ETIOLOGY

Clinical A/P Chua Ee Kiam(BDS, MDS, FAMS, Diploma in Guidance & Counselling

ETIOLOGY

Clinical A/P Chua Ee Kiam(BDS, MDS, FAMS, Diploma in Guidance & Counselling

INTRODUCTION

Disorders of the TMJ similar to other joints in the body (/)

Confusing terminology add to confusion of the etiological factors (X)

TMD became a multi-factorial etiology disorder (X)

1. Costen’s Syndrome (1934)He reinforced & established the occlusal & biomechanical approaches

2. Psychophysiological (1960-70) -the impact of physiological states and systems on psychological states and processes

3. Disc displacement (1970- 80’s)

Intra-capsular problems were clearly defined by anatomical & radiological studies

4. Current Concepts

Emotive states and their impact on persons health

CONCEPTS OF TMD

SIGNS & SYMPTOMS

1. Functional Jaw Pain2. TMJ sounds (crepitations & clicks)3. Limitation of mouth opening4. Recurrent Headache

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors Stress & bruxism Systemic conditions Abnormal growth Psychological factors Genetic / Gender factors

ETIOLOGY

Macrotrauma

- iatrogenic

[extraction of 3rd molar, intubation, long

dental procedures, yawning]

- accidental or intentional sudden force

[fights, RTA, falls]

ETIOLOGY

Macrotrauma

- 25 % had jaw trauma and 32% had iatrogenic trauma [Katzberg et al, 1980]

- 30 % had major traumatic event [Pullinger et al, 1985]

TRAUMA – DISPUTED

FRACTURED, DISLOCATED CONDYLE

Surgical fracture of condyles of Rhesus monkeys - reduced vs non-surgical closed reduction - regeneration in the latter (Walker,1960); little deformity

noted (Boyne, 1967)

Studies on trauma of the TMJ suggest remarkable adaptive properties of the entire masticatory system

Application : Some patients would like you to attribute their current jaw problems to their previous history of non-recent trauma to the oro-facial tissues

h/o Right retro-discitis and temporal tendonitis, arthroscopy

Use of Cervical traction on painful displaced TMJ disc (x)

ETIOLOGY

Macrotrauma Repetitive loading

ETIOLOGY

Repetitive loading

Destructive oral habits

[excessive chewing, hard foods, unilateralchewing, certain occupation or activities,unnatural posturing]

ETIOLOGYBiting force

- Average = 22 kg [Gibbs et al, 1986]

- Maximum = 3-5x in nocturnal bruxism

- Controlling factors

[emotional status, pain threshold, number of teeth, periodontal status]

ApplicationCan surgical disc reduction work?Can replacement of disc with plasticized materials work?

ETIOLOGY

Repetitive or Chronic loading

Muscle and joint problems had been reported

by violinists and scuba divers

[Pinto,1966; Reider, 1976]

Common to clench during weights training

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors

ETIOLOGYOCCLUSAL FACTORS/ ROLE OF OCCLUSION

1. Malocclusion

2. Bruxism

3. State of occlusion

(NWSC, Canine or Group function, Dentate vs Edentulous)

4. Occlusal Dysharmony (Muscle symmetry)

5. Unilateral Chew

6. ICP VS RCP

7. Repositioning

8. Condylar positioning

ETIOLOGY

Malocclusion

Unstable occlusion lead to muscle hyperactivity

[Olson, 1970; Moller et al, 1984; Stohler et al, 1988]

Application : Use of Jaw pulsing machines to reduce “hyperactivity”?

