Effect of maxillary anterior traction and FRⅢ type teeth correcting appliance maintaining for skeletal class Ⅲ malocclusion during growth and development of children

Objective To analyze the effect and clinical value of maxillary protraction and FRⅢ type teeth correcting appliance maintaining for skeletal class Ⅲ malocclusion during growth and development of children. Methods A total of 61 children with skeletal class Ⅲ malocclusion were treated by maxillary protraction and FRⅢ type teeth correcting appliance. The changes of indexes before and after treatment were compared. Results Cephalometric measurement showed that compared with treatment before, angle of point of sella center, nasal root point and upper alveolar seat point(SNA), angle formed by the alveolar base point, the nasal root point and the lower alveolar base point(ANB), angle of intersection between the long axis of the upper central incisor and the plane of the anterior skull base(U1-SN), angle between the main axis of the lower central incisor and the mandibular plane(L1-MP), angle between upper and lower central incisors(U1/L1)were all significantly increased after treatment(P<0.05); no significant differences were found in angle formed by the center of the saddle, the nasal root point and the lower alveolar base point(SNB)and angle of intersection between the mandibular plane and the anterior skull base plane(SN/MP)(P>0.05). After treatment, the reverse occlusion of anterior and posterior teeth of the children were released, and U1 and A moved - vertically, significant differences were found(P<0.05). Compared with treatment before, the horizontal distance from hyoid bone to x-axis and the distance from hyoid bone to cervical vertebra increased significantly after treatment(P<0.05). Compared with before treatment, the airway space in hard palate and cervical spine increased after treatment, and the difference was statistically significant(P<0.05). Conclusion Maxillary anterior traction plus FRⅢ type teeth correcting appliance can effectively treat skeletal class III malocclusion, improve the relationship between upper and lower jaws, promote the coordination of dento-maxillofacial relationship.