How can malocclusions occur?
Genetics (skeletal pattern, soft tissues, dent-alveolar)
Enviromental factors (habits pathology)
class I definition
maxilla and mandible are in good position skeletal and occlusal relationship
Class II x2 types
Maxillary protrusion
Mandibular retrognathia (mandible being too small)
Class III definition
large or prognathic mandible or both
How can an increased vertical skeletal pattern have an effect on occlusal relationship
Anterior open bite/overbite
How can a decreased vertical skeletal pattern have an effect on occlusal relationship
deep overbite
What might transverse discrepancies cause in the skeletal pattern <>
posterior cross bite
Soft tissue factors effecting malocclusion, list 5
- lips
- tongue (size, rest position)
- habits (alters tongue position)
- PDL in perio
- Adenoids (mouth breathing)
causes of midline diastema, list 6
- closes with eruption canines
- missing/small teeth
- frenum
- midline supernumerary
- proclained upper incisors
- habit
Malocclusion dent-alveolar factors
- crowding and spacing
- missing teeth
- malformed teeth (peg shaped, microdot etc)
- early loss of primary teeth
- retained primary teeth
Microdontia defintion
small teeth - need ortho
Macrodontia definition
Large teeth - need orthodontic
Anadontia definition
Hypodontia defintion
- complete absence teeth
- some absence teeth
Why may you suspect missing teeth
- delayed eruption of permanent teeth
- infra occlusion
- dental centre line issues
Definition of supernumerary teeth and what they may cause, list 4
“extra copies” teeth due to lamina dura extension
- crowding, drifting, rotations, midline diastema
early loss of primary teeth can cause: list 4
- space loss
- overerupution
- midline shift
- position of permanent teeth
What is infra-occlusion
primary teeth remain in position while adjacent teeth erupt - can cause over eruption
When (3) and why (3) would you place space maintainers?
When:
Unerupted tooth
delayed eruption
traumatic loss
Why:
maintain space and centrelines
occlusion is guided leading to better occlusion
