Ortho GD

SNA

81 (3.5)
maxilla to cranium

SNB

80.9 (3.4)
mandible to cranium

ANB

2 (2.1)
relation btw maxilla and mandible

SN-GoGn

33 (4.5)
mandibular angle

FMA

23 (7.4)
mandibular angle

Y-axis

59 (2.9)
mandibular growth direction

UFH (mm)

54 (2.9)
upper facial height

LFH (mm)

68 (3.0)
lower facial height

UFH/LFH

0.8 (0.5)
ratio of upper/lower facial heights

U1-SN

102 (6.3)
upper incisor to cranium

U1-NA

24 (3.5)
upper incisor to maxilla

U1-NA (mm)

4 (1.3)
upper incisor to maxilla

IMPA

90 (5.2)
lower incisor to manddible

L1-NB

25 (3.0)
lower incisor to mandible

L1-NB (mm)

4 (1.9)
lower incisor to mandible

nasolabial

102 (8.7)
upper lip prominence

e-line

-4U/(-2)L (1.1)
upper/lower lip prominence

normal occlusion

MB cusp of the maxillary first molar in the buccal groove of the mandibular first molar, and intra-arch relationships among teeth are correct

Class I Malocclusion

MB cusp of the maxillary first molar in the buccal groove of the mandibular first molar, (but intra-arch relationships among teeth are abnormal)

class II malocclusion

Mesiobuccal cusp of the maxillary first molar anterior to the buccal groove of the mandibular fist molar

class II division 1 malocclusion

maxillary incisors flared

class II division 2 malocclusion

maxillary incisors upright (lateral flared) and deep overbite

class III malocclusion

MB cusp of the maxillary first molar posterior to the buccal groove of the mandibular first molar

goal of modern ortho

"the creation of the best possible occlusal relationships within the framework of acceptable facial esthetics and stability of the occlusal result".

patient questioning

- CC
- med and dental hx
- motivation, expectations, and pt cooperation

goals of clinical exam and eval

to document and evaluate facial, occlusal and functional characteristics, and to decide which diagnostic records are required

extra oral photos

for eval of facial properties, profile, and smile arch

intra-oral photos

for dental diagnosis

dental casts or digital models

for dental diagnosis

panoramic xray

for checking dental development and anomalies

cephalometric xray

For skeletal measurements, diagnosis of craniofacial disharmonies, and growth status

hand wrist xray

for checking growth status

CBCT

For checking skeletal asymmetry, cranial facial abnormalities, if planning for orthognathic surgery, impaction of teeth

horizontal proportions of face

• For ideal horizontal proportions:
• Divided into central, medial and lateral equal fifths.
• we look for bilateral symmetry in the fifths of the face and for proportionality of the widths of the eyes / nose / mouth.

vertical proportions of face

The lower facial third often is slightly longer than the central third.
\-- N to ANS
\-- ANS to Me

total facial height

(N-Me) consists of: Upper Facial Height (N-ANS) & Lower Facial Height (ANS-Me)

lower facial height

mostly responsible for variances in facial height
- ANS-Me
- average 70mm, 57% of face

average facial height

121mm

lower facial height and growth

Lower facial heights greater than57% are suggestive on increased vertical facial growth; Whereas a smaller percentage is indicative of a tendency for more horizontal growth

Dolichocephalic

narrow long face

brachycephalic

wide short face

mesocephalic

neither long nor short face (normal)

face profile

comprised of many components:
- The slope of the forehead
- The contour of the nose, lips &chin
- The relative AP position of the mid-facial region and the mandible.

goals of facial profile analysis

• Eval of the mandibular planeangle.
• Eval of the relationship of the jaws in the AP plane of space
• Eval of lip posture and incisor prominence

steep mandibular plane angle

a steep (high) mandibular plane angle: long anterior facial height & anterior open bite or tendency

flat mandibular plane angle

A flat (low) mandibular plane angle: short anterior facial height & anterior deep bite or tendency

facial profile

• Patient placed in natural head position (sitting upright or standing).
Note the relationship between 2 lines:
- From the bridge of the nose (soft tissue "Nasion N") to the base of the upper lip (soft tissue "A point")
- From the base of the upper lip (soft tissue "A point") to the chin (soft tissue "Pogonion Pg")

convex profile

Suggestive of a Skeletal Class II jaw relationship

concave profile

suggests a skeletal class III tendency

straight profile

Class I Skeletal

divergence of the face

an anterior or posteriorinclination of the lower face (mandible) relative to the forehead

retrognathic

posterior divergent

mesognathic/ orthognatic

straight (divergence)

prognathic

anterior divergent

Prominence or retrusiveness of the lips can be evaluated:

By observing the distance that each lip projects forward from a true vertical reference line passing through the concavity at the base of the upper lip ("A") for the upper lip prominence and through the concavity between the lower lip and chin ("B") for the lower lip.

normal lip posture

in normal circumstances, the lips should lie ON orSLIGHTLY IN FRONT of these lines
- Lip prominence of more than 2-3 mm in the presence of lip incompetence (separated by 3-4 mm at rest) is suggestive of the anterior teeth are excessively protrusive, and conversely if it is behind the lines, is suggestive of retrusion

E line

line drawn from the tip of the nose to the tip of the chin

incisors flared buccallyh or lingually

• If the incisors are flared buccally, they align themselves along the arc of a larger circle, which provides more space to accommodate the teeth and alleviate crowding
• Conversely, if the incisors tipped lingually, there is less space, and crowding becomes worse.

