revision Flashcards
asymmetry:
minor: measurements: comparison: no of pts with it: most important area:
minor:
- desirable
- little inconsistencies are perceived aesthetically pleased
asymmetry of:
5 mm and below -> unnoticed
10 mm -> significant
The greater the degree of asymmetry, the more noticeable and the greater the desire for correction
34% of patients with dentofacial deformities were found to have clinically apparent facial asymmetry
most important area:
- lower area of face, reflected in the position of the chin (74%)
- then midface and then upper face
hemifacial microsomia:
clinical features: results from: main etiopathogenic units: etiology: soft tissue defects: classification system: difference in features from Goldenhar syndrome: tx: (*SOS*)
clinical features:
- mostly unilateral condylar underdevelopment (can be bilateral)
- abnormalities of the external and middle ear
- midline deviation, crossbite, deviation of chin and tilting of the occlusal plane, disorders of skin, eye and ear
- can vary from slight asymmetry to complete absence of one ear, small ipsilateral face, facial nerve palsy and cleft of mouth corner
- It can be also manifested at both sides of the face simultaneously in 10-15% of patients
results from:
malformation of the 1st and 2nd branchial arches
-occurs in 1/3500 = 1/5600 births
main etiopathogenic units:
condyle and angle
etiology:
- heterogeneous
- congenital disease
soft tissue defects: •skin tags •facial clefts •cranial nerve function •soft palate function •ear abnormalities •bulk of subcutaneous soft tissue •muscles of mastication and facial expression •macrostomia
OMENS:
= orbit, mandible, ear, nerve and soft tissue
Goldenhar syndrome:
addition of epibulbar dermoids and vertebral anomalies
tx:
- ortho and surgery
- if mild with sufficient muscle mass and good mandibular mobility: orthopedics and orthodontics only
- must start 6-8y old; early tx
- it varies on: patient’s age, degree of facial deformity, and degree of skeletal deformity
- extend of TMJ involvement determines timing and type of treatment
hemimandibular hyperplasia:
how common is it?
clinical features:
when does it begin:
PANORAMIC X-RAY
-excessive growth of the condyle in one of the two sides
uncommon maxillofacial deformity
clinical features:
- increase in ramus height
- rotated facial appearance
- kinking at the mandibular symphysis
- prominence of the lower border of the mandible
- maxillary and mandibular alveolar bone overgrowth
- compensatory canting of occlusal plane
- serious functional malocclusion
- diffuse enlargement of the condyle, the condylar neck, the ramus, and the body of the mandible
- clear hyperactivity in the condyle
- actively proliferating cartilage !!
begins:
usually before puberty
condylar fractures:
if left undiagnosed:
% of cases that can cause this:
tx:
can lead to:
•Face asymmetries
•Severe malocclusion
•TMJ ankylosis
25% (75% doesn’t produce asymmetry)
tx:
- IMF for a few days
- physiotherapy
- non-surgical condyle manipulation or open surgery
- orthopedics-orthodontics
-> aims to minimize the destructive influence of fracture and surgery to future mandibular growth
tmj akylosis:
= (*SOS*) classification: caused by: most common cause? clinical features: tx: (*SOS*) goals of surgical tx:
Chronic Hypomobility and Growth Disorders
Intracapsular adhesions or ossification between the disc and temporal articular surface that attach the disc-condyle complex to the articular eminence
classification:
- degree of limitation (partial or complete)
- union location (intracapsular or extracapsular)
- tissue types involved (fibrous, osseous, fibro-osseous)
caused by: »Trauma (fracture / hemarthrosis) »Previous joint surgery »Systemic or local infections »Tumors »Systemic diseases
most common:
trauma
clinical features:
- limited mouth opening w/o pain
- present for a long time
- pt does not feel that it poses a significant problem
- condyle can still rotate, with some degree of restriction on the inferior surface of the disc
- decreased opening
- lateral movements are restricted
- opening pathway deflects to the ipsilateral side
tx:
- Immediate surgical release of the joint
- Use of functional appliances for dentoalveoral influence and symmetrical function and growth
goals of surgical tx:
- Restore range of motion and function
- Avoid development of malocclusion
- Prevent recurrence of ankylosis
juvenile rheumatoid arthritis:
what does it cause?
what does it affect:
history should include:
how do we assess the occlusal plane tilting?
- produces bone resorption -> which causes: posterior rotation of the mandible, anterior open bite and if it is asymmetrical it produces also facial asymmetry
- has an effect on both bone and muscle because it is an inflammatory disorder
- damage to joint -> joint function change -> muscular function change -> mandibular morphology development changes -> unstable occlusion -> mandibular function decreases
history should include: •face trauma •bone & muscle inflammatory disorders •continuously progressing face & dentoalveolar asymmetry •syndrome or craniofacial anomaly
occlusal plane tilting assessed with:
with a spatula
why the patient in the max opening deviates to lateral deviation? /what is the dd of this opening of this person? (picture)
anatomical
functional (locking of joint, inability of full translation)
muscular (spasm)
MRI uses:
- only when we want to assess intra-articular problems relating to disc, condyle and fossa (condyle disc fossa relationship)
- only for TMJ internal assessment
hypodontia:
= classification: most common tooth missing, excluding the M3: syndromes associated: dental anomalies commonly associated: diagnosis: impact:
= developmental absence of 1 or more deciduous/permanent teeth, excluding M3
classification: mild: 1-2 missing teeth moderate: 3-6 missing teeth severe/oligodontia: > 6 missing teeth anodontia: complete absence of teeth in 1 or both dentitions
most common tooth missing:
lower P2
syndromes associated: •Cleft lip and palate •Ectodermal dysplasias •Oral-facial-digital syndromes •Down syndrome •Wiktop syndrome •Van der Woude syndrome •Ehlers-Danlos syndrome •Incontinentia pigmenti
dental anomalies:
- hypoplastic enamel
- ectopic maxillary canine tooth position
- microdontia
- molar taurodontism
- conical crown shape (peg shaped I2)
- transposition !!
