Indices in orthodontics

INDICES IN ORTHODONTICS
PRESENTED BY:
DR SHIB KUMAR NATH
(PG IST YEAR)

CONTENTS
• Introduction
• Definition
• Evolution of indices
• Ideal requirements
• Types of indices
• Method of recording and measuring
malocclusions

Commonly used indices
I. Angle's classification
II. Massler and Frankel's index recording the number of displaced/rotated teeth
III. Malalignment Index
IV. Handicapping Labiolingual Deviation Index (HLDI)
V. Occlusal feature index
VI. Malocclusion Severity Estimate (MSE)
VII. Occlusal Index (OI)
VIII. Grade Index Scale for Assessment of Treatment Need (GISATIN)
IX. Treatment Priority Index (TPI)
X. Handicapping Malocclusion Assessment Record (HMAR)
XI. Little's Irregularity Index (LII)
XII. WHO/FDI - basic method for recording of malocclusion
XIII. Dental Aesthetic Index (DAI)
XIV. Handicapping Labiollingual Deviation (HLD) (CalMOD)
XV. Peer Assessment Rating Index (PAR)
XVI. Index of Orthodontic Treatment Need (IOTN)
XVII. Memorandum of Orthodontic Screen and Indication for Orthodontic Treatment
XVIII. Ideal Tooth Relationship Index
XIX. Need for Orthodontic Treatment Index (NOTI)
XX. Risk of Malocclusion Assessment (ROMA)
XXI. Index of Complexity, Outcome and Need (ICON)
XXII. Baby-ROMA
XXIII. Aesthetic Based Orthodontic Indexes

• Evaluation of indices
• Conclusions
• References

INTRODUCTION
• The categorization of a malocclusion by its salient
features is helpful for describing and documenting a
patient’s occlusion.
• In addition, indices allow the prevalence of a
malocclusion within a population to be recorded, and
aid in the assessment of need, difficulty, and success
of orthodontic treatment.
• Malocclusions can be recorded qualitatively and
quantitatively.

• However, the large number of indices, which have
been devised, are testimony to the problems inherent
in both these approaches.
• All have their limitations, and these should be borne
in mind when they are applied.

DEFINITION
• An index has been defined as a numerical value
describing the relative status of a population on a
graduated scale with definite upper and lower limits,
which is designed to permit and facilitate comparison
with other populations classified by the same criteria
and methods. – A.L.Russel.

• An index is an expression of clinical observation in
numerical values, which is used to describe the status
of the individual or group with respect to a condition
being measured. – E.M.Wilkins.
• In the orthodontic context index is a method that
assigns a numeric score or alphanumeric label in
order to rate or categorize a person's occlusion.

EVOLUTION OF INDICES
• About the year 1800, people started to think that
certain arrangements of the human teeth constituted
perfection.
• This “idea” in the minds of men was that this
configuration was normal and hence “ideal”
occlusion.
• Soon, the notion developed that what was not ideal
was not normal and was therefore abnormal!

• In 1889, Edward H. Angle came on the scene and
declared that the relationship of the first molars
defined proper occlusion and stated that arrangements
other than his definition were abnormal and by
inference malocclusion.
• In 1960, H. L. Draker suggested a different approach
in which selected deviations from ideal were scored
and weighted. He called it the Handicapping Labio-
lingual Deviation index or HLD Index.

• Grainger developed the malocclusion severity
estimate (MSE), in the Burlington Research Center. It
can be used either on models or on patients.
• Validity and reproducibility were high.
• However, there were at least three possible
shortcomings of the MSE.

• The occlusal index (OI) was developed by Summers
in 1966 and was based on the malocclusion severity
estimate, with attempts to remedy its shortcomings.
• Grainger, in 1967, modified the MSE to develop the
treatment priority index (TPI).
• Grainger described the index as a method of assessing
the severity of the most common types of
malocclusion, and hence, provided a means of
ranking patients according to the severity of
malocclusion, the degree of handicap, or their priority
of treatment.

• In 1968, Salzmann developed the handicapping
malocclusion assessment record (HMAR).
• The assessment forms and the definition of
handicapping malocclusion presented were officially
approved by the Council on Dental Health of the
American Dental Association, and the Board of
Directors of the American Association of
Orthodontists.

• In 1972, Harvey Peck and Sheldon Peck developed a
diagnostic index for assessing tooth shape deviations
was for spatial analysis of existing or potential
malocclusions.

• The "WHO/FDI Basic Method for Recording of
Malocclusion" was published in 1979 to establish an
assessment format to determine the prevalence of
malocclusion and to estimate treatment needs of a
population.

• In 1986, Cons, a Public Health dentist, is the only
American dentist to produce any kind of an index
since then.
• Cons approached the index problem from purely the
appearance standpoint and developed the Dental
Aesthetic Index.
• The Dental Aesthetic Index has been accepted by the
World Health Organization as a screening tool.

