatment success ( 10 ). Therefore, increased awareness of anatomical diversity and meticulous radiographic assessment are essential for clinicians involved in endodontic care. The present case report describes the radiographic suspicion and subsequent clinical confirmation of an additional root in a mandibular first molar detected during orthodontic treatment, highlighting the importance of careful evaluation of panoramic radiographs before endodontic intervention. Case Presentation A 40-year-old female patient residing in Ankara underwent panoramic radiographic examination on April 28, 2021, as part of routine evaluation during ongoing orthodontic treatment. The panoramic radiograph was obtained using a Dentistomo imaging system. The patient was asymptomatic at the time of imaging, and no acute dental complaints were reported. Radiographic assessment revealed an unusual root morphology in a mandibular first molar, characterized by an atypical distal root configuration suggestive of an additional root (Fig. 1 A). The magnified panoramic view further highlighted the suspected additional distolingual root, providing clearer visualization of the morphological irregularity (Fig. 1 B). During subsequent treatment planning for root canal therapy, clinical exploration confirmed the presence of an additional root containing an independent canal. This finding validated the initial radiographic suspicion of complex root anatomy. The detection of the additional root prior to endodontic instrumentation allowed for appropriate modification of the treatment approach. Written informed consent was obtained from the patient for publication of this case report and accompanying images. Discussion Anatomical variations in the root and root canal morphology of mandibular first molars remain a major cause of diagnostic and therapeutic challenges in endodontic practice. Although the conventional anatomy is well established, numerous imaging-based studies have demonstrated that variations such as additional roots and complex canal configurations are more common than previously assumed ( 1 , 2 ). Failure to recognize these variations may compromise treatment success and increase the risk of missed canals ( 10 ). The presence of a distolingual additional root, commonly referred to as radix entomolaris, has been extensively documented in the literature and is known to exhibit marked population-based variability ( 3 – 6 , 12 ). CBCT studies have shown that the prevalence of three-rooted mandibular first molars differs significantly among ethnic groups, emphasizing the importance of individualized radiographic assessment rather than reliance on presumed anatomical norms ( 5 , 6 , 12 ). CBCT is widely regarded as the reference standard for three-dimensional evaluation of root and root canal morphology due to its superior diagnostic accuracy ( 1 , 7 ). Nevertheless, panoramic radiography remains a commonly employed initial imaging modality in routine clinical practice. Although panoramic images do not provide definitive visualization of root canal anatomy, previous investigations have demonstrated that specific projection angulations and careful assessment may reveal radiographic clues suggestive of additional roots ( 9 , 11 ). In the present case, subtle distal root irregularities observed on panoramic imaging prompted further clinical exploration, which ultimately confirmed the presence of an additional root with an independent canal. Several studies have reported an association between the presence of a distolingual root in mandibular first molars and increased complexity of root canal morphology in other teeth, suggesting a broader pattern of anatomical variation ( 13 , 14 ). Such findings highlight the need for heightened anatomical awareness when managing patients with suspected complex root configurations. Clinical case reports and case series have emphasized that early identification of radix entomolaris plays a critical role in preventing missed canals and facilitating appropriate modification of access cavity design and instrumentation strategy ( 15 – 17 ). Failure to detect additional roots may lead to inadequate debridement, increased procedural complications, and compromised long-term outcomes ( 18 , 20 ). Although classical descriptions of canal morphology have traditionally focused on maxillary molars, their fundamental principles regarding anatomical complexity and endodontic significance remain applicable to mandibular molars as well ( 19 ). The present case underscores the clinical value of meticulous radiographic evaluation, even when conventional imaging modalities are used. Recognition of subtle radiographic irregularities on panoramic images can guide clinicians toward timely detection of anatomical variations and appropriate treatment planning. This case was reported in accordance with the PRICE 2020 guidelines for endodontic case reports, ensuring transparency and completeness in reporting ( 21 ). Conclusıon This case highlights the clinical importance of recognizing anatomical variations in mandibular first molars, particularly the presence of an additional distolingual root. Careful