ETIOLOGY

Malocclusion

Occlusal contacts & chewing patterns [Gibbs et al, 1971]

Subjects with malocclusion- on mastication had shorter occlusal contacts; - and chewing patterns are irregular & less coordinated

ETIOLOGY

Malocclusion

No difference in TMD S&S between subjects with or without Ortho Tx n=402 adolescents followed up for 5 & 10 years

Egermark et al 2003

Using meta analysis–data does not indicate that Ortho tx increased prevalence of TMD

Kim et al, 2002

ETIOLOGY

MALOCCLUSIONEarly treatment of malocclusion to prevent grinding / clenching is not supported by longitudinal studies

Vanderas & Manetas Pediatr Dent, 1995

ETIOLOGY

DENTAL OCCLUSIONBody of knowledge and practice of occlusion should be taught systematically in the dental curriculum

However, occlusal adjustment (OA) is irreversible and is not usually recommended in the Tx of TMD

Non-working (balancing side) in mediotrusive position dentate patients is not an occlusal interference

ETIOLOGY

OCCLUSAL ADJUSTMENTS

Meta-analysis on Occlusal Adjustments Koh H & Robinson PG, Cochrane Database Systemic Review, 2003:

Occlusal adjustments are ineffective for treating or preventing TMDs

ETIOLOGY

STATE OF OCCLUSION

1. Non-working side contacts

- Ramfjord, 1961 claimed NWS interference were destructive in nature (X)

- Ingervall, 1972 found 85% of his sample had NWS contact on lateral excursion;

18% canine rise (/)

- Barghi & co, 1979 found no symptoms in those with NWS contacts (/)

ETIOLOGY

STATE OF OCCLUSION

2. Canine function vs Group function

Which type of occlusion reduces occlusal forces better in splints?

ETIOLOGY

STATE OF OCCLUSION

3. Dentate vs Edentulous (loss of teeth)

ETIOLOGY

4. Others

cross-bites, overjetdual bitesdifferential wearlarge RCP to ICP slides

ETIOLOGYOCCLUSAL FACTORS/ ROLE OF OCCLUSION

1. Malocclusion

2. Bruxism

3. State of occlusion

(NWSC, Canine or Group function, Dentate vs Edentulous)

4. Occlusal Dysharmony (Muscle symmetry)

5. ICP VS RCP

6. Condylar positioning

OCCLUSAL DISHARMONY

No evidence that premature contact between opposing teeth can initiate or maintain prolonged hyperactivity of jaw closing muscles (Yemm, 1976)

MPD syndrome patients were relieved of symptoms by grinding the teeth (Dawson, 1974; Ramfjord, 1983; Shore, 1976) (X)

64% of patients had improvements with mock equilibration (Goodman, 1976) (X)

Interference not the cause (La Bell et al, 2002)

ETIOLOGYOCCLUSAL FACTORS/ ROLE OF OCCLUSION

5. ICP VS RCP

More pain elicited in patients with TMD in RCP

Therapeutic position in splints

ETIOLOGY

Condylar positioning- non-concentric or concentric position

ETIOLOGY

Occlusal Factors

1. Condylar positioning

- non-concentric or concentric position

- position of centric relation [Posselt, 1951]

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors Stress & bruxism

ETIOLOGYStressIt is the disruption and disorganisation of the individual's physical and mental condition resulting from the effects of uncontrollable external events.Lundeen et al,1987 JOR 14:447

Stress is a non-specific response of the body to any demand made upon itDr Hans Seyle

ETIOLOGY

Bruxism

Static or dynamic contact or occlusion in the teeth at times other than for normal function such as mastication or swallowing.

[or clenching or nocturnal grinding]

STRESS & BRUXISM

Bruxism is thought to be a physical manifestation of an emotional problem

Stimulation of brain area associated withresponses to stress causes an increase in excitability of motor neurons of jaw-closingmuscles (Landgren, 1977)

STRESS & BRUXISM

Grinding resolves when life crises resolve

[Carlsson, 1976; Funch, 1980; Rugh, 1975, 1988]

Increased urinary levels of cathecholamines were correlated with nocturnal masseter activity

[Clark, 1980]

ETIOLOGY

Stress- High correlation between muscular pain and stressful life events

[Brooke, 1977; Lundeen, 1987; Lupton, 1969; Rugh, 1983]

