The proprioceptive impulses produced by accessory ligaments are mainly transmitted to the mesencephalic nucleus of trigeminal nerve.
35 This connection means that any disturbance of the accessory ligaments may also affect the proprioceptive system of the entire stomatognathic system. Therefore, the ligaments have a high sensitivity and inflammatory capacity. If a painproducing dysfunction in one of these ligaments is suspected, passive movements must be used to test the ligaments. The dysfunction of the accessory ligaments of the TMJ is principally due to direct or indirect trauma to the mandible, to microinjuries, to hypoxia, and to stress.
The stylohyoid and stylomandibular ligaments are known as structures that, when injured, produce throat pain that may spread to the face, ears, and temporomandibular joints. Other symptoms of injury are neuralgic pain, dysphonia, earache, dysphagia, carotidynia, and pain of the styloid process.
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Dysfunction can be due to complications with dental extractions. In particular, the SML, which is attached to the spine of the sphenoid, posterior to the transverse flexion-extension axis of the sphenooccipital synchondrosis, causes a cranial motion (torsion) of the alisphenoid, ipsilateral to the extraction of a molar from the upper jaw and contralateral to the extraction of a molar from the lower jaw, and consequent stretching of the petrosphenoid ligament (Gruber ligament), which delimits the Dorello canal. The Dorello canal is an osteofibrous canal in the dural space beneath the petrosphenoid ligament; between the apex of petrous part of temporal bone and the clivus, which contains the abducens nerve; and inside the confluence of the cavernous, the basilar, and the inferior petrosal sinuses. In dental extraction complications, symptoms can include visual disturbance, facial pain, or tinnitus.
An increase in tension or fibrosis of the ligament causes caudal traction on the base of the sphenoid with a movement of the ipsilateral alisphenoid superior.
18 Because the SML and the STML link the mandible to the base of the skull, a dysfunction of the cranial base may affect the mandible (eg, dysfunction, malocclusion) and vice versa.
Cranial dysfunction may affect TMJ motion; if the temporal bone externally rotates, the mandibular fossa moves posteriorly and medially. Internal rotation allows the mandibular fossa to move anteriorly and laterally. The mandible may deviate toward the side of the externally rotated temporal bone or away from the side of the internally rotated temporal bone.
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Sphenoid and temporal dysfunctions may also affect the TMJ through their direct articulation with the mandible through the SML, STML, and PTR.