Digital optimization of teeth setup in an edentulous patient with partial glossectomy: A case report

The purpose of this clinical report was to describe the use of a piezographic impression associated with computer-aided design and computer-aided manufacturing (CAD-CAM) for teeth setup and of digital tools for neuro-musculo-kinetic analyses. An edentulous patient with hemiglossectomy and heavily resorbed mandible consulted for complete denture rehabilitation to improve their masticatory function and speech. Master casts, wax rims, and piezographic impression were scanned for digital prosthetic work. Two digital try-ins were performed to respect the neutral zone: try-in 1 with posterior crossbite and try-in 2 without crossbite. Muscle activity and mandibular kinetics were performed for each try-in following the MAC2 protocol (six criteria): muscular tone, contraction synchrony, contraction efficiency, interocclusal rest distance, amplitude of mandibular movement, and velocity. Try-in 2 showed better data than try-in 1 in all criteria: muscle tone (respectively 71% vs. 59%), contraction synchrony (79% vs. 75%), contraction efficiency (85% vs. 77%), an increase in range of motion of 3.3 mm, and a better velocity (0.35 ± 0.12 s vs. 0.57 ± 0.14 s, p = 0.008). The piezographic impression, in combination with CAD-CAM, allowed the comparison of two prosthetic designs and the selection of the try-in with the best neuro-musculo-kinetic results.