evaluation of panoramic radiographs, despite their inherent limitations, may provide valuable clues prompting further investigation of complex root morphology. Early identification of such variations can help prevent missed canals and allow appropriate modification of endodontic treatment strategies. Clinicians should therefore maintain a high index of suspicion for atypical root anatomy when radiographic findings appear inconsistent with conventional anatomical patterns. Declarations Author Contributions All authors contributed to the conception, data interpretation, manuscript drafting, and final approval of the submitted version Conflıct Of Interest The authors declare no conflicts of interest related to this study. Fundıng This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author Contributions All authors contributed to the conception, data interpretation, manuscript drafting, and final approval of the submitted version References Yazdizadeh M, Alavinezhad P, Sadrishahrezaei A, Sharifishoshtari S. Root canal morphology of mandibular first molars: Comparison of the diagnostic accuracy of cone-beam computed tomography and the sectioning technique. Dental Research Journal. 2023;20:103. Karobari MI, Arshad S, Noorani TY, et al. Root and root canal configuration characterization using microcomputed tomography: a systematic review. Journal of Clinical Medicine. 2022;11(9):2287. Calberson FL, De Moor RJ, Deroose CA. The radix entomolaris and paramolaris: clinical approach in endodontics. Journal of Endodontics. 2007;33(1):58–63. Ribeiro FC, Consolaro A. Clinical and anthropological importance of the distolingual root in permanent lower molars. Endodontica. 1997;15:72–78. Sheth K, Banga KS, Pawar A, et al. Distolingual root prevalence in mandibular first molar and complex root canal morphology in incisors: a CBCT analysis in Indian population. Scientific Reports. 2024;14:443. Rahimi S, Mokhtari H, Ranjkesh B, et al. Prevalence of extra roots in permanent mandibular first molars in Iranian population: a CBCT analysis. Iranian Endodontic Journal. 2017;12(1):70–73. Patel S, Brown J, Semper M, Abella F, Mannocci F. European Society of Endodontology position statement: Use of cone beam computed tomography in endodontics. International Endodontic Journal. 2019;52(12):1675–1678. Gambarini G, Ropini P, Piasecki L, et al. A preliminary assessment of a new dedicated endodontic software for use with CBCT images to evaluate the canal complexity of mandibular molars. International Endodontic Journal. 2018;51(3):259–268. Jin L, Tang Y, Zhou W, et al. Detection of three-rooted mandibular first molars on panoramic radiographs using deep learning. Scientific Reports. 2024;14:30392. Cantatore G, Berutti E, Castellucci A. Missed anatomy: frequency and clinical impact. Endodontic Topics. 2006;15(1):3–31. Wang Q, Yu G, Zhou XD, Peters OA, Zheng QH, Huang DM. Evaluation of x-ray projection angulation for successful radix entomolaris diagnosis in mandibular first molars in vitro. Journal of Endodontics. 2011;37(8):1063–1068. Garg AK, Tewari RK, Agrawal N. Prevalence of three-rooted mandibular first molars among Indians using spiral computed tomography. International Journal of Dentistry. 2013;2013:183869. Yang Y, Jiang C, Chen M, Zeng J, Wu B. Vertucci’s root canal configuration of mandibular anteriors and its relationship with distolingual roots in mandibular first molars: a CBCT study. BMC Oral Health. 2022;22(1):130. Wu YC, Cheng WC, Weng PW, et al. The presence of a distolingual root in mandibular first molars is correlated with complicated root canal morphology of mandibular central incisors: a CBCT study. Journal of Endodontics. 2018;44(5):711–716. Rahhali M, Sakout M. Endodontic management of a mandibular first molar with radix entomolaris: a clinical case report. Cureus. 2025;17(4):e82342. Arora A, Arya A, Chauhan L, Thapak G. Radix entomolaris: case report with clinical implication. International Journal of Clinical Pediatric Dentistry. 2018;11(6):536–538. Mahalakshmi S, Shenoy MA, Shubha B, Chandy CJ. Radix entomolaris: a rare case series. South African Dental Journal. 2014;69(8):358–362. Zelada G, Varela P, Martín B, et al. The effect of rotational speed and root canal curvature on the breakage of rotary endodontic instruments. Journal of Endodontics. 2002;28(7):540–542. Weine FS, Healey HJ, Gerstein H, Evanson L. Canal configuration in the mesiobuccal root of the maxillary first molar and its endodontic significance. Oral Surgery, Oral Medicine, Oral Pathology. 1969;28(3):419–425. Cantatore G, Berutti E, Castellucci A. Missed anatomy: frequency and clinical impact. Endodontic Topics. 2006;15(1):3–31. Nagendrababu V, Chong BS, McCabe P, et al. PRICE 2020 guidelines for reporting case reports in endodontics: explanation and elaboration. International Endodontic Journal. 2020;53(7):922–947. Additional Declarations The authors declare no competing interests. 