Reconstruction of the dynamic velopharyngeal function by combined radial forearm-palmaris longus tenocutaneous free flap, and superiorly based pharyngeal flap in postoncologic total palatal defect.

We attempted to reconstruct dynamic palatal function using a radial forearm-palmaris longus tenocutaneous free flap in conjunction with a pharyngeal flap for a postoncologic total-palate defect in a 67-year-old male patient. This reconstruction involved 3 important tasks, namely, separating the oral and nasal cavities, preserving the velopharyngeal space to avoid sleep apnea, and maintaining velopharyngeal closure to avoid nasal regurgitation during swallowing. In our technique, the radial forearm flap separates the oral and nasal cavities with an open rhinopharyngeal space, and a superiorly based pharyngeal flap, which is sutured to the posterior end of the forearm flap, limits the rhinopharyngeal space, and forms the bilateral velopharyngeal port. Furthermore, the palmaris longus tendon, which is attached to the forearm flap, is secured to the superior constrictor muscle to create a horizontal muscle sling. Contraction of the superior constrictor muscle leads to shrinkage of the sling, resulting in velopharyngeal closure. Swallowing therapy was started 4 weeks after the surgery. The patient could resume oral intake without any difficulties 6 months after the surgery. Speech intelligibility changed from severe to minimal hypernasality.

Wear performance of bovine tooth enamel against translucent tetragonal zirconia polycrystals after different surface treatments.

The wear performances of bovine tooth enamel (BTE) against translucent tetragonal zirconia polycrystals (TZP) compared to that of feldspar porcelain and the influence of surface treatments of translucent TZP were investigated by the two-body wear test. Translucent TZP and feldspar porcelain were used as hemisphere abrader specimens with a radius of curvature of 5 mm; flat BTE surfaces were used as substrate specimens. The cross-sectional area of the worn surfaces of the substrates and the wear volume of the antagonist abraders were measured. Surface roughness, hardness and coefficient of friction as well as SEM observations and EPMA analyses were also performed to investigate the underlying mechanism of wear. The results suggested that BTE is less susceptible to wear when translucent TZP is used as the antagonist in contrast to the use of feldspar porcelain, and that surface treatment of the TZP abraders significantly influenced the wear of BTE substrates.