INDIAN DENTAL ACADEMY
Leader in continuing dental education
According to Russell, an index is defined as
‘A numerical value describing the relative status of
the population on a graduated scale with definite upper
and lower limits which is designed to permit and
facilitate comparison with other population classified
with the same criteria and the method.’
In the orthodontic context index is described as –
‘A rating or categorizing system that assigns a
numeric score or alpha numeric label to a person’s
Requirements of ideal orthodontic index are –
(Jamison H.D. and Mc Millan R.S )
1. Simple, reliable and reproducible.
2. Objective and yield quantitative data.
3. Differentiate b/w handicapping and non
4. Measure degree of handicap.
5. Quick examination.
6. Amenable to modifications.
7. Usable either on patient or on study model.
Index should be equally sensitive throughout
Index value should correspond closely with
the clinical importance of the disease stage it
Index value should be amendable to
Requisite equipment and instrument should
be practicable in actual field situation
Examination procedure should require a
minimum of judgement
The index should be facile enough to permit
the study of a large population without undue
cost on time or energy
Index should be valid during time
Angle’s classification by Angle in 1899
Incisor classification by Ballard andWayman, 1964
Skeletal classification by Houston et al, 1993
Occlusal index by Summers 1966
Handicapping Malocclusion Assessment Record (HMAR)
by Salzmann, 1968
Index ofTreatment Need by Evans and Shaw 1987
Little’s irregularity index by Little 1975
Peer Assessment rating by Richmond et al, 1992
GoslonYardstick by Mars et al, 1987
5Year olds’ Index by Atack et al ,1997
Plaque Index by Stilness & Loe , 1964
Gingival Index. by Loe & Stilness, 1963
Study prevalence of malocclusion in population.
Eg 1.Summer’s occlusal index.
2. Registration of malocclusion described by Bjork,
Krebs and Solow
Treatment need (Treatment priority) indices.
Categorize malocclusion according to levels of treatment needs.
Eg 1. Index OfTreatment Need (IOTN)
2. Draker’s Handicapping Labio – Lingual Deviation index (HLD)
3. Grainger’sTreatment Priority Index.(TPI)
4. Salzmann’s Handicapping Malocclusion Index
Treatment outcome indices.
Assesssment of changes resulting from treatment
Eg 1. Peer Assessment Rating index
2. Summer’s index
Treatment complexity index
Index of Complexity Outcome and Need (ICON)
Master and Frankel (1951)
Count the number of teeth displaced or rotated
Malalignment Index byVankrik and Pennel (1959)
Tooth displacement and rotations were
Proposed to select subjects with severe or
handicapping malocclusions and dentofacial
Applicable only to permanent dentition
First Orthodontic index to meet administrative
needs of programme planners.
Made use of weighting factors developed by trial
Had 9 components
Conditions observed HLD score
1. Cleft palate Score 15
2. SevereTraumatic deviations Score 15
3. Overjet in mm
4. Overbite in mm
5. Mandibular protrusion in mm x 5
6. Open bite in mm x 4
7. Ectopic eruption ,Anteriors only x 3
8. Anterior crowding : Maxilla
9. Anterior crowding : Mandible
Modification of earlier used HLD index
Main aim is to find presence or absence and
degree of handicap caused by components of
Has 7 components.
All measurements are made with Boley gauge
scaled in mm.
A score of 13 and over constitutes physical
Used to assess severity of malocclusion in
Nine weighted and defined measurements –
1. Molar relation
2. Over jet
4. Posterior cross bite
5. Posterior open bite
6. Tooth displacement
7. Midline relation
8. Maxillary median diastema
9. Congenitally missing maxillary incisors.
Seven malocclusion syndromes defined
1. Overjet and open bite
2. Distal molar relation, overjet, overbite, posterior
crossbite, midline diastema and mid line deviation.
3. Congenitally missing maxillary incisors.
4. Tooth displacement.
5. Posterior open bite.
6. Mesial molar relation, overjet, overbite, posterior
crossbite, midline diastema and mid line deviation.
7. Mesial molar relation, mixed dentition analysis (potential
tooth displacement) and tooth displacement.
Different scoring schemes and forms for different stages
of dental development: Deciduous, Mixed & Permanent
The precursor of theTPI was the Malocclusion
Severity Estimate (MSE) developed by Grainger
at the Burlington Orthodontic Research Center
Unlike theTPI, the MSE score was that of the
syndrome with the largest value, regardless of
the scores of the other syndromes.
TheTPI also differed from the MSE by deleting
potential tooth displacement (mixed-dentition
space analysis) and by rating distoclusion and
TPI is based on a scale of
1. 0 (near ideal occlusion)
2. 1 - 3 ( mild malocclusion)
3. 4 – 6 ( Moderate malocclusion)
4. Over 6 ( severe malocclusion)
TPI scores only occlusal characteristics,
excluding skeletal and facial components.
TPI is used in national studies of orthodontic
needs for children. Eg. USPHS study in USA of
childeren aged b/w 6-11 yrs in year 1967
The purpose of HMAR –To establish priority for treatment
according to severity as shown by score.
Weighted measurements consists of 3 parts –
1. Intra arch deviations
2. Interarch deviations
. Six handicapping dento-facial deformities
1. Facial and oral clefts
2. Lower lip palatal to maxillary incisors.
3. Occlusal interferences
4. Functional jaw limitations
5. Facial asymmetry
6. Speech impairment.
Score 8 points for each deviation.
Developed by 10 experienced British orthodontists.
Its developed mainly to assess effectiveness of
Orthodontic treatment .
Assigns scores to different occlusal traits.
Study models used.
A scoring system was developed and a ruler designed to
allow analysis of a set of study casts in 2 minutes.