The teeth protrude excessively only if the following three conditions are met:

1. The lips are separated at rest by more than 3 to 4 mm (lip incompetence)
2. Excessive effort to bring lips together (lip strain)
3. The lips are prominent and everted in the profile view

incisor prominence and race/ ethnicity

- Caucasians of Northern European background often have relatively thin lips with minimal lip and incisor prominence
- Caucasians of Southern European ancestry, Middle Eastern and Latin backgrounds normally have more lip and incisor prominence than people from northern ancestry
- Greater degrees of lip fullness and incisor prominence occur in African-American and Asian-Americans

overjet

Horizontal overlap of the incisors (2-3 mm are in the normal range)
• Reverse overjet or anterior crossbite
• Excessive overjet-CII
• Reverse overjet- CII

overbite

vertical overlap of the incisors
- normal, deep, or open

malocclusion transverse plane

• If the base of the palatal vault is wide, but the teeth lean inward, the cross bite is DENTAL.
• If the palatal vault is narrow and the maxillary teeth lean outward but nevertheless are in cross bite, the problem is SKELETAL

three assumptions of space analysis

- AP position of incisors is right
- no growth
- all the teeth are present and reasonably normal in size

space analysis \=

space available minus space required

methods of determining space available

- brass wire contouring
- segmentation of dental arch

brace wire contouring steps

1. contour brass wire into an arch form
2. place brass wire mesial to permanent first molar on one side. contour and place wire in middle of alveolar ridge
3. extend to mesial of perm first molar on other side.
4. mark wire
5. cut wire
6. stretch wire straight and measure the length

two segments of dental arch

1. incisors area (centrals and laterals)
2. premolars area (canines and PMs)

space required for permanent dentition

sum of the width of all teeth from 2nd PM to 2nd PM

negative space analysis

crowding

positive space analysis

spacing

space required for mixed dentition

Tanaka-Johnston analysis

the clinical application of the space analysis for mixed dentition in a more general form
- child should be 7-9yo and in mixed dentition
\-- four permanent lower incisors need to be present

moyers prediction

MD width sum of 4 lower incisors \= upper and lower un-erupted canine and PMs

Tanaka-Johnston's prediction

1/2(sum of lower incisors) + 10.5mm \= estimated width of mandibular canine and PMs

1/2(sum of lower incisors)+11.0mm \= estimated width of maxillary canine and PMs

crowding less than 4mm

resolving the crowding with interproximal reduction of teeth mostly anterior, or flaring of the teeth if soft and hard tissue allows it

crowding 5-9mm

resolving the crowding by expansion if the soft tissue and hard tissue allows it, if not extractions will be needed

crowding more than 10mm

resolve the crowding by extractions

leeway space

the difference between the MD width of the primary 1st and 2nd molars and the MD width of the permanent 1st and 2nd premolars
- An average of 2.5 mm can be gained in the mandibular arch per side, and 1.5 mm in the maxillary arch per side

primary space

max: space between lateral and primary canine
mand: space between canine and first molar

anterior ratio

(Lower canine width/Upper canine width) x 100 \= (%)

reasons for ceph analysis?

- orthodontic and orthognathic diagnosis and tx planning
- ortho tx outcome eval
- study and monitor growth of dentofacial structure

ceph analysis steps

1. take ceph
2. ceph film tracing
3. determine reference points and planes
4. measure various variables (angular vs linear)
5. compare measures with norms -\> diagnosis

magnification \=

Image size/actual size
\= b/a

horizontal planes

- anterior cranial base
- frankfort plane
- palatal plane
- occlusal plane
- mandibular plane

anterior cranial base

sella to nasion

frankfort plane

porion to orbitale

palatal plane

posterior nasal spine to anterior nasal spine

occlusal plane

Highest point on molar to 1/2 OB of U1-L1

mandibular plane

gonion to gnathion

vertical planes

1- NA, NB planes
2- Y-axis
3- Upper 1 axis
4- Lower 1 axis

NA, NB planes

Y-axis

sella to Gn

upper 1 axis

lower 1 axis

antero-posterior relationship

*ANB* \= SNA-SNB
Relationship between maxilla and mandible to craniobasej

ANB \=

SNA - SNB

2\= 82 - 80

SN-GoGn

relationship between mandibular plane and SN plane

FMA

angle between mandibular plane and frankfort plane

Y-axis angle

An angle between Y axis and Frankfort plane