Occlusion

The main dental occlusion functions are:

Masticatory Function: is defined by the dental arches, tongue, and zygomatic bone movements. The contact between them should be well distributed, harmonious, and atraumatic. This prevents excessive pressure on a specific area or outside the limits.

Phonetic Function: This function activates various muscles.

Deglutition Function: For perfect deglutition (swallowing), stable and synchronised contact is necessary and also a balance between the mandible muscles.

TMJ syndrome is a set of disorders that include posture and are caused by dental occlusion. It is called Temporomandibular Joint Disorder.

Main symptoms and signs of TMJ disorders

Sleep apnoea, trouble sleeping, snoring, pain in the facial muscles, vertigo, a buzzing sensation in the ear, changes in facial expression and twitches, headaches, posture alterations, anxiety, depression, loss of balance, and unexplainable falls. There are popping noises in the maxilla, which might also become stuck. The person may wake up with a migraine after a night of teeth grinding.

How is TMJ diagnosed?

The above-mentioned symptoms can be related to other causes, hence, it is not easy to obtain an exact diagnosis regarding these disorders. They are not always well-defined and stable.

  • Medical History: Obtaining the health records of a patient is the first step. The information provided by the patient and his/her family will help to make the right diagnosis.
  • Examination: Using a plumb line will help to clearly detect abnormal spine curvatures. Observing occlusal patterns is extremely important as well as examining walking and the limbs.
  • Additional Tests for Diagnosis Purposes: Orthodontics uses study models and photos of the patient. For measuring dental occlusion, a piece of carbon-paper-like material is used for the patient to bite down on.

A front and profile teleradiography is also very important. The 3D CAT scan will show the skull base. Graphic recordings (kinesiograph) are used to analyse the opening/closing paths of jaw movements. Subsequently, this data will be monitored and sent in a computer-readable format. Other exams include hip mobility tests and others that make the patient walk with eyes closed and arms extended. This provides useful information to diagnose occlusal causes that lead to changes in posture.

Diagnosing Temporomandibular Joint Disorder

The diagnosis includes all the exams, examination, medical history, and tests. It should describe the disorder as well as the related causes.

How is TMJ treated in dentistry?

  • Occlusal Equilibration: In this procedure, the enamel of the teeth is re-shaped in order to improve occlusal function.
  • Orthodontics: Treatments to correct the positioning of the teeth in the dental arches.
  • Prosthesis: Removable or fixed prostheses enable occlusal restoration, increase vertical dimension, and corrects or modifies dental arch curvature. One example is the occlusal mouth guard, commonly called a mouth guard. This device is used during the night time to prevent teeth grinding. It has a clear colour and is made of acrylic.

Surgery: By removing one or more teeth, it is possible to correct the patient’s bite directly. In the case of severe dental misalignment, orthognathic surgery is frequently used.

Medical Reference- Reviewed by VitaCentre Dental Clinic Staff and Dra. Filomena  Santos in July 29, 2022

References / Bibliography:
  1. Zarb G.A., Carlsson G.E.. – Temporomandibular Joint – Function and Dysfunction. Munksgaard, Copenhagen, Denmark, 1979.
  2. Rocabado M.J.- “Bio Mechanical Relationship of the Cranial Cervical and Hyoid Regions”. The Journal of Craniomandibular Practice, Vol. I, No.1, 1983.
  3. Posselt. T U. – Physiologie de L`Occlusion et Réhabilitation. Ed. Julien Prélat, 1968.
  4. Okeson J.P. – Management of Temporomandibular Disorders.