{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T10:42:21Z","timestamp":1777891341985,"version":"3.51.4"},"reference-count":26,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2023,4,28]],"date-time":"2023-04-28T00:00:00Z","timestamp":1682640000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["THC"],"published-print":{"date-parts":[[2023,4,28]]},"abstract":"<jats:p>BACKGROUND: Retromolar canal (RMC) arises from the mandibular canal (MC) behind the second or third molar and travels anterosuperiorly to a retromolar foramen (RMF). RMCs and RMFs have generally been ignored in anatomical textbooks and have rarely been reviewed or studied in the anatomical and dental literature until the last decades. OBJECTIVE: This study aimed to characterize RMF in a Chinese population concerning its incidence, origin, and classification via anatomical study and periapical radiography. METHODS: 123 dry adult Chinese mandibles were collected to observe the incidence of RMFs. RMFs were determined using a steel wire 0.5\u00a0mm in diameter. The passways or origins of the retromolar canal (RMC) were determined and classified via periapical radiography. For each RMF, two dentists independently measured the diameter and its distances to the lingual cortex, the buccal cortex, and the distal edge of the last tooth (or the alveolar fossa) using a vernier caliper. RESULTS: The incidence of RMFs was 31.71%. The average RMF diameter was 0.78 \u00b1 0.27\u00a0mm. From RMF, the distance was 4.27 \u00b1 1.87\u00a0mm to the lingual cortex, 8.61 \u00b1 2.23\u00a0mm to the buccal cortex, and 7.84 \u00b1 3.87\u00a0mm to the distal edge of the last tooth (or the alveolar fossa). RMCs were classified into MC type originating from the mandibular canal and AF type originating from the alveolar fossa. The diameters of MC ones were more significant than those of AF ones. There was no apparent correlation between the existence of the third molar and the presence of an RMF. CONCLUSION: The incidence of RMFs in Chinese may be about one-third, which is a potential factor in the onset of surgery accidents. RMCs can be classified into two types by their origins. One of them is MC, which originates from the mandibular canal, and the other is AF, which originates from the alveolar fossa.<\/jats:p>","DOI":"10.3233\/thc-236043","type":"journal-article","created":{"date-parts":[[2023,4,14]],"date-time":"2023-04-14T12:09:59Z","timestamp":1681474199000},"page":"497-504","source":"Crossref","is-referenced-by-count":5,"title":["Characterization of a retromolar foramen in a Chinese population: A radiographic study"],"prefix":"10.1177","volume":"31","author":[{"given":"Xiaoxu","family":"Ren","sequence":"first","affiliation":[{"name":"Department of Stomatology, Changzhi People\u2019s Hospital, Shanxi, China"},{"name":"Department of Stomatology, Changzhi People\u2019s Hospital, Shanxi, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yan","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Oral and Maxillofacial Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China"},{"name":"Department of Stomatology, Changzhi People\u2019s Hospital, Shanxi, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xuemin","family":"Yin","sequence":"additional","affiliation":[{"name":"Department of Oral and Maxillofacial Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gang","family":"Guo","sequence":"additional","affiliation":[{"name":"Department of Stomatology, Changzhi People\u2019s Hospital, Shanxi, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","reference":[{"key":"10.3233\/THC-236043_ref1","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.jds.2019.03.009","article-title":"Prevalence of bififid mandibular canal according to gender, type and side","volume":"14","author":"\u00d6zlem","year":"2019","journal-title":"Journal of Dental Sciences."},{"key":"10.3233\/THC-236043_ref2","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/j.ijom.2015.10.017","article-title":"Anthropomorphic assessment of the retromolar foramen and retromolar nerve: anomaly or variation of normal anatomy","volume":"45","author":"Motamedi","year":"2016","journal-title":"Int J Oral Maxillofac Surg."},{"key":"10.3233\/THC-236043_ref3","doi-asserted-by":"crossref","first-page":"1261","DOI":"10.1016\/0003-9969(67)90127-6","article-title":"The origin and distribution of the elements of the human mandibular retromolar canal","volume":"12","author":"Schejtman","year":"1967","journal-title":"Arch Oral Biol."},{"key":"10.3233\/THC-236043_ref4","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.morpho.2013.04.004","article-title":"Retromolar foramen and canal: a comprehensive review on its anatomy and clinical applications","volume":"97","author":"Kumar Potu","year":"2013","journal-title":"Morphologie."},{"key":"10.3233\/THC-236043_ref5","first-page":"296717","article-title":"Occurrence of the retromolar foramen in dry mandibles of South-eastern part of India: a morphological study with review of the literature","volume":"2014","author":"Potu","year":"2014","journal-title":"Anat Res Int."},{"key":"10.3233\/THC-236043_ref6","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.1016\/j.joms.2006.05.043","article-title":"Clinical and anatomical study of retromolar foramen and canal","volume":"64","author":"Bilecenoglu","year":"2006","journal-title":"J Oral Maxillofac Surg."},{"key":"10.3233\/THC-236043_ref7","doi-asserted-by":"crossref","first-page":"278","DOI":"10.61872\/sdj-2015-03-149","article-title":"Frequency and anatomy of the retromolar canal\u00a0\u2013 implications for the dental practice","volume":"125","author":"Filo","year":"2015","journal-title":"Swiss Dent J."},{"key":"10.3233\/THC-236043_ref8","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1002\/ajpa.1330730112","article-title":"Retromolar foramen of the human mandible","volume":"73","author":"Ossenberg","year":"1987","journal-title":"Am J Phys Anthropol."},{"key":"10.3233\/THC-236043_ref9","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1259\/dmfr\/23146121","article-title":"Bifid mandibular canal: literature review and case report","volume":"34","author":"Claeys","year":"2005","journal-title":"Dentomaxillofac Radiol."},{"key":"10.3233\/THC-236043_ref10","doi-asserted-by":"crossref","first-page":"10","DOI":"10.61872\/sdj-2021-01-01","article-title":"The bifid mandibular canal in three-dimensional radiography:morphologic and quantitative characteristics","volume":"131","author":"Thomas von","year":"2021","journal-title":"Swiss Dent J."},{"key":"10.3233\/THC-236043_ref11","first-page":"e510","article-title":"Failure of locoregional anesthesia in dental practice","volume":"11","author":"Boronat Lopez","year":"2006","journal-title":"Review of the literature. 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