[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-442582-105":59,"doc-detail-442582-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","type-iiib-dens-invaginatus-in-a-maxillary-second-molar-and-its-microscopic-anatomical-features-a-case-report","Type IIIb dens invaginatus in a maxillary second molar and its microscopic anatomical features - a case report","","Dens invaginatus (DI) is a developmental dental anomaly that usually affects maxillary lateral incisors, most often presenting as Oehlers type I or II; molar involvement is exceptionally rare. This case report describes a type IIIb DI in a maxillary second molar evaluated after extraction. Micro-computed tomography (micro-CT) and hematoxylin–eosin (H&E) staining were used to characterize concealed anatomy and developmental anomalies. Clinical and radiographic follow-up showed favorable outcomes.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/type-iiib-dens-invaginatus-in-a-maxillary-second-molar-and-its-microscopic-anatomical-features-a-case-report/442582/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/type-iiib-dens-invaginatus-in-a-maxillary-second-molar-and-its-microscopic-anatomical-features-a-case-report/442582.png","ImageObject",300,407,{"name":92,"@type":93},"SANS","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-09-29",true,{"@type":102,"interactionType":103,"userInteractionCount":39},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What is dens invaginatus (DI) and why is this case notable?","Question",{"text":112,"@type":113},"DI is a developmental dental anomaly caused by abnormal growth pressure or delayed development during odontogenesis. It usually affects maxillary lateral incisors, so DI in molars is extremely rare, making this case notable.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How was the type IIIb DI diagnosed in this patient?",{"text":117,"@type":113},"Cone-beam computed tomography (CBCT) identified a type IIIb DI and extensive periapical pathology with involvement extending toward adjacent tooth 16.",{"name":119,"@type":110,"acceptedAnswer":120},"What techniques were used to analyze the extracted tooth and what did they show?",{"text":121,"@type":113},"After extraction, micro-CT imaging revealed a concealed invagination orifice connecting to the oral cavity and the apex. 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BMC Oral Health (2026) 26:18 [https://doi.org/10.1186/s12903-025-07390-4](https://doi.org/10.1186/s12903-025-07390-4)  \nBMC Oral Health  \nCASE REPORT Open Access  \nType IIIb dens invaginatus in a maxillary  second molar and its microscopic anatomical features: a case report  \nMingming Li 1†, Zhiwu Wu2†, Shaoying Duan3 andYuling Zuo 1*  \nAbstract  \nBackground Dens invaginatus (DI) is a developmental anomaly that most commonly affects maxillary lateral incisors, typically presenting as Oehlers type I or II. Its occurrence in molars is extremely rare. This case presents a type IIIb DI ina maxillary second molar, analyzed post-extraction using micro-computed tomography (micro-CT) and hematoxylin– eosin (H&E) staining.  \nCase presentation A 22-year-old female presented with persistent gingival swelling and a sinus tract near tooth 16 despite prior root canal therapy. A cone-beam computed tomography scan identified a type IIIb DI in tooth 17 with extensive periapical pathology extending to tooth 16. Tooth 17 was extracted due to a poor prognosis. Subsequent micro-CT imaging identified a concealed orifice ofthe invagination connecting to both the oral cavity and the apical. H&E staining revealed detailed developmental anomalies. The three-month follow-up revealed favorable clinical and radiographic outcomes.  \nConclusions Micro-CT and histopathological analysis of the extracted DI-affected molar provided clear insights into its complex anatomy and developmental anomalies, potentially aiding more precise clinical assessment and evidence-based therapeutic decision-making in future cases.  \nKeywords Dens invaginatus, Micro-computed tomography, Maxillary second molar  \n†Mingming Li and Zhiwu Wu contributed equally to this work.  \n*Correspondence:  \nYuling Zuo  \n[zuozuoe2024@yeah.net](zuozuoe2024@yeah.net)  \n1Department of Stomatology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China  \n2School of Stomatology, Zhejiang Chinese Medical University, Stomatology Hospital of Zhejiang Chinese Medical University, Hangzhou 310053, China  \n3Department of Stomatology, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing 400037, China  \nBackground  \nDens invaginatus (DI) is a developmental dental anomaly resulting from abnormal growth pressure or delayed development during odontogenesis. However, its precise etiology remains unclear. DI is classified into two types based on the location of the invagination: coronal dens invaginatus (CDI), caused by infolding of the enamel organ, and radicular densinvaginatus (RDI), resulting from the invagination of Hertwig’s epithelial root sheath into the dental papilla [1] . CDI is more prevalent and is typically subclassified into Oehlers types I, II, IIIa, and IIIb (Fig. S1A) . Among these, type III is relatively rare [2] .  \n© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit [http://creati](http://creati)[vecommons.org/l](vecommons.org/l)icenses/by-nc-nd/4.0/.  \nLi et al. BMC Oral Health (2026) 26:18 Page ","cbCaijxX2UZDZjoE","https://ap.wps.com/l/cbCaijxX2UZDZjoE","pdf",1755892,"English","# Abstract\n## Background\n## Case presentation\n## Conclusions\n# Background\n## Classification and epidemiology\n## Imaging and diagnostic challenges\n# Case presentation","[{\"question\":\"What is dens invaginatus (DI) and why is this case notable?\",\"answer\":\"DI is a developmental dental anomaly caused by abnormal growth pressure or delayed development during odontogenesis. It usually affects maxillary lateral incisors, so DI in molars is extremely rare, making this case notable.\"},{\"question\":\"How was the type IIIb DI diagnosed in this patient?\",\"answer\":\"Cone-beam computed tomography (CBCT) identified a type IIIb DI and extensive periapical pathology with involvement extending toward adjacent tooth 16.\"},{\"question\":\"What techniques were used to analyze the extracted tooth and what did they show?\",\"answer\":\"After extraction, micro-CT imaging revealed a concealed invagination orifice connecting to the oral cavity and the apex. H\\u0026E staining demonstrated detailed developmental anomalies.\"}]","Type IIIb dens invaginatus in a maxillary second molar and its microscopic anatomical features - a case report | PDF",1790700868]