Question

Review of TMJ development, anatomy and function, their relationship to clinical
dentistry and their aspects in the management of TMJ disorders.

Q1/H1 Discuss the development of the TMJ, its unique features in terms of
structure and function and its clinical significance.
Q2/H2
Discuss the clinical findings of relevance and the different investigations
indicated for TMJ disorders.
Q3/H3 Discuss five common TMJ disorders and their management.

Answer 1

1) TMJ develops in 12 week in utero and two slit like joint cavities form inside the developing mandible and temporal bone. The growth centre is in mandibular condyle which disappeads after the attainment of maturity by an individual.

The Temporomandibular joint is formed by the bilateral synovial articulation between the articular surface of temporal bone of the skull as the roofside and the mandible at the base . Hence it is named as Temporomandibular joint.

TMJ is unique in structure due to articular disc. The disc is composed of dense fibrocartilagenous tissue that is found between the head of the mandibular condyle with the mandibular fossa of temporal bone. This is the second joint which has articular surface .

This joint is unique in function like it is a bilateral joint that functions as one unit.

2)PAIN-

Myofacial pain dysfunction syndrome, involving the muscles of mastication , due to internal derangement.eg. Disc displacement
.Other causes include osteoarthritis of temporomandibular joint,Temporal arteritis.

Examination - Auscultation and palpating at external acoustic meatus. On disc displacement pop sound can be heard.

3)

Myofascial pain syndrome which is caused by tension, fatigue, spasm in the muscles of mastication. The treatment includes muscle relaxation , analgesic and habit modification and bite splinting.

Ankylosis of the temporomandibular joint is immobility or fusion of the joint. This condition is treated by excercises , corrective surgery and condylactomy according to the severity of disorder.

The arthritis of TMJ - Infectious arthritis, traumatic arthritis, osteoarthritis, secondary degenerative arthritis and rheumatoid arthritis . Management - Oral hygeine , corticosteroids , NSAIDs , jaw excercises.

The internal temporomandibular joint derangement is anterior misalignment or displacement of the articular disk above the condyle. Management may include analgesics, jaw rest, muscle relaxation, physical therapy, and bite splinting if required then surgery could also be opted.

Mandibular condylar hyperplasia is the accelerated growth of condyle of mandible . During active phase of hyperplasia surgery is done and after cessation of growth orthodontics performs repositioning of mandible.