Final Flashcards
What is considered severe over jet?
7-10mm
What is considered severe reverse over jet (class 3)
-3 - -4mm
What is considered severe open bite?
-3 - -4mm
Most facial deformities in the U.S are what type?
Mandibular deficiency
Vertically maxillary excess
Or both
(This makes up 2% of the population)
What percent of the population has asymmetry in their face?
0.1%
What are some causes of dentofacial deformities?
Inherited tendencies
Prenatal problems
Systemic conditions during growth
Trauma
Environmental influences
Multifactorial nature of facial development ___ prediction of inherited pattern
Precludes
What does fetal alcohol syndrome cause in regards to congential facial abnormalities?
Midfacial hypoplasia
What are three environmental influences that may influence facial growth?
Respiratory difficulty
Mouth breathing
Tongue position
What are some things that trauma can cause in regards to facial growth?
TMJ ankylosis
Assymetric mandibular growth
True or false… any non-restorable teeth should be extracted before surgical intervention
True
When malocclusion involves ____, treating with Orthodontics alone may result in adequate ____ but poor facial or dental esthetics or poor long term prognosis for post-treatment retention (over-compensation).
Skeletal discrepancy
Occlusion
True or false.. it is typically better to delay surgery until growth complete in pts with problem of excess growth. However, surgery can be considered earlier for patients with growth deficiencies
True
What is compensatory response?
Undesirable angulation of anterior teeth
What is decompensation?
Aim of presurgical orthodontics to align the teeth in proper proportion to the arches. Magnifies the appearance of the defect
How long does presurgical orthodontics typically take?
12-18 months
What is the advantage of a vertical ramus osteomoty?
You arent involving the nerve
What is the advantage of rigid fixation (vertical ramus osteotomy)?
You dont have to wire the teeth shut
Is the bilateral saggital split osteotomy used for mandibular excess or deficiency?
Deficiency
What surgery would you do if it is a class 2 dental relationship but the A-P position of the chin is ok?
Total subapical osteotomy
What allows the adequate collateral circulation for mobilization of total maxilla in regards to maxillary excess?
Palatal and buccal gingival Pedicles
In maxillary excess, you may find what classes of occlusion?
1 2 3 Open bite Transverse discrepancy
Vertical maxillary excess is often associated with apertognathia. What is that?
Anterior open bite
Results from excess downward growth of maxilla
Causes downward rotation of mandible
Result of premature contact of posterior teeth
Corrected by superior repositioning of maxilla in one or several pieces. Le fort osteotomy with or without segmentalization
What class of occlusion do you often see in maxillary/mid-face deficiency?
Class 3 with reverse anterior over jet