Background: Many patients with obstructive sleep apnea (OSA) use nasal continuous positive airway pressure (nCPAP) as a first-line therapy. Previous studies have reported midfacial hypoplasia in children using nCPAP. The aim of this study is to assess the craniofacial changes in adult subjects with OSA after nCPAP use.
Methods: Forty-six Japanese subjects who used nCPAP for a minimum of 2 years had both a baseline and a follow-up cephalometric radiograph taken. These two radiographs were analyzed, and changes in craniofacial structures were assessed. The cephalometric measurements evaluated were related to face height, interarch relationship, and tooth position.
Results: Most of the patients with OSA were men (89.1%), and the mean baseline values for age, BMI, and apnea-hypopnea index (AHI) were 56.3 ± 13.4 years, 26.8 ± 5.6 kg/m(2), and 42.0 ± 18.6/h. The average duration of nCPAP use was 35.0 ± 6.7 months. After nCPAP use, cephalometric variables demonstrated a significant retrusion of the anterior maxilla, a decrease in maxillary-mandibular discrepancy, a setback of the supramentale and chin positions, a retroclination of maxillary incisors, and a decrease of convexity. However, significant correlations between the craniofacial changes, demographic variables, or the duration of nCPAP use could not be identified. None of the patients self-reported any permanent change of occlusion or facial profile.
Conclusion: The use of an nCPAP machine for > 2 years may change craniofacial form by reducing maxillary and mandibular prominence and/or by altering the relationship between the dental arches.