Surgical Anatomy. The temporo-maxillary articulation possesses many anatomical features that should be understood before entering upon the clinical aspects of dislocations of this joint. It is a ginglymo-arthrodial joint with an inter-articular fibro-cartilage dividing the cavity into two distinct articulations, each with its separate and complete synovial membrane. The function of the upper articulation is that of gliding, used in lateral grinding motions and when the chin is protruded. The lower articulation has a purely hinge-like action for raising and lowering the mandible. The nature of the articulation permits only forward dislocation unless fracture complicates the condition.
Dislocations of the jaw are almost always the result of muscular action, although violence can cause it too. A blow on the chin or angle of the jaw while the mouth is open may lead to luxation. It occurs in yawning, talking, singing, coughing, and vomiting due to overaction of the external pterygoid muscle.
Etiology. This dislocation occurs more commonly in middle-aged persons and is seen more frequently in women than men. It usually results from muscular action rather than violence.
Symptoms. In bilateral dislocation, the mouth opens widely with considerable pain during displacement. The patient's speech becomes almost unintelligible due to articulation impossibility. Unilateral dislocation causes a twisted appearance of the face and can be felt below the zygomatic arch.
Treatment. Reduction is accomplished by forcing the rami of the jaw downward and backward as the body of the bone is raised. The thumbs are protected by a towel or heavy bandages, introduced into the mouth and carried back to the last molars on either side. Downward and backward pressure forces the condyles over the articular eminences as the body of the bone is raised.
After-Treatment. The jaw should be fixed for two weeks following the accident using a four-tailed or Barton bandage. Patients must avoid opening their mouths too far for at least another month after removal of dressings to prevent recurrence.
Prognosis. Reduction is usually accomplished without difficulty in recent cases, with perfect restoration of function except for a tendency towards habitual luxation.
Key Takeaways
- Dislocations of the jaw are typically caused by muscular actions rather than violent impacts.
- Symptoms include an open mouth, drooling saliva, and difficulty in speech.
- Treatment involves forcing the rami of the jaw downward and backward to reduce displacement.
Practical Tips
- Use a towel or heavy bandages to protect your thumbs during reduction.
- Fix the jaw for two weeks after treatment using a four-tailed or Barton bandage.
- Avoid opening the mouth too wide for at least another month post-treatment.
Warnings & Risks
- Muscle spasm can seriously obstruct reduction, sometimes necessitating anesthesia.
- Formation of adhesions and changes in the glenoid cavity may require open incision or resection.
Modern Application
While this chapter provides foundational knowledge on diagnosing and treating jaw dislocations, modern medical practices have advanced surgical techniques for complex cases. However, understanding basic anatomy and initial treatment steps remains crucial for emergency situations.
Frequently Asked Questions
Q: What are the common causes of jaw dislocation?
Jaw dislocation is usually caused by muscular action such as yawning or talking, but can also result from a blow to the chin or angle of the jaw while the mouth is open.
Q: How do you recognize symptoms of a jaw dislocation?
Symptoms include an open mouth with drooling saliva and difficulty in speech. In unilateral cases, there's also a twisted appearance on one side of the face.
Q: What is the recommended treatment for reducing a jaw dislocation?
Treatment involves forcing the rami of the jaw downward and backward while raising the body of the bone to push the condyles over the articular eminences.