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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-9448209","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":624916584,"identity":"df31ea58-4f13-4494-b0f6-0cc71aeecbdf","order_by":0,"name":"Esma Deniz Barc","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwUlEQVRIiWNgGAWjYDCCAwwMzEBKjoGBh0QtxqRrSWwgWgvf8d7Dnwtq7qVvOH724IMPDHZyug0EtEieOZdgPONYce6GM3nJhjMYko3NDhDQYnAjxyCZhy0hd8OBHDNpHoYDidsIarn/xuAwz7+EdIPzb4jVcoPHsJm3LSEBaB2RWiTP5Bgzz+xLMJx5442x4QwDIvzCd/yM8eeCbwnyfOdzDB98qLCTI6gFDhTAKg2IVQ4C8g2kqB4Fo2AUjIIRBQCL/0SH4BFbwgAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-4636-4312","institution":"Dicle University","correspondingAuthor":true,"prefix":"","firstName":"Esma","middleName":"Deniz","lastName":"Barc","suffix":""}],"badges":[],"createdAt":"2026-04-17 10:57:34","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":true,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-9448209/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9448209/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107307084,"identity":"9e392c56-a12f-4350-ba97-4a2b1c93bb0e","added_by":"auto","created_at":"2026-04-20 08:34:41","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1090539,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Panoramic radiograph obtained during orthodontic treatment showing an unusual root morphology in a mandibular first molar.\u003c/p\u003e\n\u003cp\u003e(B) Magnified view of the same region highlighting the suspected additional distolingual root (arrow), which was subsequently confirmed during endodontic access.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9448209/v1/abedc15a8307a75908ac1b86.png"},{"id":107487142,"identity":"81d7ed7e-8a31-45d4-9e8d-7e69e4c22faa","added_by":"auto","created_at":"2026-04-22 02:39:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1203092,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9448209/v1/2258bd07-cf45-4123-9030-7b6ea2d2fba2.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eRadiographic Detection of an Extra Root in a Mandibular First Molar: A Case Report\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introductıon","content":"\u003cp\u003eAnatomical variations in the root and root canal morphology of mandibular first molars represent a significant challenge in endodontic diagnosis and treatment planning. Although mandibular first molars are generally described as having two roots and three canals, numerous studies have demonstrated substantial variability in root number and canal configuration, which may adversely affect endodontic outcomes if not properly identified (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAmong these variations, the presence of an additional distolingual root\u0026mdash;commonly referred to as radix entomolaris\u0026mdash;has been widely reported and is considered clinically important due to the frequent presence of an independent root canal system (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). The prevalence of this anatomical variation has been shown to differ considerably among populations, as demonstrated by cone-beam computed tomography (CBCT)\u0026ndash;based studies conducted in various ethnic groups (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCBCT has been shown to provide superior accuracy in the assessment of complex root and root canal morphology and is regarded as the reference standard for three-dimensional evaluation (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Nevertheless, panoramic radiography remains a commonly used initial imaging modality in routine dental practice because of its availability and lower radiation dose. Although panoramic imaging is limited in depicting detailed root canal anatomy, recent evidence suggests that careful evaluation may reveal subtle radiographic features indicative of additional roots in mandibular first molars (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFailure to detect such anatomical variations before endodontic treatment may result in missed canals and compromised treatment success (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Therefore, increased awareness of anatomical diversity and meticulous radiographic assessment are essential for clinicians involved in endodontic care.\u003c/p\u003e \u003cp\u003eThe present case report describes the radiographic suspicion and subsequent clinical confirmation of an additional root in a mandibular first molar detected during orthodontic treatment, highlighting the importance of careful evaluation of panoramic radiographs before endodontic intervention.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 40-year-old female patient residing in Ankara underwent panoramic radiographic examination on April 28, 2021, as part of routine evaluation during ongoing orthodontic treatment. The panoramic radiograph was obtained using a Dentistomo imaging system. The patient was asymptomatic at the time of imaging, and no acute dental complaints were reported.\u003c/p\u003e\n\u003cp\u003eRadiographic assessment revealed an unusual root morphology in a mandibular first molar, characterized by an atypical distal root configuration suggestive of an additional root (Fig. \u003cspan refid=\"Fig1\"\u003e1\u003c/span\u003eA). The magnified panoramic view further highlighted the suspected additional distolingual root, providing clearer visualization of the morphological irregularity (Fig. \u003cspan refid=\"Fig1\"\u003e1\u003c/span\u003eB).