Maturational Changes Flashcards
How does weight change typically in adult life?
Typically adults gain an average of 40 lbs between the ages of 20 and 50
How do facial dimensions change in adult life?
The maxilla and the mandible grow forward
Ramus of the mandible lengthens reflecting growth of the pterygoid sling (masseter +internal pterygoid)
Teeth in both jaws were carried forward by late jaw growth
The nose grew nearly twice as much as the jaws
Why do teeth occlusal relationships return to original relationship after orthodontic treatment when a retainer is not used?
It is caused by late disproportionate growth rather than return of tooth structure to old orthodontic relationship.
What kind of changes are considered normal in adults?
Growth never stops following adolescence. Instead it is very slow and occurs over several decades.
What are the types of soft tissue changes seen in the face?
Decrease in lip fullness
Downward movement of the lips relative to the teeth leading to less display of the maxillary incisors and greater display of the mandibular incisors
Deepening of the skin folds and loss of skin tone
When is lip fullness most increased?
There is an adolescent growth spurt of the lips especially in girls and lip fullness increases until the age of 16 and then declines.
How does skin change with age?
Slight jowling (cheek drooping) as skin tone declines (skin becomes less elastic)
Submental fat deposits (under chin)
Deepening of paranasal skin folds
Droop of commisures of the lips
How do teeth change over time?
2 Major changes:
Wearing away of the enamel surfaces
Decrease in size of the pulp chamber
Why doesn’t pulp exposure happen often with heavy wear caused by abrasive forces with primitive diets?
This is due to the reduction in size of pulp chambers with age. Especially the molars.
What happens to the gingiva with growth?
The gingiva retracts exposing more of the crown during adolescent growth, however, this occurs to a much lesser extent compared to the eruption of the teeth.
Gingival recession is not a normal occurrence with ageing. It is a result of pathology.
What happens to incisor alignment at age 15 or 16?
They start to become more crowded and irregular with time until the early 20s.
What are the problems with the assertion that third molars cause incisor crowding?
Lower incisor crowding occurs even in people whose third molars are congenitally missing.
Numerous studies of relationship between 3rd molar presence, position, or other characteristics have reported little or no correlation with incisor crowding
What are the theories for late incisor crowding? How true are they?
Third molar push
Interproximal wear of teeth in primitive diet helps with alignment (Aboriginal people don’t tend to develop crowding from the olden days)
What are the problems with interproximal wear of teeth theory?
Modern day aboriginal people still don’t develop incisor crowding.
How does mandibular growth relate to late incisor crowding?
When there is excessive mandibular growth that causes the teeth to tip lingually shortening the arch (remember the compensation of teeth to fight the mandibular growth and class III occlusion)
