Unit C module 4 Flashcards
What are the major units of the craniofacial complex?
Cranium and cranial base
Maxilla
Maxillary dentoalveolar process
Mandibular dentoalveolar process
Mandible
What structure do the cranium and cranial base resemble on scammon’s growth curves?
The cranial base and the cranium
What is the growth pattern of the face like?
It is influenced by an interaction between neural and general body growth.
The facial skeleton grows according to the cephalocaudal gradient where the structures closest to the brain follow the neural growth curve and the mandible lags behind and gradually catches up to the rest of the head but doesn’t do so really until the adolescent growth spurt is complete.
How do the facial soft tissues grow?
The cephalocaudal gradient is also followed here especially in the nose. The nose becomes more prominent during adolescence.
The mandibular musculature grows and becomes stronger during adolescence. The lips follow the same pattern.
The soft tissue chin is an exception as it becomes more prominent with mandibular growth.
What kind of trend is seen in the patterns of facial growth among adolescents?
It is constant. I.e if the mandible is deficient in childhood it tends to still be deficient during adolescence and adulthood.
What kind of radiographs can be used to assess facial growth?
Cephalometric superimpositions.
How are facial growth patterns understood?
In terms of the functional units of the face moving in separate planes of space (AP, vertical, or transverse)
What is a class II jaw relationship?
Occurs when the maxilla is positioned a significant amount anteriorly relative to the maxilla. A class II relationship results in overjet that is much larger than usual.
What is a class III jaw relationship?
When the maxilla is positioned behind the mandible.
What causes a class III relationship?
The A-P relationship in the position of the jaws can have several causes: Mandibular excess (mandibular prognathism), maxillary deficiency, or a combination of both.
What kind of variations can exist in class I relationships?
The upper and lower teeth can be displaced anteriorly relative to their skeletal bases.
This is called bimaxillary protrusion
What are the vertical variations in skeletal growth?
2 extremes are skeletal open bite (long face) and skeletal deep bite (short face)
What causes a open bite/long face?
Maxilla that has grown more in the posterior than the anterior resulting in a palatal plane that appears tipped down posteriorly and downward-backward rotation of the mandible.
Can also be caused by a short mandibular ramus which also leads to downward-backward rotation of the mandible often with increased gonial angle and steep mandibular plane.
What common pattern is seen with a deep bite?
The maxillary incisors are tipped forward
What causes a deep bite?
A long mandibular ramus
Decreased gonial angle
Flat mandibular plane
