Inclination of retromolar pad and its relationship to occlusal plane in edentulous subjects: An observational study

: The muscle attachments and strong cortical bone beneath, the retromolar pad (RMP) make it least in resorption than the bony mandibular residual alveolar ridge. The stock trays are typically flat for resorbed ridges that put excessive strain on the RMP region, stock trays frequently need to be modified arbitrarily. Also various studies are conducted on relationship of retromolar pad to occlusal plane on dentulous subjects but less on edentulous subjects. So, this study is conducted to record the angular dimensions of retromolar pad to residual ridge and its relation to occlusal plane. To determine the angle made by slope of retromolar pad with crest of ridge and its relationship to occlusal plane. On 80 study (40 male and 40 female subjects) master casts, RMP inclines and residual ridge crests were marked with markers. The angle between the slope of retromolar pad and crest of ridge were then measured using a protractor that was kept at eye level. To check relationship of retromolar pad to occlusal plane a metallic scale is used by dividing the retromolar pad into three zones (upper, middle and lower third). The angle made by slope of retromolar pad with crest of ridge is measured in range of 123-167 on right side and 112 -173 degrees left side in female subjects and 105-175 degrees on right side and 125-173 on left side male subjects. An occlusal plane was checked intraorally and extraorally on cast by sliding scale on occlusal rim. The scale coincides at the point of junction of upper third and middle third extending the level of plane of occlusal rim in more than half of selected subjects. The paired sample t-test gave a p-value of 0.048. The mean angle obtained was 146+12.36 in male and 150+ - 14.87 degrees in female subjects to which stock metal tray can be incorporated. The present study demonstrated a mean angle of 146 degrees in male and 150degree in female subjects which would be adequate to accommodate higher angles upto 175 degrees in both the subjects. This mean angle can be considered as standard angle for incorporation in stock metal tray for fabrication of complete dentures. Also the present study demonstrated the junction of upper third and middle third of retromolar pad is considered as safer option in determining occlusal plane in mandibular arch and its relationship to occlusal plane due to its least resorption than mandibular residual alveolar ridge.