1. 1
Dr. Tran Ngoc Quang Phi

2. 2
Backgrounds
Angle classification
Six keys Andrew
Crown form
Arch form
Bolton analysis
Golden proportion

3. 3
Angle Classification
Malposition → individual tooth
Buccal or labial, lingual, mesial, distal, torso (rotation), infra
and supra.
Impacted
Malocclusion → anteroposterior relationships of
permanent first molars and canines.
Canine relationship:
The upper canine fits distal to the lower canine
Molar relationship
Class I: normal relationships → mesial buccal cusp
UFM≡mesial sulcus LFM.
Class II: distal buccal cusp UFM≡mesial sulcus LFM
Class III: buccal cusp USP≡mesial sulcus LFM

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5. 5
Angle classification extension
Class II division 1:
Narrowing of the upper arch, lengthen and protruding UC.
Abnormal function of the lips, nasal obstruction, mouth
breathing.
Class II division 1 subdivision: class I on one side.
Class II division 2:
Crownding, overlaping and lingual inclination UC
Normal nasal and lip function
Class II division 2 subdivision: class I on one side.
Class III subdivision: class I on one side.
Mild class II: between class I and class II
Mild class III: between class I and class III

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Class I Molar or Class I Canine?

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♦

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♦ ♦

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Four items that you "must complete" for
successful orthodontic treatment
1. The teeth must be straight at the end of treatment.
2. There must not be any spaces between the front
teeth.
3. There must not be any overjet (the patient refers to
overjet as "overbite").
4. The teeth must (generally) bite together at the end
of treatment. It is OK to have a bicuspid out of
occlusion, but the teeth must not be open molar to
molar.

13. 13
Six keys Andrew
1. Molar relationship :
Class I Angle
Cusp‐embrasure relationship buccally
Cusp‐fossa relationship lingually
2. Crown angulation:
All tooth crowns are angulated mesially (mesio‐distal tip)
3. Crown inclination:
Incisors are inclined labially
Upper posterior teeth are inclined lingually, similarly from
the canine to the premolars; upper molars are inclined
slightly more than the canine and the premolars.

14. 14
Angulation and inclination

15. 15
Lower posterior teeth are inclined lingually,
progressively from canine to molars
4. Rotations:
Rotations are not present
5. Spaces
Spaces are not present between teeth
6. Curve of Spee
The plane is either flat or slightly curve

16. 16
Curve of Spee
Yes No

17. 17
Anterior Crown form
Central incisor crown
form:
•Triangular‐shaped
incisors: need to be
reshaped to avoid one‐
point contact (→ black
triangle and unstable)
•Rectangular‐shaped
incisors: good esthetics
•Barrel‐shaped incisors: do
not provide ideal esthetics

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19. 19
Canine crown form
Markedly curved facial contour
Narrow and pointed incisally Wide and flattened incisally
Relatively flat facial contour

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Arch form
Square Ovoid Tapered

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The original arch form is considered the most stable
position since this is the "in balance" position of the
teeth and surrounding muscles: the neutral zone.
Any alteration of this position may result in instability
in retention.
Relapse tendency after changing arch form (De La
Cruz‐1995, Burke‐1998): inter‐canine width.
Expansion the lower arch form: 10%.
Tapered Ovoid Square
Japaneses 12% 42% 46%
Caucasians 44% 38% 18%

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Systemized management of arch form
Determine the arch form at the start of treatment
Template ♦
Computerized cast analysis @
Arch wire stocked:
Round arch wire (NiTi and SS): ovoid only
.019/.025 (.018/.025 ) HANT: three shapes
45% ovoid
45% square
10% tapered
.019/.025 (.018/.025 ) SS: ovoid only →

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♦

27. 27
Bolton analysis
Anterior Bolton analysis
Max 6: 40.0 – 54.5 (+0.5)
Mand 6: 30.9 – 42.1 (+0.4)
Overall Bolton analysis
Max 12: 85 – 110 (+1)
Mand 12: 77.6 – 100.4 (+ 0.9)
Ideal ratio → canine class I
Determine distance between hooks or loop
Bolton discrepancy → proper solution

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Anterior Bolton analysis Full archBolton analysis

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Ideal ratio in Bolton analysis
Maxillary 6 Mandibular 6 Maxillary 12 Mandibular 12
40.0 30.9 85 77.6
40.5 31.3 86 78.5
41.0 31.7 88 80.3
41.5 32.0 89 81.3
90 82.1
48.0 37.1 91 83.1
48.5 37.4 96 87.6
97 88.6
51.5 39.8 103 94.0
52.0 40.1 104 95.0
106 96.8
54.5 42.1 107 97.8

