Interceptive Orthodontics Flashcards
name 5 potential causes of an unerupted maxillary central incisor
- supernumerary (most commonly tuberculate)
- trauma to deciduous tooth
- crowding
- downs syndrome
- CLP
- cleidocranial dystosis
- ectopic position of tooth germ
where would the mesial cusp of the upper 6 be in a full unit class 2 (molar class)
in the embrasure of the lower 5 and 6
what distance is the average overjet
2-3mm
name 4 risks associated with leaving unerupted teeth in situ
- root resorption of adjacent teeth
- ankylosis to bone
- cyst formation
- resorption of unerupted tooth crown
what landmarks give the best prognosis of success for spontaneous eruption of impacted canines once Cs are extracted
- unerupted canine has not passed midpoint of lateral
name 5 potential treatment options for unerupted canines
- do nothing and monitor
- interceptive extraction of Cs
- Surgicaly removal of unerupted canines
- auto transplantation
- exposure and bonding of orthodontic attachment
name 4 potential aetiologies for the high incidence of unerupted maxillary canines
- ectopic position of the tooth germ
- long path of eruption
- genetic predisposition (associated with dental anomalies in other family members)
- crowding (last tooth in upper arch to erupt)
how do we assess intra orally if there is suspected unerupted canines
- palapate bucally and labially to feel for unerupted teeth
- assess mobility of Cs if still present
- assess mobility of lateral incisors incase of root resorption
- angulation of adjacent lateral incisors (tend to tip distally if root being pushed on palatal side)
what 2 combinations of radiographs can be used to apply parallax
2 periapicals
OPT and maxillary occlusal
give 2 justifications for taking a lateral cephalogram
- assess severity of underlying skeletal pattern (if relevant to treatment planning))
- extra view of unerupted tooth
definition of interceptive orthodontics
any procedure which will eliminate or reduce the severity of a developing malocclusion
if extracting deciduous teeth to ‘encourage permanent teeth to erupt’ what is the ideal stage of development of the successor
permanent tooth sees 1/2 to 2/3 root development
how is space gained in the arch for incoming permanent teeth
- leeway space
- increase in intercanine width through lateral growth of jaws
- upper incisors erupt onto a wider arc (more proclined)
discuss leeway space
difference between the width of the deciduous canine and molars and incoming permanent canine and premolars
- 1-1.5mm gained in upper arch
- 2-2.5mm gained in lower arch
name 4 reasons for interception in the early mixed dentition
- impacted 6s
- unerupted central incisors
- early loss of deciduous teeth
- carious 6s
treatment of impacted 6s in the early mixed dentition
- if patient under 7, wait 6 months and will hopefully resolve on its own
- placement of orthodontic separator between contact of 6 and E to create space
- extract E
- distal disking of E
what is a consequence of early loss of deciduous teeth
localised crowding
balancing extraction
aims to maintain position of dental centre lines
removal of tooth from opposite side of same arch
compensating extraction
aims to prevent overeruption and maintain buccal occlusion
(always take upper)
early loss of what teeth indicates need for balancing extraction
C or D
what is the ideal time to extract carious 6s so that the space is closed by the 7
when the 7s bifurcation is beginning to calcify
(8s will also ideally be present and the arch will have moderate crowding)
what amount of mandibular displacement due to cross bite indicates a need for orthodontic treatment
more than 2mm
give 6 instructions for a patient you have just fitted a removable appliance
- wear full time even when eating
- remove when brushing (ideally brush every time after eating)
- avoid sugary foods and drinks
- avoid hard, sticky foods which may damage appliance
- speech will initially be affected
- excess saliva may initially be produced
- may want to remove for contact sports
signs of an infra occluded (ankylosed) deciduous tooth)
dull percussion tone
no PDL space or lamina dura on radiographs
risks of doing nothing for an infra occluded deciduous tooth
- permanent successor becomes ectopic
- infra occlusion worsens and adjacent teeth tip making tooth inaccessibe for extraction
- caries and perio due to OH difficulties
treatment of infra occluded deciduous teeth with successor present
- monitor for 6-12 months
- extract if successor near complete root formation or more than 12 months
treatment of infra occluded deciduous teeth with absent successor
- if deciduous good condition, retain and place onlay?
- extract if below adjacent contact points
