[Evaluation of the effect of two types of arch expansion combined with maxillary protraction in the treatment of Class III bony malformations].

PURPOSE: To evaluate the efficacy of rapid maxillary expansion and maxillary alternate rapid expansion combined with maxillary protraction in the treatment of Class III bony malformations.

METHODS

A total of 82 patients with skeletal Class III malocclusion admitted to Jiaozhou Central Hospital of Qingdao from May 2021 to April 2024 were selected and divided into two groups according to admission time. The control group (n=40) was treated with simple maxillary rapid arch expansion combined with maxillary protraction. The experimental group (n=42) was treated with maxillary alternate rapid expansion and contraction combined with maxillary protraction, the therapeutic effect of the two groups was compared.

RESULTS

Three months after treatment, the Z-angle, H-angle and upper lip angle of the experimental group were significantly higher than those of the control group, and the lower lip inclination was significantly lower than that of the control group(P＜0.05). SNA, U1-NA, ANB indexes, maximum occlusal contact area and maximum biting force in the experimental group were significantly higher than those in the control group, while U1-L1 and SNB indexes were significantly lower than those in control group (P＜0.05). The masticatory efficiency and oral health impact scale (OHIP-14) scores of the experimental group were significantly higher than those of the control group(P＜0.05).

CONCLUSIONS

Rapid maxillary expansion combined with maxillary protraction can improve the occlusal function and masticatory efficiency of patients with skeletal Class III malocclusion, and improve the soft and hard tissue indexes of the patients.