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

Abstract

Objective: To investigate the upper airways for anteroposterior width against different growth patterns and for alterations during various Class II treatments. Materials and Methods: Cephalograms from three treatment groups (headgear, activator, and bite-jumping appliance) were evaluated by a single investigator at baseline and at the end of orthodontic treatment. Cephalograms were used to determine upper airway width at different levels in the anteroposterior plane. Patients in the headgear group were additionally divided into six subsets on the basis of y-axis values to assess the influence of different growth patterns. Results: Small increases in pharyngeal width were noted at all vertical level segments, both at baseline and during orthodontic treatments. No significant differences in these small increases were noted across various treatment modalities and growth patterns. Conclusion: Upper airway changes did not significantly vary with the different treatment modalities investigated in the present study. Nevertheless, reductions in pharyngeal width potentially triggering or exacerbating obstructive sleep apnea syndrome (OSAS) are always possible in the headgear phase. (Angle Orthod. 2011;81:440-446.)

Upper airway changes after Xbow appliance therapy evaluated with cone beam computed tomography

“…There are a few studies [21][22][23][24][25] reporting the effects of functional appliances used in the treatment of Class II malocclusions on the upper airway; however, these studies evaluated the airway dimensions by using conventional radiographic methods. Conventional radiographic methods are two-dimensional reflections of three-dimensional structures, and overlapping of anatomic structures can be misleading.…”

“…[17][18][19][20] There are a few studies [21][22][23][24][25] reporting the effects of Class II functional appliances on the upper airway with conventional radiographic methods. The introduction of cone-beam computed tomography (CBCT) has enabled threedimensional examination of the airway, with the further benefit of low radiation dose.…”

Effects of Functional Appliance Therapy on the Depth of the Pharyngeal Airways: Activator vs. Forsus

“…Eventually, the main objective of our study, i.e., subsequent effects of these appliances on the dimensions of pharyngeal airways, will be addressed. Having reviewed the literature, there are very few published studies [4,[10][11][12][13][14] that have investigated the effect of functional appliances on the dimensions of awake pharyngeal airways. Of these studies, four have included either headgear [4,10,12] or maxillary expansion [11] appliances in combination with functional appliances, and the other two studies have used only removable [13] The sample was then divided into two groups.…”

“…Having reviewed the literature, there are very few published studies [4,[10][11][12][13][14] that have investigated the effect of functional appliances on the dimensions of awake pharyngeal airways. Of these studies, four have included either headgear [4,10,12] or maxillary expansion [11] appliances in combination with functional appliances, and the other two studies have used only removable [13] The sample was then divided into two groups. The first group consisted of the subjects who were treated with removable functional appliances (Activator type), and the second group consisted of those who were treated with fixed functional appliances, Forsus Fatigue Resistant Device (FRD) (3M Unitek Corp, Monrovia, Calif).The sex and age distribution of the treatment groups are shown in Table 1.…”

De ‘Richtlijn OSAS bij kinderen’

“…Er zijn aanwijzingen dat de faryngeale luchtweg van kinderen door behandelingen met een cervicale headgear wordt vernauwd (Pirilä-Parkkinen et al, 1999;Godt et al, 2011). Een aanzienlijke orthodontische retrusie van onder-en bovenincisieven door middel van vaste apparatuur met skelettale verankering veroorzaakt bij volwassenen vernauwing van de bovenste luchtweg (Chen et al, 2012).…”