TMJ Injury and Dysfunction

Acute dislocation presents dramatically: the patient cannot close the mouth, the chin deviates to the contralateral side (or sits centrally in bilateral dislocation), there is a palpable preauricular hollow where the condyle should sit, with drooling and difficulty speaking.

Condylar fracture presents with preauricular pain and swelling, restricted mouth opening, malocclusion (the bite feels wrong - the most reliable clinical clue for mandibular fracture), trismus, deviation on opening to the side of the fracture, and sometimes external auditory canal bleeding. Bilateral condylar fractures cause an anterior open bite.

Primary TMD is what most patients labelled TMJ actually have. Cardinal features: jaw pain (preauricular, masseter, or temporalis), clicking or popping with movement, mouth-opening limitation, morning stiffness, headache (often temporal), tinnitus, and ear fullness. Bruxism, parafunctional clenching, occlusal abnormalities, stress, anxiety, and poor sleep are frequently associated.

Structured TMD assessment: pain location and modification by jaw function; TMJ noises in the last 30 days; locking or catching; diet limitation; bruxism and parafunction; sleep quality and OSA features; psychosocial impact; exclusion of dental, ENT, salivary gland, and lymph node pathology; cranial nerve screen (especially trigeminal and facial nerve).

Examine for tenderness over the joint and over the masseter and temporalis bellies (looking for familiar pain reproduction); palpate during opening and closing for clicking, deviation, and crepitus; measure inter-incisal distance with a ruler. Maximal unassisted opening of at least 35 mm is normal. In suspected disc displacement without reduction (closed lock), maximum assisted opening under 40 mm with functional limitation supports the diagnosis. Asymptomatic clicking alone is NOT TMD - pain or functional limitation is required.

Most TMJ presentations are clinical diagnoses and do not need imaging. Imaging is an adjunct, not a substitute.

For acute atraumatic anterior dislocation, reduction is usually performed before imaging. Do NOT attempt routine bedside reduction before imaging or OMFS discussion if the mechanism is traumatic, or if there are signs of fracture, posterior or superior dislocation, CSF leak, EAC bleeding, malocclusion, or neurological deficit. Post-reduction imaging is sometimes performed if reduction was difficult or fracture is suspected.

For suspected condylar fracture, the imaging pathway depends on setting and severity. In dental and OMFS isolated-mandible pathways, OPG plus PA mandible is commonly used, with CT added where displacement, comminution, high-energy trauma, or complex facial injury is suspected. In ED major trauma, panfacial trauma, or high-energy mechanisms, CT facial bones is usually the most appropriate initial imaging.

For chronic TMD, MRI is the imaging of choice when internal derangement is suspected and conservative management has failed - it is the only modality that accurately depicts disc position. CT or CBCT is for hard-tissue assessment when justified. High-resolution musculoskeletal ultrasound is increasingly used in MSK/SEM clinics as a dynamic adjunct, although MRI remains the reference standard.

If there is altered consciousness, focal neurological deficit, or other NICE NG232 criteria after trauma, CT head within 1 hour. Cervical spine imaging follows NICE NG41.

Acute anterior dislocation (atraumatic) - the single most-tested skill on this topic. Adequate analgesia is essential; some clinicians use procedural sedation. GAUZE-WRAP both thumbs to protect against a reflex bite at the moment of reduction. Place thumbs on the patient's lower molars (or just lateral on the alveolar ridge), with fingers wrapped externally around the mandible. Apply firm, slow, steady inferoposterior pressure - downward first to disengage the condyle from above the articular eminence, then posterior to walk it back into the fossa. If bilateral, reduce one side at a time. Confirm by restored bite, audible relocation, and resolution of the preauricular hollow. Advise post-reduction soft diet, avoidance of wide opening, supportive bandage if cooperation uncertain, and dental or OMFS follow-up. Recurrent dislocation may need surgical management.