- supernumerary teeth !!
- infra-occlusion
- delayed teeth eruption
diagnosis: HISTORY –CLINICAL EXAMINATION •Abnormalities in the eruption of teeth •Prolonged retention of deciduous teeth •Inconsistencies in eruption timing between contralateral teeth more than 6 months •Deviation from the normal eruption sequence •Generalized delay in dental development RADIOGRAPHIC EXAMINATION •OPG
impact:
reduces quality of life for those affected due to detrimental effects on appearance (esthetics), function (mastication), and psychosocial well-being
Adjunctive orthodontic treatment:
=
examples:
= tooth movement carried out to facilitate other dental procedures necessary to control disease and to restore function
examples:
- Uprighting of abutment teeth
- tooth loss -> drifting into space
- with this you can facilitate placement of replacement of prosthetic teeth - Redistribution or closure of spaces
- replace the space with an abutment tooth
- roots may need to be repositioned to permit implant placement - Intrusion of over-erupted teeth
- tooth loss side effect: over-eruption of opposing teeth
- can interfere with restoration of space so we can intrude the over-erupted tooth - Extrusion of fractured teeth
- in order to bring the fracture line supragingivally to allow placement of a restoration
- there is a limit to this, as excess extrusion will reduce the amount of tooth supported by bone, reducing the crown-to-root ratio - Alignment of anterior teeth
- alignment of healthy teeth with restorations is not an acceptable procedure
- conservative tx options (ortho, bleaching, enameloplasty) should be offered
- a clinician should present only treatment options that involve predictable, conservative restorations or that preserve healthy tooth structure - Crossbite correction (functional with trauma)
- Adjunctive ortho applications in implantology
risks of orthodontic tx:
- root resorption
- loss of periodontal support
- demineralization
- enamel damage
- intra-oral soft tissue damage
- pulpal injury
- extra-oral damage
- failure to achieve tx objectives
(study slide 152)
root resorption:
etiology:
types:
post-tx:
risk factors:
etiology:
multifactorial
-> apical displacement tx duration and genetics play a role
(study slide 116 of revision)
types: (it is not a single entity)
1. moderate generalized resorption:
- inevitable
- 1-2 mm resorption during tx
- affects almost all teeth
- no consequences
- no action needed
- severe generalized resorption:
- unknown etiology (related to auto-immune response?)
- doesn’t matter if you do ortho or not
- rare
- not orthodontist fault
- risk of tooth mobility -> tx: follow up and give instructions - severe localized resorption:
- loss of more than ¼ of the root length of some teeth, usually maxillary incisors
- in 2-3% of ortho pts
- related to ortho tx
- one cause is movement of root apices against the lingual cortical plate
- risk of tooth mobility -> tx: follow up and give instructions
post-tx:
x-ray exam is mandatory, and the patient and referring dentist should be informed if a root resorption has occurred
Long-term, a tooth with a short root has a very favorable prognosis and need not be extracted and replaced by an implant or other restoration
risk factors:
- shortened roots w/ evidence of previous root resorption
- pipette-shaped or blunted roots
- teeth with previous trauma
- patient habits (nail biting)
- iatrogenic: excessive forces, intrusion, prolonged tx time
loss of periodontal support:
risk of harmful effects with tooth movement explanation:
cortical laminae thickness explanation:
with a perio patient we need to have:
-as long as a tooth can be moved within the envelope of the alveolar process, risk of the development of harmful side effects in the marginal tissue is minimal regardless of the dimensions and quality of the soft tissue
The thickness of the cortical laminae varies in different locations. In the incisor and canine region, the cortical bone plate at the labial aspect of the teeth is considerably thinner than at the lingual aspect
need:
adequate medical and dental history, appropriate intraoral x-rays and complete perio chart
most important iatrogenic effect of fixed appliance orthodontic therapy:
Decalcification of enamel
preventive dentistry:
explain it:
measures to be taken:
To prevent the development of lesions and assure proper tx, the clinician must be familiar with the major aspects of caries process and current principles of it
Unesthetic discoloration or resin remnants and discolored caries lesions formed during ortho tx
measures to be taken:
- Good OH
- Fluoride dentifrice (x2 daily) and rinse (x1 daily)
- Avoidance of carbonated soft drinks (may induce enamel erosion)
- OH monitoring (ex: gingival bleeding)
- Complex appliances that complicate plaque removal should be avoided on the maxillary anterior teeth
- Topical F solns, gels or varnishes
