TMJ Pathology & Diagnosis First Lecture

Question 1

Congenital or Developmental
Disorders
(4)

Answer 1

Aplasia
Hypoplasia
Hyperplasia
Neoplasia

Question 2

Aplasia
 What is it?
 — is the most common
developmental defect.
 Unilateral or bilateral?
 — is often affected
 (2) on opening may occur
 Rare
 More SEVERE than — !

Answer 2

Faulty or incomplete development of the cranial
bones or mandible.
Lack of condylar growth
Either
Auditory apparatus (i.e. Pinna of
ear deformed)
Occlusal shift & deviation
Hypoplasia

Question 3

Developmental/Congenital
Anomalies affecting TMJ
 Aplasia-

Answer 3

Lack of condylar growth is the
most common developmental defect.
Occlusal shift & deviation on opening may
occur. Rare

Question 4

Treatment of
Condylar Aplasia
(3)

Answer 4

Osteoplasty
Correction of malocclusion
Other surgical treatment possible
depending on function and
esthetics

Question 5

Hypoplasia
(4)

Answer 5

 Incomplete development/underdevelopment of the cranial bones or the
mandible.
 Congenital or acquired (i.e. Treacher-Collins syndrome).
 Growth is normal but proportionately reduced & less severe than in
aplasia
 Condylar hypoplasia can be secondary to trauma.

Question 6

Treacher-Collins syndrome:
mandibulofacial dysostosis
(4)

Answer 6

1. Downward-slanting eyes
2. Notched lower eyelids
3. Underdeveloped midface
4. Deafness

Question 7

Mandibular Hypoplasia:
High risk for

Answer 7

obstructive sleep
apnea

Question 8

Mandibular Hypoplasia
Post-treatment with

Answer 8

mandibular advancement
surgery (bilateral sagittal
split osteotomy)

Question 9

skipped
Condylar Hypoplasia
 (2)
 Congenital: (2)
 Acquired: (6)

Answer 9

Unilateral or bilateral

idiopathic, early onset

forceps deliveries, trauma
especially after jaw fracture, radiation,
infection, circulatory disorder, endocrine
disorders

Question 10

Condylar Hypoplasia
What is it?
Can be secondary to…

Answer 10

 Growth is normal but proportionately reduced & less severe than in
aplasia
 Condylar hypoplasia can be secondary to trauma.
 Pt. fractured R. condyle at age 6. Panorex- age 15

Question 11

Condylar
Hypoplasia
Clinical
Symptoms
 If unilateral:
(3)

Answer 11

 Facial asymmetry
 Limitation of lateral
excursion
 Mandibular midline
shift

Question 12

Hyperplasia
What is it?
(2)?
— increase in the number of
normal cells.
Localized:
Mandibular —

Answer 12

Overdevelopment of cranial bones or mandible.
Congenital or acquired.
Non-neoplastic
condylar hyperplasia
prognathism

Question 13

Mandibular prognathism –

Answer 13

excessive size of
mandible causing protrusion of chin but normal
condyle size, shape, & function

Question 14

Mandibular Hyperplasia
tx (3)

Answer 14

LeForte I Osteotomy
Bilateral Sagittal osteotomy
Chin Augmentation

Question 15

Condylar Hyperplasia
Clinical Symptoms
If Unilateral growth, it will cause:
(2)

Answer 15

1. A progressive crossbite on the
   contralateral side
2. Open bite in adults

Question 16

Treatment of Condylar
Hyperplasia
(5)

Answer 16

 Leave alone
 Wait until after mandibular growth is completed
 Orthognathic surgery & possible osteotomy of enlarged
condyle
 Orthodontics
 Symptomatic care

Question 17

Coronoid Hyperplasia
(3)

Answer 17

 Coronoid Impingement may result from
benign overgrowth of the coronoid
process
 May result in limited jaw opening
 Visible on Panorex, CBCT, MDCT or MRI

Question 18

Unilateral Condylar Hyperplasia
creating malocclusion
Transpharyngeal projection:

Answer 18

Condylar head is enlarged,
and the neck is thick.

Question 19

Neoplasia
What is it?

RARE as an underlying
cause of —.
–% of malignant
neoplasias (breast,
prostate, lung
cancers)metastasize to
the mandible
can affect …

Answer 19

Benign, malignant, or
metastatic from a
distant site.
Uncontrolled growth of
abnormal tissue.
TMD
1

condyle (I.e.
osteoma, fibrous
dysplasia,
chondrosarcoma, benign
giant cell tumor)

Question 20

OSTEOCHONDROMA
R L
Benign, Solitary Osteochondromas (OCs) arise in response
to an event (e.g. trauma, X-radiation) [1] rather than as
a true neoplasm. Typically, OCs represent –% of all
bone tumors and ~–% of benign bone tumors

Answer 20

10-15
35

Question 21

OSTEOCHONDROMA
* OCs generally occur in …
* Bones that form from a — are susceptible to single or
multiple osteochondritic lesions.
* This species of bone tumor frequently remains
asymptomatic until they become large enough
to interfere with …

Answer 21

young adults (~30 y/o),
but also appear during middle age or later
(~≥ 50y/o).

cartilage anlagen
(e.g., mandible)

mandibular function (i.e.
opening, lateral excursion) or cause a shift in
the midline & malocclusion.

