Craniofacial morphological changes induced by a mandibular repositioning oral appliance and their significance
TONG Mao rong, XIA Xi rong, ZHANG Xi long,CAO E hong, ZHAO Yin yin, SHI Yi (Department of Respiratory Diseases, Jinling Hospital , Nanjing 210002,China)
Objectives: To identify any craniofacial morphological changes induced by a mandibular repositioning oral appliance (MRA) and to explore the possibility of predicting the treatment response to MRA by cephalometric analysis in patients with obstructive sleep apnea (OSA). Methods: Seventy OSA patients [male/female: 63/7; age: (50.5±11.6) years; BMI: (27.6± 4.6 ) kg/m 2; AI: (34.9±21.3) episodes/hour; and oxygen saturation nadir: (66.3±16.5) %] were enrolled. MRA was fabricated individually for each patient after the consultation by a dentist. Polysomnographic (PSG) examination was repeated with MRA in place 3 months after the initiation of the MRA therapy. For cephalometric analysis, a pair of cephalograms of each patient was obtained, one with and another without MRA. Results and Conclusions: After 3 months' treatment, AI was (156±19.2) episodes/hour, significantly reduced compared with the pre treatment average AI (34.9±21.3 episodes/hour, P 0.000 1). Oxygen saturation nadir improved from (66.3±16.5)% (pre treatment) to (74.1±15.5)% (with MRA) ( P 0.001). A reduction of AI≥50% was achieved in 42 patients. Insertion of MRA led to anterior shift of the mandible, increase in upper airway width and area and decrease in upper airway length. Those with evident retrognathia and longer anterior upper facial height were more likely to benefit from the MRA management.