Orthodontic treatment for obstructive sleep apnea syndrome

We report a case where obstructive sleep apnea syndrome (OSAS) was improved with orthodontic treatment. The lower dental arch was expanded, the distance between the left and the right lower molars was increased to 9.0 mm, overjet and overbite reflecting malocclusion changed from 10.2 to 4.5 mm and from 9.9 to 5.0 mm, respectively, and number of apnea/hypopnea episodes per hour decreased from 26.3 to 9.3/h. In conclusion, the expansion of lower dental arch with orthodontic treatment could lead to an increased airway diameter on both sides resulting in the improvement of OSAS.