Exam 3 - Dentofacial Orthopedics Pt 2 Flashcards
What did Bretiner 1940 do?
- experiment in monkeys which changed positions of the mandible anteriorly and posteriorly via intermaxillary elastics
Bretiner (1940) used elastics fixed to teeth which produced which type of malocclusions?
Class 2 and Class 3
- change in POSITION of mandible
Histologically, what did Bretiner (1940) demonstrate?
changes in ramus, gonial angle, glenoid fossa
What did Jansen and Bluher (1965) do?
- studied POSTERIOR AND SUPERIOR traction of mandible in monkeys
- placed a hook in basal bone of mandibular symphysis and used extraoral traction
What type of modification is the milwaukee brace?
vertical
What type of modification is Jansen and Bluher?
anteroposterior
What type of modifiction is Breitner 1940?
anteroposterior
What was the net effect of the Milwaukee brace?
- reduction of lower facial height and chin projection anteriorly
- creates a prognathasim
What is the Milwaukee brace used for?
- treatment of young patients with polio or scoliosis
- mandible rotated upward and forward around condyles
After years of observation and experimentation, what 6 things did they discover when the milwaukee brace is used?
- reduction of gonial angle
- shortened ramus
- lower face height decreased
- intraoral space decreased
- molars intrude
- maxillary and mandibular incisors tip labially
On Macaca mulatta, what 3 effects were found using a milwaukee brace?
- ramus height decreased
- molars intruded
- labial tipping maxillary and mandibular incisors
In the rheus monkey (macaca mulatta), what did they discover?
changes in mandibular length
What type of effect is Robin’s Monobloc?
postural change effects
loose acrylic plate that imposed a given position on the mandible
Robin’s monobloc
What does a robin’s monobloc do?
monobloc is a passive appliance creating a reflex mechanism which triggers the muscles of mastication into closing
During closure, what does the robin’s monobloc do?
guides mandible to a protusive position
What does the Andresen activator promote?
remodeling changes of the mandible due to change in posture
What does the Andresen activator do?
- facets in posterior acrylic allow mesial eruption of mandibular posterior teeth and
- distal eruption of maxillary posterior teeth
- correcting class II malocclusion
What does the Andresen activator result in?
modification in vertical and anterior-posterior proportions of face
What 4 things does a bionator (1980s) appliance do?
- cut down (simpler) activator
- reduced bulk of the appliance
- ability to reposition the mandible
- modify dental eruption
Are Herbst appliances bonded or fixed?
Both!
What is a Twin block?
uses forces of occlusion as the functional mechanism to correct the malocclusion
a “tissue borne” appliance
frankel appliance
Where is most of the Frankel appliance located?
vestibule
What does a Frankel appliance generate?
arch expansion due to buccal shields
What does a frankel appliance reduce?
dental crowding through alveolar bone development
What does a Frankel appliance promote?
mandibular differential growth/headgear effect reducing maxillary growth
How often are class III activators used?
rarely
What does a class III activator do?
skeletal movement
- downward and backward rotation of the mandible
- reduces the protrusion of the chin
What does the ideal patient for chin cup therapy look like?
mild skeletal problem with the ability to bring the incisors end-to-end or nearly so
What is a face mask?
- splinting of maxillary teeth using an acrylic occlusal splint
- may include palatal expander
What force and duration is required for a face mask?
force = 12 to 16 oz
duration = minimal 14 to 16 hrs/day (including bedtime)
What are the two indications for a face mask?
- children aged 6-8
- exerts force on maxilla via elastics that attach to a maxillary splint producing both tooth movement and displacement of the maxilla
What is the contraindication of a face mask?
in children above 9 years of age the treatment produces more dental movement and very little skeletal change
