Anatomical status of the human musculus uvulae and its functional implications

In our ongoing series of anatomical studies to determine the three‐dimensional architecture of the human velar muscles, we have previously reported on the palatopharyngeus. The present study deals with the musculus uvulae (MU), in which the positional relationships of its origin to the posterior nasal spine and the palatine aponeurosis, as well as the interrelation between its anatomical status and functions, have yet to be clarified. Macroscopic and microscopic examinations were performed on 25 and 2 cadavers, respectively. In the former, bilateral MUs and their adjacent structures were exposed mainly from the nasal aspect. In the latter, the soft palates embedded in paraffin were cut into frontal and sagittal sections and alternately processed with HE and Azan stains. The left and right MUs adjacent to each other were found to run longitudinally along the midline beneath the nasal aspect of velum. It was overlaid by glandular tissue that increased in amount as it coursed distally. After originating from the oral surface of palatine aponeurosis, it ran backward to cross above the sling formed by the levator veli palatini muscles of both sides and reached the tip of uvula with its muscle fibers intermingled with glandular tissue. Past studies have proposed three functions of MU to enhance the efficiency of velopharyngeal closure: space occupier, stiffness modifier, and velar extensor. All of the above‐described anatomical characteristics of MU could be explained as being adapted for these functions. This implies that MU is actively responsible for maintaining the velopharyngeal closure efficiency. Clin. Anat. 27:1009–1015, 2014. © 2014 Wiley Periodicals, Inc.     

Recurrent plexiform schwannoma involving the carotid canal

Plexiform schwannoma (PS) is a rare variety of benign nerve sheath tumor characterized by a multinodular plexiform growth pattern. PS is usually confined to the head and neck or skin. The pre-operative diagnosis of PS is difficult, and this has lead to a common misdiagnosis as a schwannoma. In addition, studies have indicated that an incomplete resection of PS often results in tumor recurrence. Here we describe a rare case of PS presented in the parapharyngeal space. Our case involved a 36-year-old man with swelling of the pharynx, who presented with a soft cervical mass. MRI revealed a multinodular mass in the left parapharyngeal space, and further pathological diagnosis by the referral hospital indicated schwannoma. A cervical approach was taken and the tumor was removed with preservation of the nerve sheath by intracapsular resection. The tumor recurred within one year after the first surgery in the same lesion of the left parapharyngeal space. The second surgical approach was a combination of a facial dismasking flap and trans-pterygopalatine fossa. The mass was resected completely, and the diagnosis of PS was confirmed by histopathology. While schwannoma commonly occurs in the head and neck, parapharyngeal space PS is rare, and pre-operative pathological diagnosis of PS is difficult. MRI studies of PS revealed distinctive features that we found useful in pre-operative diagnosis. Intracapsular resection of PS with nerve preservation has a very high recurrence rate of the tumor. Therefore, if MRI findings suggest PS we recommend removing the tumor completely without nerve preservation will offer the most curative outcome.     

Comparison of osseous healing after sagittal split ramus osteotomy and intraoral vertical ramus osteotomy

The sagittal split ramus osteotomy (SSRO) is generally associated with greater postoperative stability than the intraoral vertical ramus osteotomy (IVRO); however, it entails a risk of inferior alveolar nerve damage. In contrast, IVRO has the disadvantages of slow postoperative osseous healing and projection of the antegonial notch, but inferior alveolar nerve damage is believed to be less likely. The purposes of this study were to compare the osseous healing processes associated with SSRO and IVRO and to investigate changes in mandibular width after IVRO in 29 patients undergoing mandibular setback. On computed tomography images, osseous healing was similar in patients undergoing SSRO and IVRO at 1 year after surgery. Projection of the antegonial notch occurred after IVRO, but returned to the preoperative state within 1 year. The results of the study indicate that IVRO is equivalent to SSRO with regard to both bone healing and morphological recovery of the mandible.