Cranio-Mandibular Relations Flashcards
Why should cranio-mandibular relationships be considered?
Diagnosis allows practitioner to have a list of the problems and allows treatment to commence and then the formation of a treatment plan
What is the cephalocaudal gradient?
The head initially grows much more quickly than the body initially to the extent where the head is almost 50% of the size of the foetal body at 2 months and then the head shrinks and the body gets larger proportionally over time.
What trends are seen in the skull relative to the entire body and within the skull?
The cephalocaudal gradient shows differences in proportion of head size relative to the body size.
The cranial skull is much larger compared to the facial skeleton in infants and in the adult the rest of the face develops over time to make it more proportional.
What do scammon’s curves show? What do they show for the mandible and the maxilla?
The percentage of the adult form size that different parts of the body make up (i.e percentage of its adult size that a specific tissue or organ is).
Until the 20th year of age the size of the skull continues growing
What do scammon’s curves show?
The percentage of the adult form size that different parts of the body make up (i.e percentage of its adult size that a specific tissue or organ is).
What are the 3 dimensions of skeletal proportions?
Anteroposterior
Vertical
Transverse
How is the vertical dimension assessed clinically?
In a normal patient the forehead until the lower eyebrows should be 1/3rd, the space between the lower eyebrow and the bottom of the nose should be 1/3rd, and the space from the bottom of the nose to the tip of the chin should be 1/3rd.
How is the transverse dimension assessed clinically?
Side of the face until the lateral side of the orbit.
Corners of the eye form the next lines
The medial corners of the eyes to the middle of the nose form the final portion.
How can the 3 dimensions of the face be assessed radiographically?
Cephalometrics: Skeletal landmarks are used for diagnosis.
What are the major uses of cephalometric radiographs?
Diagnosis
Monitoring growth and treatment effects
What is overjet?
The horizontal overlap of the maxillary central incisors over the mandibular central incisors. I.e how much the upper front teeth protrude forward in relation to the lower front teeth.
What is overbite?
The vertical overlap of the maxillary central incisors over the mandibular central incisors.
What is normal occlusion?
The mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar.
What is a class 1 malocclusion?
Same as normal occlusion but characterized by crowding, rotations, and other positional irregularities.
What is a class 2 malocclusion?
The mesiobuccal cusp of the upper first molar occludes anterior to the buccal groove of the lower first molar. There are two subtypes of Class II malocclusion.
This can include upper incisors tilting outwards creating significant overjet (Division 1) and upper incisors labially inclined (division 2)
