list 4 ways to assess growth
1. interview information
2. clinical height/weight
3. adolescent changes (secondary sex characteristics, facial hair, voice change)
4. radiographically (ceph)
define lip incompetence
separation of the lips at rest more than 3-4mm. indicates dentoalveolar protrusion
define the "abnormal" mandibular plane angles
: long vertical face with anterior open bite
: short vertical face with deep bite
how is the maxilla's position evaluated with a profile analysis?
a line from the bridge of the nose to the base of the upper lip
how is the mandible's position evaluated in a profile anaylsis?
a line from the base of the upper lip downward
how does the nasolabial angle relate to lip protrusion?
lip protrusion = nasolabial angle > 90 degrees, < 109 degrees
how is the vertical facial relationship evaluated in a profile analysis?
dividing the face into 3rds
define E-line and how it is used
a reference line used to judge lip protrusion drawn from the tip of the nose to the pogonion
what are the normal vertical lip to tooth relationships during smiling and repose?
: lips to gingival margin and dental midline along the long axis
: 2-3mm of max. incisors showing
what are the normal measurements of an overbite?
3mm or 50% of mandibular incisors covered by max. incisors
and overbite of >3mm. (class III usually have a negative overjet)
what radiographs are required for the primary dentition?
BW and Pano
what radiographs are required during a late mixed dentition?
evaluation of canines with occlusal or PA radiograph
what radiographs are required for the permanent dentition?
pano and PBW or FMS
what methods are used to measure space in the permanent and mixed dentitions?
: direct measurement
: tanaka-johnston method
list 2 ways that space analysis is useful for prediction
1. a way to quantify the amount of crowding within the arches by comparing the space available vs amount of space required
2. predict if there will be enough space in the arch without growth modification or surgery
list the 6 assumptions underlying space analysis
1. all permanent teeth are developing normally
2. width of mand. inc. correlates with width of perm. teeth
3. prediction tables are valid
4. mesial molar shift is predictable
5. AP position of inc. is correct
6. space available will not change due to growth
how is the amount of space available determined?
1. arch perimeter is measured from first molar to first molar along contact points.
2. subtract size of incisors and predicted size of canines/premolars from space available
why are sizes of permanent teeth always predicted from lower incisors?
they are the most consistent teeth in the mouth and correlate best with upper canines/PM. upper laterals are extremely variable.
how is the tanaka-johnston analysis used to predict mandibular canine/pm in one quadrant?
[(MD width of the 4 lower incisors)/2] + 10.5mm
how is the tanaka-johnston analysis used to predict maxillary canine/pm in one quadrant?
[(MD width of the 4 lower incisors)/2] + 11mm
define Bolton Analysis
Tooth-size analysis: comparison of MD widths of max teeth to mand teeth
which teeth are analyized using the bolton analysis?
max to mand canine, pm, and m
which teeth usually account for discrepancies in the bolton analysis?
upper laterals and lower 2nd pm (termed bolton discrepancy)
what angular method is used to evaluate the AP position of the maxilla? what are the average angles for each class?
What angular method is used to evaluate the AP position of the mandible?
what angular method is used to evaluate the AP position of the maxilla to the mandible?
ANB = SNB - SNA
what angular method is used to evaluate the vertical face
mandibular plane angle to FH
FH to UI
: normally 110
FH to LI
: normally 90
what are the proportional methods to evaluate the vertical face?
% face height
: 55% NA to A
: 45% A to P
what is the interincisal angle?
formed by the long axis of both upper and lower incisors. greater angle = more upright incisors. Smaller angle = protrusion
define bimaxillary protrusion
both jaws have protruding teeth
at what points are two ceph radiographs compared?
lined up on S and N points.
extra/intraoral exam, skeletal/dental malocclusion, cephalometric analysis, space analysis