Abstract
Purpose: This study investigated the hypothesis of a direct association between the shift of incisal point and the diameter of the oropharynx space, and nocturnal oximetry with and without prosthodontic mandibular advancement (PMA) which is one type of oral appliance used to treat obstructive sleep apnea syndrome (OSAS), and to indicate the effects of PMA.
Methods: A total of 19 patients with OSAS were subjected to finger pulse oximetry recording and lateral cephalometric radiography: with and without PMA. The distance of the oropharynx space (PNS-AS, SPAS, MAS, and IAS) and the shift of incisal point with PMA were measured. The oxygen desaturation index (ODI4%) and the cumulative percentages of time spent at saturations below 90%(CT90) during sleeping were calculated. Spearman's rank correlation test was used to measure the relationship between the increase of the velopharyngeal space and the distance of the mandible. The ODI4%, CT90 and distance of the velopharyngeal space were compared for all subjects with and without PMA by Wilcoxon's linking test.
Results: There was a strong relationship between the increase of the lower part (IAS) and the distance of anterior shift of incisal point (r=0.61, p=0.01). ODI4% and CT90 significantly decreased (p<0.01) and the three liners of the oropharynx (SPAS, MAS, IAS) significantly increased with PMA (p<0.01).
Conclusions: It was shown that prosthodontic mandibular advancement could reduce the ODI4% and CT90 value in patients with OSAS, by enlarging the oropharynx space.