Condylar fracture: urgent imaging and OMFS referral or discussion. Most non-displaced condylar fractures are managed conservatively (soft diet, jaw rest, analgesia, early mobilisation guided by OMFS) with good functional outcomes. Displaced or bilateral fractures, fractures associated with malocclusion that cannot be corrected non-surgically, and intracapsular fractures threatening growth in children may need open reduction or intermaxillary fixation.

Primary and post-traumatic TMD - conservative, multimodal, patient-led. The evidence-based first-line bundle (2025 RCS/FDS, NICE CKS):

• •Patient education and reassurance (most TMD is self-limiting and improves over weeks to months)
• •Short course of NSAIDs if not contraindicated
• •Soft diet during flare
• •Jaw exercises (limited opening, controlled translation, posture work) ideally guided by a physiotherapist with orofacial training
• •Stress and parafunctional habit modification
• •Screen for sleep disturbance and OSA where bruxism, morning headache, or persistent pain is prominent
• •Splint therapy (hard occlusal stabilisation splint fabricated by a dentist) helps a meaningful subset, particularly with bruxism or nocturnal clenching
• •NICE CKS supports a very short course (2 to 5 days) of low-dose diazepam (e.g. 2 mg) for acute severe muscle spasm and trismus when other measures are inadequate - long-term use is contraindicated
• •Avoid long-term opioids, prolonged immobilisation, and early irreversible occlusal adjustment

Refer onward when conservative management fails after at least 8 to 12 weeks, imaging suggests internal derangement requiring arthrocentesis or arthroscopy, there is locked jaw not responding to manipulation, or the picture suggests pathology beyond SEM scope. Botulinum toxin to masseter is NOT first-line for refractory TMD - evidence is uncertain, there are concerns about muscle atrophy and TMJ bony changes, and its use should be specialist-led.

After acute dislocation: soft diet and avoidance of wide opening for 7 to 14 days, graduated return to normal function, and dental review for occlusal assessment. Recurrence prevention focuses on awareness of triggers (yawning posture, prolonged dental work without rest breaks).

After condylar fracture: OMFS-led and protocol-driven. Early mobilisation within constraints set by the surgical or non-operative plan, jaw range exercises, soft diet for 4 to 6 weeks, oral hygiene, graduated return to function. Trismus is the dominant complication and benefits from supervised mobility work, sometimes with TheraBite or similar devices.

For primary and post-traumatic TMD, rehabilitation is the management. Expect symptoms to improve over weeks to months with conservative care; the natural history is favourable for most patients. Ongoing self-management (jaw posture awareness, avoiding parafunctional habits, stress management, sleep hygiene) is key to relapse prevention. Persistent symptoms beyond 3 months despite adequate conservative management warrants specialist referral.

• •2025 RCS / Faculty of Dental Surgery guideline on painful TMD in adults - current UK primary anchor for biopsychosocial framing and conservative-first management.
• •NICE CKS: Temporomandibular disorders - primary care assessment and management; supports very short course of low-dose diazepam for acute severe spasm.
• •BAOMS - UK specialty consensus for condylar fracture management.
• •NICE NG232 (Head injury) - applies to any TMJ injury with associated head trauma.
• •Botulinum toxin to masseter for refractory TMD - evidence remains uncertain; specialist-led, NOT first-line.

• •Anterior TMJ dislocation reduction: gauze-wrapped thumbs on lower molars, slow inferoposterior pressure.
• •Malocclusion is the most reliable clinical sign of mandibular or condylar fracture.
• •Do NOT reduce traumatic or atypical dislocation before imaging and OMFS discussion.
• •Primary TMD: conservative-first; refer onward after 8 to 12 weeks of failed conservative management.
• •MRI is the only modality that accurately depicts disc position; routine imaging is NOT indicated in uncomplicated primary TMD.
• •Jaw claudication, temporal headache, or visual symptoms in over-50s = giant cell arteritis until proven otherwise (sight-threatening).