Correlation between cephalometric variables and obstructive sleep apnoea severity in children.

Aim Alterations in craniofacial growth have been associated with obstructive sleep apnoea in children. The main objectives of this study were to analyse the correlation between cephalometric variables and Obstructive Apnea/Hypopnea Index (OAHI) in order to investigate if craniofacial features may influence the severity of obstructive sleep apnoea and to study the correlation between upper nasopharyngeal width and maxillomandibular skeletal discrepancy in sagittal and vertical plane. Materials and methods Study Design: Correlations between cephalometric variables and obstructive sleep apnoea/hypopnea index and between upper airways space and maxillomandibular skeletal discrepancy were investigated. Forty-seven children with obstructive sleep apnoea diagnosed by overnight sleep study (polysomnography) underwent a lateral radiograph, orthodontic and ear-nose-throat examinations. Cephalometric analysis according to Kirjavainen has been performed to define skeletal and upper airways variables. Statistics: Spearman’s correlation analysis was performed between OAHI and all cephalometric variables. Pearson’s correlation analysis was performed between cephalometric variables of upper airway space and cephalometric variables related to maxillomandibular discrepancy. Chi-square test was used to compare occlusal features with adenoidal and tonsillar hypertrophy. Kruskal-Wallis rank test was used to compare OAHI with occlusal variables and adenotonsillar hypertrophy. Results The results show a positive correlation between OAHI and maxillomandibular discrepancy measured by ANB angle (rho=0.32; p=0.023). A significant correlation was found between upper nasopharyngeal width and vertical maxillomandibular skeletal discrepancy: 1) ad1-PNS were correlated to Mandibular Plane/SellaNasion angle (r=-0.36; p=0.012), Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007), and Posterior-Anterior Facial Height % (r=0.29; p=0.045); 2) ad2-PNS was correlated to Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007). No statistically significant differences were found in non-parametric tests between OAHI and occlusal variables or adenoidal and tonsillar hypertrophy. Conclusions The present study shows a significant correlation between maxillomandibular discrepancy and the severity of OSA. Moreover, the reduction of nasopharyngeal width was correlated to maxillomandibular hyperdivergent growth pattern. These results support the presence of a correlation between sleep-disordered breathing and craniofacial features even if the cause-effect relation is still unclear. Based on these evidences, we suggest the importance of orthodontic evaluation in the management of paediatric OSA