Evaluating Oxygen Saturation Variations in Adults with and Without Mandibular Retrognathism as a Predictor for Obstructive Sleep Apnea

Introduction: Skeletal Class II malocclusion due to retrognathic mandible usually presents with a small-sized or a backward-positioned lower jaw when compared to adults with skeletal Class I malocclusion. This constricts the tongue space within the oral cavity and causes the tongue to fall back into the airway while the adult sleeps in a supine position. The purpose of this study was to compare the changes in oxygen saturation (SpO2) levels recorded through continuous nocturnal pulse oximetry in adults with skeletal Class I and Class II malocclusions. Methods: One hundred subjects admitted to a tertiary care centre for elective surgery and with no history of pulmonary or cardiac conditions were screened and selected for skeletal Class I [Group 1(n=50)] and Class II [Group 2(n=50)] facial patterns. Continuous nocturnal pulse oximetry data were recorded during sleep with the help of a pulse oximeter and the data were analysed. The statistical test used for determining significance was Mann-Whitney U test. Results: The mean SpO2 recorded in group 1 was 97.83% and in group 2 was 95.46% which was significantly lower than in Group 1 (P<0.001). Conclusion: The mean SpO2 in adults with Class II skeletal pattern was significantly reduced when compared with adults having Class I skeletal pattern. Continuous nocturnal pulse oximetry can serve as an essential screening tool prior to polysomnography to help differentiate the severity of sleep apnea.