The effects of facial mask/bite block therapy with or without rapid palatal expansion.

INTRODUCTION: The aim of this study was to compare the effects of the Facial Mask in combination with a mandibular bite block (FM/BB) or with rapid maxillary expansion with a bonded device (RME/FM) in patients with Class III malocclusions. SUBJECTS AND METHODS: The FM/BB sample included 22 subjects, 12 girls and 10 boys. The average age for the FM/BB group before treatment (T1) was 8.7 +/- 1.2 years, the mean age after active treatment (T2) was 10.4 +/- 1.3 years, and the mean duration of treatment was 1.7 +/- 0.8 years. The RME/FM sample comprised 17 subjects, 10 girls and 7 boys. The average ages were 7.8 +/- 1.8 years at T1 and 9.3 +/- 1.9 years at T2. The mean duration of observation was 1.5 +/- 0.6 years. Lateral cephalograms were analyzed at T1 and T2. The T2 to T1 changes in the 2 groups were compared with an independent sample t-test (p. <0.05). RESULTS: The comparison between the 2 treatment protocols for Class III malocclusion showed that there were no significant differences for any measurements in either the sagittal of the vertical planes form T1 to T2. CONCLUSIONS: Facial masks in combination with different typed of full-coverage occlusal splints resulted in very similar dentoskeletal outcomes regardless of presence or absence of RME. Both the Bite Block appliance and the splinted RME aided in limiting the posterior rotation of the mandible.