• Grade Index Scale for assessment of treatment need:
• The Swedish National Board developed a four grade
index scale designed to determine whether a patient's
malocclusion, to classify patients ranging from those
who need very urgent orthodontic treatment to those
of little need to identify who fall within the scope of
treatment in the Swedish public dental services.
• However, the criteria were not well defined and the
cut off points were vague.

• In 1987, the British Orthodontic Standards Working
Party convened a series of meetings with a group of
10 experienced Orthodontists to develop an index of
treatment outcome from study casts of various treated
and untreated occlusions.
• Richmond designed a ruler to allow analysis of a set
of study casts in 2 minutes (approx).
• The result was the Peer Assessment Rating or PAR
index.

• More recently in 1989, Brook and Shaw (EJO)
developed the index of orthodontic treatment
need (IOTN), which consisted of the dental
health component and the esthetic component.
• The index was found to be satisfactorily valid
and reproducible.

• In 1992, Haeger also developed a static occlusal
analysis in centric occlusion based on ideal interarch
and intraarch relationships and called it ideal tooth
relationship index.

IDEAL REQUIREMENTS
1. Clarity, simplicity and objectivity
 Index should be easy to use.
 The objectives should be clear. Use of indices should
ensure uniform interpretation and application of
criteria.
Tang EL, Wei SH. Recording and measuring malocclusion:Review.
AJODO1993;103:344-51

2. Validity : Index should measure the condition
precisely for what it has been designed for a valid
period of time.
3. Reliability (reproducibility) : The measurement
should be consistent at different times. It enables the
same findings to be achieved by the same or
different observers .

4. Acceptability : To the profession and public.
5. Quantifiability : It should be amenable to
statistical analysis.
6. Sensitivity : The index should be able to detect
reasonably small shifts in either direction in the
group condition

TYPES OF INDICES
(W. C. Shaw AJO 1995)
There are five types of index, each for a distinct
purpose.
1. Diagnostic classification Angle's classification with
its subclasses used to describe incisor and buccal
segment relationships separately allows ease of
communication between orthodontists.

2. Epidemiologic indices These indices record every
trait in a malocclusion to allow estimation of the
prevalence of malocclusion in a given population.
Other indices of this type score tooth alignment in a
way that allows study of tooth irregularity and
periodontal disease, or treatment stability Eg:
Epidemiologic registration of malocclusion by
Bjork, Krebs, and Solow, The FDI method,
Summer's occlusal index.

3. Treatment need (treatment priority) indices Allow
categorization of malocclusion according to the level
of treatment need. These indices yield a score for
each trait or component that is then weighted to
calculate an overall score. A simpler method of
assigning treatment priority is to establish a list of
conditions or traits in categories that denote the
extent to which treatment is considered necessary.
Eg: i) Draker's HLD index. ii) Grainger's treatment
priority index. iii) Salzman's handicapping
malocclusion assessment. iv) IOTN.

4. Treatment outcome indices Several indices have
been developed to evaluate treatment success. PAR
index described later has been developed
specifically for this purpose. Summer's index has
also been used to assess the outcome of treatment.
5. Treatment complexity index At present no index has
been described to specifically measure treatment
complexity but the desirability of such an index in
public health orthodontics is recognized and efforts
are presently underway to develop one.

METHOD OF RECORDING AND
MEASURING MALOCCLUSIONS
The methods of recording and measuring malocclusion
can be broadly divided into two types: QUALITATIVE
and QUANTITATIVE.
 QUALTITATIVE METHODS OF MEASURING
MALOCCLUSION
1) Angle's method of classifying malocclusion in 1899
2) Massler & Franel's index recording the no. of
displaced/rotated teeth in 1951.
3) Draker's HLD Index in 1960.

4) Occlusal feature index of Poulton & Aaronson that
records lower anterior crowding, cuspal inter-
digitation, overjet and overbite.
5) Malocclusion severity index by Grainger in 1961
6) Summer's Occlusal index in 1966
7) Treatment Priority Index by Grainger in 1967
8) Salzmann HMAR in 1968.

• QUANTITATIVE METHODS OF MEASURING
MALOCCLUSION
1) In 1951 Massler and Frankel made the initial
attempt to develop a quantitative method of
assessing malocclusion. The total number of
displaced or rotated teeth was the basis for the
evaluation of prevalence and incidence of
malocclusion in population groups.
2) In 1959, VanKirk and Pennell proposed the
malignment index, which involved the grading of
tooth displacement and rotation quantitatively.

3) Draker developed the handicapping labiolingual
deviation index (HLDI) in 1960
4) Poulton and Aaronson proposed the occlusal feature
index in 1961.

