MALFUNCTION OF THE MANDUCATORY SYSTEM

MALFUNCTION OF THE MANDUCATORY SYSTEM

1. INTRODUCTION: The major objective of the dentist is to preserve, restore or maintain the integrity of the masticatory system which is the victim of three main pathologies: caries, periodontal diseases and occlusal pathology. Having gone far beyond the framework of the tooth; the dentist has become aware of the role that he can and must play in the diagnosis and treatment of disorders of the masticatory system; because the synergy of all the elements of the stomatognathic system can be disrupted by even a minimal alteration of one of its components.
2. DEFINITION OF DAM: it is a defect in the adaptation of the masticatory system to an occlusion disorder or a parafunction increased by a psychological or general disorder. DAM does not manifest itself immediately; if the symptoms predominate in women before the age of 35, the often non-painful joint signs predominate in elderly subjects.
3. ETIOLOGY: according to GOLA, CHOSSEGROS and ORTHLIEB, the recognition of the etiologies of DAM is a delicate undertaking due to the number and complexity of the intertwined factors and the very varied modes of reaction of the system.
   1. predisposing factors: natural or acquired, they create the bed of the disease
      1. occlusion disorders:
         • premature occlusals: these are occlusal contacts occurring before maximum intercuspidation, during the closing movement 
         • occlusal interferences: they are more harmful if they appear suddenly (cap, extraction) or are unique and concentrated on a tooth or on the non-working side 
         • loss of posterior wedging 
         • modification of the vertical dimension of occlusion: very significant, sudden and especially asymmetrical modifications can cause a DAM
         • occlusal anomalies of skeletal origin: maxillomandibular and condylar dysmorphoses can be responsible for DAM 
4. ligamentous hyperlaxity:
   • spontaneous (MARFAN syndrome)
   • acquired (functional promandibulia) discocondylar detachment (floating disc) 
5. Parafunctions: will develop exaggerated static (tensing) or dynamic (bruxomania) forces or lingual interposition or atypical swallowing. Other parafunctions are rarely found in violin players or scuba divers.
   2. triggering factors: they suddenly disrupt the homeostasis of the masticatory system 

1. emotional shock: increasing para functions (mourning, divorce, exam)
2. sudden change in occlusion: orthodontics, iatrogenic prosthesis 
3. behavioral modification: excessive chewing of gum, change of chewing side , change of sleeping posture (ventral decubitus)
4. trauma: TMJ contusion, condylar fracture, forced mouth opening.
5. maintenance factors: these are factors which are added to or replace the initial pathology, they complicate the treatment and worsen the prognosis.
   1. secondary migration 
   2. subtractive joint remodeling
   3. prosthetic instability  

The DAM candidate presents 4 risk factors: joint hyperlaxity, posterior toothlessness, anterior guidance disorder due to parafunction or dysfunction

4. pathogenesis  : the muscle spasm disrupts the synergy and synchronism which govern the proper functioning of the different muscles of the complex whose limits go far beyond the masticatory complex;

This results in the appearance of pain in the muscles sometimes located a long way from the muscle that was first used.

This propagation of pain has been explained by the existence of anatomical pathways connecting trigger zones or reference zones. 

The cause-effect relationship between occlusal interferences and muscle spasm is indeed well established.

However, it would be a mistake to consider occlusion as the primary factor in the etiology of these functional disorders.

A simple psychological factor can also be responsible for a discordance; even an upheaval 

It is therefore the different combinations between psychic tension and occlusal interferences which can break the fragile balance of the system.

MALFUNCTION OF THE MANDUCATORY SYSTEM

5. SYMPTOMATOLOGY: the clinical manifestations of DAM are extremely polymorphic; some are suggestive and immediately point towards the masticatory system, others are more equivocal and can lead to confusion.
   1. muscular manifestations: linked to spasms, they result in pain, limited mouth opening, muscular hypertrophy
      • Clinically, external pterygoid spasm manifests itself as earache or pre-auricular or pseudo-sinus pain. 
      • the masseter: spasm of the deep bundle results in earache and pre-auricular pain. spasm of the superficial bundle causes pain, trismus and sometimes muscle hypertrophy
      • the temporal: the spasm of the anterior and middle bundles explains the very frequent temporal headaches; the spasm of the posterior bundle is the cause of otalgia
      • spasm of the internal pterygoid results in pseudo-anginal pain 

In the long term, you may experience tinnitus in the form of buzzing or whistling. 

