Effect of Anatomical Variations of Retromolar Pad on Edentulous Restoration

This study aimed to quantify the morphology of the retromolar pad (RMP) and its correlation with alveolar ridge resorption, as well as to evaluate its role in edentulous restorations through multidisciplinary research.

This multimethod study comprised three components: (1) a cross-sectional analysis of 200 edentulous mandibular models to quantify retromolar pad (RMP) dimensions-including height, area, and others- to classify RMP shapes (pear, triangular, bar) according to Cawood's classification of ridge resorption; (2) finite element analysis (FEA) simulating occlusal loads on three representative RMP morphologies to evaluate stress distribution and displacement; (3) Clinical trial involving 15 edentulous patients (Cawood classes V-VI), each receiving two dentures-one fabricated using a conventional tray (ATD group) and the other using a modified tray designed for the RMP (MTD group)-to compare patient satisfaction and denture fit, assessed via root mean square (RMS) deviation.

Model analysis revealed significant dimensional variations among RMP shapes, with a weak negative correlation between RMP morphology and alveolar ridge resorption (Rs = -0.31, P < .001). FEA identified pear-shaped RMP as exhibiting the lowest stress concentration (305.7 kPa) and minimal displacement (236.3 μm). Clinically, dentures from the MTD group demonstrated significantly better fit, indicated by a lower RMS value, and higher patient satisfaction regarding retention and comfort compared to the ATD group.

RMP morphology influence restorative outcomes in edentulous jaws, with pear-shaped RMP providing superior effect. RMP can be utilized to enhance complete denture retention, particularly for patients with severe alveolar ridge resorption.