1. UNIVERSITY OF SYDNEY
Orthodontic Diagnosis
Dr. Mohammed Almuzian
B.D.S. (Hons), M.Sc.Orth. (Distinction), D.Clin.Dent.Orth. (UK), M.Sc. HCA (Merit) (USA), MFDS RCS (Edinburgh), MFD RCS
(Ireland), MJDF RCS (England), MFDS RCPS (Glasgow), MRCDS Orth. (Sydney), M.Orth. RCS (Edinburgh), FIADFE (USA),
IM.Orth. RCS (England/Glasgow)
1/1/2015
.

2. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 20151
Orthodontic Diagnosis
Diagnosis is the definition of the problem. Treatment planning is based on
diagnosis and is the process ofplanning changes needed to eliminate the
problems. Treatment is execution of the plan. (Arnnett 1993)
The database information sources
1. Questions of the patient (written and oral),
2. Clinical examination of the patient
3. Evaluation of diagnostic records, including dental casts, radiographs and
photographs.
Questionnaire/Interview
1. Chief Complaint
It usually started by this question:
‘’Tell me whatbothers you aboutyour face or your teeth’’
This will influence the treatment plan in case of:
1. Treatment approach. For example: Is the patient bothered by the appearance or
function of an anterior open bite or is it the long face or the gummy smile that are
the main concern? This may strongly influence the choice between Young Kim
type orthodontic mechanics and a Le Fort osteotomy.
2. Expectation of the patients

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3. Decision in the borderline case. Forexample: Is the patient bothered by the
prominent upper teeth or also by the receding chin? This may profoundly affect
the chosen plan in cases of borderline skeletal severity.
2. Medicalhistories
1. Has the child been hospitalized? This help to evaluate history of trauma
2. Immunization update? Since soft tissue injuries increased in orthodontic
appliance wearer.
3. Allergy to medication or other thing? Specially to medication or latex, nickel
4. Infectious disease?Infection control
5. Heart diseases?Forantibiotic cover
6. Arthritis? Mandibular growth
7. Cancer?Evaluate radiation or chemotherapy which affect growth and need good
OH and orthodontic treatment is preferable to be postponed until curing
8. Tonsiland adenoid and sinus? AOB
9. Diabetis?Good OH
10.Epilepsy? Trauma by braces and need good OH due to hyperplasia
11.Growth problem? May be patient took growth pills which affect growth
modification appliance.
12.Long-term medication of any type, and if so, for what purpose. This may
reveal systemic disease or metabolic problems that the patient did not report in
any other way. Chronic medical problems in adults or children do not

4. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 20153
contraindicate orthodontic treatment if the medical problem is under control, but
special precautions may be necessary , In adults being treated for arthritis or
osteoporosis, high doses ofprostaglandin inhibitors or resorption-inhibiting
agents may impede orthodontic tooth movement
3. Dental history
1. GDP attendance?Motivation and awareness
2. Complication following any dental treatment? To avoid it
3. Number of brushing and diet control? To controlit before orthodontic
treatment.
4. Previous orthodontic treatment? Increased risk for OIIRR
5. Any x-ray taken? To reduce unnecessary repeat
6. Dental family problem? Like hypodontia or class III.
7. Trauma to teeth or jaw? Traumatized teeth resorb faster or TMJ fracture may
affect growth.
8. Pain or clicking in TMJ? Need to be address and reported to avoid potential
legal action
9. Habit? Aetiology of malocclusion and stability of results
4. PhysicalGrowth Evaluation
This can be done by:
1. Questioning about how rapidly the child has grown recently, whether clothes or
shoes sizes have changed,

5. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 20154
2. Evaluating the signs of sexual maturation
3. Height weight growth chart
4. Cervical maturity
5. Hand wrist technique
6. Dental development
5. Behavioural Evaluation
Asking, “Do you think you need braces which can do this?” This will help to
determine:
1. Patient expectation
2. Patient concern
3. Type of motivation whether internal or external motivation.
4. The degree of cooperation
Clinical Evaluation
Frontal View
Facialtype Facialindex 1.3:1
Bizygomatic facialwidth 70% of TFH
Bitemporal width 60 % of TFH
Bigonialwidth 50% of TFH

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Vertical heights TFH (190-210mm) is one-tenth of
standing height
upper third from
hairline (trichion) to
glabella,
Equal (62-70 mm for each)
middle third from
glabella to subnasale,
lowerthird from
subnasale to softtissue
menton
Upper lip 19-22mm
Lower lip and chin 42-48mm
Interlabial gap 1-5mm
Symmetry
assessment
Facialmidline Middle of philtrum of upper lip
(Cupid’s bow) and glabella
centre of the nasal bridge to
Middle of philtrum of upper lip
vertical perpendicular from
glabella
‘Rule of fifths’. Each fifth =width of an eye=
34mm

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Mouth width=distance between
the medial iris margins=65mm
Alar base width=intercanthal
distance= one fifth=34mm
Skeletalbase
assessment
Mandibular assessment Chin-Jawline
parallel to interpupillary line
Maxillary assessment Orbital rim
Cheek contour
sclera show
Paranasal hollowing/flatness
Lip assessment Vertical lip lines level Lower lip cover incisal third of
U1.
U1 exposure at rest 2–4 mm
Lip activity Normal
Hypo or hyper
Lip morphology Vermilion show of lower lip
12mm, upper lip 9mm.
Lip position competent
incompetence
Potentially competent

