Soft tissue facial profile in Class III malocclusion: long-term post-pubertal effects produced by the Face Mask Protocol

Abstract

Summary Objectives The objective of this study was to analyze soft tissue changes produced by rapid maxillary expansion and facial mask therapy in growing Class III patients. Materials The treated group consisted of 32 Caucasian patients (15 females and 17 males) with dentoskeletal Class III malocclusion treated with the Face Mask Protocol (FMP, rapid maxillary expander, facial mask, and removable lower bite-block). All patients were evaluated before treatment (T1; mean age, 8.4 years), at the end of active treatment (T2; mean age, 10.7 years), and at a post-pubertal follow-up observation (T3; mean age, 15.8 years). The treated group was compared with a matched control group of 20 untreated subjects (10 females and 10 males) with dentoskeletal Class III malocclusion. Statistical comparisons between two groups were performed with the independent samples t-test (P < 0.05). Results Significant improvements were found during the long-term T1–T3 interval for profile facial angle (–5.8°), nasolabial angle (–4.4°), mandibular sulcus (–10.3°), upper lip protrusion (+0.7 mm), and lower lip protrusion (–1.1 mm) in the treated group. No significant post-pubertal effects were found in terms of lower face percentage between two groups. Limitations This study has a retrospective design and it used a historical control sample. Conclusion The FMP induced positive effects on soft tissue facial profile with a good long-term post-pubertal stability.

Evaluation of the effects of maxillary expansion and protraction on facial soft tissue profile in unilateral cleft lip and palate patients using cone beam computed tomography

“…The angle of facial convexity showed a significant reduction in in the treated (-4.2°) than the control group (0.6°). This was more compared with that reported by Pavoni et al (-3.6°) in skeletal Class III non cleft patients 24 . This result could be related to the combined significant maxillary advancement associated with reduction of the mandibular prognathism 35 .…”

“…There was a significant reduction in the lower lip protrusion in the treated (-1.1°) compared with the control group (0.4°). This could be attributed to the change of the sagittal position of the mandible caused by the chin cup part of the face mask 24 .…”

“…Tinlund et al showed -1.2° change in the prominence 31 . This could be produced by 2 factors, force application on the chin from the chin cup portion of the face mask 24 and the mandibular autorotation 37 . The significant increase in the soft tissue facial height was interpreted by the counterclockwise rotation of the maxilla with autorotation of the mandible 24 .…”

“…This could be produced by 2 factors, force application on the chin from the chin cup portion of the face mask 24 and the mandibular autorotation 37 . The significant increase in the soft tissue facial height was interpreted by the counterclockwise rotation of the maxilla with autorotation of the mandible 24 . This could improve the characteristic facial height reduction and jaw overclosure in cleft patients 31 .…”

“…The orthopedic protraction was then started, using 5/16" elastics (American Orthodontics, Sheboygan, Wis) attached from the hooks to the facemask (Hubit Co.,Ltd, Gyeonggi-do, South Korea). The facemask was adjusted on each patient's face ( Figure 2) to render its pads comfortable and to make the angle between the elastics and the occlusal plane nearly 30 degrees to counteract the rotation of the maxilla in a counterclockwise direction 23,24 . Elastic force was measured with a force tension gauge (Dentaurum, Pforzheim, Germany).…”