5 components- Weighting
1. Upper & lower anterior segment - 1
2. Left and right buccal segments - 1
3. Over jet - 6
4. Overbite - 2
5. Centerlines - 4
Individual scores are summed to get a final score..
Index is applied to both the start and end of treatment study
casts, and change in total score reflects the success of
Change expressed as:
1. Reduction in weighted PAR score : 22 point reduction – Greatly
2. % reduction in weighted PAR score:
< 30% reduction – worse/ no better
> 30% reduction – Improved.
Indicator of clinical performance.
Limitations of PAR
1. Generic weightings of Over jet and overbite.
2. Sensitive to malocclusion with high over jet.
3. Overbite low weighting.
4. Zero weighting for displacements.
5. Facial profiles not considered Eg. Bimaxillary protrusion
11 American Orthodontists examined a sample of 200 sets
of study casts and rated them for malocclusion severity
and perceived treatment difficulty.
The results of this study made it possible to derive a set of
weightings for the PAR index that would represent
groupings of malocclusion severity and treatment
difficulty, according to perceptions of panel of
Index has two components-
1. Dental Health component – derived from
occlusion and alignment.
2. Aesthetic component – Derived from
comparison of dental appearance to standard
Aesthetic component is calculated by direct
examination, but dental health component can
be studied by dental casts.
A special ruler summarizes the information needed
for dental health component.
Assessed in order :
1. Missing teeth
4. Displacements (Contact point)
According EVANS,MR,SHAW(1987,EU J ORTHOD)314-318
Grades 8 – 10 = definite need for treatment.
5 – 7 = moderate/ borderline need
1 – 4 = No/ slight need
1. In aesthetic component ,Class III not
2. Facial profile not considered.
3. Class I bimaxillary protrusion not
Based on expert opinions of 97
orthodontists from various countries.
For use on patients and Dental casts.
A single assessment method to record
complexity, outcome and need.
5 components taking about 1 min to measure.
1. Aesthetic component
2. Upper arch Crowding/ Spacing
Score according to amount of crowding or spacing
Impacted teeth in either arch immediately scored 5
Spacing in one part can cancel out crowding elsewhere.
4. Incisor open bite/ overbite
Open bite measured at mid incisal edges
Deep bite is measured at deepest part of overbite.
5. Buccal segment Antero posterior
Quality of buccal segment interdigitation is measured (not Angles
1. Overjet not considered.
2. Lower anterior crowding not considered.
3. Midline shift not taken in account.
This index is simple to use and faster than
separate indexes for various facets of
AJO(2007)onyeaso investigated relationship
between ICON,DAI,PAR andABO objective
They found overall good assesment between
the ICON and other indices.
The purpose of this study was to develop a valid and
reliable index that provides relatively objective
judgments of dental-facial attractiveness.
The subjects in this study were eighth- and ninth-
grade children. Few were seeking orthodontic
treatment and few were not seeking treatment.
Photographs of the children were rated for dental-
facial attractiveness by lay and dental judges.
Point 1 Point 2 Point 3
Point 4 Point 5
Children were also assessed for severity of
malocclusion by means of theTreatment Priority
Children seeking treatment were perceived as
significantly less attractive than children not
The relationship between dental-facial
attractiveness and overall severity of
malocclusion is also established as proved by
The GoslonYardstick is a clinical tool that
allows categorization of the dental
relationships in the late mixed and or early
permanent dentition in to 5 discrete
Objective : 1. To categorize malocclusions in
patients with UCLP to represent severity of
malocclusion and the difficulty of correcting
2.To compare long term results of different
approaches to the early treatment of
children with UCLP.
Development ofYardstick – Clinical features
considered most important in characterizing
malocclusion in children with UCLP are –
1. A- P arch relationship –Class III incisor relationship>
class II div I
2. Vertical labial segment relationship – Open bite>
Reduced overbite > deep overbite.
3. Transverse relationship – Canine crossbites > molar
To test the application of these subjective criteria
study models of 30 cases were taken.
These models were ranked by 4 orthodontists and
separated in 5 groups , which then formed basis for
Group 1 – excellent
Group 2 – good
Group 3 – fair
Group 4 – poor
Group 5 – very poor
Group 1 or 2 - simple orthodontic treatment/ no
Group 3 – complex orthodontic treatment
Group 4 – limit of orthodontic treatment without
Group 5 – Orthognathic surgery
American board of
orthodontics(ABO)developed an index to
represent the objective evalution of difficulty
of a case presented for the phase III of ABO
Index was called the descrepency index or DI
It evaluating dental models and
Clinical features of a patient’s condition
include overjet,overbite,ant.open bite,lateral
open bite,crowding,occlusion ,lingual
posterior crossbite and buccal posterior
Cephalometric parametres includeANB
angle,IMPA angle and SN-GoGn angle.
TheABO is considering several option for
applying the descrepancy index to phase III
It can be applied on the condition like-
Missing or super numery teeth
Anomalies of tooth size and shape
Excessive curve of wilson.
A quantitative method of evalution of the
extent of abnormality from given standard
requires grading the abnormality and
assigning a score based on severity of
problem,which is perceived by the degree of
aesthetic/functional impairment produced.
Each index is designed with a definete
purpose and should be valid in its application.
1. Contemporary Orthodontics – Proffit
2. Longitudinal evaluation of theTreatment Priority
Index (TPI) AJO-DO 1989
3. Goslon yardstick:A new system of assessing dental
arch relationships in childeren with UCLP – Michael
Mars, Dennis A. Plint : 1987 A cleft Palate journal
4. A dental-facial attractiveness scaleTedesco , Albino,
Cunate AJO-DO 1983
5. The Development of PAR Index – S. Richmond
6. Relationship b/Wondex of ICON,DAI,PAR and ABO