title: Comparison between dental and basal arch forms in normal occlusion and Class III malocclusions utilizing cone-beam computed tomography.
abstract: OBJECTIVE
  The purpose of this study was to investigate the relationship between the mandibular dental and basal arch forms in subjects with normal occlusion and compare them with those of Class III malocclusion using cone-beam computed tomography (CBCT).
  
  
  METHODS
  CBCT images of 32 normal occlusion (19 males, 13 females; 24.3 years) and 33 Class III malocclusion subjects (20 males, 13 females, 22.2 years) were selected. Facial axis and root center points were identified from the left to right mandibular first molars. Distances between the facial axis and root center points for each tooth were calculated, and 4 linear and 2 ratio variables were measured and calculated for each arch form. The variables were compared between groups by independent t-test. Pearson correlation coefficient was applied to assess the relationships between dental and basal variables within each group.
  
  
  RESULTS
  The mandibular dental and basal intercanine widths were significantly greater in the Class III group than in normal occlusion subjects (p < 0.05). The dental and basal intercanine widths as well as the dental and basal intermolar widths were strongly correlated in normal occlusion and moderately correlated in Class III malocclusion.
  
  
  CONCLUSIONS
  The dental arch form demon strated a strong positive correlation with the basal arch form in the normal occlusion group and moderate correlation in the Class III malocclusion group. These results might be helpful for clinicians to have a better understanding of the importance of basal arch form in the alveolar bone.
authors.affiliation: Department of Orthodontics, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kyung Eun
authors.initials: KE
authors.lastname: Suk
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: Mohamed
authors.initials: M
authors.lastname: Bayome
authors.forename: Young-Ok
authors.initials: YO
authors.lastname: Nam
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Sameshima
authors.forename: Yoon-Ah
authors.initials: YA
authors.lastname: Kook
keywords: Basal arch form; Class III malocclusion; Cone-beam computed tomography; Dental arch form; Normal occlusion