TMJ SYMPTOMS & Causes
- Headaches (tension or migraine)
- Pain behind the eyes or blurring of vision
- Unexplained tooth pain
- Earaches, congestion or ringing in ears
- Clicking, popping or grating sound in the jaw joints
- Limited opening or locking of the jaw
- Pain when chewing
- Facial pain and/or numbness of face and head
- Neck and/or throat pain
- Difficulty in closing the teeth together
- Tired jaw
- Hearing loss
- Poor posture
- Neck and upper back restriction, tight facial/mouth muscles/myofascial trigger points
- Trauma or whiplash
- Your teeth and your bite
- Clenching or grinding
- Mouth breathing
- Parafunctional habits: nail biting, frowning, chewing on pencils, etc.
Now let’s get in to what causes TMJ/TMD with a bit more detail.
Causes of Temporomandibular Disorders
The identification of a definite, common cause of TMDs is lacking. For this reason, most of the factors discussed in this section are not proven causes but are rather associated with TMDs.
Factors that cause the onset of TMDs are called INITITATING FACTORS.
Factors that increase the risk of TMDs are called PREDISPOSING FACTORS.
Factors that interfere with healing or enhance the progression of TMDs are called PERPETUATING FACTORS.
There is not a single cause, factor or theoretical model that can explain the onset of TMDs.
From Orofacial Pain: Guidelines for Assesssment, Diagnosis, and Management, 5th Edition
Trauma is described as any force applied to the masticatory structures that exceeds that of normal functional loading. Most Trauma can be divided into 3 categories:
- Direct Trauma:
- Jaw fracture from some impact
- In children, condylar and subcondylar fractures from impact
- Impact injury to the jaw that causes disc displacement
- Wide or prolonged opening, such as with yawning or dental procedure
- Third molar extraction
- Intubation – medical term for insertion of a tube into the mouth
- Indirect Trauma:
- Acceleration-Deceleration (whiplash) after a motor vehicle accident
- Any neck injury, can refer pain to the TMJs, face, and head
- Any sustained or repetitious adverse loading of the masticatory system
- Poor posture
- Mouth breathing
- Parafunctional habits:
- Clenching is more of a single contraction episode, and this can occur during day or night
- Bruxing is an oral parafunctional activity that can occur day or night. Bruxing is classified as a series of rhythmic contractions, tooth grinding. ~ 20 to 38% of children brux, and 25% to 50% of adults brux
- Lip biting
- Nail biting
- Sucking on the inside of one’s cheeks
- Skeletal Relationships:
- Genetic or developmental
- Retrognathia – the jaw or mandible is receded posterior or set back from normal
- Micrognathia – abnormal smallness of the jaw or mandible
- Steep articular eminence
- Occlusal Relationships: Basically how the upper and lower teeth come together
- Large overjet
- Anterior open bite
- Unilateral posterior crossbite
- Lack of firm posterior tooth contact (missing back teeth)
- Malocclusion following dental filling or crown
- Systemic Factors:
- Vascular disorders
- Altered collagen metabolism
- Hypermobility – I personally feel I see a lot of this and corresponding TMDs
- Local or Peripheral Factors:
- Chewing efficiency or lack of
- Masticatory ( Jaw) muscle tenderness
- Pathologic and/or adaptive responses to disease
- Disc derangement/Osteoarthritis, what came first?
- A “sticky” disc or “adhered” disc
- Prolonged immobilization of the jaw, leading to capsular tightness
- Female hormones
- Genetic Factors: Little research is available with regard to genetic susceptibility for TMDs
- A recent study examined the relationship between catechol-o-methyl transferase (COMT) polymorphism, pain sensitivity , and the risk of TMD development
- Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) Study
Psychosocial factors include individual, interpersonal, and situational variables that impact the patient’s capacity to function adaptively.
- General Distress
- Excessive sympathetic nervous system activity as an overresponse to life stressors
- Limited coping skills
- Physical response to stress
- Primary gain produces positive internal motivations. For example, a patient might feel guilty about being unable to perform some task. If he has a medical condition justifying his inability, he might not feel so bad.
- Secondary gain can also be a component of any disease, but is an external motivator. If a patient’s disease allows him/her to miss work, avoid military duty, obtain financial compensation, obtain drugs, or avoid a jail sentence, these would be examples of secondary gain.