Palatopharyngeal anatomy and physiology

Innervation of human soft palate muscles

Our objective was to determine the branching and distribution of the motor nerves supplying the human soft palate muscles. Six adult specimens of the soft palate in continuity with the pharynx, larynx, and tongue were processed with Sihler's stain, a technique that can render large specimens transparent while counterstaining their nerves. The cranial nerves were identified and dissection followed their branches as they divided into smaller divisions toward their terminations in individual muscles. The results showed that both the glossopharyngeal (IX) and vagus (X) nerves have three distinct branches, superior, middle, and inferior. Only the middle branches of each nerve contributed to the pharyngeal plexus to which the facial nerve also contributed. The pharyngeal plexus was divided into two parts, a superior innervating the palatal and neighboring muscles and an inferior innervating pharyngeal constrictors. The superior branches of the IX and X nerves contributed innervation to the palatoglossus, whereas their middle branches innervated the palatopharyngeus. The palatoglossus and palatopharyngeus muscles appeared to be composed of at least two neuromuscular compartments. The lesser palatine nerve not only supplied the palatal mucosa and palatine glandular tissue but also innervated the musculus uvulae, palatopharyngeus, and levator veli palatine. The latter muscle also received its innervation from the superior branch of X nerve. The findings would be useful for better understanding the neural control of the soft palate and for developing novel neuromodulation therapies to treat certain upper airway disorders such as obstructive sleep apnea.

Palatopharyngeus the missing palatal muscles: Anatomical and physiological review

The first true anatomical descriptions of the normal anatomy of the palate and pharynx were published by Von Luschka in 1868, and then in 1935 anatomist James Whillis described pharyngeal sphincter. Later, in 1941 Michael Oldfield noted that the muscular elements of the soft palate have a sling-like function. Although there have been conflicting descriptions of the role of the palatopharyngeus, multiple function such as speech, swallowing, and respiration, it could role in all this function. Although, the palatopharyngeus muscle has many important functions, but it remains the missing muscle that we need to know more about it.

Palatal myoclonus: algorithm for management with botulinum toxin based on clinical disease characteristics

OBJECTIVES/HYPOTHESIS

To review the clinical characteristics and management of patients with palatal myoclonus and devise an algorithm for treatment with botulinum toxin based on presenting symptoms, clinical examination findings, and involved muscle groups.

STUDY DESIGN

Retrospective chart review at two clinical research centers.

METHODS

Between 1985 and 2011, 15 patients with a diagnosis of essential palatal myoclonus were assessed. Data were collected on patient demographics, disease characteristics, and treatment outcomes.

RESULTS

Patients were more commonly female (60.0% vs. 40.0%) with average age at onset of 35.6 years. In 40.0% of patients, the myoclonus began after a viral upper respiratory tract infection. Two-thirds of patients had been previously treated unsuccessfully with oral medications. Predominant presenting symptoms included clicking tinnitus (46.7%), nonaudible awareness of palatal movements ± rhinolalia (20.0%), or both (33.3%). Clinical examination revealed co-incident involvement of pharyngeal musculature in 53.3%. Palatal site for initial botulinum toxin injection depended on the predominant presenting symptom: for tinnitus, 2.5 U were injected transorally into the tensor veli palatini muscle at the level of the pterygoid hamulus/lateral soft palate; for palatal movements, the injection was placed medially on either side of the uvula. Dose and location of subsequent injections were tailored depending on response to the toxin and location of subsequent observed maximal muscular contractions.

CONCLUSIONS

Palatal myoclonus can present with tinnitus or patient-perceived palatal movements. Management with botulinum toxin can be tailored to address the muscles contributing to the predominant presenting symptoms.

Morphologic characteristics of palatopharyngeal muscle

In an effort to clarify the morphologic characteristics of the palatopharyngeal muscle, we examined its origin, insertion, and positional relationship with other muscles. We found that the origin of the palatopharyngeal muscle was both the oral and the nasal side of the soft palate; it was also attached to both the palatal aponeurosis and the soft palate median. However, in some cases the muscle originated on the nasal side was lacked. When the palatopharyngeal muscle originated from both the oral and the nasal side, it traveled through its insertion via the levator muscle of the palatine velum. This insertion was seen in a wide area and could be divided into three parts: the pharynx anterior, central, and posterior walls. In the central pharyngeal wall, insertion into the pharyngeal aponeurosis, inferior constrictor pharyngeal muscle, and esophagus were observed. The present results suggest that the palatopharyngeal muscle has a close positional relationship with the levator and tensor muscles of the palatine velum, the pharyngeal constrictor muscles, and the esophagus.

Morphologic Characteristics of the Superior Pharyngeal Constrictor Muscle in Relation to the Function During Swallowing

To clarify the morphologic characteristics of the superior pharyngeal constrictor muscle, which plays an important role in swallowing, the gross anatomy of the pterygopharyngeal, buccopharyngeal, mylopharyngeal, and glossopharyngeal parts of the muscle was examined. Morphology of the origin of the muscle at the buccopharyngeal part could be divided into three types: type A, membranous morphology from superior to inferior areas; type B, membranous only in superior area; and type C, complete lack of membrane. In all three types, the muscle at the buccopharyngeal part transitionally originated from the buccinator muscle. Morphology of the origin of the muscle at the mylopharyngeal part could be divided into two types: type A, tip of the origin on the mylohyoid line; and type B, tip of the origin away from the mylohyoid line. The present study found that the superior pharyngeal constrictor muscle is attached to the buccinator muscle (which plays an important role in mastication) with mucosa and originates from the mandible and root of the tongue. These findings suggest that the superior pharyngeal constrictor muscle may also play an important role in the expression of smooth coordinated movements associated with ingestion, from mastication to swallowing.