Growth and Orthodontist

Question 1

Endochondral Ossification

Answer 1

Bone develops from cartilaginous precursor

Question 2

Intramembranous ossification

Answer 2

bone is formed by osteoblast present in mesenchymal tissue
takes place in mandible, maxilla and cranial vault

Question 3

surface remodelling

Answer 3

process of resorption and deposition of bone allows the size and shape of facial bone to change

Question 4

primary displacement

Answer 4

change in position is caused by the bone itself changing in size

Question 5

secondary displacement

Answer 5

caused by the growth of adjacent bone - such as in the change in the position of the maxilla due to the growth of the cranial base

Question 6

Craniofacial growth theories

Answer 6

1. Sutural theory (SICHER)
   - sutures have innate growth potential
2. Cartilaginous theory (SCOTT)
   - propose cartilage as the primary determinant of growth
3. Functional matrix theory
   - genetic control influences soft tissue development

Question 7

growth problems during orthodontics

Answer 7

5% ortho cases have growth problem
severe skeletal II (insufficient mandible growth)
severe skeletal III (excessive mandible growth)
severe skeletal open bite (excessive vertical growth)

Question 8

Maxillary growth

Answer 8

predominant enlargement is posterior and superior
displacement downward and forward
deposition of bone on alveolar ridges
- inc facial height
- edentulous pts eg

Question 9

Nasomaxillary complex growth

Answer 9

passive displacement, created by the growth in the cranial base that pushes the maxilla forward
active growth of the maxillary structures and nose

Question 10

mandibular growth

Answer 10

Condylar region
- Endochondral growth

Symphyseal suture closes during first year

Alveolar bone forms with development of teeth and resorbs when teeth are lost

Deposition of bone on posterior ramus, resorption on anterior of ramus

Question 11

what is growth required for ?

Answer 11

functional appliance tx
distal movement of posterior teeth
overbite reduction
spontaneous reduction
occlusal settling
rapid maxillary expansion

Question 12

how is growth influenced in the maxilla

Answer 12

reverse pull headgear
class III cases

Question 13

how is growth influenced in the mandible

Answer 13

functional appliances
majority of the effect is dentoalveolar

Question 14

how to make use of growth

Answer 14

overbite reduction
spontaneous space closure