TmJ ExaminationMohammad MortazaviMehdi Dehghan

Anatomy Of Tmj Epidemiology Of TMD Etiology Of Tmd Assessment Some Temporomandibular Disorders

Index

Anatomy Of TmjThe TMJ articulation is a joint that is capable of hinge-typemovements and gliding movements. The bony componentsare enclosed and connected by a fibrous capsule. Themandibular condyle forms the lower part of the bony jointand is generally elliptical, although variations in shape arecommon.The articulation is formed by the mandibularcondyle occupying a hollow in the temporal bone

Anatomy Of Tmj

Articular DiscA fibrocartilage made up primarily of dense collagen of variable thickness and referred to as a disc occupies the space between the condyle and mandibular fossa

Retrodiscal TissueA mass of soft tissue occupies the space behind the disc andcondyle. It is often referred to as the posterior attachment.The posterior attachment is a loosely organized system ofcollagen fibers, branching elastic fibers, fat, blood and lymphvessels, and nerves. Synovium covers the superior and inferiorsurfaces

Temporomandibular Ligaments• Capsular Ligament

• Lateral Temporomandibular Ligament

• Accessory Ligaments

Capsular LigamentThe capsular ligament is a thin inelastic fibrous connective tissue envelope that attaches to the margins of the articularsurfaces The fibers are oriented vertically and donot restrain joint movements. The medial capsule is composed of loose areolar connective tissue. The capsule and the lateral discal ligament join and attach to the lateral aspect of the neck of the condyle

Lateral Temporomandibular Ligamentseparated from it by dissection. Its fibers pass obliquely frombone lateral to the articular tubercle in a posterior and inferiordirection and insert in a narrower area below and behindthe lateral pole of the condylethis ligament was identified as an oblique band from thecondylar neck to the anterosuperior region on the eminenceand as a horizontal band from the lateral condylar pole toan anterior attachment of the eminence.A recent studywas unable to confirm a distinct structure separate from thecapsule.

Accessory LigamentsThe sphenomandibular ligament arises from the sphenoidbone and inserts on the medial aspect of the mandible at thelingula. It is not considered to limit or affect mandibularmovement. The stylomandibular ligament extends from thestyloid process to the deep fascia of the medial pterygoidmuscle. It is thought to become tense during protrusivemovement of the mandible and may contribute to limitingprotrusive movement.

Muscles of Mastication

Between 65 and 85% of people in the United States experienceone or more symptoms of TMD during their lives.Approximately 12% experience prolonged pain or disabilitythat results in chronic symptoms. Although the prevalenceof one or more signs of mandibular pain and dysfunction ishigh in the population, only about 5 to 7% have symptomssevere enough to require treatment.

TMD patients are similar to headache and back pain patients with respect to disability, psychosocial profile, pain intensity,hronicity,and frequency. The lower prevalence of TMD signs andsymptoms in older age groups supports the probability that asignificant portion of TMDs are self-limiting.

Epidemiology

The lack of a clear single cause of TMDs has resulted inthe proposal of a multifactorial etiology.Multiple factors come together contributing to the initiation, aggravation, and/or perpetuation:1. Parafunctional habits (eg, nocturnal bruxing, toothclenching, lip or cheek biting)2. Emotional distress3. Acute trauma to the jaw4. Trauma from hyperextension (eg, dental procedures,oral intubations for general anesthesia, yawning,hyperextension associated with cervical trauma)5. Instability of maxillomandibular relationships6. Laxity of the joint7. Comorbidity of other rheumatic or musculoskeletaldisorders8. Poor general health and an unhealthy lifestyle

Etiology

In most cases, the correct diagnostic classification can be reached by using the history and examination findings.Diagnostic imaging is of value in selected conditions but not as a routine part of a standard assessment. Diagnostic imaging can increase accuracy in the detection of internal derangements and abnormalities of articular bone History Range of Mandibular Movement Physical Examination:

◦ Palpation of the TMJ◦ Palpation of Masticatory Muscles Palpation of Cervical Muscles

Tmj Noise Assessment of Parafunctional Habits Diagnostic Imaging

Assessment

Assessment Table

QUESTIONS TO BE ASKED: Do you have pain in the face,front of ear and the temple area? Do you get headaches , earaches , neckache , or cheek pain? When is the pain at its worst ? Do you experience pain when using the jaw? Do you experience pain in the teeth? Do you experience joint noises when moving your jaw or chewing? Does your jaw ever lock or get stuck? Does your jaw motion feel restricted? Have you had any jaw injury? Have you had treatment for jaw symptoms? if so , what was the

effect? Do you have any other muscle , bone , or joint problem such as

arthritis?

