TMJ injuries
| 2nd most common facial fractures in ED | |
|---|---|
| History | Mechanism suggests site of injury - In children a fall onto the point of the chin may fracture the mandibular condyle(s) - A lateral blow common in interpersonal violence is associated with mandibular body or ramus fracture - A downward blow to the partially opened mouth may dislocate the TMJ - Anterior dislocation most common with excessive mouth opening Assess as with Head injury - previous TMJ dislocations - connective tissue disorder |
| Examination | Lost teeth? (and therefore possible aspiration) C spine concerns? Look feel move + inspect rest of the face Neurovascular assessment needs to include → mental nerve = chin/lower lip/lower gum/teeth → lingual/long buccal nerve = tongue/cheek Specific significant signs: - Asymmetrical mandible suggests displaced fracture or unilat dislocation - Bilat dislocation = unable to close mouth - Sublingual haematoma = mandible fracture - Lacerations to gum mucosa = open mandibular fracture - Fracture through tooth-bearing region = open fracture - Bleeding from ear - fracture of temporal bone, associated with mandibular condyle fracture |
| Diagnostic investigations | OPG vs CT (if maxfax going to get involved) |
| Differentials | |
| Immediate management | Can be reduced +/- procedural sedation 1. thumbs on molars → push down then posteriorly |
A patient who can bite a tongue depressor between their teeth on each side of the mouth and resist the clinician trying to pull it out is unlikely to have a fracture – in a sample of 12 paediatric patients, this was found to be 100% sensitive and 88.9% specific for fractures (diagnosed on CT) - https://dontforgetthebubbles.com/mandible-injuries/
Discharge advice (not really for trauma - from CKS)
- Soft diet
- Rest
- Avoid wide yawning, teeth grinding or jaw clenching, chewing gum or pencils, biting nails
- Cold/heat, or massaging affected muscles may be helpful
sources/links
https://www.rcemlearning.co.uk/reference/mandibular-and-temporomandibular-joint-injuries/
https://pubmed.ncbi.nlm.nih.gov/25278137/ Gorchynski et al 2014 describe a 'syringe' technique for reducing TMJ dislocations.
https://dontforgetthebubbles.com/mandible-injuries/
https://foamcast.org/2016/12/23/episode-62-dental-emergencies/
https://cks.nice.org.uk/topics/temporomandibular-disorders-tmds/management/management/