Intro Flashcards
orthodontics is
Speciality of dentistry concerned with: - Growth and development of teeth, face and jaws - Diagnosis, prevention and correction of dental and facial irregularities
what does orthodontic assessment include
systematic evaluation of the face and skeletal bases in 3D Position of the teeth depend to a large extent on the size, shape and relative position of the underlying bones (i.e. the maxilla and mandible)
position of teeth depend on
depend to a large extent on the size, shape and relative position of the underlying bones (i.e. the maxilla and mandible)
what is the key skeletal relationship that impacts occlusion
relation ship of jaw Where does maxilla line in relation to mandible – anteroposterior skeletal relationship
Frankfurt plane
Top of ear hole to orbital rim needs to parallel to floor for orthodontic assessment Reproducible by getting pt to stare into own eyes in mirror
what is ignored in orthodontic assessment
Chin completely separate from mandible – not used in assessment
2 bone points used in orthodontic assessment
Basal bone of maxilla –curvature of upper lip, below nose Innermost curvature of lower lip mandible
Class 1 skeletal relationship
mandible 2-3mm behind maxilla - normal
class 2 skeletal relationship
maxillary base is in front of mandible significantly (10mm approx.) expect overjet teeth
class 3 skeletal relationship
maxillary base is in line with mandible reverse overjet expected
mandibular hypoplasia causes
CLASS 2 Juvenile arthritis condyle crumbling Smaller lower jaw
mandibular prognathism and maxillary hypoplasia causes
CLASS 3 Large lower jaw And smaller upper jaw
orthodontic dimensions
3D problem – facial asymmetry - Hemimandibular hypertrophy
Hemimandibular hypertrophy
3D problem -> facial asymmetry Many female late teen – early 20s Gradual onset Lack eruption on one side undereruption on other side causing maxillary cant
hemifacial microsomia
syndrome Failure to develop condyle, ramus and body to differing tegress Progressive facial asymmetry Can graft (2/3 successful)
example of syndrome impacting orthodontics
hemifacial microsomia
Mandibular retromaphia causes
class 2 point A (maxilla) in front of B (mandible)
lateral cephalometry taken when
Only take if skeletal problem – so only class 2 or 3
orthodontic tx options for skeletal discrepancies
Growing patients - Growth modification techniques to promote or restrict growth of either jaw Adults who have completed growth - Orthognathic Surgery
growing patients orthodontic Tx options for skeletal discrepancies measn
growth modification
orthodontic appliances to alter growth in skeletal discrepancies of growing pts (3)
Functional appliances – grow mandible (wear 24 hours a day) Headgear – reduce maxillary Reverse pull facemask and RME – promote maxillary growth
orthognathic surgery
- split and move Single jaw or bimaxillary procedures
orthodontic treatment for adults who have completed growth but have skeletal discrepanacies
orthognathic surgery