title: Decreased Amount of Supporting Alveolar Bone at Single-Rooted Premolars Is Under Estimated by 2D Examinations.
abstract: The purpose of this study was to relate the proportions of bone-supported root length of a 2D view into the amount of a 3D bone-attached root surface area (BA-RSA) by using a dental laser scanner examination. White-light 3D scanning technology was used to probe 36 maxillary and 35 mandibular single-rooted premolars. The bone-supported height (BSH) and BA-RSA at designated levels (95-25%) were compared using statistical t tests. The 100% BSH and BA-RSA of the maxillary/mandibular premolars were 12.6 ± 1.60 mm/13.45 ± 1.47 mm (p < 0.05) and 220.78 ± 35.31 mm2/199.51 ± 26.33 mm2(p < 0.01), respectively. Approximately 79-80%, 59-60%, and 35-36% premolars 2D BSH remained in comparison to 75%, 50%, and 25% 3D BA-RSA preservation, respectively. However, corresponding to a 75%, 50%, and 25% 2D BSH reserve, premolars retained 67-68%, 39-41%, and 15-17% 3D BA-RSA, respectively. When taking 1.0 mm connective tissue attachment into account, 60% 3D BA-RSA and 50% 2D BSH loss were noted at the 5.1-5.4 mm clinical attachment level. Assigning a periodontal prognosis and determining the severity of periodontitis for premolars with alveolar bone loss based on 3D's or 2D's measurement is inconsistent.
authors.affiliation: Department of Periodontics, Chang Gung Memorial Hospital and Chang Gung University, Linkou; School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hsiang-Hsi
authors.initials: HH
authors.lastname: Hong
authors.affiliation: Department of Periodontics, Chang Gung Memorial Hospital, Linkou, Taiwan.
authors.forename: Chung-Chieh
authors.initials: CC
authors.lastname: Chang
authors.affiliation: California Northstate University, College of Medicine, Elk Grove, CA, United States.
authors.forename: Adrienne
authors.initials: A
authors.lastname: Hong
authors.affiliation: Instrument Department, Chang Gung Memorial Hospital, Linkou, Taiwan.
authors.forename: Heng-Liang
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Department of Periodontics, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Yen-Li
authors.initials: YL
authors.lastname: Wang
authors.affiliation: Department of Periodontics, Chang Gung Memorial Hospital and Chang Gung University, Linkou, Taiwan.
authors.forename: Shih-Hao
authors.initials: SH
authors.lastname: Chang
authors.affiliation: Department of Nephrology, Chang Gung Memorial Hospital and Chang Gung University, Linkou, Taiwan.
authors.forename: Tzung-Hai
authors.initials: TH
authors.lastname: Yen
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008963:Molar / Q000000981:diagnostic imaging / Q000473:pathology*; D017622:Periodontal Attachment Loss / Q000000981:diagnostic imaging*; D010518:Periodontitis / Q000000981:diagnostic imaging / Q000473:pathology*; D014092:Tooth Root / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*