Comparisons of two protocols for the early treatment of Class III dentoskeletal disharmony

Objective: To assess the short-term outcomes of splints, Class III elastics, and chincup (SEC III) and rapid maxillary expansion and facial mask (RME/FM) protocols. Materials and methods: 25 patients with Class III dentoskeletal disharmony (10 males, 15 females) treated with the SEC III protocol were evaluated at the beginning (T1, mean age 7.5 +/- 1.4 years) and at the end of treatment (T2, mean age 8.7 +/- 1.4 years). The SEC III group was compared to a matched sample of 32 Class III patients (16 males, 16 females) treated with the RME/FM protocol and to a matched control group (CG) consisting of 23 subjects (12 males, 11 females) with untreated Class III dentoskeletal disharmony. The statistical comparisons between the three groups were performed with analysis of variance with Tukey's post hoc tests. Results: With respect to the CG the SEC III and the RME/FM groups showed significantly favourable effects in terms of maxillary advancement (SNA +1.2 and +1.4 degrees, respectively), control of mandibular projection (SNB -1.3 and -1.4 degrees, respectively), and intermaxillary relationships (ANB +2.6 and +2.9 degrees, respectively; WITS +3.7 and +2.6 mm, respectively). The RME/FM group showed a significantly greater increase in the intermaxillary divergency than the SEC III group (+1.8 degrees) and the CG (+2.0 degrees). Limitations: A limitation of this study is its short-term nature. Conclusions: Both SEC III and RME/FM protocols are efficient treatments for Class III dentoskeletal disharmony. The SEC III protocol produces more favourable control in intermaxillary vertical relationships than the RME/FM therapy.