title: Evaluation of root and alveolar bone development of unilateral osseous impacted immature maxillary central incisors after the closed-eruption technique.
abstract: BACKGROUND
  In this study, we evaluated root and alveolar bone development in unilateral osseous impacted immature maxillary central incisors by cone-beam computed tomography before and after closed-eruption treatment, in comparison with naturally erupted contralateral immature maxillary central incisors.
  
  
  RESULTS
  The study included 30 patients, 20 boys and 10 girls, with a mean age of 8.44 ± 1.20 years (range, 6.5-11.2 years). After treatment, the root lengths of both the impacted maxillary central incisors (10.66 ± 2.10 mm) and the contralateral maxillary central incisors (11.04 ± 1.76 mm) were significantly greater than their pretreatment values (6.67 ± 1.94 and 9.02 ± 2.13 mm, respectively). The root canal widths of the incisors decreased significantly after treatment. From the posttreatment cone-beam computed tomography images, the ratio of exposed root length to total root length and the thickness of the alveolar bone at 1 mm under the alveolar crest and at the apex were calculated to evaluate alveolar bone development. Impacted immature maxillary central incisors differed significantly from contralateral immature maxillary central incisors in labial exposed root length, labial ratio to total root length, and lingual alveolar crest. Clinical crown height was higher (statistically but not clinically) for the impacted incisors (9.87 mm) than for the contralateral incisors (9.37 mm).
  
  
  CONCLUSIONS
  Impacted immature incisors grew to the same stage as did erupted contralateral incisors after closed-eruption treatment. Both incisor types had some alveolar bone loss, and thin alveolar bone surrounded the roots.
authors.affiliation: Postgraduate student, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Xiangru
authors.initials: X
authors.lastname: Shi
authors.affiliation: Resident, Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Xie
authors.affiliation: Resident, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Junkang
authors.initials: J
authors.lastname: Quan
authors.affiliation: Resident, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Xiaozhe
authors.initials: X
authors.lastname: Wang
authors.affiliation: Resident, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Resident, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Chenying
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Professor, Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing, China. Electronic address: zhengsg86@gmail.com.
authors.forename: Shuguo
authors.initials: S
authors.lastname: Zheng
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000254:growth & development*; D001846:Bone Development / Q000502:physiology; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000254:growth & development*; D009805:Odontogenesis / Q000502:physiology*; D016382:Orthodontic Appliance Design; D050793:Orthodontic Extrusion / Q000295:instrumentation / Q000379:methods*; D019227:Tooth Apex / Q000000981:diagnostic imaging; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D019228:Tooth Crown / Q000000981:diagnostic imaging; D014078:Tooth Eruption / Q000502:physiology; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000254:growth & development*; D014095:Tooth, Impacted / Q000000981:diagnostic imaging / Q000628:therapy*