Pterygoid muscle

CT and MRl are important methods for the initial evaluation of a paraganglioma. Even though the findings are usually not specific for this tumor and may mimic other nerve sheath neoplasms, these studies are highly effective to demonstrate the extension of the tumor into different regions like the carotid canal, the inner and middle ear, mastoid process, posterior fossa or pterygoid muscles. (Fig. 19.2a,d,e)... 

Findings observed on osteopathic examination were compression of the occipital condyles bilaterally (the left side greater than right], left parietal bone externally rotated, right medial pterygoid muscle spasm, and an anterior sacral base. No bossing ofthe frontal and parietal bones was noted and there was no overlapping of sutures present. 

Movements of the TMJ result chiefly from the actions of the muscles of mastication—the temporalis, masseter, medial pterygoid, and lateral pterygoid muscles. The various movements of the TMJ result from the cooperative activity of several muscles, either bilaterally or unilaterally. 

Actions When contracted bilaterally, the lateral pterygoid muscles protract and depress the mandible. When contracted unilaterally they produce contralateral lateral glide of the mandible. 

Medial pterygoid A thick quadrilateral muscle located deep to the ramus of the mandible it embraces the inferior head of the lateral pterygoid muscle. 

Elevation is the opposite of depression. The motion is achieved mainly through the actions of the temporalis and medial pterygoid muscles. 

Protraction (protrusion) is motion that involves anterior giide of both condyles and articular disks along the articular tubercles. It is achieved through bilateral contraction of the medial and lateral pterygoid muscles. 

Lateral excursion is movement that involves lateral glide of the ipsilateral mandibular condyle, accompanied by slight medial rotation of the contralateral condyle about the medial, shifting axis. It is achieved by unilateral contraction of the contralateral medial and lateral pterygoid muscles. 

Lateral pterygoid A short, thick muscle with two heads of origin. 

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