{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T06:20:13Z","timestamp":1788848413935,"version":"build-2803163510"},"reference-count":44,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,4,10]],"date-time":"2023-04-10T00:00:00Z","timestamp":1681084800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["82071147"],"award-info":[{"award-number":["82071147"]}]},{"name":"National Natural Science Foundation of China","award":["82171000"],"award-info":[{"award-number":["82171000"]}]},{"name":"National Natural Science Foundation of China","award":["2021YJ0428"],"award-info":[{"award-number":["2021YJ0428"]}]},{"name":"National Natural Science Foundation of China","award":["CSA-02020-02"],"award-info":[{"award-number":["CSA-02020-02"]}]},{"name":"National Natural Science Foundation of China","award":["LCYJ2020-TD-2"],"award-info":[{"award-number":["LCYJ2020-TD-2"]}]},{"name":"Sichuan Science and Technology Program","award":["82071147"],"award-info":[{"award-number":["82071147"]}]},{"name":"Sichuan Science and Technology Program","award":["82171000"],"award-info":[{"award-number":["82171000"]}]},{"name":"Sichuan Science and Technology Program","award":["2021YJ0428"],"award-info":[{"award-number":["2021YJ0428"]}]},{"name":"Sichuan Science and Technology Program","award":["CSA-02020-02"],"award-info":[{"award-number":["CSA-02020-02"]}]},{"name":"Sichuan Science and Technology Program","award":["LCYJ2020-TD-2"],"award-info":[{"award-number":["LCYJ2020-TD-2"]}]},{"name":"Young Clinical Research Fund of the Chinese Stomatological Association","award":["82071147"],"award-info":[{"award-number":["82071147"]}]},{"name":"Young Clinical Research Fund of the Chinese Stomatological Association","award":["82171000"],"award-info":[{"award-number":["82171000"]}]},{"name":"Young Clinical Research Fund of the Chinese Stomatological Association","award":["2021YJ0428"],"award-info":[{"award-number":["2021YJ0428"]}]},{"name":"Young Clinical Research Fund of the Chinese Stomatological Association","award":["CSA-02020-02"],"award-info":[{"award-number":["CSA-02020-02"]}]},{"name":"Young Clinical Research Fund of the Chinese Stomatological Association","award":["LCYJ2020-TD-2"],"award-info":[{"award-number":["LCYJ2020-TD-2"]}]},{"name":"Research and Develop Program, West China Hospital of Stomatology, Sichuan University","award":["82071147"],"award-info":[{"award-number":["82071147"]}]},{"name":"Research and Develop Program, West China Hospital of Stomatology, Sichuan University","award":["82171000"],"award-info":[{"award-number":["82171000"]}]},{"name":"Research and Develop Program, West China Hospital of Stomatology, Sichuan University","award":["2021YJ0428"],"award-info":[{"award-number":["2021YJ0428"]}]},{"name":"Research and Develop Program, West China Hospital of Stomatology, Sichuan University","award":["CSA-02020-02"],"award-info":[{"award-number":["CSA-02020-02"]}]},{"name":"Research and Develop Program, West China Hospital of Stomatology, Sichuan University","award":["LCYJ2020-TD-2"],"award-info":[{"award-number":["LCYJ2020-TD-2"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>We aimed to establish the characteristics and potential etiological risk factors of eruption disturbances in mandibular second molars (MM2). We retrospectively enrolled patients with eruption disturbances in MM2. A total of 143 MM2 with eruption disturbances from 112 patients (mean age 17.45 \u00b1 6.35) were included in this study. Panoramic radiographs were employed to determine the risk factor, angulation type, impaction depth, tooth development stage, and associated pathology. The novel classification method of MM2 was based on impaction depth and angulation. Of 143 MM2, 137 and 6 were diagnosed with impaction and retention, respectively. Insufficient space was the most frequent risk factor for eruption disturbances. There were no significant differences between retention and impaction regarding sex, age, or side. The most frequent impaction type was Type I. The most frequent angulation of impacted MM2 was mesioangular. Impacted MM2 with shallower depth were more frequently associated with the presence of first molar undercut. Impaction types did not differ according to age, side, development stage, or distance from the MM1 distal surface to the anterior border of the ramus. Dentigerous cysts were associated with earlier MM2 development stages and greater MM2 depth. In conclusion, MM2 impaction types differed according to the risk factor, angulation type, MM1 undercut, and presence of cysts. Early MM2 development stage and greater MM2 depth were risk factors for MM2 eruption disturbances with cysts.<\/jats:p>","DOI":"10.3390\/jcm12082798","type":"journal-article","created":{"date-parts":[[2023,4,10]],"date-time":"2023-04-10T07:11:43Z","timestamp":1681110703000},"page":"2798","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Radiographic Features of Mandibular Second Molars with Eruption Disturbances: A Retrospective Study"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6826-2128","authenticated-orcid":false,"given":"Qianyun","family":"Kuang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hong","family":"Zhou","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huiyi","family":"Hong","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Donger","family":"Lin","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meng","family":"You","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Oral Radiology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenli","family":"Lai","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hu","family":"Long","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1051\/orthodfr\/2016034","article-title":"Orthodontic management of the impacted mandibular second molar tooth","volume":"87","author":"Mah","year":"2016","journal-title":"Orthod. Fr."