The Longitudinal Effects of Orthodontic Therapy on the Obstructive Apnea Hypopnea Index (AHI).

Abstract

Objectives: To evaluate the cross-sectional relationship between sleep apnea and dental model measurements, cephalometric measurements (skeletal, dental, airway) and sleep-disordered breathing (SDB) questionnaires, in a convenience sample of orthodontic patients starting therapy. Materials and Methods: Fifty-four orthodontic patients (male 46%, mean age 25.29 +/- 12.32) scheduled to start orthodontic treatment were prospectively evaluated with sleep studies, lateral cephalograms, intraoral dental scans and SDB questionnaires before orthodontic treatment. The primary outcome of interest was the obstructive Apnea Hypopnea Index (AHI) and whether or not the obstructive AHI score exceeded sleep apnea threshold. Predictors included dental model measurements, cephalometric (skeletal, dental, airway) measurements and SDB questionnaires: Epworth Sleepiness Scale and Pediatric Sleep Questionnaire. Results: Results indicate statistically significant negative relationships between obstructive AHI and maxillary arch length (p= 0.013), maxillary intercanine width (p=0.004), mandibular intercanine width (p=0.026), maxillary arch perimeter (p=0.010), SNB (angle between sella, nasion and supramentale) (p= 0.043), upper incisor inclination (p=0.010) and position (p=0.001) (U1-NAdeg and U1-NAmm). Obstructive AHI had statistically significant positive relationship with upper airway length (p=0.007) (UAL) and pediatric sleep questionnaire (p=0.017). Conclusion: Higher obstructive AHI scores were seen in an unselected population of orthodontic patients with posteriorly positioned and retroclined upper incisors, retrognathic mandible, increased length of the upper airway, decreased maxillary arch length, constricted maxillary and mandibular inter canine widths, decreased arch perimeter and higher pediatric sleep questionnaire. Orthodontists have an important opportunity to screen their patients with compatible findings for OSA.