malocclusion Flashcards
what was an important part of ortho that was not of concern in the early days
The way upper and lower teeth contacted one another
the father of moddern ortho (inveted terms of malocculsion)
edward angle
angle’s postulate said what was the key to occlusion
Maxillary first moloars: that the mesiobuccal cusp of upper first shoud be in the bucal groove of the lower first
-if all else were aligned, everything else would occldude
where does angles line of occulsion pass through
- The central fossae of the maxillary posterior teeth and across the cingualum of the uper canine and insicors
- buccal cusp of the mandibular posterior teeth and incisal edge of canine and incisors
what is class II occlusion
Lower molar distal
what is a class III occlsion
Lower molar is mesial
what angles classification does not have a line of occusion
class II Class III
what is a class I occlusion
Normal of molars
Line of occlusion incorrect due to poorly aligned teeth
what angle’s classification does not have problems
Just simple normal occlusion
how important did angle view dental occlusion
That facial asthetics would follow
- not true
what did cephalmoetric radiology show
That the Joints/jaws were partly invovled in how teeth occluded leading to Class I, II, and III not jsut malposed teeth.
skeletal class II
Small mandible to maxilla
skeletal class III
large mandible to maxilla
what became the ortho goal after angle
Correct possition of teeth and jaw
- in addition to soft tissue
how was the extent of malocclusion calculated
using an irregularity index
- the total distance between incisor contects
overjet
the horizontal overlap of inciors
what is normal overjet
2-3mm, the tickness of one incors
what does excessive overjet correlate to
class II
what does reverse overjet correlate to
class III
what is better description of malocclusion overjet or angle’s classification
Overjet
what percent of the population has the correct overjet
1/3
1/3 increased
moderat(5-6mm): 10%
gross overjet (greater than 7)”5%
how common is reverse overjet
5% of asian
.5% african americans
.3 whites
overbite
vertical overlap
what is normal overbite
contact at or above the cingulum about 1-2mm
what is an open bie
no overlap(negative overbite)
how common is overbite
half is ideal
moderate over bite is more common that open bite
extremes are about equal
how does crowding change with age
it increases with age
how does overjet change with age
it increases with age
what is more common, deep or open bite
Deep bite
what racial group has more open bites
African americans
what racial group has more deep bites
Whites
what is the problems with malocclusion
Psychosocial problems due to discrimination b/c dental and facial appearance
Problems with oral function
greater change of trauma
what are the oral function problems associated with maoclusion
Difficult to move jaw (bad muscle coordination
tmd
problems with mastication and speech
do people with bad occlusion usually report difficulty eating
No
does severe malocclusion usually lead to TMD
No
can malocclusion lead to dificulties in swallowing and speach
Rare
- can speak even with terrible oclusion, but usally adapts with tongue (also for swallowing
risk due to protruding upper incisors and excesss overjet
greater risk of injury to the teeth during childhod
what can extremem overbite lead to
DAmgaged tissue lingual to the pper inciros or labial to the lower
- even loss of teeth
do poorly aligned teeth lead to caries
No
how is ortho treatment shown to be needed
By the worst ortho related problem
how is ortho treatment need scaled
based on the IOTN with 1 as no need and 5 as extreme need
WHEN DO PEOPLE MOST NEED ORTH
gRADE 4 AND 5
what perecents of races are level 4 and 5 ortho
Whites: 15%
blacks: 20%
hispanic: 15%
what area tends to think they don’t need ortho treatment
In the country
