Molar and canine occlusal changes in study casts before and after treatment with cervical headgears

We carried out a retrospective study on 246 pairs of casts to compare the extent of changes in occlusal relationship and overjet reduction induced by cervical headgears. MATERIAL AMD METHODS: Molar-canine occlusal relationships and overjet were determined from study casts made immediately before headgear treatment. Those findings were then compared to another cast made immediately after headgear monotherapy and before multiband-appliance administration. Headgear treatment lasted at least 6 months. Only patients whose upper first molars were distalized by at least 4 mm were included.

Strikingly, the distalization and overjet reduction induced by headgear treatment were most pronounced in posterior positions and decreased progressively toward more anterior positions along the arch. The mean amount of distalization was 6.87 mm at molar, and 1.87 mm at canine positions. The mean reduction of initial overjet was 0.78 mm. No significant differences resulted by grouping the data based on upper anterior tooth inclinations before treatment. Significant differences, however, were obtained by grouping the data based on initial overjet. Significantly greater changes in molar-canine occlusal relationships and overjet reductions were observed in patients with a major initial overjet of > 6 mm than in those with a relatively minor overjet of < 4 mm.