\u003c/p\u003e\n\u003cp\u003eDuring subsequent treatment planning for root canal therapy, clinical exploration confirmed the presence of an additional root containing an independent canal. This finding validated the initial radiographic suspicion of complex root anatomy. The detection of the additional root prior to endodontic instrumentation allowed for appropriate modification of the treatment approach.\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAnatomical variations in the root and root canal morphology of mandibular first molars remain a major cause of diagnostic and therapeutic challenges in endodontic practice. Although the conventional anatomy is well established, numerous imaging-based studies have demonstrated that variations such as additional roots and complex canal configurations are more common than previously assumed (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Failure to recognize these variations may compromise treatment success and increase the risk of missed canals (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe presence of a distolingual additional root, commonly referred to as radix entomolaris, has been extensively documented in the literature and is known to exhibit marked population-based variability (\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). CBCT studies have shown that the prevalence of three-rooted mandibular first molars differs significantly among ethnic groups, emphasizing the importance of individualized radiographic assessment rather than reliance on presumed anatomical norms (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCBCT is widely regarded as the reference standard for three-dimensional evaluation of root and root canal morphology due to its superior diagnostic accuracy (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Nevertheless, panoramic radiography remains a commonly employed initial imaging modality in routine clinical practice. Although panoramic images do not provide definitive visualization of root canal anatomy, previous investigations have demonstrated that specific projection angulations and careful assessment may reveal radiographic clues suggestive of additional roots (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). In the present case, subtle distal root irregularities observed on panoramic imaging prompted further clinical exploration, which ultimately confirmed the presence of an additional root with an independent canal.\u003c/p\u003e \u003cp\u003eSeveral studies have reported an association between the presence of a distolingual root in mandibular first molars and increased complexity of root canal morphology in other teeth, suggesting a broader pattern of anatomical variation (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Such findings highlight the need for heightened anatomical awareness when managing patients with suspected complex root configurations.\u003c/p\u003e \u003cp\u003eClinical case reports and case series have emphasized that early identification of radix entomolaris plays a critical role in preventing missed canals and facilitating appropriate modification of access cavity design and instrumentation strategy (\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Failure to detect additional roots may lead to inadequate debridement, increased procedural complications, and compromised long-term outcomes (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Although classical descriptions of canal morphology have traditionally focused on maxillary molars, their fundamental principles regarding anatomical complexity and endodontic significance remain applicable to mandibular molars as well (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe present case underscores the clinical value of meticulous radiographic evaluation, even when conventional imaging modalities are used. Recognition of subtle radiographic irregularities on panoramic images can guide clinicians toward timely detection of anatomical variations and appropriate treatment planning. This case was reported in accordance with the PRICE 2020 guidelines for endodontic case reports, ensuring transparency and completeness in reporting (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e).\u003c/p\u003e"},{"header":"Conclusıon","content":"\u003cp\u003eThis case highlights the clinical importance of recognizing anatomical variations in mandibular first molars, particularly the presence of an additional distolingual root. Careful evaluation of panoramic radiographs, despite their inherent limitations, may provide valuable clues prompting further investigation of complex root morphology. Early identification of such variations can help prevent missed canals and allow appropriate modification of endodontic treatment strategies. Clinicians should therefore maintain a high index of suspicion for atypical root anatomy when radiographic findings appear inconsistent with conventional anatomical patterns.