Study Objectives <p>Determine whether cone-beam computed tomography (CBCT) or computed tomography (CT) measurements of the upper airway, craniofacial structures and soft tissues provide diagnostic or prognostic value for obstructive sleep apnea (OSA) in dental sleep medicine.</p> Methods <p>Following PRISMA guidelines, a comprehensive search was conducted in PubMed, Embase, Cochrane Library, Web of Science and ClinicalTrials.gov. Eligible studies until September 2025 included polysomnography or polygraphy confirmed OSA, CBCT- or CT-based measurements, and either PSG/PG-confirmed non-OSA controls, defined OSA severity strata or treatment responder classifications. Data were extracted for diagnostic and therapeutic studies and risk of bias was assessed with the QUIPS tool.</p> Results <p>Of 392 records, 11 met inclusion criteria (7 diagnostic, 4 therapeutic). Most were subject to high risk of bias and showed heterogeneity in imaging protocols, measurements and outcome definitions, with little adjustment for age, gender or body mass index. Individuals with OSA often had smaller retropalatal minimum cross-sectional area (CSAmin) whereas findings for retroglossal dimensions, total airway volume, skeletal morphology and soft-tissue measures were inconsistent and lacked clear correlation with disease severity. In therapeutic studies, upper-airway volume generally increased, but baseline CBCT- and CT-derived variables and treatment-related airway enlargement did not reliably distinguish responders from non-responders.</p> Conclusions <p>Available evidence does not support CBCT- and CT-derived airway, skeletal or soft-tissue parameter as useful tools for diagnosing and grading of OSA or predicting treatment response. Given the high radiation exposure associated with both modalities, routine CBCT or CT solely for OSA screening or outcome prediction in dental sleep medicine is not justified and should be limited to established guidelines or surgical planning.</p> Trial registration <p>PROSPERO ID CRD42024556837.</p>