Effectiveness of Customized Oral Appliances in Mild‐to‐Moderate Obstructive Sleep Apnea: A Systematic Review of Randomized Controlled Trials

ABSTRACT Background Oral appliance (OA) therapy has gained wide acceptance for the management of obstructive sleep apnea (OSA). Although various types of OAs have been developed, the efficacy of the newer devices in patients with mild to moderate OSA remains unclear. Objective This systematic review aimed to evaluate the clinical efficacy of customized titratable OAs in improving sleep in adults with mild‐to‐moderate OSA. Methods A comprehensive literature search of the Medline, Embase, Scopus, the Cochrane Library, and Web of Science databases for relevant randomized controlled trials (RCTs), published between 2000 and 2025, was performed. The primary outcomes were the apnea–hypopnea index (AHI), oxygen desaturation index (ODI), Epworth Sleepiness Scale (ESS) score, and mean oxygen saturation (SpO 2 ). The secondary outcomes included sleep efficiency and the percentage of total sleep time. Results Of the 1316 articles retrieved in the literature search, 122 fulfilled the inclusion criteria, including 32 RCTs that compared OAs with control interventions. Most studies reported significant improvements in AHI, with mandibular advancement devices demonstrating consistent efficacy across multiple trials. Improvements in the ESS, ODI, and SpO 2 were also observed in several studies. Conclusion Customized, titratable OAs are effective in reducing AHI and improving sleep‐related outcomes in patients with mild‐to‐moderate OSA.