Dr. Baruch Tetri

Jaw lock (TMJ)

Board-certified periodontist
August 26, 2022

Have a locked jaw?
Let's work through the following questions
with Dr. Tetri

1
Why can the jaw lock?
2
How dangerous is it?
3
What should you do before seeing a doctor?
4
What diagnostic and treatment methods are used here?

What is a jaw lock?

TMJ: The temporomandibular joints
It is a condition where the movement of the lower jaw is severely restricted due to a spasm of the jaw muscles (internal pterygoid, masseter, temporalis). It locks in one of the positions—either open or closed. Your speech and the ability to swallow become impaired, and breathing becomes difficult.
TMJ: The temporomandibular joints
The temporomandibular joint (TMJ) is a paired anatomical entity that provides horizontal/vertical movement of the lower jaw relative to the upper jaw. The jaw mobility is provided by the joint and the chewing muscles of the face, controlling these movements. If they are damaged, the jaw is locked.
Symptoms of a locked jaw
Jaw locking is preceded by the following symptoms:
  • Crunching/clicking when opening or closing the mouth
  • Constant feeling of tension in the facial muscles
  • Pain in the ear area even at rest
  • Limited closing of the jaw
  • Asymmetrical opening of the mouth.
Once the jaw is locked, the following symptoms appear:
  • Profuse salivation
  • Swallowing problems
  • Slurred speech or complete inability to open the mouth
  • Change in the facial symmetry
  • Prolapse/retraction of the lower jaw
  • Strong clenching of the teeth
  • Sometimes the body temperature goes up.

Causes of a jaw lock

1
Trigeminal nerve injury
The trigeminal nerve can become injured due to mechanical trauma to the jaw or during dental treatment (local anesthetic injection, tooth extraction, or implantation). It controls the movement of the facial muscles.
2
Abnormal bite
Impaired occlusion leads to compensatory, protective contractions of the masticatory muscles and the development of the parafunctional activity. The temporomandibular joint is overloaded due to constantly increased tone, which leads to locking.
3
Bruxism
Involuntary clenching or grinding of teeth in sleep puts a lot of stress on the TMJ, which eventually leads to its dysfunction.
4
Arthritis
Rheumatoid arthritis and osteoarthritis are the most common causes of cartilage damage in the temporomandibular joint. The joint clicks at some point, after which the jaw locks.
5
Apnea
Before an apnea attack, the throat muscles relax and the jaw clenches hard to prevent blocking of the respiratory passages. This leads to excessive stress on the jaw and causes TMJ problems.
6
TMJ osteoarthritis
It is a chronic pathology that leads to the cartilage destruction and the osteophytes formation. The functional activity of the TMJ is reduced, and the amplitude of lower jaw movements becomes limited.
7
Tetanus
A tetanus infection causes prolonged contraction of the masticatory muscles, resulting in their painful spasm and jaw locking.
Forms
Usually, an adult can open their mouth to an average of 4–5 cm.

Depending on the degree of mouth opening restriction, there are three forms of trismus:
Light
Up to 3 cm
Medium
Up to 2 cm
Heavy
Up to 1 cm

Causes of a jaw lock

1
Jaw clicking and locking
After a characteristic clicking sound associated with the release of the joint from the bed, the jaw pops out and locks in an open or closed position.
2
Jaw locking and shifting
In a unilateral trismus, the jaw shifts to the right or left and the face becomes distorted. The facial muscles stiffen and swell up.
3
Locked jaw and ear pain
Spasm of the chewing muscles leads to locking of the lower jaw, accompanied by ear pain.
4
Locked jaw with open mouth
When yawning or opening the mouth wide while eating, the jaw condyle comes out of the articular cup, preventing you from closing the mouth.
5
Locked jaw with closed mouth
When the jaw is locked, you can't open the mouth even slightly or a little mobility remains, but it is accompanied by a lot of pain.

How to unlock the jaw: What can be done?

A warm and a cold compress
Before visiting a doctor, you can alternately apply a warm and a cold compress to the sore joint once every hour for 5–10 minutes. You can apply cream to relax the spastic muscles during a break. This will help to relieve the condition slightly and possibly unlock the jaw.

If the jaw keeps locking, you can try relaxing the chewing muscles with finger massage, applying medium force.

You can take an over-the-counter painkiller from your medicine cabinet to relieve pain.
A warm and a cold compress

Jaw stuck: Should I see a doctor?

At the first symptoms, see a doctor. It is necessary to treat the TMJ dysfunction immediately. Do not self-medicate and bring the situation to a critical state when the mouth will not open/close at all.

What doctor should I see?

Given the relationship between occlusal pathologies and temporomandibular joint dysfunction, TMJ dysfunction should be treated by a physician with gneuromuscular dentistry skills.
Dr. Tetri
"I am a board-certified orthopedist, periodontist, implantologist, and gneuromuscular dentist. I work with complex clinical cases that other clinics will not take on. I offer my patients an interdisciplinary approach to treatment—a council of doctors of different specializations in one place. I will solve your problem when the classic approach offered at Florida clinics doesn't work!"

Diagnosis

CT scan
Allows a qualitative examination of the maxillofacial area. It shows:

  • Position of the articular disk
  • Damage level of the epiarticular soft tissues
  • Abnormalities of the articular disk
  • Thickness and structure of the masticatory muscles
  • Changes in the shape and size of articular surfaces of the TMJ, etc.

EMG

Special sensors are attached to the patient's face (from the temporal lobe to the mandibular joint) to calculate the compression strength of the masticatory muscles. The sensors are extremely sensitive, with data accuracy up to 20 microns, and detect even the slightest deviations from the correct occlusion.

ESG

This is a technique for obtaining an objective characteristic of the TMJ pathology and analyzing the relationship of the articular disk with the articular head, based on a noise recording during several cycles of mouth opening and closing.

Jaw lock: GNM treatment

There is no sole treatment plan—it is individual and depends on the clinical situation. A combination of the following methods is used:

Splint therapy

An occlusal splint is placed on the patient's teeth:

  • It forces the articular heads to the correct position
  • It regulates the activity of the facial muscles
  • It helps to stretch the shortened ligaments
  • It fixes the jaw in an anatomically correct position.
TENS
Transcutaneous Electrical Nerve Stimulation is ultra-low-frequency electromyostimulation of the masticatory muscles, which relieves their spasm and restores elasticity.

After "resetting", the facial muscles return to the physiologically correct position. The lower jaw and temporomandibular joints return to place.
Bite correction
Orthodontic treatment with braces or aligners can be performed after normalization of the TMJ function.

Ideally, you should plan the bite correction process in a special program before treatment begins. An intraoral scanner takes digital impressions, then they are loaded into the program, and after that a 3D model of the correct bite is projected.

Tooth restoration

If teeth are destroyed or missing, they are restored with inlays/onlays, veneers, crowns, or a bridge on implants.

Preventing jaw stuck

  • It is necessary to have preventive check-ups at the dentist every 4 months
  • To timely treat dental diseases and risk factors for the development of TMJ dysfunction (neurological diseases, bruxism, etc.)
  • To correct bite anomalies in time
  • To periodically undergo tone correction of the masticatory muscles
  • If teeth are missing, they can be restored with dentures on implants.

Schedule a consultation with Dr. Tetri to find out the reason why your jaw is locked and what you need to do to get it working properly again!