Effects of Maxillary Protraction and Fixed Appliance Therapy on the Pharyngeal Airway

Abstract

In young individuals diagnosed with maxillary deficiency treated with reverse headgear, the nasopharyngeal airway dimensions were improved after the treatment, and favorable effects of the treatment remained over the posttreatment period of 4 years.

Changes in pharyngeal airway dimensions and hyoid bone position after maxillary protraction with different alternate rapid maxillary expansion and construction protocols: A prospective clinical study

“…This finding was in agreement with those of previous studies. 11,14,15,25 One of the main effects of maxillary protraction is clockwise rotation of the mandible (shown as a decrease in SNB and an increase in SN-MP variables) as shown in this study, and the slightly posterior movement of the mandible did not appear to cause any change on oropharyngeal dimensions.…”

“…[4][5][6][7][8][9] Although a number of studies [10][11][12][13][14][15][16][17] have been published about the pharyngeal airway effects of maxillary protraction, there were conflicting findings. Significant changes for nasopharyngeal [10][11][12]14,15 and oropharyngeal 10,12 airway dimensions after maxillary protraction were reported by some clinicians, whereas the studies by Hiyama et al, 13 Mucedero et al, 17 and Baccetti et al…”

Changes in upper airway width associated with Class II treatments (headgear vs activator) and different growth patterns

“…We determined the pharyngeal anteroposterior width at several vertical levels and refer to the majority of currently available studies 5,[23][24][25][26][27][28]33,37 as the ''PAS (posterior airway space)'' of each level. As an additional parameter, we evaluated the distance from the anterosuperior point to the mandibular base.…”

“…22 However, patients with OSAS frequently showed other characteristics in connection with pharyngeal narrowness, including a retrognathic jaw position, dolichocephalic architecture of the facial skull, and a caudal position of the hyoid bone, 1 such that the width of the pharyngeal space became relevant to a number of different orthodontic issues and treatments. [23][24][25] With regard to prognathism, various study groups 7,[26][27][28][29] demonstrated increases in nasopharyngeal and oropharyngeal width during treatment with a maxillary expansion appliance and facemask. In skeletal Class II cases, pharyngeal narrowing was visible, especially the root-of-tongue level, which improved during treatment with functional orthodontic appliances.…”

Effect of Class III bone anchor treatment on airway

“…Some have reported short-and long-term improvements of nasopharyngeal and upper airway space following maxillary protraction. 17,18 Kaygisiz et al 18 found that the improved airway dimensions obtained from face mask treatment were retained 4 years posttreatment. Others, including Baccetti et al, 19,20 have reported no difference in nasopharyngeal or oropharyngeal airway dimensions between face mask subjects and untreated controls.…”