Relationship between PALM scale endotypes and surgical outcomes in maxillomandibular advancement for obstructive sleep apnea

OBJECTIVE: To evaluate whether phenotypic classification according to the PALM framework (pharyngeal collapsibility, arousal threshold, loop gain, and muscle responsiveness) can predict postoperative outcomes in patients with obstructive sleep apnea (OSA) undergoing maxillomandibular advancement (MMA). Secondary objectives were to explore its usefulness in preoperative planning and to assess the influence of body mass index (BMI) on surgical response. METHODS: A retrospective study was conducted on 59 patients with OSAS who underwent MMA between 2017 and 2023. Patients were classified using a modified PALM system based on preoperative AHI and therapeutic CPAP pressure requirements. Postoperative outcomes were assessed by polysonnography, and regression analyses examined the relationship between percentage changes in AHI and BMI. RESULTS: PALM 1 patients showed a significantly greater reduction in AHI compared with PALM 2 patients and higher rate of surgical success.No significant correlation was found between changes in AHI and BMI. CONCLUSION: PALM phenotyping demonstrated predictive value for MMA outcomes, supporting a more personalized approach to OSA management.