[Skeletal Class â ¢ patients treated with Fränkel function regulator type â ¢ in the early and late mixed dentition].

ABSTRACT

OBJECTIVE: To investigate the outcome of skeletal Class Ⅲ patients treated with Fränkel 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)°, (1.2±1.6)°, (2.6±4.2)°, (1.8±2.7) mm, (4.2±7.6)°, (2.6±7.5)°, (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)°and (1.4±4.2)°(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.