Temporomandibular Joint

Temporomandibular Joint

Structure, Function, Dysfunction and Treatment

Chris Keating

Overview

Durable Can withstand 597N from women and

847N from men. Moved very often

Phonation, mastication, swallowing, facial expression

Anatomy-Bone

Zygomatic Arch

Sphenoid Temporal Mandible

Head

Anatomy- Muscles

Masseter elevates and protrudes

mandible

Temporal elevates and retracts

mandible

Innervation:

Mandibular (V3)

Anatomy- Muscles

Lateral Pterygoid Bilaterally- protraction Unilaterally-

contralateral swing

Medial Pterygoid Elevation, protrusion,

unilaterally: grinding

Innervation: Mandibular (V3)

Digastric-opening

Anatomy- Nerves

Auriculotemporal (sensory) MMA*

Inferior alveolar (sensory) mylohyoid nerve-

mylohyoid m. Lingual (sensory) Buccal (sensory) muscular branches (to

muscles of mastication)Chorda tympani

Anatomy- Arterial Supply

Deep Auricular Anterior Tympanic Middle Meningeal Maxillary External carotid

Anatomy- Ligaments

Sphenomandibular

Stylomandibular

-limits protrusion movement

Joint capsule

Lateral ligament

-limits depression, posterior movement

Anatomy- The 4 Joints

Synovial joint Articular disc

(fibrocartilage) Two joint cavities

(upper cavity) protrusion/retrusion

(lower cavity) hinge motion

Extracapsular ligaments

Anatomy- Joint Surfaces

Glenoid fossa formed by Posterior Glenoid Spine and Articular Eminence

Mandibular head of the mandible (medial and lateral poles)

Fibrocartilage Traebecular Bone (thin/translucent)

Deep perpendicular Superficial parallel

Biomechanics

Disk is a biconcave (Bow Tie/Danish)

Convex mandible Convex glenoid fossa Lower joint- hinge Upper joint- gliding Increases congruency of

boney structures Pressure mainly on center

of disk CPP- Teeth tightly clinched Capsular pattern- Limits in

mouth opening

Capsule

Highly vascular and innervated

Fiber runs from temporal to mandible

Very strong and tight in lateral/inferior fibers

Loose and Thin superior/anterior/medial fibers Prone to anterior

dislocation due to capsule weakness and incongruence

Articular Disk

Collegen, GAGs, Elastin *changes may occur in proportion Anterior and Posterior are innervated and vascular Middle load bearing portion avascular and not innervated Maintains congruency

Bilaminar retrodiskal pad*

Disk attachments

Medial and laterally to the mandible- firmly Anteriorly to capsule/lateral pterygoid

tendon (restricting posterior motion) Posterior has 2 portions separated by fat

pad Superior attaches to SGF and is elastic and

allows for disk movement during mouth opening Inferior to the neck of the mandible and is

nonelastic

Movement

Movement and Measurement

Protrusion and Retrusion strictly gliding motion without rotation (6-9cm, 3cm)

Depression/Elevation gliding and rotation simultaneously (2 fingers Proximal IP)

Lateral Deviation- rotation on ipsilateral side with translation on contralateral side (1 central incisor)

Dysfunction

Degenerative Conditions Internal Derangement Inflammation Capsular Fibrosis Osseous Mobility Conditions Posture Pulmonary Issues

Dysfunction- Degenerative

OA- One TMJ RA- Both TMJ Severe internal derangements lead to higher

chances of degenerative changes Tanaka, 2000

Degeneration of the TMJ is not a normal part of aging and degeneration is not necessarily associated with symptoms or dysfunction. Nannmark, 1990 and Leeuw, 1996

Dysfunction- Derangement

Dysfunction- Derangement

Clicking or popping indicates severity of derangement (reciprocal click)

Mainly anterior due to structural weakness Hypertrophy of lateral pterygoid Overstretching of retrodiskel tissue Sound is mandible moving in and out of disk

with reduction Without reduction there is a mechanical

blocking of mouth opening

Dysfunction- Inflammation

Rheumatoid Arthritis- Systemic Gout- Urate crystals Psoriatic Arthritis- Joint pain Ankylosing Spondylitis- Spinal pain Systemic lupus Erythematosus- Autoimmune

disease ***Capsular Fibrosis can be result of long term

inflammation, trauma or immobilization***

Dysfunction- Osseous Mobility

Hypermobility due to many causes but can result in endrange sticking or feeling of jaw going out of place.

