Bruxism

Bruxism can be defined as non-functional, habitual contact of teeth, that may include grinding or gnashing, clenching and tapping of the teeth.

Daytime/Diurnal Bruxism

Conscious or subconscious grinding of teeth usually during the day, usually silent except in patients with organic brain disease.
It can occur along with parafunctional habits such as chewing pencils, nails, cheeks and lips.

Night time/Nocturnal Bruxism

Subconscious grinding of teeth characterised by rhythmic patterns of masseter EMG activity.

Occlusal discrepancies (Faulty restorations, deflective occlusal contacts, malocclusion): Can be attributed to the alteration of definite afferent impulses, originating in the periodontium.
Psychological factors (Nervous tension): Repressed anger, aggression, anxiety, etc.
CNS disturbances such as cortical lesions, cerebral palsy, mental retardation and tuberculous meningitis.
Hereditary factors such as children of bruxing parents.
Allergy: Nocturnal bruxism may be initiated reflexly by increased negative pressures in the tympanic cavities from intermittent allergic edema of the eustachian tube mucosa.
Other oral habits such as chronic biting and chewing of toys and pencils, thumb- and finger-sucking, tongue thrusting and mouth breathing.
Systemic factors:
- Magnesium deficiency.
- GI disturbances from food allergies, enzymatic imbalances, leading to chronic abdominal distress.
- Subclinical nutritional and vitamin deficiencies,
- Endocrine disorders eg. hyperthyroidism.
Occupational factors: Over enthusiastic students, compulsive over achievers or athletes.

The signs and symptoms of bruxism depends on the frequency, intensity and the age of the patient.

Dental Findings

Increased tooth mobility (may be more in the morning).
Non-functional patterns of occlusal wear and atypical wear facets.
Increased tooth sensitivity (due to excessive abrasion of enamel).
Dull percussion sounds.
Soreness to biting stress.
May cause fracture of restoration or root fracture.
Sometimes, pulp may be exposed due to attrition, leading to dental abscess.
Bruxism might be an essential factor for the spread of gingivitis into deeper periodontal structures and alveolar bone loss.

Musculature

TMJ Findings

Pain in the joints, usually dull and unilateral.
Crepitation and clenching within the joint.
Restriction of mandibular movements.
Deviation of chin during mandibular movements.
The disc may become worn or perforated and wear patterns are often correlated with condylar remodelling.

Other Findings

Chronic headaches and facial pain (often of muscular contraction type).
Grinding and tapping sounds.
Soft tissue trauma.
Small ulcerations or ridging on the buccal mucosa opposite the molar teeth.
There is a comorbidity between obstructive sleep apnea and nocturnal bruxism, and bruxism is included among the sleep-related movement disorders in the International Classification of Sleep Disorders.

The various treatment modalities include:

Occlusal adjustment (correction of any prematurities or occlusal interferences in restorations).
Occlusal splint, Bite plane or Bite guard.
Restorative treatment.
Psychotherapy.
Relaxation training.
Medications.
Electric method (electrogalvanic stimulation for muscle relaxation).
Orthodontic treatment.

Occlusal Splint/Bite Plane/Bite Guard

Vinyl bite guard that covers occlusal surfaces of all teeth can be worn at night to prevent continued abrasion.
The occlusal surface of the bite guard should be flat to avoid occlusal interference.
They also helps in passive stretching of painful muscle fibres by raising the bite.

Restorative Treatment

Endodontic treatment with crown is indicated if the abrasion is severe and pulp exposure is imminent.

Psychotherapy

Counselling the patient can lead to a decrease in tension and also create a habit awareness.
Can lead to an increase in voluntary control and reduced tooth parafunction.

Relaxation Training

In this technique, the patient is instructed to tense the muscle group in consideration and relax, thereby training the patient to relax the muscle group voluntarily.
Hypnosis, conditioning, etc. are also indicated for subjects in whom bruxism is due to a central cause.

Medications

Vapocoolants such as ethyl chloride for pain within the TMJ area.
Local anaesthetic injections directly into the TMJ or into the muscles,
Tranquilizers, sedatives and muscle relaxants.
Placebos may be used to rule out psychological etiology.
Medications such as diazepam may be prescribed for a few days to alter sleep arousal and anxiety level.
Low doses of tricyclic antidepressants may be used to inhibit the amount of REM sleep.

Orthodontic Treatment

Correction of malocclusion such as Class II and Class III, that may predispose to bruxism is recommended.

McDonald and Avery's Dentistry for the Child and Adolescent (11th edition) -Mosby (2021).
Textbook of Orthodontics (2nd Edition), Gurkeerat Singh, Jaypee Brothers Medical Publishers (P) Ltd.
The image used is in public domain (Source : Wikimedia Commons).

*This article is an excerpt from the above mentioned books and Medical Sutras does not make any ownership or affiliation claims.