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Application?
•Chose the T –loop arch wire
•Adjust for the best fit occlusion

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Golden proportion
618.1=
==
+
ϕ
ϕ
b
a
a
ba

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→

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DIAGNOSIS
Collect data
Orthodontic questionaire
Clinical examination
X‐rays : POG and CEP
Models
Pictures
Cephalometric analysis
Model anlysis
→ Diagnosis: problem list

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Orthodontic Questionaire
MEDICAL HISTORY
Under a physician's care at this time? Yes/No. Explain
Taking any medication at this time? Yes/No. Specify
Allergic to any medication? Yes/ No. Specify
Any other allergies? Yes/No. Specify
Need to be premedicated (antibiotics) for routine dental
procedures? _Yes _No. Specify and reason

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Following diseases or conditions? (If yes, explain and
date):
AIDS__ Bleeding disorder __ Anemia__
Lung disease__ Cerebral palsy__ Heart condition__
Arthritis__ Hepatitis__ Kidney disease__Rheumatic
fever___ Asthma__ Diabetes__ Epilepsy__
Injury to face/head__
Tonsil/adenoid surgery__ Previous surgery__
Females: Is the patient pregnant? __ Yes __ No

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DENTAL HISTORY
Date of last dental examination
Any injury to the face/teeth/gum? Explain and date.
Any previous orthodontic treatment/consultation?
Does the patient:
Grind his/her teeth at night?
Bite his/her fingernails?
Suck thumb, finger, pacifier, etc.?
If yes, at what age was the habit discontinued? __years
Has another member of the family had orthodontic
treatment? Whom?

40. 40
Medical conditions to be considered in
orthodontic treatment
Medical condition Implications Action
Asthma Root resorption Monitor every 6 mo for evidence
of EARR
Allergies Allergic reaction Determine materials causing
allergy
Coagulation disorders Bleeding risk Extraction?
Diabetes Periodontal disease Monitor adequate control of
diabetes
Epilepsy, High blood
pressure
Gingival
hypertrophy
Plaque control, gingivectomy if
necessary
Heart valve conditions Endocarditis Premedication when extraction,
fitting bands
Rheumatoid arthritis TMJ degeneration Monitor TMJ
Xerostomia Caries Fluoride supplement

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PATIENT'S ATTITUDE AND MOTIVATION
Is the patient aware of the problem?
Consultation here prompted by _________________
Patient's interest in having treatment is:
__ Wants treatment ___ Willing if necessary __ Unwilling
If the patient’s teeth were to be changed, how would you
like them changed? _______________________________
If any features of the face could be changed, what would
you like to see? ___________________________________

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GROWTH STATUS: (child patients only)
Height__________ cm Weight _________kg
Females: Has the patient started her menstruation?
__ Yes __ No. If yes, at what age? ________
Males: Voice changes? __ Yes __ No
Facial hair growth? __ Yes __ No
Has the patient had any recent rapid growth? ___________
If so, how much?_______________

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Rational for Orthodontic questionaire
Chief complaints
Determine patient’s motivation, expectation
Medical and Dental history
Reveal the causes of problems
Relation between the patient’s conditions and
orthodontic treatment
Growth and development
Timing of orthodontic treatment

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CLINICAL EXAMINATION
Esthetic analysis
Macro esthetics: facial proportion
Mini esthetics: tooth – lip relationships
Micro esthetics: dental appearance
Functional analysis
TMJ
Occlusion
Periodontal health
Bad habit

45. 45
Macro esthetics: facial proportion
General view
Dolicofacial, brachyfacial, mesiofacial →
Frontal view
Vertical
Proportion
Chin height
Lower face height
Horizontal
Proportion: rule of fifth
Midline asymmetry

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Vertical proportion

47. 47
Horizontal proportion

48. 48
The lower third @
A. Increase face height:
Dolicofacial pattern
Vertical maxillary excess (VME) ♦
High lip line: anterior teeth display too much
Gummy smile
Lip length: normal
≠ Short lip ♦
Excesssive chin height ♦
B. Decrease face height
Brachyfacial pattern
Vertical maxillary deficiency
Mandibular defienciency ♦
Short chin height ♦

49. 49
Dolicofacial
•Long and thin faces. Weak
muscles of mastication that are
not strong enough to hold the
teeth together during
orthodontic treatment.
•Non extraction treatment of
these cases may result in bite
opening during the treatment.
•When extraction, space closes
quickly.
Be careful when treating a
protrusion case

50. 50
Mesiofacial
•Mesiofacial is not long and
thin facial features, and not
short and square facial
features.
•In these cases you can extract
and the extraction spaces will
close "normally".
•You can treat these case types
non extraction and the teeth
will remain in occlusion
during treatment.

