Asymmetry Flashcards
The face is _____ totally symmetrical
NEVER
asymmetric development of the jaws severe enough to cause a problem is
relatively _____
rare
The evaluation of a patient’s ______ _____ is one of the most critical aspect of diagnosis.
frontal symmetry
Even the most esthetic faces are associated with ____ forms of facial asymmetry.
mild
*may be esthetic for one person but not the other
The individuals seeking orthodontics are often associated with facial asymmetry that may be ____ ___ the acceptable norms.
greater than
Facial asymmetries are ____ prevalent in Ortho patients
more
What are the 3 types of facial asymmetries
Skeletal
Functional
Soft tissue
*dental alveolar is another
Types of mandibular deviation
Hyperplastic, hypoplastic, or combination
Etiology
Prenatal causes
Genetic
- facial cleft syndromes: Unilateral CL-CP
Etiology - Congential
- Hemifacialmicrosomia
- Neurofibromatosis
- Birth trauma
- Intra uterine pressure during pregnancey.
Etiology - Environmental
- Trauma & infection.(5%)
- Muscle dysfunction.
- Functional deviations.
- TMJ derangements.
- Hemi mandibular hypertrophy.
- Pathologies
Diagnosis consist of
Patient History
* Clinical examination
* Extra-Oral examination. * Intra-Oral examination.
* Para-clinical examination * Radiographic examination
* Photographic analysis
* Digital videography
* Articulated study models
Extraoral evaluation consist of
- Frontal
- Vertical
- Sub-Mento Vertex
- The pupils are assessed for level with the horizon. If level, then use as horizontal reference line. (Inter-Pupillary line)
Intra oral eval consist of
- FUNCTIONAL EXAMINATION * Maximal opening.
- Postural rest position.
- CR-CO discrepancy.
- Motor & sensory evaluation
- Evaluation of the dental midlines. * Unilateral cross bites.
- Vertical occlusal evaluation.
- Transverse cant of maxilla.
Centric Relation definition
centric relation is defined as a musculoskeletal stable position, with the condyles forward, as far upward as possible, centered transversely and with the articular disc properly interposed
Centric Occlusion definition
centric occlusion (CO) or maximum intercuspidation is 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 intercuspidation through muscles and ligaments
No CR-Co Shift means
there is a dental or skeletal asymmetry.
What type of radiographs can be used for eval asymmetry
- Lateral cephalogram
- Panoramic radiograph
- Submento vertex view
- CBCT.(Best)
Lower dental midline tx
Lower midline deviations will usually have an effect on the occlusion.
It is important to diagnose the deviation properly and plan the adequate correction.
Asymmetric occlusion =
Asymmetric mechanics
Asymmetry Treatment in Growing Individuals (pediatrics)
Orthopedic appliances in conjunction with orthodontics are used to help improve or correct the developing imbalance.
* Hybrid Functional Appliances * DistractionOsteogenesis
Asymmetry Treatment in Non-Growing Individuals. (Adults)
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.
* DistractionOsteogenesis * Surgical Osteotomy
* Maxillary surgeries: * Le-fort I
* Mandibularsurgeries:
* Bilateral Sagittal Split Osteotomy (BSSO)
* Inferior body osteotomy * Genioplasty
Deviations caused by functional shifts
- Mild => minor occlusal adjustments.
- Moderate to Severe deviations => orthodontic treatment to align the teeth
*functional shift can also be the result of a skeletal asymmetry, rapid maxillary expansion, orthognathic surgery, and orthodontic treatment may be indicated
Occlusal Splints - deprogrammers are used for
to properly evaluate the presence and extent of the functional shift by eliminating the habitual posturing and de- programming the musculature.
Soft tissue asymmetries can be tx by
either augmentation or reduction surgery.
Augmentations include
the use of bone grafts and silicone implants to re-contour the desired areas of the face.
