Micro-Computed Tomography-Based Three-Dimensional Anatomical Structure of the Region Around the Pterygoid Hamulus

Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus.

Cadaveric specimens were stained with iodine-potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model.

Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus.

Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes.