Maxillary incisor proclination effect on the position of point a in class ii division 2 malocclusion

Abstract

Objective: To test the hypothesis that the magnitude of alteration in the position of point A is notassociated with proclination of the upper incisors in Class II division 2 malocclusion.Materials and Methods: Cephalometric films were taken for 30 Class II division 2 patients (8males and 22 females; average age, 18.3 years) before and after upper incisor proclination. Thetotal change in the position of point A was measured by superimposing the pretreatment andpostproclination lateral cephalograms on the sella-nasion line at the sella. To determine the localeffect of alveolar bone remodeling associated with upper incisor proclination on the position ofpoint A, postproclination tracing of the maxilla was superimposed on the pretreatment tracingaccording to the Bolton template of maxillary superimposition.Results: The total vertical displacement in Point A position was downward by 0.84 mm (P - .002),and the total horizontal displacement was forward by 0.45 mm (P - .054). Assessment of localchanges in point A revealed that the position of point A had moved backward by 0.60 mm (P - .001).No significant change was observed in the value of the sella-nasion-point A angle (SNA).Conclusion: The hypothesis is rejected. The position of point A is affected by local bone remodelingassociated with proclination of the upper incisor in Class II division 2 malocclusion, but thisminor change does not significantly affect the SNA angle. (Angle Orthod. 2009;79:880-884. © 2009 by The EH Angle Education and Research Foundation, Inc.