Orthodontics Flashcards
definition of local causes of malocclusion
localised problem or abnormality within either arch which produces a malocclusion
due to variation of tooth number, variation in tooth size/form, abnormalities in tooth position, abnormalities of soft tissues or local pathology
local causes of malocclusion due to variation in tooth number
supernumerary teeth
hypodontia
retained primary teeth
early loss of primary teeth
unscheduled loss of permanent teeth
4 types of supernumerary teeth
supplemental
odontome
tuberculate
conical
4 occlusal features that can be present due to a prolonged digit sucking habit
anterior open bite
posterior cross bite
proclined upper anteriors
retroclined lower anteriors
4 methods used to dissuade a digit sucking habit
positive reinforcement
bitter tasting nail polish
gloves/elastoplast
habit breaking appliance
effect of prolonged digit sucking habit on posterior dentition
narrowed dental arch, changes in palatal shape, permanent skeletal change
consideration XLA of carious 6s
take a radiograph - what information are you looking for to identify suitability of timing for these extractions
stage of eruption of 2nd molars, calcification of 7s bifurcation, degree of crowding, malocclusion type
if XLA of tooth 16, 36, and 46
what will you do with 26?
extraction
advantages of XLA of 1st permanent molars of poor prognosis at 9y/o
unerupted 2nd molar will mesially drift into contact with 2nd premolar [may not need ortho]
removal of pain
prevents spread of caries
disadvantages of XLA 1st permanent molars of poor prognosis at 9y/o
opposing arch can overerupt
GA may be required
difficult to chew without 7s through
disrupts eruption sequence
malocclusion
loss of permanent tooth
risk of GA
bad experience
what might a child require to get 3 permanent molars extracted
GA or sedation
8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
what is important about dental history to determine
was there trauma to the primary tooth
8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
what part of physical examination is important
if permanent central incisor is palpable
8 y/o whos primary upper incisor become black and firm 3 years ago and fell out recently
he is missing 21
given the history, give an account of events which most likely caused non-eruption of central incisor
trauma to the primary central incisor
this could have damaged the tooth germ, altered eruption path, disturbed dental follicles
ankylosis of the primary tooth caused displacement of tooth germ and dilaceration of the root
what are the principles of ortho management of non-eruption of upper central incisors
remove any primary and supernumeraries
ensure space for eruption
check contralateral
radiographs and monitor
refer
space maintainer URA if necessary
closed exposure - surgery to raise mucoperiosteal flap, orthodontic traction hook bonded to palatal surface, flap replaced with gold chain entering oral cavity through attached mucosa
open exposure - elliptical flap cut over crown, reserved for impactions which are soft tooth only and tooth crown is superificial
principles of orthodontics tx for unerupted permanent central incisor
restore stability, function, aesthetics
facilitate other forms of dentistry like crowns/bridges
what is the incisor relationship of a pt with proclined upper incisors and increased overjet
class II div 1
methods to clinically assess a pt antero-posterior skeletal pattern
visual assessment of facial profile
palpatation of skeletal bases
ANB on cephalogram
non-skeletal aetiological causes of class II div 1
digit sucking habit
tongue thrusting
what type of orthodontic appliance can be used to harness growth potential for a patient with class II division 1
twin block therapy/appliance
promotes mandibular advancement, guides lower jaw forward when biting
brief account of how it is though mandibular growth occurs
Development intramembranously but is proceeded by cartilaginous facial skeleton
Endochondral ossification, where cartilage becomes bone
Growth from condylar cartilage, downwards and forwards, surface resorption anteriorly and lingually with deposition laterally and posteriorly
Grows in width, length and height throughout puberty
if class II div 1 has forward growth rotation, what would you expect to observe in the skeletal pattern
retruded maxilla
increased lower vertical height
reasons for abnormalities in tooth number
hypodontia
retained primary teeth
supernumerary
early loss of primary teeth
unscheduled loss of permanent teeth
ways to measure vertical skeletal relationship
FMPA
LAFH to TAFH [upper anterior facial height to lower anterior face height]
