Vertical dimension in dental sleep medicine oral appliance therapy

The objective of this pilot study was to evaluate the effect of a multidimensional approach to occlusal registration, including vertical dimension as assessed using pharyngometry, on the success of oral appliance therapy. Successful medical improvements resulting from therapy were determined by secondary polysomnographic studies. Thirty patients were enrolled in this pilot study. Their initial apnea-hypopnea index (AHI) scores ranged from 6.0 (mild obstructive sleep apnea) to 81.6 (severe obstructive sleep apnea). Occlusal registrations were taken using pharyngometer readings to establish vertical and anteroposterior (AP) positions for each patient and compared to the AP-only position in the same patient, determined using a George Gauge at 70% protrusion. All follow-up sleep tests occurred 31-45 days after the delivery of oral appliances set at the multidimensional vertical and AP positions determined by pharyngometry. No appliance titration was required. In the 26 patients who completed the study, the mean AHI before therapy was 20.7, and the mean AHI after therapy was 7.8, a 62.3% decrease. Within the limitations of this study, the pharyngometer-established occlusal position was effective in lowering AHI without the need for appliance titration procedures, which are typically required when the 70% protrusive George Gauge occlusal registration method is used. Additionally, the position determined with the 70% George Gauge was, on average, 5.0 mm more protrusive than the pharyngometer registration.