The Relationship Between Sagittal Upper Airway Size And Surrounding Structure With Delaire Cephalometric Analysis

Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder, which is characterized by repetitive episodes of complete (apnea) or partial (hypopnea) obstruction of the upper airway during sleep. These conditions usually result in oxygen desaturation,affect the function of respiratory system,circulatory system,nervous system,endocrine system and so on. Now, the syndrome arouse people′s attention in clinic gradually.The pathogenesis of OSAS is complicated, including the change of upper airway anatomy,upper airway dilator muscle activity,reflex responsiveness,nervous system adjustment and so on. Many researches now focus on the change of the morphology of airway as well as the factors which have relationship with upper airway in patients of OSAS. But there are few researches on the correlation of the size of upper airway and surrounding in non-OSAS group. However, the research of non-OSAS group is the base and background of the OSAS group, through the research of this group, can we get a deeper understanding with the pathogenesis of OSAS, make proper treatment plan and assess the effect of treatment exactly.The database of measurements of craniofacial skeletal structure of non-snoring males with malocclusion aged from 11 to 16 years old before treatment was built,the lateral cephalometric films of each patient were measured by modified Delaire cephalometric analysis to find out the discrepancies of craniofacial structure in real condition and ideal equilibrium, multiple regression analysis was used to examine the relationship of upper airway size and craniofacial characteristics discrepancies, to identify the factors that affect the pharyngeal airway size remarkably, then measures can be taken to control these factors to prevent the stegnosis of upper airway.The findings:1. Pearson correlation matrix analysis of craniofacial structures and sagittal dimensions and areas of upper airway showed that:The sagittal upper airway size of non-snoring males with occlusion is substantially correlated to the craniofacial skeletal structures; and the structures had different correlations with every part of upper airway.2. Multiple regression analysis of craniofacial structures and sagittal dimensions of upper airway showed that:The size of nasopharyngeal space (PNS-ad) correlated with upper face height, the inclination of ramus plane, percentage of cranial height to cranial base. The size of palatopharyngeal space (Ve-PVe) correlated with upper face height, percentage of cranial height to cranial base. The size of hypopharyngeal space (Ph1-Ph2) correlated with the angle between cervical vertebrae tangent and cranial base, mandibular plane angle, the length of mandibular body and percentage of cranial height to cranial base.3. Multiple regression analysis of sagittal areas of upper airway and craniofacial structures as well as the areas of soft palate and tongue showed that:The area of nasopharyngeal space (NA) correlated with the length of maxillary, the inclination of palate plane, the angle between cervical vertebrae tangent and cranial base;The area of palatopharyngeal space (PA) correlated with percentage of cranial height to cranial base, the length of mandibular body and percentage of maxillary area to cranial base. The area of hypopharyngeal space (HA) had no correlated with the surrounding structure remarkably;The area of laryngopharyngeal space (LA) correlated with the length of ramus, the length of mandibular body, the percentage of cranial height to cranial base and anterior cranial base angle.Based on these findings, it′s concluded that the sagittal upper airway size of non-snoring young males with malocclusion is substantially correlated to the craniofacial skeletal structures, the types of craniofacial growth and the skeletal structure around can make effect on upper airway space remarkably. For some types of airway constriction caused by the deformity of craniofacial structures, orthopedic treatment can be used to correct the malformed structures to increase the pharyngeal space and improve ventilation function.