Soft tissue changes of early skeletal Class III malocclusion patients after maxillary protraction treatment / 实用口腔医学杂志

ABSTRACT

Objective:To examine the soft tissue changes of early skeletal Class III malocclusion patients after maxillary protraction treatment. Methods:60 skeletal anterior crossbite patients, 27 males, 33 females in the late mixed dentition were selected. The age ranged from 8 to 11 years. Mean age was 9.3 years. The patients were divided into treatment group and control group. Average treatment time was 12.1 months. Pre- and post-treatment lateral cephalograms of both groups were traced and analyzed. Difference between pre- and post-treatment was analyzed with paired t-tests. Results:After treatment, Ns-Sn-Pos, Ns-Prn-Pos, Sn-S-Si and Cm-Sn-UL decreased significantly,while Sn-Ns-Si and UL-E increased significantly. No significant change was found in S-Ns-Sn and LL-E. Conclusion:Soft tissue profiles are significantly improved by maxillary protraction treatment in the late mixed dentition. The concave profiles were changed to straight or nearly normal profiles. The relationship among nose, upper lip, lower lip and chin become harmonious. The curve of the lips tends to be smooth and harmonious.