title: Correlation analysis of three-dimensional changes of hard and soft tissues in class III orthognathic surgery patients using cone-beam computed tomography.
abstract: BACKGROUND
  This study was to investigate the correlation between changes of the soft and hard tissues three-dimensionally in class III orthognathic patients using cone-beam computed tomography.
  
  
  METHODS
  Cone-beam computed tomography images were obtained within 2 weeks before surgery and at 6 months after surgery in 18 adult class III patients who underwent Le Fort I osteotomy and bilateral intraoral vertical ramus osteotomy. Subjects were divided into group 1 with no mandibular asymmetry (menton deviation, <2 mm; n = 9) and group 2 with mandibular asymmetry (menton deviation, >4 mm; n = 9). Landmarks were designated on the reconstructed three-dimensional models. Correlations and proportions of changes of the soft tissue to hard tissue were calculated.
  
  
  RESULTS
  There were significant correlations of ΔB' to ΔB and ΔPog' to ΔPog in both groups on the horizontal axis (P < 0.05), and their proportions were 0.53 and 0.67 in group 1 and 0.77 and 0.88 in group 2, respectively. There were significant correlations of ΔB' to ΔB, ΔPog' to ΔPog, and ΔMe' to ΔMe on the sagittal axis in both groups (P < 0.05), and their proportions were 0.94, 0.84, and 0.96 in group 1 and 0.95, 0.91, and 1.03 in group 2, respectively. There were significant correlations of the three-dimensional distances between ΔB' to ΔB, ΔPog' to ΔPog, and ΔMe' to ΔMe in both groups (P < 0.05), and their proportions were 0.92, 0.79, and 0.95 in group 1 and 0.92, 0.88, and 0.97 in group 2, respectively. However, there were no significant correlations between changes in soft and hard tissues on the vertical axis in both groups (P > 0.05).
  
  
  CONCLUSIONS
  In class III orthognathic patients with mandibular asymmetry, the proportions of ΔB' to ΔB, ΔPog' to ΔPog, and ΔMe' to ΔMe on the horizontal and sagittal axes and the three-dimensional distances were different from patients with no mandibular asymmetry.
authors.affiliation: From the Departments of *Orthodontics, †General Dentistry, and ‡Oral and Maxillofacial surgery, School of Dentistry, Yonsei University, Seoul, South Korea.
authors.forename: Tae-Yeon
authors.initials: TY
authors.lastname: Lee
authors.forename: Kyung-Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Hyung-Seog
authors.initials: HS
authors.lastname: Yu
authors.forename: Kee-Deog
authors.initials: KD
authors.lastname: Kim
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Jung
authors.forename: Hyoung-Seon
authors.initials: HS
authors.lastname: Baik
mesh_terms: D000328:Adult; D059925:Anatomic Landmarks; D054893:Cone-Beam Computed Tomography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging* / Q000601:surgery; D056948:Orthognathic Surgical Procedures / Q000379:methods; D019340:Osteotomy, Le Fort / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D055815:Young Adult