TMJ Pathology and Diagnosis Flashcards
what are the congenital and developmental disorders
- aplasia
- hypoplasia
- hyperplasia
- neoplasia
what is aplasia
faulty or incomplete development of the cranial bones or mandible
what is the most common developmental defect
lack of condylar growth
aplasia can be ___ or _____
unilateral or bilateral
what is often affected in aplasia
auditory apparatus
is aplasia more severe than hypoplasia
yes
what may occur with aplasia
occlusal shift and deviation on opening
- rare
what is the tx of condylar aplasia
- osteoplasty
- correction of malocclusion
- other surgical treatment possible depending on function and esthetics
what is hypoplasia
- incomplete development/underdevelopment of the cranial bones or the mandible
- growth is normal but proportionately reduced and less severe than in aplasia
what type of condition is hypoplasia
congenital or acquired (Treacher-Collins)
condylar hypoplasia can be secondary to:
trauma such as a fracture
what are the facial features in treacher collins syndrome: mandibular dysostosis
- downward slanting eyes
- notched lower eyelids
- underdeveloped midface
- deafness
mandibular hypoplasia (retrognathia) is a high risk for:
obstructive sleep apnea
condylar hypoplasia is ___ or ____
unilateral or bilateral
describe the congenital condylar hypoplasia
- idiopathic
- early onset
describe the acquired condylar hypoplasia
- forceps deliveries
- trauma especially after jaw fracture
- radiation
- infection
- circulatory disorder
- endocrine disorders
in condylar hyoplasia growth is normal but:
proportionately reduced and less severe than in aplasia
condylar hypoplasia can be secondary to:
trauma
what are the clinical symptoms of condylar hypoplasia if unilateral
- facial asymmetry
- limitation of lateral excursion
- mandibular midline shift
describe hyperplasia
- overdevelopment of cranial bones or mandible
- congenital or acquired
- non neoplastic increase in the number of normal cells
- localized: condylar hyperplasia
what is manidbular prognathism
- excessive size of mandible causing protrusion of chin but normal condyle size, shape, and function
what is the tx for hyperplasia
- LeForte I Osteotomy
- Bilateral Sagittal Osteotomy
- Chin Augmentaiton
in condylay hyperplasia if unilateral growth it will cause:
- a progressive crossbite on the contralateral side
- open bite in adults
what are the treatments for condylar hyperplasia
- leave alone
- wait until after mandibular growth is completed
- orthognathic surgery and possible osteotomy of enlarged condyle
- orthodontics
- symptomatic care
coronoid impingement may result from:
benign overgrowth of the coronoid process
coronoid hyperplasia may result in:
limited jaw opening
coronoid hyperplasia is visible on:
panorex, CBCT, MDCT, or MRI
what is neoplasia
- benign, malignant or metastatic from a distant site
- uncontrolled growth of abnormal tissue
- rare as an underlying cause of TMD
_____ of malignant neoplasias (breast, prostate, lung cancers) metastasize to the mandible
1%
neoplasia can affect:
condyle (osteoma, fibrous dysplasia, chondrosarcoma, benign giant cell tumor)
when do osteochondromas occur
in young adults (30 y/o) but also appear during middle age or later (greater than or equal to 50 yo)
what bones are susceptible to single or multiple osteochondritic lesions
bones that form from a cartilage anlagen
when do osteochondromas present
remains asymptomatic until they become large enough to interfere with mandibular function or cause a shift in the midline and malocclusion
neoplasia is rare in _____ but more common in ______
condyle;ramus
describe benign neoplasias
does not usually destroy bony margins
describe malignant neoplasias
usually destroys bony margins - examine cortical outline of mandible on pano
what carcinomas should be considered with neoplasias
parotid and regional carcinomas
what are hypermobility disorders
- 2 typs
- the 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 or by the clinician
what is subluxation
- partial or incomplete condylar dislocation during wide mouth opening but the patient can close voluntarily
- usually accompanies by a joint sound (soft pop or click)
- may result from anatomical diffrence, habit or trauma
how is subluxation diagnosed
- normal translation beyond eminence which does not lead to open lock (luxation) and condyle can return to mandibular fossa voluntarily
- soft pop at maximum opening
- deviation to opposite side (if unilateral)
- excessive translation on opening (max opening in >60mm)
what is the tx for subluxation
- retruded opening exercises
- control yawn with hand under chin; avoid bid macs, cut up apples and fruits into small pieces
- avoid prolonged mouth opening at dental appt - this can cause an open lock
- manage muscle hyperactivity
- eminectomy (surgical reduction of articular eminence if steep)
what is another name for the dislocation of condyle
luxation, open lock
describe the dislocation of the condyle
- condyle is forcibly moved beyond the articular eminence
- unable to return to a closed position voluntarily
- may be caused by yawning, dental appt, or truama
- sudden open lock of jaw
how is luxation, open lock (dislocation of condyle) diagnosed
- inability to close the mouth without a specific manipulative maneuver
- radiograph reveals that condyle translates well beyond the eminence
- the dislocation may be momentary or prolonged
- pain may accompany dislocation and persist afterwards
how is luxation, open lock (dislocation of the condyle) treated
- seat the pt upright
- ask pt to relax the jaw muscles
- apply digitial pressure to move mandible in inferior and posterior direction. requires significant force. Call oral surgeon in clinic if available
- rx: NSAIDs or muscle relaxants for pain
what are the types of ankylosis
- bony
- fibrous
- intr articular
- extra articular
what is TMJ ankylosis
fibrous or bony fusion between the mandibular condyle and fossa, which is usually traumatically causede by condyle fracture
what could ankylosis also be caused by
infections, degenerative diseases, injection of corticosteroids, forceps delivery and complications of TMJ surgery
if there is right TMJ ankylosis, restricted mandibular movement with deflection to ________ side on opening
affected side
what is best for detecting boney ankylosis
CBCT or MDCT
what is ordered to detect fibrous ankylosis
MRI
ankylosis usually develops at what age
before the age of 10 but could develop at any age
ankylosis patients usually present with:
progressive limitation of mouth opening, facial deformity, and obstructive sleep apnea syndrome
ankylosis may be associated with:
trauma
what is the clinical exam for anklyosis
- firm, unyielding restriction due to either intra-artciular fibrous or bony ankylosis
- not associated with pain
- cannot clinically differentiate between this condition and other disorders causing restriction of mouth opening
- may need MRI to r/o anterior disc displacement or myospasm, or exploratory arthroscopy
what is the dx of anklyosis
- limitation of opening
- marked deviation to affected side
- marked limitation lateral movement to opposite side (if unilateral)
- hard end feel when stretching patient to maximum opening
- absence of pain
- CBCT or pano may aid in dx but not always. MRI may show soft tissue ankylosis
- MDCT is best to show bony ankylosis
imaging of fibrous anklyosis reveals:
absence of ipsilateral condylar translation on opening but disc space is seen
- MRI is needed for dx
describe intra capsular anklyosis
- immobilization location within the joint
describe the extracapsular anklyosis
rigidity of periarticular tissues (surrounding the joint) resulting in joint stiffness or immobilization
what is the etiology of ankylosis
- abnormal intrauterine development
- birth injury or fractures
- chin trauma (posterior)
- malar- zygomatic fractures
- congenital syphilis
- inflammation or speticemia
- metastatic malignancies
- radiation treatment
what are the txs for anklyosis
- range of motion exercises
- therabite
- physical therapy
- surgery
what is the surgical proceudre for ankylosis
surgical micro scissors placed through cannula to cut fibrous band in lateral capsular adhesion
