[Skeletal Class Ⅲ patients treated with Frankel function regulator type Ⅲ in the early and late mixed dentition].

OBJECTIVE: To investigate the outcome of skeletal Class Ⅲ patients treated with Frankel function regulator type Ⅲ (FR Ⅲ)in the early mixed and late mixed dentition. METHODS: The samples consisted of 45 mild and moderate skeletal Class Ⅲ patients(26 males, 19 females; meanage, [7.9+/-1.3] years) treated with FR Ⅲ. According to Hellman's dental developmental stages, these samples were divided into early-treated group(n=24) and late-treated group(n=21). Lateral cephalograms were taken at the beginning and the end of treatment. Twenty-one measurements on hard and soft tissue were included. RESULTS: After treatment, SNA, ANB, NA-Apo, Wits, U1-SN, U1-NA, Overjet, UL-EP were significantly increased (1.0+/-1.9) degrees , (1.2+/-1.6) degrees , (2.6+/-4.2) degrees , (1.8+/-2.7) mm, (4.2+/-7.6) degrees , (2.6+/-7.5) degrees , (3.6+/-2.3) mm and (0.8+/-2.2) mm(P<0.05). OP-SN and IMPA were significantly decreased (1.5+/-3.7) degrees and (1.4+/-4.2) degrees (P<0.05). There were significant differences in SNA, ANB, UL-EP, IMPA, L1-NB between early-treated group and late-treated group(P<0.05). CONCLUSIONS: FR Ⅲ was suitable for the treatment of mild and moderate skeletal Class Ⅲ patients. The result was better in the early-treated patients than in late-treated ones.