Orthodontists' perceptions of the impact of phase 1 treatment for Class II malocclusion on phase 2 needs

The most appropriate timing for the treatment of Class II malocclusions is controversial. Some clinicians advocate starting a first phase in the mixed dentition, followed by a phase 2 in the permanent dentition. Others see no clear advantage to that approach and recommend that the entire treatment be done in the late mixed or early permanent dentition. This study examines how orthodontists, blinded to treatment approach, perceive the impact of phase 1 treatment on phase 2 needs. The sample consisted of 242 Class II subjects, aged 10 to 15, who had completed phase 1 or observation in a randomized clinical trial (RCT). For each subject, video orthodontic records, a questionnaire, a fact sheet, and a cephalometric tracing were sent to five randomly selected reviewing orthodontists blinded to subject group and study purpose. Reviewing orthodontists were asked to assess treatment need, general approach, need for extractions, priority, difficulty, and determinants. Orthodontists agreed highly on treatment need (95%) and moderately on treatment approach (84%) and extraction need (80%). They did not perceive differences in need, approach, or extractions between treated and control groups. Treated subjects were judged as less difficult (p = 0.0001) and to have a lower treatment priority (p = 0.0001) than controls. In ranking problems that affect treatment decisions, the orthodontists ranked dental Class II (p = 0.005) and skeletal relationships (p = 0.004) more highly in control than in treated patients. These data indicate that orthodontists do not perceive phase 1 treatment for Class II as preventing the need for a second phase or as offering any particular advantage with respect to preventing the need for extractions or other skeletal treatments in that second phase. They do view early Class II treatment as an effective means of reducing the difficulty of and priority for phase 2.