},{"key":"ref_2","first-page":"3541997","article-title":"Textbook and color atlas of tooth impactions: Diagnosis, treatment, prevention","volume":"112","author":"Andreasen","year":"1997","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1067\/mod.2000.97938","article-title":"Tooth anomalies associated with failure of eruption of first and second permanent molars","volume":"118","author":"Baccetti","year":"2000","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1016\/S0889-5406(95)70081-1","article-title":"The surgical uprighting of mandibular second molars","volume":"108","author":"Pogrel","year":"1995","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"561","DOI":"10.1016\/j.coms.2020.07.008","article-title":"Surgical exposure of impacted teeth","volume":"32","author":"Alberto","year":"2020","journal-title":"Oral Maxillofac. Surg. Clin. N. Am."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"670","DOI":"10.2319\/102111-656.1","article-title":"Impacted mandibular second molars","volume":"82","author":"Fu","year":"2012","journal-title":"Angle Orthod."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"773","DOI":"10.2319\/072506-306.1","article-title":"Prevalence of ectopic eruption, impaction, retention and agenesis of the permanent second molar","volume":"77","author":"Bondemark","year":"2007","journal-title":"Angle Orthod."},{"key":"ref_8","first-page":"521","article-title":"Impaction of permanent mandibular second molars in ethnic Chinese schoolchildren","volume":"74","author":"Cho","year":"2008","journal-title":"J. Can. Dent. Assoc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e564","DOI":"10.4317\/medoral.18869","article-title":"Impaction of permanent mandibular second molar: A retrospective study","volume":"18","author":"Cassetta","year":"2013","journal-title":"Med. Oral Patol. Oral Cir. Bucal."},{"key":"ref_10","first-page":"209","article-title":"Surgical correction of mesially impacted mandibular second molars","volume":"37","author":"Haralabakis","year":"2003","journal-title":"J. Clin. Orthod. JCO"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"148","DOI":"10.2319\/010206-461R.1","article-title":"Uprighting partially impacted permanent second molars","volume":"77","author":"Sawicka","year":"2007","journal-title":"Angle Orthod."},{"key":"ref_12","first-page":"114","article-title":"Disturbed eruption of the lower second molar: Clinical appearance, prevalence, and etiology","volume":"55","author":"Varpio","year":"1988","journal-title":"ASDC J. Dent. Child."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1045","DOI":"10.2319\/030711-165.1","article-title":"E-space preservation","volume":"81","author":"Sonis","year":"2011","journal-title":"Angle Orthod."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1111\/j.1600-0714.1991.tb00913.x","article-title":"Eruption disturbances of permanent molars: A review","volume":"20","author":"Raghoebar","year":"1991","journal-title":"J. Oral Pathol. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1111\/j.1600-0714.1989.tb01338.x","article-title":"Secondary retention of permanent molars: A histologic study","volume":"18","author":"Raghoebar","year":"1989","journal-title":"J. Oral Pathol. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1016\/0300-5712(91)90007-L","article-title":"Clinical, radiographic and histological characteristics of secondary retention of permanent molars","volume":"19","author":"Raghoebar","year":"1991","journal-title":"J. Dent."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1038\/sj.bdj.2018.216","article-title":"Diseases associated with mandibular third molar teeth","volume":"224","author":"McArdle","year":"2018","journal-title":"Br. Dent. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"S462","DOI":"10.4103\/jpbs.JPBS_140_20","article-title":"Prevalence and pattern of impacted mandibular third molar: An institution-based retrospective study","volume":"12","author":"KalaiSelvan","year":"2020","journal-title":"J. Pharm. Bioallied Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1177\/0022034515615857","article-title":"Predictors of third molar impaction: A systematic review and meta-analysis","volume":"95","author":"Carter","year":"2016","journal-title":"J. Dent. Res."},{"key":"ref_20","first-page":"103","article-title":"The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study","volume":"66","author":"Haavikko","year":"1970","journal-title":"Suom. Hammaslaak. Toim. Fin. Tandlakarsallskapets Forh."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Jaro\u0144, A., and Trybek, G. (2021). The pattern of mandibular third molar impaction and assessment of surgery difficulty: A retrospective study of radiographs in east Baltic population. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18116016"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"322","DOI":"10.5483\/BMBRep.2008.41.4.322","article-title":"Downregulation of matrix metalloproteinases in hyperplastic dental follicles results in abnormal tooth eruption","volume":"41","author":"Kim","year":"2008","journal-title":"BMB Rep."},{"key":"ref_23","first-page":"341905","article-title":"Mechanism of human tooth eruption: Review article including a new theory for future studies on the eruption process","volume":"2014","year":"2014","journal-title":"Scientifica"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1177\/154405910808700509","article-title":"Mechanisms of tooth eruption and orthodontic tooth movement","volume":"87","author":"Wise","year":"2008","journal-title":"J. Dent. