Correction of Class III malocclusions through morphological changes of the maxilla using the protraction face mask by three different therapeutic approaches

Rom J Morphol Embryol. 2019;60(2):605-615.

Abstract

Face mask (FM) therapy used for maxillary protraction improves the facial profile in patients with Class III malocclusion. The aim of this study was to compare the sagittal morphological changes of the maxilla through three different therapeutic approaches, respectively using removable appliances (RA), rapid maxillary expansion (RME) and surgically assisted rapid maxillary expansion (SARME), each of them in combination with the FM therapy in growing and non-growing patients. The sample, consisting of 42 orthodontic patients aged 7-21, was divided into four groups, according to their age. The first group of patients, aged 6-9 (RA + FM group), received treatment with RA in combination with FM, the second group of patients, aged 10-13 (RME + FM pubertal group), received treatment with RME in combination with FM, the third group of patients, aged 14-16 (RME + FM postpubertal group), received treatment with RME and FM, and the fourth group of patients, aged 17-21 (SARME + FM group), underwent SARME in combination with FM. To assess the sagittal skeletal changes of the maxilla, the sella-nasion-A point (SNA) and A point-nasion-B point (ANB) angles were measured at the beginning and after the FM therapy. The differences in the evolution of the SNA angle between the groups were statistically significant (p<0.001). Post-hoc analysis showed that patients aged 6-9 had the highest evolution, statistically higher than patients aged 14-16 (p=0.007) or patients aged 17-21 (p<0.001). The evolution of the SNA angle was significantly higher in patients aged 10-13, in comparison to patients aged 17-21 (p<0.001). The efficiency of the FM therapy alone or associated with RME depends on patients' growing period. In non-growing patients, the FM therapy is efficient when associated with SARME.

MeSH terms

  • Adolescent
  • Adult
  • Female
  • Humans
  • Male
  • Malocclusion, Angle Class III / therapy*
  • Orthodontic Appliance Design / methods*
  • Young Adult