• Spasm of the depressor muscles can cause pharyngeal paresthesias with a feeling of tightness in the throat 
• The muscles of the tongue are often stressed in DAM, resulting in glossodynia. 
• cervical muscle spasm: neck pain, shoulder pain and headaches

2. joint manifestations  : 

1. pain  : typically located at the joint or in the ear; it is unilateral or bilateral, it is aggravated by chewing hard food, yawning or sneezing, cold or humidity, fatigue or parafunctions. Palpation of the TMJ during movements is painful.
2. Joint noises  : Joint noises result from a lack of coordination between the movements of the condyle and those of the meniscus; instead of remaining in the center, the condyle is outside the concavity and exceeds the edge of the meniscus;
   • A cracking or popping sound is heard when the condyle suddenly returns from the edge to the center, they are common and occur when opening and closing the mouth 
   • Crepitations: perceived on palpation of the anterior surface of the external auditory canal or the pretragal region, they correspond to the friction of the often eroded articular surfaces

3. Dynamic disturbances  :
   • The jump: visual and tactile sign which gives the patient the sensation when opening the mouth that the mandible is coming loose; the opening then occurs in two stages.
   • Condylar subluxation can be seen unilaterally or bilaterally. 
4. Mandibular dyskinesia 
   • Trismus: is relatively common
   • Deviation of the mandible: simultaneous palpation of the two joints allows the different progression of the two condyles to be followed
     3. alveolo-dental manifestations  : apart from muscular and articular signs, patients suffering from DAM may complain of dental and periodontal disorders.
     4. cranio-cervico-facial manifestations:
        • headaches 
        • dizziness when waking up
        • ocular manifestations (pain, photophobia, tearing)
        • neuralgia
        • psychalgia
        • pain and posture problems

6. CLINICAL EXAMINATION: In order to arrive at a correct diagnosis, it is essential to gather all the information concerning the patient’s condition and record it in a well-organized manner.
7. Questioning  : it should allow you to note:

1. The reason for consultation  : it may be pain; joint noises, limitation of mouth opening, dislocation or subluxation 
2. The evolutionary mode
   • Appearance: -sudden or gradual

                              -spontaneous or provoked (yawning, prolonged dental care)

• Intensity: discomfort, sensitivity, superficial pain, moderate pain, severe pain, paroxysmal pain
• Duration: a few hours, a few days, a few weeks, permanent
• Presence of trigger zones
  3. personal and family history  : it is necessary to specify:

• the profession: certain professions require nervous tension or a pathogenic posture (violinist, switchboard operator, dentist)
• family situation: possible emotional problems 
• the existence of a rheumatic past.
  2. exo oral examination  : as soon as the patient enters, the anomalies must be noted:

• facial: tense face, asymmetry, scar, abnormal movements (tics and para function), muscular hypertrophy, profile anomalies (pro and retro-mandibulia)
• Postural: head carriage, scoliotic attitude, gait 
• study of the masticatory system: 

• Muscles: palpation of the muscles is done in two stages; muscle at rest and muscle contracted or stretched, contraction occurs during mouth closure and propulsion on the other hand stretching occurs during opening and retropulsion. We examine the elevator, depressor and cervical muscles.
• The temporomandibular joint: the examination is carried out by:
  • Palpation: this is done at rest and during mandibular movements, it allows us to assess the limitation of movements, the existence of joint noises, and pain.
  • Auscultation: this is done using a stethoscope and allows you to hear different types of noise.
• Mandibular movements: see mouth opening; closing, propulsion and diduction 

Limitation of mouth opening and preserved propulsion and diduction: muscular originLimitation of mouth opening and altered diduction: articular origin

3. Dental check-up 
4. Occlusal analysis  : carried out in the mouth then on an articulator, allows premature births and interferences to be highlighted 
5. Examination of functions  : chewing; swallowing, phonation, respiration 
6. additional examinations  :
   1. Clinical tests  : 