- TMD patients experienced 2x more stressful events controls

[Speculand, 1984]

ETIOLOGY

Bruxism1. Psychological Input

2. Muscular Input

3. Dental Input

EMG RECORDINGS

Development of portable EMG instruments (Burgar & Rugh, 1983)

Aid in identification of oral habits due to increase in masticatory muscle activity

EMG evaluations of resting muscle activity

Patients with MPD tended to respond to stresswith greater masticatory and facial muscleactivity (Johnson, 1972, Mercuri, 1979)

IDENTIFICATION OF MUSCLE HYPERACTIVITY & ORAL HABITS

Interviews – awareness, reports by others Questionaires – oral symptoms, life-styles Pain & activity charting - insights regarding

cyclic trends Clinical examination EMG recordings

BRUXISMEffect on :-

1. Masticatory Muscles- contraction of muscles bring teeth together- which increases muscle tension- lactic acid accumulation- hypertrophy of muscle- cause splinting, trismus, contracture

ETIOLOGY

BRUXISMEffect on :- TMJ

- cause pain

- disc displacement

- bone changes

ETIOLOGY

BRUXISM

Effect on :- Teeth

- teeth are subjected to wear

- mobility of teeth

- fractured teeth and restorations

ETIOLOGY

BruxismEffect on :-Teeth

ETIOLOGY

BruxismEffect on :-

Teeth

EFFECTS OF BRUXISM ON TEETH & ORAL TISSUES

ETIOLOGY

BruxismEffect on :-

Mucosa

Association between Nocturnal Bruxism & Sleep

Bruxing is a 8 sec per event [Clarke et al, 1979]

In bruxists those with pain had more bruxing events during REM sleep [ Ware & Rugh, 1988]

Level of sustained contraction is higher in REM than non-REM sleep [Rugh & Ware, 1987]

Sleep Cycle

- In adult 80% non-REM & 20% REM sleep- REM sleep last about 5-15 mins.- complete cycle of sleep = 60-90 mins.- non-REM sleep restore body functions- REM sleep restore function of cortex & brain

ETIOLOGY

Systemic Conditions

1. Joint Laxity

2. Rheumatoid Arthritis3. Reiter’s Syndrome ("the patient can't see, can't pee and can't bend

the knee“)

4. Systemic Lupus Erythematosus

ETIOLOGYSystemic conditions

1. Joint Laxity

No association was found between intra-articular disorders and systemic hypermobility (p > 0.05).

Relationship between systemic joint laxity, TMJ hypertranslation, and intra-articular disorders.Conti PC, Miranda JE, Arauio CR; Cranio. 2000 Jul;18(3):192-7.

ETIOLOGY

Systemic conditions

1. Joint Laxity

2. Rheumatoid Arthritis

ETIOLOGY

Systemic ConditionsIn patients with systemic conditions such aspsoriasis, poly rheumatoid arthritis & Sjogren’s syndrome

- 33% had radiographic erosions of TMJ and - 54% had anterior open bite[Nordahl S et al, Acta Odont Scan 1997]

RA

Rheumatoid Arthritis - degenerative & inflammatory forms- auto immune disease - destruction of synovial tissues- rapid arthritic breakdown produces painful articularsymptoms & masticatory muscle symptoms

Psoriatic Arthritis

Pain R TMJ x 3 years; ROM 25/32mm; AOB

1 year later – flattened L>R condyles; RA

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors Stress & bruxism Systemic conditions Abnormal growth

ETIOLOGYAbnormal growth

- Enlarged condyle

- Enlarged coronoid

- Hypertrophy of masticatory muscles

- Abnormal active growth of jaw

- Tumour

ABNORMAL GROWTH

ENLARGED CORONOIDS

Past history of jaw stuck x 3 years; Jaw shifts to left on opening;Class III

Dx: Hypoplasia R condyle

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors Stress & bruxism Systemic conditions Abnormal growth Psychological factors

n=191 TMD patients Mean Age: 38.4yrs (16-65, majority 25-44) Female: Male : 3.1 : 1 Muscle Disorders : 31.4% Disc displacements : 15% Arthralgia, arthritis, arthrosis : 13% Depression : 39.8% Somatization : 47.6%