History

Checklist

Range of Mandibular Movement

The maximum opening distance between the incisal edges of upper and lower incisor is measured using scale , Boley gauge or rulerNormal opening – 40 to 55 mmNormal opening can also be estimated by patient’s own fingerNormal : three finger end on endTwo finger opening reveals reduction in opening but not necessarily reduction in functionOne finger opening indicates reduced function

Range of Mandibular Movement

Normal lateral range of movement is >7mmMeasurements are made with teeth slightly seperated,measuring the displacement of lower midline from maxillary midline.Any condition (tumor, muscle spasm, fracture, ankylosis,displaced meniscus) that prevents the normal translation of one condyle will not prevent the contralateral condyle fromsliding forward normally . The result is deviation of the chintoward the affected side .

Palpation of the pretragus area; the lateral aspect of the temporomandibular joint (TMJ).

Intra-auricular palpation; the posterior aspect of the TMJ

Palpation of the massetermuscles

Bimanual palpation of the masseter muscle

Palpation of the lateral pterygoidmuscle

Palpation of the medial pterygoid muscle

Palpation of the temporalis muscle

Palpation of the sternocleidomastoid muscle.

Auscultate TMJ noises

It is difficult to determine the presence of active oral habits,and only indirect means are generally available. Patients areoften unaware of tooth clenching or other behaviors contributingto jaw hyperactivity while awake. Self-report, monitoringdaytime jaw activity and tooth position, and reportsby sleeping partners of tooth-grinding noises are helpful.Assessing tooth wear, soft tissue changes (lip or cheekchewing, an accentuated occlusal line, and scalloped tongueborders), and hypertrophic jaw-closing muscles may suggesthyperactivity.

Assessment of Parafunctional Habits

TMJs can be examined by using plain-film radiography,tomography, arthrography, CT, MRI, single-photon emissioncomputed tomography, and radioisotope scanningMRI has become the imaging method ofchoice to assess disc form and position.

Diagnostic Imaging

Disc displacement with reduction

Symptoms Clicking or popping noise in TMJ May feel “catching” in TMJ Signs Reciprocal click May have deviation in active vertical mandibular range ofmotion and/or in protrusionNo restriction in active vertical mandibular range motion

Temporomandibular Disorders

With Reduction

Tmj Noise: Reciprocal click opening click

Anterior Disc Displacement

Disc displacement without reduction (Closedlock)

SymptomsHistory of clicking or popping noise in TMJ Limited mandibular range of motion Signs Signs No TMJ soundsRestriction in active vertical mandibular range motion andlaterotrusionMay have deflection in active vertical mandibular range of motion and/or in protrusion

Temporomandibular Disorders

Without Reduction

Tmj Nosie:

No click Possibly crepitus

Anterior Disc Displacement

Myalgia Symptoms Pain in localized area of one masticatory muscle (usually masseter or temporalis) Fatigue with chewing Signs Tender muscles upon palpation Sometimes limited active vertical range of mandibular motion

Temporomandibular Disorders

Subluxation/dislocation (Open lock) Symptoms Jaw “catches” open when yawning or opening mouth wide (if gets stuck open then dislocation) Pain in TMJ when jaw gets stuck Loud pop when opening wide SignsExcessive active mandibular vertical range of motionEminence popResidual tenderness in TMJ upon palpation if recent episode

Temporomandibular Disorders

Capsulitis/arthritis SymptomsPain in TMJ or in front of earPain exacerbated by jaw functionMay have limited mandibular function secondary to pain SignsTMJ tender to palpationTMJ pain worsened upon clenchingLimited active mandibular range of motion, laterotrusion,protrusion

Temporomandibular Disorders