51. 51
Brachyfacial
•Short, square faces with
very strong muscles of
mastication.
•Short clinical crowns with
some excess enamel wear on
the occlusal surface of the
teeth.
•In these cases, if you
extract, then the extraction
spaces will close slowly.

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♦

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♦

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Pre‐orthodontic Post‐
orthodontic@

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@@

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Short lip: @
Philtrum height < commisure height
Inverted lip

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Asymmetry
Upper midline asymmetry
Orthodontist : < 2mm
Dentist : 2 – 4mm
Non‐professional person: >4mm
Lower midline asymmetry
Cause
Upper : missing tooth, impacted tooth, crowding…
Lower: causes as upper arch, esp: TMJ
Always the tough cases

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Profil view
Proportion
Convex, straight, concave
Straight: anterior divergence, posterior divergence
Mandibular plane angle
Lower face
Maxillary projection
Mandibular projection
Chin projection
Lip
Lip posture and incisor prominence
Lip fullness
Labiomental sulcus
Throat form
Chin – throat angle
Throat length
Submental contour

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Profil view

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Black pattern

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Convex treatment?
Be careful not to set the patient's expectations too
high for reducing a convex profile: it takes 2‐3mm of
tooth retraction to result in 1mm of lip retraction.
Move the chin forward to reduce feeling convex
Lefort I + BSSO for comprehensive treatment

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Mini esthetics: Tooth – lip relationship
Philtrum height
Commisure height
Interlabial gap
Incisal display at rest
Smile analysis
Emotional smile and social smile
Incisal display on smile
Gingival display
Smile arc
Buccal coridor width
Arch form
Transverse cant

69. 69
Vertical measurements
A: Philtrum height
B: Commisure height
C: Interlabial gap
D: Incisal display at rest
A: Incisal display on smile
D: Smile arc
C: Gingival display
B: Crown height and width

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Emotional smile and social smile
Major zygomaticus muscle Risorius muscle

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Smile arc
The contour of the incisal edges of the maxillary anterior
teeth relative to the curvature of the lower lip during a
social smile

72. 72
Transverse cant

73. 73
Gummy smile
Crown lengthening
Orthodontic treatment
Lefort I Osteotomy
Plastic surgery

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Micro esthetics:
gingival and dental appearance
Tooth proportion: crown height and width
Width relationship and golden proportion
Gingival height , shape and contour
Connectors and embrasures
Tooth shade and color

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Crown height and width
The width of central
upper incisor should be
about 80% of it’s height.
The disproportion
should be done before
orthodontic treatment is
completed.

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Width relationship and golden proportion

77. 77
Gingival shape and contour
Gingival shape of upper
central incisors and canines
is more elliptical.
Gingival shape of upper
lateral incisors and
mandibular incisors is a
symmetric half‐oval or half‐
circular one.
The gingival zenith of
central and canine is located
distal to the longitudinal
axis.
The gingival zenith of lateral
incisors coincides with the
longitudinal axis.

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Connectors and embrasures
Connector # contact point area:
Include the areas above and below
the contact point.
Greatest between the central incisors
and diminish from the centrals to the
posteriors.
Embrasures: triangular spaces incisal
and gingival to the connector.
Gingival embrasures are filled by
interdental papillae.
Short interdental papillae → black
triangle.
Tapered crown form → black triangle

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Clinical considerations
Open bite
Tongue thrust
Functional shift
Missing tooth
Lower Anterior Tissue Thickness

80. 80
Open bite
Principle: Teeth erupt until they hit something.
Open bite: the lower
incisor does not contact
the upper incisor. There
are obvious open bite
cases where the teeth are
separated in the anterior.
In some class II cases
where the amount of
overlap of the upper
incisor vs. the lower
incisor is normal (1/3
coverage), but the lower
incisor does not contact
the tooth nor the palate.

