The proposed research is designed to describe and compare the short-and long-term dental, skeletal, esthetic, and functional outcomes and efficacy of the three major alternatives commonly employed in the treatment of Class II malocclusions: 1) """"""""growth modification"""""""" (functional appliances in children followed by a phase of adolescent treatment with fixed appliances); 2) one-step fixed-appliance therapy in adolescents and adults; and 3) combined orthodontic/surgical treatment in adults. Because of the non-specific character of Class II malocclusions, the elective nature of treatment, and the inequality of the risks involved in various treatment alternatives (e.g., surgery as opposed to orthodontics), it is concluded that ethical, prospective trials would of necessity be severely limited in scope. The present research, therefore, will employ a longitudinal, partially retrospective design in which steps are taken to eliminate the types of bias that often compromise case-control studies: selection will be independent of outcome and will be designed to identify overlapping samples of patients for whom there is empirical evidence of uncertainty concerning the optimal choice of therapy. This approach will minimize susceptibility bias and thus will permit clinically meaningful comparisons between pairs of logical alternatives (e.g., extracting versus non- extraction edgewise or adult orthodontics versus surgery) in patients for whom either approach might commonly be employed. Because there is controversy surrounding the effect of both fixed and functional appliances on facial growth and occlusal development, comparable samples of untreated Class II subjects will be employed to differentiate between normally occurring changes and those due specifically to treatment. In addition to the description and comparison of treatment changes and subsequent relapse, the resulting data will provide insight into the predictability and propriety of contemporary therapeutic goals, the perceived utility of various treatment outcomes and the anatomical bases for the esthetic preferences of Blacks and whites. Because the present studies will draw from extensive pools of carefully executed and routinely documented treatments, it is probable that they can be conducted as outlined and completed within the initial period of support.

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National Institute of Dental & Craniofacial Research (NIDCR)
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Saint Louis University
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Bowman, S J; Johnston Jr, L E (2000) The esthetic impact of extraction and nonextraction treatments on Caucasian patients. Angle Orthod 70:10-Mar
Scott, S H; Johnston Jr, L E (1999) The perceived impact of extraction and nonextraction treatments on matched samples of African American patients. Am J Orthod Dentofacial Orthop 116:352-60
Johnston Jr, L E (1999) Bearbaiting in dentistry: a specialty under siege. Alpha Omegan 92:14-8
Johnston Jr, L E (1998) The value of information and the cost of uncertainty: who pays the bill? Angle Orthod 68:99, 101-2
Johnston Jr, L E (1998) A comparative analysis of Class II treatments: a retrospective/prospective alternative. Clin Orthod Res 1:142-6
Hagler, B L; Lupini, J; Johnston Jr, L E (1998) Long-term comparison of extraction and nonextraction alternatives in matched samples of African American patients. Am J Orthod Dentofacial Orthop 114:393-403
McKnight, M M; Daniels, C P; Johnston Jr, L E (1998) A retrospective study of two-stage treatment outcomes assessed with two modified PAR indices. Angle Orthod 68:521-4;discussion 525-6
Johnston Jr, L E (1998) Growth and the Class II patient: rendering unto Caesar. Semin Orthod 4:59-62
Lai, M; McNamara Jr, J A (1998) An evaluation of two-phase treatment with the Herbst appliance and preadjusted edgewise therapy. Semin Orthod 4:46-58
Johnston Jr, L E (1996) Balancing the books on orthodontic treatment: an integrated analysis of change. Br J Orthod 23:93-102

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