Bruxism and Fatigue of the Jaw Muscles
Table of Contents
What is bruxism?
Bruxism is a repetitive oral parafunctional habit of forcefully clenching or grinding the teeth side to side, occurring during sleep or while awake. Sleep bruxism is more common, and many people are unaware of it themselves — they only learn about it when a partner hears the grinding sound. The biting force during bruxism reaches 6–10 times that of normal chewing, overloading the teeth, the temporomandibular joint, and the masticatory muscles.
Hypertonicity of the masseter and temporalis
When bruxism is repeated, the masseter and temporalis muscles enlarge and become chronically tight. The jaw feels stiff and fatigued upon waking, and pressing on both cheek areas (the masseter) reproduces marked tenderness. Hypertonicity of the temporalis leads to pain in the temple area, which is often confused with tension-type headache.
Effects on the temporomandibular joint
Sustained overload pushes the articular disc forward, causing anterior disc displacement and accelerating degeneration of the articular cartilage. In the teeth, occlusal wear (attrition), cervical fractures (abfraction), and enamel cracks appear.
Korean medicine treatment
- Acupuncture: Needling Xiaguan (ST7), Jiache (ST6), and Touwei (ST8) relaxes the masseter and temporalis. Electroacupuncture (4 Hz continuous wave) suppresses muscle fiber hyperactivity.
- Pharmacopuncture: Anti-inflammatory pharmacopuncture injected into the belly of the enlarged masseter rapidly relieves muscle tension.
- Herbal medicine: Modified Eokgansan (Yokukansan) calms internal liver wind, while Sanjoin-tang (Suanzaoren-tang) improves sleep quality. Gami-soyo-san is added for patients with severe stress.
Occlusal splint and stress management
Wearing a stabilization splint at night prevents tooth wear and reduces the load on the TMJ by 20–30%. The splint is fabricated in collaboration with a dentist. Because bruxism is closely tied to psychological stress, relaxation breathing (4-7-8 breathing) before bedtime or massaging the jaw with warm water can help. Caffeine and alcohol worsen sleep bruxism, so intake should be limited from the evening onward.