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Rolled blind upper lip
Smile analysis The smile arc Ui slightly touch vermilion
borderof L lip
Width of smile Visible U4
Posedsmile 70-100% exposure of incisors 7-
8mm
Maximum smile 100% exposure of incisors 9-
11mm +4mm gingival show
Dentoalveolar
assessment
Overbite 3mm or 1/3-1/2 of the Li height
Occlusalplane (Upper,
lower, anterior posterior)
parallel to interpupillary line
Maxillary dental midline Coincident with FML and LML
Mandibular dental
midline
Coincident with FML and UML
Profile View
Totalprofile analysis
1. Soft tissue nasion to FH  Maxilla should be approximately 2-3 mm in

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 (Sandler 2006) front, and the softtissue pogonion should lie 2
mm behind this facial plane.
2. Steiner_Kole technique
3.
It is used to determine the convexity of the
dentofacial complex by using SN-MP angle
which is 32 degree.
The face can be classified into divergent,
convergent or normal
Angle of convexity (facial
convexity or facialangle)
Burstone
Glabella-subnasale-pog 11-30 degree
Powellanalysis Nasofrontal angle 160 degree
Nasofacial angle 40 degree
Nasomental angle (Totalfacial angle)160 degree
Mentocervical angle 100 degree
Analysis of the high midface
Soft tissue glabella 2mm ahead of the soft tissue nasion
Orbital rim 2mm posterior to the eye globe

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Check bone contour. smoothly convex from the outer canthus of the
eye through the sub-pupil area to end in the alar
base
Analysis of the maxillary area
Nasalbase Subnasale is on 0 degree Meridian line
Nasalprojection Distance from tip of the nose to TVL 22m
AP lip position The upper lip normally touch the True Vertical
Line TVL
The upper lip should be 4 mm behind E line
The lips should touch S line
H line should touch U lip & bisect the nose.
Relationshipof upper lip to
nose
Naso-labial angle
85–120
Analysis of the mandibular area
AP lip position The lower lip 0.5mm-2mm behind TVL
The lower lip 2 mm behind E line

11. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 201510
The lower lip should touch or 1mm ahead of S
line
Relationshipof lowerlip to
chin
Labiomental angle
110–130
AP chin position Bass aesthetic line touch softtissue Pog
Soft tissue pog should be 0 ± 2 mm to Zero
Meridian
Holdaway angle (n-pog-ls) 15 degree
Z angle (FH-pog-ls or li) 71-89 degree
Relationshipof chin to
submental plane
Lip-chin-submental plane angle: average 90–110
Submental plane length 40mm
1. Dental Appearance: Micro-Esthetics.
1. ToothProportions
 Golden Proportion
 Height-Width Relationships
 Gingival Heights, Shape and Contour
2. Connectors and Embrasures
3. ToothShade and Color

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Functional analysis
1. Evaluation of TMJ
 Temporomandibular joint dysfunction
 Joint noises
 Discomfort with jaw movement / muscle tenderness
 Amount of opening and lateral excursion in mm. Opening is usually > 40 mm and
lateral excursion > an upper incisor width.
2. Evaluation of swallowing
Normal swallowing process includes:
 Lip seals
 Tip of tongue moved upward to touch the palate
 Teeth are contacted slightly
 Floor of mouth elevated
In abnormal adaptive behaviour one of the scenarios might occur:
 Tongue to lower lip swallow (Cl2 d1 and AOB)
 Lower lip to palate (CL2d1 with normal incomplete OB)
 Tongue to upper lip (CLIII)
 Mandibular posturewith lip to lip seal (mod CL2D2)

13. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 201512
3. Dynamic occlusionassessment
 Assessment of functional occlusion including (canine guidance, group function
and incisor guidance)
 Assessment of ICP and RCP (sometime the patient has habitual CR in order to
help to achieve oral seal, or due to respiratory needs, or for aesthetic
camouflaging (to camouflage underlying skeletal problem) or to decrease load on
incisor in cl3)
 Path of closure: either deviation or displacement. The displacement can occur
backward with Cl2d2 or forward in cl3 or laterally in crossbite.
Intraoral examination
1. Evaluation of Oral Health
1. Count number of teeth
2. Caries
3. Any other pathology
4. PD examination
Using WHO probe, examine all first molars and upper right and lower left central
incisor with a force of 20-25gm.
 Code0: healthy (need no treatment)
 Code1: bleeding no probing (OHI)
 Code2: bleeding + calculus or overhang (OHI+scalling)

14. Dr. Mohammed Almuzian, Lecturer., University of Sydney, 201513
 Code3: bleeding + probing 3.5-5.5mm (OHI+sclling+ RP)
 Code4: more than 6mm probing (surgery)
2. Static occlusalassessment
 Labial segments (crowding , spacing, inclination, angulation, rotation and
malposition)
 Buccal segments (crowding , spacing, inclination, angulation, rotation and
malposition)
 OJ
 OB
 CL
 Crossbite
 COS
Evaluation of diagnostic records, including dental casts, radiographs and
photographs.
Orthodontic diagnostic records help in:
1. Diagnosis
2. TP
3. Monitor treatment and growth changes
4. Presentation for patient

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5. Mediolegal
6. Teaching
7. Audit and research
Storage:
Their use is widespread but is associated with several problems, mainly storage,
breakage and loss. For medico-legal purposes, the British Dental Association
suggests that records should be kept for a minimum of 11 years after completion
of treatment. Sometime, digital study model can be used with reasonable degree
of reproducibility compared to plaster study model. Noar, 2012
Gold standard records
1. Study model: Han and Vig 1991showed that in class II cases, the study model
alone in a majority of cases (55%), provided adequate information for treatment
planning, and incremental addition of information from other types of diagnostic
records made small differences.
2. Cephalometric: Nijkamp 2008, that cephalometrics are not required for
orthodontic treatment planning, as they did not influence treatment decisions for
patient with class II malocclusion.
Articulating the study model:
Ellis and Benson 2013, Articulation of the study models did not affect the
treatment planning decisions in a meaningful manner.