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contributions\u003c/h2\u003e \u003cp\u003eAll authors contributed to the conception, data interpretation, manuscript drafting, and final approval of the submitted version\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConflıct Of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflicts of interest related to this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFundıng\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the conception, data interpretation, manuscript drafting, and final approval of the submitted version\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eYazdizadeh M, Alavinezhad P, Sadrishahrezaei A, Sharifishoshtari S. Root canal morphology of mandibular first molars: Comparison of the diagnostic accuracy of cone-beam computed tomography and the sectioning technique. Dental Research Journal. 2023;20:103.\u003c/li\u003e\n\u003cli\u003eKarobari MI, Arshad S, Noorani TY, et al. Root and root canal configuration characterization using microcomputed tomography: a systematic review. Journal of Clinical Medicine. 2022;11(9):2287.\u003c/li\u003e\n\u003cli\u003eCalberson FL, De Moor RJ, Deroose CA. The radix entomolaris and paramolaris: clinical approach in endodontics. Journal of Endodontics. 2007;33(1):58\u0026ndash;63.\u003c/li\u003e\n\u003cli\u003eRibeiro FC, Consolaro A. Clinical and anthropological importance of the distolingual root in permanent lower molars. Endodontica. 1997;15:72\u0026ndash;78.\u003c/li\u003e\n\u003cli\u003eSheth K, Banga KS, Pawar A, et al. Distolingual root prevalence in mandibular first molar and complex root canal morphology in incisors: a CBCT analysis in Indian population. Scientific Reports. 2024;14:443.\u003c/li\u003e\n\u003cli\u003eRahimi S, Mokhtari H, Ranjkesh B, et al. Prevalence of extra roots in permanent mandibular first molars in Iranian population: a CBCT analysis. Iranian Endodontic Journal. 2017;12(1):70\u0026ndash;73.\u003c/li\u003e\n\u003cli\u003ePatel S, Brown J, Semper M, Abella F, Mannocci F. European Society of Endodontology position statement: Use of cone beam computed tomography in endodontics. International Endodontic Journal. 2019;52(12):1675\u0026ndash;1678.\u003c/li\u003e\n\u003cli\u003eGambarini G, Ropini P, Piasecki L, et al. A preliminary assessment of a new dedicated endodontic software for use with CBCT images to evaluate the canal complexity of mandibular molars. International Endodontic Journal. 2018;51(3):259\u0026ndash;268.\u003c/li\u003e\n\u003cli\u003eJin L, Tang Y, Zhou W, et al. Detection of three-rooted mandibular first molars on panoramic radiographs using deep learning. 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International Endodontic Journal. 2020;53(7):922\u0026ndash;947.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Dicle University","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":"Mandibular first molar, Additional root, Radix entomolaris, Panoramic radiography, Root canal morphology","lastPublishedDoi":"10.21203/rs.3.rs-9448209/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9448209/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAnatomical variations in the root morphology of mandibular molars can complicate endodontic treatment if not accurately identified. Although panoramic radiography is not considered a definitive modality for assessing root canal anatomy, it may provide valuable preliminary clues indicating complex root configurations.\u003c/p\u003e \u003cp\u003eWe report a case of an additional root detected in a mandibular first molar of a 40-year-old female patient during ongoing orthodontic treatment. A panoramic radiograph obtained on April 28, 2021, revealed an unusual distal root morphology suggestive of an anatomical variation. During treatment planning for root canal therapy, the presence of an additional root with an independent canal was clinically confirmed.\u003c/p\u003e \u003cp\u003eThis case emphasizes the importance of careful radiographic assessment of mandibular molars, particularly when panoramic imaging reveals subtle morphological irregularities. Early recognition of such variations may help prevent missed canals and improve endodontic outcomes.\u003c/p\u003e \u003cp\u003eIn conclusion, clinicians should remain vigilant for atypical root anatomy in mandibular molars and consider further diagnostic evaluation when conventional radiographs raise suspicion of complex root morphology.\u003c/p\u003e","manuscriptTitle":"Radiographic Detection of an Extra Root in a Mandibular First Molar: A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-20 08:34:34","doi":"10.21203/rs.3.rs-9448209/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":"e9d89ad6-7ddc-47f9-b476-6a01b7194da4","owner":[],"postedDate":"April 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":66517216,"name":"Dentistry"}],"tags":[],"updatedAt":"2026-04-20T08:34:37+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-20 08:34:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9448209","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9448209","identity":"rs-9448209","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}