Objective: To determine if significant differences exist in timings and rates of Peak Mandibular Growth (PMG) and mandibular projections of subjects with vertical, average and horizontal facial growth patterns. Methods: Sixty-three Caucasian orthognathic subjects with cephalograms (9 to 18 years) available from the Burlington Growth Centre were categorized into average, vertical and horizontal growth pattern groups based on their change in Y axis from age 10 to 16 years. PMG timing and rates were determined and mandibular projections measured. Comparisons were made by ANOVA. Results: Inter-group differences of PMG timing or rate were not statistically significant. Although not statistically significant, PMG of vertically growing females was 14 month earlier than all other subgroups. Horizontal mandibular projection differences approached significance in older children. Conclusions: No statistically significant differences were found in the timing or rate of PMG in different facial growth patterns. Differences in horizontal mandibular projections approached significance with growth.

Objective: To determine if significant differences exist in timings and rates of Peak Mandibular Growth (PMG) and mandibular projections of subjects with vertical, average and horizontal facial growth patterns. Methods: Sixty-three Caucasian orthognathic subjects with cephalograms (9 to 18 years) available from the Burlington Growth Centre were categorized into average, vertical and horizontal growth pattern groups based on their change in Y axis from age 10 to 16 years. PMG timing and rates were determined and mandibular projections measured. Comparisons were made by ANOVA. Results: Inter-group differences of PMG timing or rate were not statistically significant. Although not statistically significant, PMG of vertically growing females was 14 month earlier than all other subgroups. Horizontal mandibular projection differences approached significance in older children. Conclusions: No statistically significant differences were found in the timing or rate of PMG in different facial growth patterns. Differences in horizontal mandibular projections approached significance with growth.