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Tongue thrust
A test for anterior tongue thrust is to:
Take a small sip of water.
Close the teeth together with the lips open.
Swallow.
A patient with an anterior tongue thrust will either:
Not be able to keep his/her lips open.
Will tilt his/her head back for gravity to keep the water from squirting
forward.
Will squirt the water between the teeth forward onto their shirt (child
patient).
A good exercise to give a patient with an anterior tongue thrust
(especially in the presence of open bite or excess anterior overjet) is:
Take a small sip of water.
Close the teeth together with the lips open.
Swallow with the throat muscles. Tell the patient to hold their hand
on their throat as they learn this exercise to feel the muscle
contraction.

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Functional Shift
Forward functional shift
Lateral functional shift
Unilateral crossbite
Dental midlines not
centered.
The asymmetric face
from the frontal view.

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84. 84
Missing Tooth
This seems very obvious, but in many cases where a
tooth has been lost, the space has closed
spontaneously by dental drifting. It is very easy to not
notice a missing tooth in a dental arch when doing
your examination.
Be certain that you count 4 incisors, 2 canines, 4
bicuspids, etc. in each arch, before checking "none."

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Lower Anterior Tissue Thickness
Principle: The lower arch is considered the limiting
arch in edgewise diagnosis.
To align crowded teeth, advancement (forward
movement) of the teeth will inevitably occur.
If the advancement of the lower incisors is significant,
then a periodontal defect (stripping of gingival tissue
is the most common) can occur.
Advancement of incisors with "thin tissue" has more
risk than advancement with "thick tissue" labial to the
lower incisors. As the teeth advance, the tissue will
become thinner.

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Cephalometric analysis: lanmarks

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Planes

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Growth direction

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SNB
Mandible is protrusive if > 83
Mandible is average if 76 – 82
Mandible is retrusive if <75

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Cephalometric analysis – Skeletal
Description Measurement Mean Range
Pal. plane to Md. Plane: Skeletal
Open/closed
ANS‐PNS to Md. plane 280 Closed 240 – 330 Open
Md. Plane angle: Skeletal Open/closed FH – MA: Child
Adult
260
220
Closed 200 – 300 Open
240 – 330
Y – Axis Vert/Hor Growth SGN ‐ FH 590 Hor. 570 – 620 Vertical
Maxilla to Cranium N ⊥ A +1mm Retruded ‐1 to +3 Protruded
Maxilla to Cranium SNA 820 Retruded 760 – 830 Protruded
Mandible to Cranium N ⊥ Po : Child
Adult
‐7mm
‐1mm
Retruded ‐10 to ‐4 Protruded
‐4 to ‐1
Mandible to Cranium SNB 790 Retruded 750 – 830 Protruded
Maxilla to Mandible ANB 20 Class I : + 20 to +4.50
Class III tendency: +0.50 to +1.50
Wits A, B ⊥ Occlusal plane 0 mm Class I : ‐1 to +2

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Cephalometric analysis –
Dental
Description Measurement Mean Range
Interincisal Angle to 1300 Best finish 125 0 – 1300
Lower Incisal Inclination to MP 920 Retroclined 890 – 980 Proclined
Lower Incisal Protrusion to NB +4mm Retruded +1 to +6 Protruded
Lower Incisal Protrusion to APo +2mm Retruded 0 to +4 Protruded
Upper Incisal Inclination to SN 1030 Retroclined 990 – 1060 Proclined
Upper Incisal Protrusion to APo 5mm Retruded +2 to +7 Protruded
Upper Incisal Protrusion to A vertical
(to FH)
4mm Retruded +2 to +6 Protruded
1
1
1
1
1
1
1
1
1

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Cast analysis

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109. 109
Cast analysis by software

110. 110
Advantages of computerized analysis
Accurate
Easy
More information:
Arch form
Loop distance (Bolton analysis)
Determine asymmetric Arch
Space analysis
Rotation
Prediction

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DETERMINE THE PROBLEMS
Kind of problems:
Dental problems
Skeletal problems
Facial problems
Occlusal problems
TMJ problems
Periodontal problems
Causative factors
Degree of problems

112. 112
Ackerman and Proffit diagram
Aligment (spacing and crowding)
Profile (convex, straight, concave)
Sagittal deviation (Angle class)
Vertical deviation (deep bite, open bite)
Transsagittal deviation (combine Angle class and cross
bite)
Sagittovertical deviation (combine Angle class and deep
bite or open bite)
Verticotransverse deviation (combine cross bite and deep
bite or open bite)
Transsagittovertical deviation (combine of problems in
three planes of space)

