Revision lecture Flashcards
Up to what % disposition do pts of an increased overjet have to trauma?
50%
Why do class II div I have an increased risk of trauma to their upper anterior teeth?
Proclined teeth with lost support of the lips (lip incompetence) leave them more at risk
What 2 qualities would an alternation in transverse skeletal relationship lead to intra-orally?
Centre-line shift
X-bite
What is a scissor bite?
Ginormous upper jaw, relatively normal lower jaw
Upper jaw significant placed buccal to lower, no occlusal contact
Which incisal relationship is a scissor bite classically seen in?
Class II div II
What are the 3 categories of crowding
Mild crowding: 1-4mm
Moderate: 5-8mm
Severe crowing >8mm
What is the definition of an incisal relationship of class II div I?
Lower anteriors lie posterior to the cingulum plateau of the upper incisors with an increased overjet
What is the definition of an incisal relationship of class II div II?
Upper central incisors are retroclined with sometimes a reduced overjet
Name an approach for assessing a dental panoramic
- Presence/absence of teeth (supernumeries? hypodontia?)
- Developmental position of teeth & abnormalities of eruption (maxillary canines? infraocclusion?)
- Presence of disease
- Presence of pathology
- Normal anatomy
What are odontomes?
benign tumor-like growth made up of dental tissue that resembles abnormal teeth
A compound odontoma has a tooth-like structure and is arranged in a uniform manner, similar to a normal tooth, while a complex odontoma has a mixed structure of disorganized tissue mass
What 4 things do we assess when considering the prognosis of ectopic canines?
- X - height from occlusal plane (closer the better)
- Y - proximity to midline
- Z - angulation of the canine/long axis obliquity (lower the better)
- Labial/palatal positioned (parallax)
What can a lateral cephalogram radiograph conclude in orthodontics?
Quantify the severity of the skeletal discrepancy
Assess jaw bases in relation to anterior cranial base
Assess each jaw base in relation to one another (eg ANB/MMPA)
Assess relationship of dentition to jaw base
Which type of malocclusion is an adaptive tongue trust most common in
Anterior open bite
Tongue fills gaps and pushes forward to create an anterior oral seal
What is dento-alveolar disproportion?
Disproportion between the size of the jaw and number of teeth
Either spacing or crowding
What is the aetiology of crowding?
Dento-alveolar disproportion
Not enough jaw space for the number of teeth
What could be a differential diagnosis of a midline diastema?
Early forming/ conical / mesiodens supernumery teeth
What are the characteristics of conical supernumery teeth?
Offshoot of the dental lamina
Develop between 1/1
Sing/multiple; erupt unless inverted
No effect or cause crowding (increased dento-alveolar disproportion) /diastema
XLA if interfere w ortho tx
What length of time does it become a concern if a contralateral permanent tooth doesn’t erupt?
6 months
Which type of supernumery impedes eruption?
Tuberculate
Prevents eruption of the incisors
Where do tuberculate (late forming) supernumerys commonly form? Do they commonly erupt?
Palatal of upper 1/1
Rarely erupt
Whats the tx of a tuberculate supernumery impeding eruption of the upper incisors
XLA primary teeth and supernumery
Ensure adequate space
75% will erupt spontaneously
Can surgically remove overlying bone &/or E&B w gold chain
How does a supplemental supernumery originate?
Dichotomy of the tooth germ
What is the tx for a supplemental supernumery?
XLA most displaced tooth
What dental characteristics does digit sucking cause?
AOB/ reduced or incomplete OB
Buccal X bite
Class II Div I incisor relationship
(retroclination= crowded lower, proclination= spaced upper)
Centre-line discrepancy (thumb rarely in midline)
Adaptive tongue swallow
Digit deformity (thumb will look like a finger not a thumb)
