Clinical Curative Effect of a Fixed Appliance with Maxillary Protraction in the Treatment of Skeletal Class III Malocclusion

Abstract

Objective: To observe the effect of a fixed appliance with maxillary protraction in the treatment of skeletal Class III malocclusion, and to analyze soft and hard tissue variations. Material and methods: The study consisted of 78 cases with concave profile of skeletal Class III malocclusion, including 44 males and 34 females (aged 8-15years, mean 13.7years). According to the dental age, all cases were divided into four categories: Group A (n=14, mixed dentition); Group B (n=40, early permanent dentition, without mandibular second molar eruption); Group C (n=26, early permanent dentition, with mandibular second molars’ eruption) ; and Group D (n=24, permanent dentition). Cephalometric and hand-wrist radiographs were taken before treatment, while other cephalometric radiographs were taken after treatment. Statistical analysis was performed by software using SPSS 17.0. Results: The maxillary sagittal variation could be significantly affected by growth (ANS-Ptm) and forward movement of the maxilla (A-y, ANS-y). The direction of mandibular growth had been changed after treatment. The profile of soft tissue had also been remodeled. Conclusion: A fixed appliance with maxillary protraction was effective for patients with skeletal III malocclusion. The appliance could stimulate maxillary growth and inhibit mandibular protrusion in mixed dentition, early permanent dentition and some permanent dentition.