Short-term effects of the Sander bite-jumping appliance on the pharyngeal airways in subjects with skeletal Class II malocclusion: A retrospective case-control study

Background: Skeletal Class II subjects present often a retruded mandible that might increase the probability of breathing disorders. Objective: To evaluate the effects of functional treatment by means of the Sander bite-jumping appliance (BJA) on the upper airways of growing subjects. Methods: Thirty-four subjects (21 males, 13 females; mean age 11.1 ± 1.2 years) with skeletal Class II malocclusion due to mandibular retrusion were treated with the Sander BJA (BJA group). The control group consisted of thirty-four untreated subjects with skeletal Class II malocclusion (25 males, 9 females; 10.4 ± 1.2 years; CTR group). The effect of the Sander BJA appliance on the airway dimensions was evaluated by comparing lateral cephalograms recorded before (T0) and after (T1) the period of observation/treatment. Within- and between-group comparisons were statistically evaluated according to the distribution of the data (P <.05). Results: The oropharyngeal region (ph_pph) increased in the BJA group (1.8 ± 3.2; P =.001) but the difference respect to the CTR group was not statistically significant (0.73 ± 4.0; P =.314; P =.077). The tongue height (th) increased in the BJA group (2.8 ± 3.7; P <.001), and this increase was statistically significant respect to the CTR group (0.6 ± 4.7; P =.461; P =.038). In the BJA, the Ans_Pns_P angle showed a statistically significant decrease (−3.8 ± 7.8; P =.007) compared to the CTR group (−0.1 ± 5.4; P =.705; P =.026). Conclusions: The airway dimensions increased for both control subjects and Class II patients treated with Sander BJA due to physiological growth. The Sander BJA induced a statistically significant change in the tongue and soft palate position, but the clinically relevant of these changes is questionable.