Question 22

Neoplasia
 Rare in — but more
common in —
 Benign:
 Malignant:
 Consider (2)

Answer 22

condyle, ramus
does not usually
destroy bony margins
Usually destroys
bony margins- Examine cortical
outline of mandible on Panorex
parotid and regional
carcinomas

Question 23

Hypermobility Disorders: 2 types
of TMJ Dislocations:
Hypermobility disorders include two types of TMJ dislocations
in which the

Answer 23

disc-condyle complex is positioned anterior to the
articular eminence and is unable to return to a closed position
without a specific maneuver by the patient (i.e., subluxation or
partial dislocation) or by the clinician

Question 24

Subluxation
(3)

Answer 24

Partial or incomplete condylar
dislocation during wide mouth opening
but the patient can close voluntarily
Usually accompanied by a joint sound
(soft pop or click)
May result from anatomical
difference , habit, or trauma

Question 25

Diagnosis of Subluxation
(4)

Answer 25

 Normal translation beyond eminence which
does not lead to open lock (luxation) & condyle
can return to mandibular fossa voluntarily.
 Soft pop at maximum opening
 Deviation to opposite side (if unilateral)
 Excessive translation on opening

Question 26

Treatment of Subluxation
(5)

Answer 26

1. Retruded opening exercises
2. Control yawn with hand under chin; Avoid Big
   Macs, cut up apples and fruits into small pieces
3. AVOID prolonged mouth opening at DENTAL APPT.-
   this can cause an open lock.
4. Manage muscle hyperactivity
5. Eminectomy (surgical reduction of articular
   eminence)

Question 27

Dislocation of Condyle
(Luxation, open lock)
(4)

Answer 27

 Condyle is forcibly moved beyond the articular
eminence
 Unable to return to a closed position voluntarily
 May be caused by yawning, dental appt. or
trauma
 Sudden open lock of jaw

Question 28

Diagnosis of Dislocation of Condyle
(Luxation, open lock)
1. What is it
2. Radiograph reveals
3. The dislocation may be
4. — may accompany dislocation and persist
afterwards.

Answer 28

Inability to close the mouth without a specific
manipulative maneuver
that condyle translates
well beyond the eminence
momentary or prolonged
Pain

Question 29

Treatment of Dislocation of Condyle
(Luxation, open lock)
(4)

Answer 29

1. Seat the patient upright.
2. Ask pt to relax the jaw muscles.
3. Apply digital pressure to move mandible in inferior &
   posterior direction. Requires significant force. Call
   ORAL SURGEON in clinic if available.
4. Rx: NSAIDs or Muscle Relaxants for pain

Question 30

Types of Ankylosis
(4)

Answer 30

1. Bony
2. Fibrous
3. Intra-articular
4. Extra-articular

Question 31

Ankylosis
(2)

Answer 31

 Temporomandibular joint ankylosis represents
fibrous or bony fusion between the mandibular
condyle and fossa, which is
usually traumatically caused by condyle fracture.
(1)
 It could also be caused by infections, degenerative
diseases, injection of corticosteroids, forceps
delivery and complications of TMJ surgery

Question 32

Right TMJ
Ankylosis

 — is best for detecting boney
ankylosis
 — is ordered to detect fibrous ankylosis

Answer 32

Restricted mandibular movement with
deflection to the affected side on opening
CBCT or MDCT
MRI

Question 33

ANKYLOSIS
Usually develops before age of –,
however, it could develop at any
age.
Patients usually present with
(3)
May be associated with —

Answer 33

10
progressive limitation of mouth
opening, facial deformity, and
obstructive sleep apnea syndrome.
TRAUMA

Question 34

Bony Ankylosis of R. Condyle with
obliteration of disc space & no condylar
translation :
R L
Condyle is
Fused to

Answer 34

glenoid
fossa

Question 35

AnkylosisClinical
Exam
Firm, unyielding restriction due to either
Not associated with —
Cannot clinically differentiate between
this condition and other disorders
causing restriction of mouth opening.
May need — to r/o anterior disc
displacement or myospasm, or
exploratory —

Answer 35

intra-articular fibrous or bony ankylosis
pain
MRI, arthroscopy

Question 36

Diagnosis
of
Ankylosis
Limitation of —
Marked deviation to — side
Marked limited lateral movement to —
side (if unilateral)
—end feel when stretching patient to
maximum opening
Pain?
— may aid in diagnosis but not
always. — may show soft tissue ankylosis.

Answer 36

opening
affected
opposite
Hard
No pain
CBCT or Panorex, MRI

Question 37

Fibrous
Ankylosis
 Imaging reveals …
 — is needed for diagnosis

Answer 37

absence of
ipsilateral condylar
translation on opening but
disc space is seen

MRI

Question 38

Ankylosis
 Intracapsular:

 Extracapsular:

Answer 38

immobilization located
within the joint

rigidity
of periarticular tissues
(surrounding the joint)
resulting in joint
stiffness or
immobilization

Question 39

Etiology of Ankylosis
(8)

Answer 39

 Abnormal intrauterine development
 Birth injury or fractures
 Chin trauma (posterior)
 Malar-zygomatic fractures
 Congenital syphilis
 Inflammation or septicemia
 Metastatic malignancies
 Radiation treatment

Question 40

Treatment of Ankylosis
(4)

Answer 40

1. Range of Motion (ROM)
   exercises
2. Therabite
3. Physical therapy
4. Surgery

Question 41

Surgical micro scissors placed
through cannula to cut

Answer 41

fibrous band in lateral
capsular adhesion