What are the 3 major clinical problems of maxillary growth?
- Maxillary hypoplasia (Class III)
- Maxillary Prognathism (Class II)
- Transverse deficiency (posterior cross bite)
How many hours a day does maxillary growth retaining head gear need to be worn?
12-16 hours a day *not 6 hours like teeth
How much skeletal moment can Maxillary protraction-face mask and reverse pull head gear induce?
3mm or less
- Usually done before age 10-11
- Often lasts 6-8 months
What is a palatal expander is used to treat what?
Often used to treat transverse deficiency .
*Palatal suture is the target here.
How fast is Rapid palatal expansion?
1mm/day (mostly adolescent patients) used 2-3 weeks
How fast is Slow palatal expansion?
1mm/week (used for late adolescent or young adult)
How long must retention be maintained after palatal expansion?
3-6 months for bone consolidation
W-arch and Quad helix appliances instead of Jackscrew-type expanders are often used for who?
Preschoolers/Preadolescent (rare)
RPE in adolescents and preadolescents produces what _____% dental and ______% skeletal movement.
50%-50%
For large skeletal moment in palatal expansion ________ is required.
(SARPE) surgical assisted RPE
T or F, Functional appliances can accelerate mandibular growth, but may not increase the final size of the mandible.
True
What are common unwanted effects of functional appliances?
Lower incisor proclination and upper incisor retroclination (which might help with over-jet in some patients, but might not be good choice for patients who already have too much proclination or retroclination)
What is the most common treatment for mandibular prognathism?
Mandibular surgical setback after the cessation of growth.
*Mandibular restraining chin cup is rarely used.
T or F, orthodontics is great way to widen the mandible….
Nope, the mandible fuses at 7-8 yrs old and so surgical procedure (distraction osteogenesis) is the best option usually
What orthodontic device can “kind of” achieve mandibular widening?
Schultz and Williams appliances, but they actually expand the dento-alveolus, but not the basal bone.
What is distraction osteogenesis?
Basically, create and maintain a gap in bone structure to induce bone growth.
What are the 4 main passes of Distraction osteogenesis?
- Latency = time between operation and start of distraction.
- Distraction = the period that distractor activation takes place.
- Consolidation = the post distraction period (APPLIANCE STILL IN PLACE) to allow new bone to form.
- Remodeling = the period that the regenerated bone continues to remodel (after appliance removal)
