Occlusal Problems in the Mixed Dentition Flashcards
What is crown root dilaceration?
- trauma causes displacement of unerupted permanent crown and root formation continues in different direction
- can occur at any part of root
- usually due to trauma in primary dentition
Management: surgical exposure and use of light ortho forces to pull tooth into place e.g. wire on back of teeth
Give some information regarding supernumeraries?
- can be exact copies of adjacent teeth - supplemental teeth e.g. 2, premolars or 8
- contain tooth material but don’t look like teeth (conical or tuberculate supernumeraries)
- can occur anywhere, most common in premaxilla
- maxillary midline = mesiodens
- some erupt
- usually impede eruption of permanent teeth
- usually extracted or surgically removed
What are peg shaped incisors?
- unknown aetiology
- commonly affects laterals
- cause spacing and problems with aesthetics
- may be associated with absent contra-lateral incisor
- increased risk of ectopic canines
What is hypodontia?
- congenital absence of one or more teeth
- can be hereditary
- most commonly affects upper 2’s and lower 5’s
- spacing and aesthetics biggest problem
- more common in permanent dentition
- presents with delayed exfoliation/eruption
- radiographs confirm diagnosis
What are neonatal teeth?
- primary teeth that erupt at birth
- can cause feeding problems
- if very mobile, should be extracted
What are eruption cysts?
- appear as blue mucosa overlying an unerupted tooth
- most common over e’s and 6’s
- asymptomatic
- resolve as tooth erupts
What are impacted teeth?
- primary or permanent teeth that fail to erupt fully
- can be partially erupted
- usually due to an obstruction (supernumerary), primary failure of eruption, insufficient space, ectopic teeth (erupting/forming in wrong position)
What is an infra-occluded tooth?
- incorrectly called submerged
- usually due to ankylosis - adjacent teeth erupt and ankylosed teeth remain unchanged vertically - gives an appearance of submerging
- due to no permanent successor or idiopathic
What can retained deciduous teeth indicate and how can they be managed?
- appear normal
- missing permanent successor or ankylosis
- usually require extraction due to ankylosis - can deflect permanent successor
- leave in situ if missing permanent successor
Give some reasons on premature loss of primary teeth?
Caries, trauma, balancing extractions, compensating extractions, serial extractions
What effect can caries have on premature loss of primary teeth?
- significant effect on permanent successor
- most frequently see mesial drifting of 6’s resulting in premolar overcrowding
- usually leaves spacing, drifting of adjacent teeth to extraction site
What effect does trauma have on premature loss of dentition?
- avulsion of primary incisors can result in a centre line shift in incisors
- can experience delayed eruption of permanent successor - fibrous mucosa may form
- intrusion of deciduous incisors can cause deflection of permanent successor (crown/root dilaceration)
- drifting of adjacent incisors, centre line off
What is balancing extractions?
- if you take out a tooth on one side of the arch, you may consider extracting the contra-lateral tooth e.g. URC and ULC
- mostly done if concerned will cause a centre line shift during the eruption of the permanent incisors
- C’s and D’s most likely to have an effect
- rarely E’s
What is compensating extractions?
- if extracting in one arch, considering extracting same tooth in the opposing arch
- mostly considered for 6’s
- if extracting a LR6, this can cause overeruption of the UR6 which can cause occlusal interference
- if extracting an upper, rarely have to compensate and extract lower
What is serial extractions?
Kjellgren 1948
- planned sequence of extractions to relieve incisor crowding in the mixed dentition
- minimise demands of orthodontic services
- advantages and disadvantages