• Krogh-Poulsen test: biting an object (wooden tongue depressor) at the level of the molars on the painful side
  • if there is worsening of the pain on this side; therefore muscular damage
  • if we have relief on this side: therefore joint damage 
• GERBER resilience test: the patient is asked to clench his teeth on a tin foil wedge on one side and an occlusion tape on the other side
  • if the occlusion ribbon remains blocked then the joint has a reserve potential 
  • if the occlusion ribbon is not blocked; the joint no longer has any reserve potential (joint in compression)

• static and dynamic movement comparison test: pain during mandibular movements is preferentially of articular origin
  2. Radiological examinations
• panoramic: allows you to appreciate the condylar regions, the alveolar arches, the mandibular morphology,
• teleradiography: allows a profile view of the skull and dental arches 
• SCHULLER transcranial incidence: it only shows the lateral part of the joint, it assesses the position of the condyle and the state of the bone surfaces
• tomography: visualizes bone structures and joint space in 3 dimensions 
• CT scan: allows you to see the joint space, bone surfaces and disc calcifications.
• Magnetic resonance imaging: non-invasive, its indication should be limited to atypical cases and before surgery.
• Sonography: records temporomandibular sounds and objectifies joint noises.

5.        Diagnosis  :
6. Positive diagnosis  : a methodical clinical examination easily leads to the diagnosis and the presence of one or more of these clinical signs should be noted: 

• When opening the mouth: limitation of mouth opening, mandibular deviation
• Joint pain and noises in one or both TMJs
• Muscle tenderness on palpation 
• Radiating pre-auricular pain
• Highlighting occlusal interferences

2. Differential diagnosis  : should be made for pain and dysfunction 

• Oropharyngeal mucosal lesion 
• Dental injury
• Maxillary sinusitis
• Inflammatory ear lesion 
• Problem with the salivary glands
• Facial neuralgia
• Headaches and migraines
• Arthritis
  6. Treatment  :
     1. Symptomatic treatment  :
        1. drug treatment  : analgesics, muscle relaxants, anti-inflammatories, anxiolytics, tranquilizers
        2. muscle relaxation  : is done by:

• occlusal splint
• physical therapy: application of heat, infrared rays 
• infiltration of anesthetic products into the ATM 
• muscle relaxation exercises
  3. psychotherapy 
     2. Etiological treatment  : to re-establish a balanced and stable occlusion and functional in harmony with the neuro-musculo-articular system, we can carry out 

• Tooth extractions 
• Coronary arteries
• Orthodontics
• Prosthetic restoration 
• Selective grinding
• If during the examination the presence of harmful habits or postural tics is found, functional rehabilitation is carried out; onychophagia must be combated by the patient himself.
  3. Prophylactic treatment  :
     1. in infants  :

• advise the choice of soft pacifiers 
• Swallowing rehabilitation can begin at 3 years of age 
• early elimination of harmful habits (thumb or foreign body sucking)
• monitor sleep position
  2. in children  :

• Childhood bruxism is a cause of infragnathia and loss of the DVO
• 6 year old tooth; key tooth in occlusal relationships, must be monitored 
• retain space after extraction by a space maintainer 
• early detection of malpositions
  3. in young adults  :
     • examine teeth periodically
     • limit extractions
     • extract DDS in wrong position 
     • during interventions on the mandible support it strongly

4. in adults 
   • regular check-ups at the dentist
   • compensate for tooth loss 
   • dental care 
   • retention of loose teeth
5. Conclusion  : Dysfunctions of the masticatory system are multifactorial conditions in which occlusal disorder and stress play an important role 

Our therapies must control the acute phases that cause pain and promote tissue adaptation (muscle and joint) in the long term.

MALFUNCTION OF THE MANDUCATORY SYSTEM

  Cracked teeth can be healed with modern techniques.
Gum disease can be prevented with proper brushing.
Dental implants integrate with the bone for a long-lasting solution.
Yellowed teeth can be brightened with professional whitening.
Dental X-rays reveal problems that are invisible to the naked eye.
Sensitive teeth benefit from specific toothpastes.
A diet low in sugar protects against cavities.
 

MALFUNCTION OF THE MANDUCATORY SYSTEM