Palpation of lateral pole reveals large indentation

Deviation to the contralateral side Dislocation creates same symptoms No significant difference in occurrence

between pt with or without symptoms of TMJD

Dysfunction- Posture

Signs and symptoms of cervical spine injury parallel that of TMJ s/s

Postural stresses that injure the c-s also apply stresses to the TMJ (OA joint, subocciptial, stylohyoid, digastric)

Proper screening of TMJ can limit progression of dysfunctions

Pulmonary issues/distress can promote a forward head posture recreating postural stresses. (Restrictive Disease, Chronic use of assessory muscles)

Patient History

Is there pain on opening or closing?

Pain with eating? What movements cause

pain? Mouth breather?

May lead to changes in internal pressure due to tongue placement which in turn alters external pressure (buccinator/orbicularis oris).

Leading to balance problem in the neck

Patient History

Any clicking? (one or two?) Has your jaw or mouth ever locked? Oral habits? Teeth grinder (Bruxism)? Teeth sensitivity? Any difficulty swallowing? Ear problems? Headaches? Voice changes? Felt dizzy or faint? Dental splints? When is the last time they saw a dentist?

Observation

Cervical posture Bite (under, over, cross, mal) Profile Tongue movement Bony contours

Examination

AROM (neck, mouth) PROM- rarely done MMT Compensations? Abnormalities (C-type, deviation) Chin movement normally towards painful

joint (Early-spasm of pterygoid :: Late- Capsular)

Palpation Functionality

Special Tests

Imaging- X-ray, MRI Reflexes (jaw) Dermatome Cranial nerve testing Auscultation

Crepitus (DJD) Clicking (Derangement)

Chvostek test Tap parotid gland under masseter muscle + if facial muscles twitch

Treatment-Initial

Splints Modalities (Heat, Ice, Laser*-more

effective?/Estim-TENS, US T/NT) Muscle Techniques

Relaxation, Strengthening, Stretching, Massage Joint mobilization (one joint at a time)

Caudal, Lateral, Medial, Posterior, Anterior

Treatment- Surgery

Arthroscopic Lateral release, manipulation, injection

“lysis and levage” Walker repair reported as 86%

successful Very effective in conjunction with PT* Significant decreases in pain and

increases in function* Therapy started within 24 post-op

Stage I- first 2 weeks post-surgery

Ice pack Postural correction Resting tongue position instruction Active therapeutic exercises with tongue Active controlled condylar rotation

Stage II- 3–6 weeks post-surgery

Moist hot pack Ultrasound Postural correction Gentle periauricular massage Active to assistive exercises Active vertical and lateral mandibular movement Isometric exercises Gentle stretching exercises Home exercise program

Stage III- after 7 weeks

Myofascial release technique for masticatory muscles and neck muscles

Intrinsic condylar mobilization Rhythmic stabilization technique

Patients normally recover within 9-12wks

Reference

Clinical Management of a Patient Following Temporomandibular Joint Arthroscopy Pbys Tber. 1992; 72:355-3G4.1

Walker Repair of the Temporomandibular Joint 2007 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 65:1958-1962, 2007

A Systematic Review of the Effectiveness of Exercise, Manual Therapy, Electrotherapy, Relaxation Training, and Biofeedback in the Management of Temporomandibular Disorder Physical Therapy . Volume 86 . Number 7 . July 2006

The effect of physiotherapy on post-temporomandibular joint surgery patients D. W. OH, K. S. KIM & G. W. LEE Physiotherapy Section, Department of Rehabilitation Medicine, Yongdong

Severance Hospital, Seoul, South Korea Arthroscopic management of a temporomandibular closed lock

Australian dental journal 1998:43;(5):301-304 http://www.dentistrytoday.net/ME2/Segments/Publications http://www.activebodyclinic.com/common_TMJ_Thesis.html Orthopedic Physical Assessment

4th, Magee Joint Structure and Function

4th, Levangie and Norkin Grant’s Atlas of Anatomy

11th, Agur and Dalley Essential Clinical Anatomy

3rd , Moore and Agur