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1179\/bjo.15.3.199","article-title":"Incidence of lower second permanent molar impaction","volume":"15","author":"Evans","year":"1988","journal-title":"Br. J. Orthod."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.ajodo.2009.08.034","article-title":"Mandibular second molar impaction. Part I: Genetic traits and characteristics","volume":"140","author":"Shapira","year":"2011","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1016\/0030-4220(85)90070-2","article-title":"The incidence of unerupted permanent teeth and related clinical cases","volume":"59","author":"Grover","year":"1985","journal-title":"Oral Surg. Oral Med. Oral Pathol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"798","DOI":"10.14219\/jada.archive.1974.0158","article-title":"The prediction of the size of unerupted canines and premolars in a contemporary orthodontic population","volume":"88","author":"Tanaka","year":"1974","journal-title":"J. Am. Dent. Assoc."},{"key":"ref_29","first-page":"632","article-title":"Tanaka-Johnston mixed dentition analysis for southern Chinese in Hong Kong","volume":"76","author":"Ling","year":"2006","journal-title":"Angle Orthod."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1007\/s00784-009-0364-3","article-title":"A retrospective overview of treatment choice and outcome in 126 cases with arrested eruption of mandibular second molars","volume":"15","author":"Kenrad","year":"2011","journal-title":"Clin. Oral Investig."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1581","DOI":"10.1016\/j.joms.2017.02.027","article-title":"Surgical uprighting is a successful procedure for management of impacted mandibular second molars","volume":"75","author":"Padwa","year":"2017","journal-title":"J. Oral Maxillofac. Surg."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"e150","DOI":"10.4317\/jced.51382","article-title":"Etiological factors in second mandibular molar impaction","volume":"6","author":"Cassetta","year":"2014","journal-title":"J. Clin. Exp. Dent."},{"key":"ref_33","first-page":"185","article-title":"A study of impacted love: Kissing molars","volume":"11","author":"Gulses","year":"2012","journal-title":"Oral Health Dent. Manag."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1259\/dmfr.21.1.1397452","article-title":"Rosette formation of impacted molar teeth in mucopolysaccharidoses and related disorders","volume":"21","author":"Nakamura","year":"1992","journal-title":"Dentomaxillofacial Radiol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"946","DOI":"10.2319\/120113-883.1","article-title":"Association between mandibular third molar formation and retromolar space","volume":"84","author":"Ghougassian","year":"2014","journal-title":"Angle Orthod."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"183","DOI":"10.5152\/TurkJOrthod.2020.19059","article-title":"Up-to-date approach in the treatment of impacted mandibular molars: A literature review","volume":"33","author":"Tamer","year":"2020","journal-title":"Turk. J. Orthod."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.1148\/radiographics.19.5.g99se021107","article-title":"Cysts and cystic lesions of the mandible: Clinical and radiologic-histopathologic review","volume":"19","author":"Scholl","year":"1999","journal-title":"Radiographics"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1053\/joms.2003.50145","article-title":"Interesting eruption of 4 teeth associated with a large dentigerous cyst in mandible by only marsupialization","volume":"61","author":"Ertas","year":"2003","journal-title":"J. Oral Maxillofac. Surg."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1111\/j.1600-9657.2008.00616.x","article-title":"Conservative management of a dentigerous cyst secondary to primary tooth trauma","volume":"24","author":"Gondim","year":"2008","journal-title":"Dent. Traumatol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1007\/s12663-012-0393-3","article-title":"Dentigerous cyst associated with mandibular 2nd molar: An unusual entity","volume":"14","author":"Jindal","year":"2015","journal-title":"J. Maxillofac. Oral Surg."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1007\/s00247-002-0816-2","article-title":"Radiographic features of large cystic lesions of the jaws in children","volume":"33","author":"Bodner","year":"2003","journal-title":"Pediatr. Radiol."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Terauchi, M., Akiya, S., Kumagai, J., Ohyama, Y., and Yamaguchi, S. (2019). An analysis of dentigerous cysts developed around a mandibular third molar by panoramic radiographs. Dent. J., 7.","DOI":"10.3390\/dj7010013"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"578","DOI":"10.1016\/S0889-5406(99)70192-7","article-title":"Eruption speed and rate of angulation change of a cyst-associated mandibular second premolar after marsupialization of a dentigerous cyst","volume":"116","author":"Miyawaki","year":"1999","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1016\/j.ajodo.2003.04.001","article-title":"Clinical conditions for eruption of maxillary canines and mandibular premolars associated with dentigerous cysts","volume":"124","author":"Hyomoto","year":"2003","journal-title":"Am. J. Orthod. Dentofac. Orthop."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/8\/2798\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:13:14Z","timestamp":1760123594000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/8\/2798"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,4,10]]},"references-count":44,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["jcm12082798"],"URL":"https:\/\/doi.org\/10.3390\/jcm12082798","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,4,10]]}}}