Facial & Dental Asymmetry Flashcards
The face is never totally —.
symmetrical
Severe — development of the jaws to cause a problem is
relatively rare
asymmetric
A patient’s — evaluation is one of the most critical
aspects in orthodontic diagnosis
frontal symmetry
Even the most esthetic faces are associated with
mild forms of facial
asymmetry
The individuals seeking orthodontic treatment, are often associated
with
facial asymmetries that may be greater that the acceptable
norms
Classification of Facial
Asymmetries
FACIAL ASYMMETRIES
(3)
Skeletal asymmetries
Functional asymmetries
Soft tissue asymmetries
Mandibular deviation
* Hyperplastic mandible
Etiology
- PRENATAL CAUSES
- GENETIC
- CONGENITAL
- POSTNATAL CAUSES
- ENVIRONMENTAL
- GENETIC
(2)
- Facial cleft syndromes
- Unilateral cleft lip – cleft palate
CONGENITAL
(4)
- Hemi-facial microsomia
- Neurofibromatosis
- Birth trauma
- Intra-uterine pressure during pregnancy
ENVIRONMENTAL
(6)
- Trauma & infection
- Muscle dysfunction
- Functional deviations
- TMJ derangements
- Hemi-mandibular hypertrophy
- Pathologies
DIAGNOSIS
(3)
- Patient Medical History
- Clinical examination
- Para-clinical examination
- Clinical examination
(2)
- Extra-oral examination
- Intra-oral examination
- Para-clinical examination
(4)
- Radiographic examination
- Photographic analysis
- Digital videography
- Articulated study models
EXTRA-ORAL EVALUATION
(3)
- Frontal
- Vertical
- Sub-Mento Vertex
EXTRA-ORAL EVALUATION
(3)
- The pupils are assessed for level with the horizon
- If level, then use as horizontal reference line
- Inter-pupillary plane
INTRA-ORAL EXAMINATION
(5)
- FUNCTIONAL EXAMINATION
- Evaluation of the dental midlines.
- Unilateral cross bites.
- Vertical occlusal evaluation.
- Transverse cant of maxilla.
- FUNCTIONAL EXAMINATION
(4)
- Maximal opening.
- Postural rest position.
- CR-CO discrepancy.
- Motor & sensory evaluation
- CENTRIC RELATION
(1)
- A musculoskeletal stable position, with the condyles forward, as
far upward as possible, centered transversely and with the
articular disc properly interposed
- CENTRIC OCCLUSION ( maximum intercuspation)
- A dental determined position, Tooth morphology and position are
the primary influences determining the mandibular position and
movements. The condylar position is strongly determined by the
dental contacts and intercuspation through muscles and ligaments
NON-FUNCTIONAL
(2)
- No CR-Co Shift.
- There is a dental or skeletal asymmetry
RADIOGRAPHIC EXAMINATION
* Taking an accurate radiograph is crucial as the — is an important
factor in radiographic assessment.
head position
We can use different radiograph to evaluate asymmetry, such as:
(4)
- Lateral cephalogram
- Panoramic radiograph
- Sub-mento vertex view
- CBCT. (Best)
Lower dental midline
Lower midline deviations will usually have an effect on the occlusion.
It is important to diagnose the deviation properly and plan the adequate
correction.
SKELETAL ASYMMETRIES
* Asymmetry Treatment in Growing Individuals
(1)
- Orthopedic appliances in conjunction with orthodontics are used to
help improve or correct the developing imbalance.
- Orthopedic appliances in conjunction with orthodontics are used to
help improve or correct the developing imbalance.
(2)
- Hybrid Functional Appliances
- Distraction Osteogenesis
SKELETAL ASYMMETRIES
* Asymmetry Treatment in Non-Growing Individuals. (Adults)
(3)
- Surgical Conditions with severe skeletal asymmetries are not able to be corrected by
orthodontic camouflage and growth modification so surgical procedures are used to
correct the deformities or asymmetries. - Distraction Osteogenesis
- Surgical Osteotomy
Surgical Osteotomy
(4)
- Maxillary surgeries:
- Mandibular surgeries:
- Inferior body osteotomy
- Genioplasty
- Maxillary surgeries:
(1) - Mandibular surgeries:
(1)
- Le-fort I
- Bilateral Sagittal Split Osteotomy (BSSO)
FUNCTIONAL ASYMMETRIES
* Deviations caused by functional shifts
* Mild =>
* Moderate to Severe deviations =>
minor occlusal adjustments.
orthodontic treatment to align the teeth
NOTE:
* Because functional shift can also be the result of a skeletal asymmetry, (3) may be
indicated in the management of these cases.
rapid
maxillary expansion, orthognathic surgery, and orthodontic treatment
Occlusal Splints=Deprogrammers
(1)
- Occlusal splints may be necessary to properly evaluate the presence and
extent of the functional shift by eliminating the habitual posturing and de-
programming the musculature.
SOFT TISSUE ASYMMETRIES
* Deformities caused by soft tissue imbalance can be treated by either
(2)
* Augmentations include the use of s(2) to re-contour the
desired areas of the face.
augmentation or reduction surgery.
bone grafts and silicone implants
