TMJ (Jaw)
Bruxism
이갈이 (Bruxism)
Repetitive grinding/clenching stressing teeth, joints, and muscles
- How common
- Very common (8–12% of adults)
- Typical age
- All ages, most common 20–50
What is it?
CNS arousal and stress drive repetitive masticatory muscle activation causing grinding/clenching. Classified as sleep or awake bruxism.
Commonly affected: Occlusal surfaces, masticatory muscles, TMJ
How it develops
- Central Arousal/StressSympathetic activation, sleep microarousals
- Rhythmic Muscle ActivationRhythmic masseter/temporalis activation
- Tooth Wear/Joint LoadOcclusal attrition, joint overload
- Secondary ComplicationsMyofascial pain, TMD, headache, tooth fracture
Symptoms
- Morning jaw fatigueMorning masseter/temporalis fatigue
- Tooth wear/sensitivityFlattened occlusal surfaces, cold sensitivity
- Tension headacheTemporal headache, morning exacerbation
- Grinding sounds (sleep)Reported by bed partner
- Cheek indentationsLinea alba — white line on buccal mucosa
How it is examined
- Occlusal attritionFlattened wear facets
- Masseter hypertrophy/tendernessBilateral masseter hypertrophy/tenderness
- Linea alba on buccal mucosaWhite line along occlusal plane in cheek
- Scalloped tongueTooth indentations on tongue margins
Imaging
Panoramic usually normal; assess tooth wear and bone.
- Tooth attrition visible
- Usually normal joint
- Possible condylar sclerosis in chronic
MRI not indicated for bruxism alone; assess associated TMD.
- Often normal
- Muscle changes not well seen
- Possible disc/joint changes
Non-surgical care
- Nighttime occlusal splintNight guard protects teeth (first-line)
- Stress managementCBT and relaxation techniques
- Sleep hygiene/awarenessLimit caffeine/alcohol/tobacco; awake bruxism awareness
- Botulinum toxin injectionMasseter injection for refractory cases
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
No surgical indication
Procedures that may be discussed
- Conservative and dental management only
Outlook
Splint and stress management control most cases; management rather than cure.