Prevalence of TMD subtypes, psychologic distress & psychosocial dysfunction in Asian patients

Yap AUJ, Chua EK et al J Orofac Pain 2003 (17) 21-8

Significant and strong correlation (r = 0.74) was observed between depression and reporting of multiple non-specific physical symptoms

Depressive symptoms in Asian TMD patients and their association with non-specific physical symptoms reporting

Yap AUJ, Chua EK & Tan KBC J Oral Pathol Med 2004; 33: 305-310

ETIOLOGY

Psychological factors

1. Chronic pain

2. Anxiety levels

3. Depression

4. Personality Profile

5. Emotional Distress

ETIOLOGY

Psychological factors1. Chronic pain

2. Anxiety levels

- 26% more anxious [Fricton, 1985]

- less tolerant of pain when anxious [Melzack, 1984]

ANXIETY (AN EMOTIONAL STATE)

Pain thresholds are lowered and pain conditions feel worse during anxiety. Anxiety may elicit a variety of oral habits.

• 26% of MPD patients were clinically anxious

[n=16; Fricton, 1985]

• 17% suffer from anxiety [Gerschman, 1987]

• 62% had major life event preceding treatment

[Marbach, 1978]

FEAR

SLEEP DEPRIVATION ANXIETY

PAIN

ETIOLOGY

Psychological factors1. Chronic pain

2. Anxiety levels

3. Depression

Lowers pain threshold and decrease patient’s

willingness to tolerate pain

Objective outcome maybe good but subjective outcome

poor

52% moderately depressed (n=368 of chronic facial

pain patients) & 18% severely depressed

[Gerschman, 1987] Hamilton Depression Scale

23% depression (n=164) [Fricton, 1985]

DEPRESSION

ETIOLOGY

Psychological factors

1. Chronic pain

2. Anxiety levels

3. Depression

4. Personality Profile

History of HA, Insomnia, difficulty breathing, tongue discomfort, pain left masseter & temporal, discomfort on palatal of upper teeth, upper teeth had descended, lower teeth shifted

RED FLAGS

1. Clinically significant anxiety or depression

2. Evidence of drug abuse3. Repeated failures with

conventional therapies4. Evidence of secondary gain5. Over dramatization of symptoms6. Inconsistent, vague or

inappropriate report of pain7. Major life events

ETIOLOGY

Psychological factors1. Chronic pain

2. Anxiety levels

3. Depression

4. Personality Profile

5. Emotional Distress

ETIOLOGY

Genetic factors

NATURE: The human genome - The sequence of the human genome(Feb 15, 1981)Looking at diseases in a new way

ETIOLOGY

Genetic factors

NATURE: The human genome - The sequence of the human genome(Feb 15, 1981)Looking at diseases in a new way

Zhifeng Zhu et al, Nature Vol. 452 24 April 2008 p 997-1002Genetic variation in human Nucleopeptide Y (NPY) – gene

that affects mood

ETIOLOGY

Gender factorsWhy women?

Bingekors K & Isaacson D European J of Pain 2004 :8, 435-450

Females are more prone to HA 3.6:1; Shoulder ache 2.6:1; Back ache >1:1 ; Arms & legs .1:1)

Females different pain system – different receptor system

Gender specific pains – Labour pains & menstrual pains are natural and second nature

Injected saline in 22 year olds males and females

During follicular phase in females -estrogens levels high

During this period, Males show up with less pain 3.5/10; females 5.5/10)

And to maintain same pain levels more infusion is needed in males.

ETIOLOGY

Macrotrauma Repetitive loading Occlusal factors Stress & bruxism Systemic conditions Abnormal growth Psychological factors Genetic / Gender factors