Date of Degree
MS (Master of Science)
Robert N. Staley
Class II malocclusion in non-growing individuals is treated in one of two ways - masking or surgery. If the dentoskeletal discrepancy is great enough, masking usually involves extraction of two maxillary premolars and subsequent incisor retraction and closure of overjet. This is the option of choice for patients without profile concerns, or who have medical or financial concerns. However, this treatment modality can sometimes result in less-than-ideal results. In the present study, we sought to understand what factors may influence the outcomes of this type of treatment. 65 subjects were included in this study. The total sample was divided into good and compromised finish categories based on objective criteria of overbite, overjet, and AP position of the maxillary canines. The good finish group was further subdivided into two groups, acceptable and excellent finishes. Several variables were measured on each subject's initial and final casts and compared between groups to determine whether any were associated with a particular finish group. At the initial time point, a mesial displacement of the maxillary right first molar by 3.35mm or less was found to correspond significantly to an excellent finish. This may indicate that if an individual presents with molars that are Class II by 3 mm or less, the prognosis is better than if that same individual had a greater Class II discrepancy. None of the other variables for the initial time point were found to be significantly different, suggesting that treatment mechanics, rather than a pre-existing occlusal factor, plays a predominant role in treatment outcome. At the final time point, we found that the maxillary arch length and tooth-size arch-length discrepancy were greater in the compromised group, indicative of excess spacing in this group at the end of treatment. Based on the other findings of this study, we attribute this result to differences in the mechanics used by individual practitioners. This hypothesis is further supported by our findings that none of the variables measuring patient compliance were found to be different between the good and compromised group. In the future, studies examining the particular mechanics used, and compliance where applicable, in this population will yield valuable insights into this area of patient research.
Camouflage, Compromise, Malocclusion
vi, 36 pages
Includes bibliographical references (pages 35-36).
Copyright 2014 Tyler Carl Prestwich