Surgical versus orthodontic correction for Class II patients: age and severity in treatment planning and treatment outcome.

Treatment options for Class II malocclusion include orthognathic surgery. Treatment choices are particularly difficult for young patients because of the uncertainty regarding future growth. Surgical treatment has generally been considered necessary for older patients with more severe Class II problems. The treatment records of more than 500 patients with Class II malocclusion were reviewed. Patients were grouped according to their initial treatment plan (surgery or orthodontics) and treatment outcome (overjet [OJ] reduced to < 4 mm or not). Discriminant function analyses using data from the patient's pretreatment cephalogram were used to determine whether age, in combination with malocclusion severity, could predict the choice of treatment, and whether a simple set of pretreatment variables could predict the success or failure of OJ reduction. The derived equations were tested in a similar group of growing Class II children. Although the data showed clinicians use patient's age in determining treatment choice, age did not seem to be associated with treatment outcome. The majority of the variability that determined the success or failure of OJ reduction was not explained by patient's age or malocclusion severity. These findings suggest other factors, including psychosocial variables, need to be explored if we are to gain a better understanding of why treatments succeed or fail.