Effect of modified and conventional facemask therapy on condylar position in Class III patients

To assess the effects of varying force direction of maxillary orthopedic protraction on mandibular condylar position.

The conventional facemask group (Group 1) comprised 22 patients, 11 girls, and 11 boys (mean age: 9.3 ± 1.3 years); the modified facemask group (Group 2) comprised 22 patients, 12 girls, and 10 boys (mean age: 9.4 ± 1.5 years); and the control group (Group 3) comprised 21 subjects, 11 girls, and 10 boys (mean age: 9.8 ± 1.9 years). Changes in mandibular position indicator (MPI ®) measurements of the SAM ® 3 articulator were evaluated. Treatment and control changes within groups and between groups were analyzed statistically. Intra-group comparisons were tested with the non-parametric Wilcoxon's test and inter-group changes with Kruskal-Wallis. The statistical significance of inter-group differences was further assessed with the Mann-Whitney test for independent samples with Bonferroni's correction.

Antero-posterior positional changes of the left condyle were found higher in the controls than in Group 1 (p<0.016). Superior-inferior positional changes of the left condyle were also found significantly higher in controls than in Group 2 (p<0.016). No other significant changes in condylar position were determined in either group. In the treatment groups, asymmetrical condylar position diminished and became symmetrical with treatment in the antero-posterior direction (Group 1: 13.64%, Group 2: 36.37%) plane. In controls, the antero-posterior change of asymmetry was smaller (antero-posterior change: 7.60%).

These findings generally suggest that modified and conventional facemask therapy with expansion had no adverse effects on the temporomandibular and masticatory system.