Mandible dislocation
Background
- Anterior Dislocation
- Most common
- Mandibular condyle is forced in front of the articular eminence
- Risk factors: Prior dislocation, weak capsule, torn ligaments
- Often occurs spontaneously while pt is yawning, "popping" ears, or laughing
- Posterior Dislocation
- Follows a blow to the mandible that may or may not break the condylar neck
- Condylar head may prolapse into the external auditory canal
- Lateral Dislocation
- Often associated w/ mandibular fracture
- Superior Dislocation
- Occur from blow to the partially opened mouth
- Associated w/ cerebral contusions, facial nerve palsy, deafness
Clinical Features
- Anterior Dislocation
- Difficulty speaking or swallowing
- Malocclusion
- Pain localized anterior to the tragus
- Prominent-appearing lower jaw
- Preauricular depression
- Posterior Dislocation
- Must examine the external auditory canal
- Lateral Dislocation
- Condylar head is palpable in the temporal space
Diagnosis
- Spontaneous atraumatic anterior dislocation: diagnosis is clinical
- Traumatic dislocation: obtain CT scan
Treatment
- Anterior Dislocation Reduction
- Analgesia
- Inject local anesthetic into the preauricular depression just ant to the tragus
- Muscle relaxation
- Short-acting IV benzo (e.g. midazolam)
- Technique
- Place pt in seated position (anterior approach) or supine (posterior approach)
- Apply gauze over gloved thumbs for protection
- Placed gloved thumbs in pt's mouth over the occlusal surfaces of the molars
- Apply pressure downward and backward (toward the pt)
- If dislocation is bilateral it may be easier to relocate one side at a time
- Analgesia
Disposition
- Admit:
- Open dislocation
- Superior dislocation
- Associated w/ fracture
- Nerve injury
- Inability to reduce
- Discharge spontaneous, successfully reduced anterior dislocation with:
- Soft diet
- Do not open mouth wider than 2cm x2wk
- Support the mandible with a hand when they yawn
Source
- Tintinalli