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DENTAL PROBLEMS
Intra‐arch problems
Inter‐arch problems
Causative factors
Degree of the dental problems

115. 115
Intra‐arch problems
Position :
Protrusion or retrusion of incisors
Malposition
Impaction
Rotation
Angulation
Inclination:
Procline or recline
Spaces:
Spacing or crowding
Curve of Spee

116. 116
Inter‐arch problems
Molar relationship
Class I, II, III
Canine relationship
Class I, II, III
Vertical relationship:
Overbite, deep bite, open bite
Horizontal relationship:
Overjet, end‐to‐end, anterior crossbite.
Posterior crossbite
Upper and lower incisor angulation
Inter‐arch discrepancy
Midline relationship:
Midline asymmetry

117. 117
Causative factors
Spacing
Large jaw
Small teeth
Missing teeth
Lateral over‐expansion of arches or forward proclination of
anterior teeth.
Crowding
Small or constricted arches
Large teeth
Retroclination
Mesial drift of posterior teeth

118. 118
Openbite
Bad habit: thumb sucking, finger sucking or pacifier
using, tongue thrush, lip habit.
High tongue posture
Airway obstruction: allergies, enlarged tonsils,
adenoids, septum problem…
Intracapsular TMJ problems
Skeletal growth abnormalities

119. 119
Diagnosis of Impacted Teeth
Impacted Teeth : not erupted for 2 years following the
normal eruption age.
The eruption path is blocked, or if the eruption stops after
the tooth strays to a position labial or lingual to another
tooth.
The most common impaction: the upper canine.
DIAGNOSIS OF AN UPPER IMPACTED CANINE
Panoramic x‐ray: Any overlap of the canine crown with the
lateral incisor roots → impaction?.
Palatal or labial?
Palpate the labial tissue
Occlusal x‐ray

120. 120
Crowding and impacted tooth
The "impacted tooth" may be BLOCKED OUT of the
arch because of crowding: in a good position but
cannot erupt due to a lack of space →blocked out.
Evaluate the root formation to determine eruption
potential: incomplete root formation → eruption
potential.
Tx: space is made with open coils or extraction and a
deadline # 12 months is set to wait for its eruption.

121. 121
Consideration in impacted tooth
Position: labial (good) or palatal
Angulation: the more vertical the more success
Space available: enough?
The path to the correct position?
The age: best under 25
The risk:
Ankylosis
Damage the adjacent teeth

122. 122
Degree of problems:
Diagnostic Parameters
1. Canine and molar relationships: RM, RC, LM, LC
2. Angle classification
3. Overbite
4. Overjet
5. Stage of dental development
6. Presence of crossbite: with or without functional
shift
7. Space analysis
8. POG interpretation
9. CEP interpretation

123. 123
1. Canine and molar relationships: RM, RC, LM, LC
a. Class I
b. Class II*
c. Class III*
d. Not fully erupted
2. Angle classification
a. Class I malocclusion
b. Class II malocclusion, division 1, 2 and subdivision*
c. Class III malocclusion, subdivision*

124. 124
3. Overbite
a. Normal (5 % ‐ 20%)
b. Moderate deep bite (20% ‐ 50%)
c. Severe deep bite ( > 50%)*
d. Edge to edge
e. Anterior open bite
4. Overjet
a. Normal (1 – 3mm)
b. Excessive ( > 3mm)*
c. Edge to edge
d. Underjet (negative overjet)

125. 125
5. Stage of dental development
a. Deciduous dentition
b. Early Mixed dentition
c. Late Mixed dentition
d. Permanent dentition
6. Presence of cross bite: with or without functional shift
a. None
b. Anterior
c. Posterior
d. Both

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7. Space analysis
a. Adequate arch length ( +1 to ‐1mm)
b. Mild crowding (‐2 to ‐3mm)
c. Moderate crowding (‐4 to ‐6mm) or Severe (> ‐6mm)
d. Mild spacing (1 – 3mm)
e. Moderate spacing (4 to 6mm) or Severe (> 6mm)
8. POG interpretation
a. Normal
b. Abnormal: missing, supernumerary, ectopic, impacted
tooth)
9. CEP interpretation
a. Normal
b. Beyond the normal range: 1 SD
c. Beyond the normal range: 2 SD
d. Beyond the normal range: 3 SD