INDICES USED IN
ORTHODONTICS
Angle's classification
(Angle, E.H. (1899) Classification of malocclusion. Dental Cosmos, 41, 248-264.)
• Angle's Classification is devised in 1899 by father of
Orthodontic, Dr Edward Angle to describe the classes
of malocclusion, widely accepted and widely used
since it was published.
• Angle's Classification is based on the relationship of
the mesiobuccal cusp of the maxillary first molar and
the buccal groove of the mandibular first molar.
• Angle's Classification describes 3 classes of
malocclusion.

Massler and Frankel's index recording the number
of displaced/rotated teeth
(MASSLER, M.; FRANKEL, J. M. Prevalence of malocclusion in children
aged 14 to 18 years. American Journal of Orthodontics, v. 37, n. 10, p. 751-768)
• Introduced in 1951 by Massler & Frankel to produce
a way to record the prevalence of malocclusion which
will satisfy 3 criteria: simple, accurate and applicable
to large groups of individual;
• yield quantitative information that could be
statistically analysed, reproducible so that results are
comparable.
• This index uses individual teeth as unit of occlusion
instead of a segment of the arch. Each tooth is
examined to determine whether it is in correct
occlusion or it is maloccluded.

Procedure:
• The total number of maloccluded teeth is counted and
recorded.
• Each tooth is examined from two different aspects:
occlusal aspect and then the buccal and labial
surfaces with the exclusion of third molars.
• Tooth that is not in perfect occlusion from both
occlusal aspect (in perfect alignment with contact
line) and buccal aspect (in perfect alignment with
plane of occlusion and in correct interdigitation with
opposing teeth) is considered as maloccluded.

• Each maloccluded tooth is given a value of 1 while
tooth in perfect occlusion is given a score of 0.
• score of more than 10 would be classified as
sufficient severity that would require orthodontic
treatment;
• score between 1 and 9 would be classified as normal
occlusion in which no orthodontic treatment is
indicated.

• Advantages: this index is simple, easy and able to
provide prevalence and incidence data in populations
group.
• Disadvantage with this index: primary dentition,
erupting teeth and missing teeth are left out in the
scoring system and difficulties in judging conformity
of each tooth to an ideal position in all planes.

Malalignment Index
(Vankirk, Lawrence (1959). "Assessment of malocclusion in population
groups". American Journal of Orthodontics. 45 (10): 752–758. )
• Introduced in 1959 by Lawrence Vankirk and Elliott
Pennell.
• This index requires the use of a small plastic, gauge-
like tool designed for assessment.
• Tooth rotation and displacement are measured.

procedure:
• The mouth is divided into 6 segments, and is
examined in the following order: maxillary anterior,
maxillary right posterior, maxillary left posterior,
mandibular anterior, mandibular right posterior and
mandibular left posterior.
• The tool is superimposed over the teeth for the
scoring measurement, each tooth present is scored 0,
1 or 2.

• 2 types of malalignment are being measured, rotation
and displacement.
• Rotation is defined as the angle formed by the line
projected through contact areas of observed tooth and
the ideal arch line.
• Displacement is defined as both of the contact areas
of the tooth are displaced in the same direction from
the ideal alignment position.

• Score of 0 represents ideal alignment with no
apparent deviation from the ideal arch line.
• Score of 1 represents minor malalignment: rotation of
less than 45º and displacement of less than 1.5mm.
• Score of 2 represents major malalignment: rotation of
more than 45º and displacement of more than 1.5mm.

Handicapping Labiolingual Deviation
Index (HLDI)
• This index was proposed in 1960 by Harry L. Draker.
• HLDI was designed for identification of dento-facial
handicap. The index is designed to yield prevalence
data if used in screenings.
(Draker, Harry L. (1960). "Handicapping labio-lingual deviations: A proposed
index for public health purposes”. American Journal of Orthodontics. 46 (4):
295–305.)

Occlusal feature index
(Poulton, Donald R.; Aaronson, Sanford A. (1 September 1961). "The relationship between occlusion and
periodontal status". American Journal of Orthodontics. 47 (9): 690–699)
• Occlusal Feature Index is introduced by Poulton and
Aaronson in 1961.
• The index is based on four primary features of
occlusion that is important in orthodontic
examination.
• Occlusal Feature Index recognises malocclusion is a
combination of the way teeth occlude as well as the
position of the teeth relative to the neighbouring teeth.
• However, the scoring system is not sensitive enough
for case selection for orthodontic purposes.

Malocclusion Severity Estimate (MSE)
Tang, EL; Wei, SH (April 1993). "Recording and measuring malocclusion: a review of the
literature". American Journal of Orthodontics and Dentofacial Orthopedics. 103 (4): 344–51.
• Introduced in 1961 by Grainger.
• MSE measured 7 weighted and defined measurement:
1) Overjet
2) Overbite
3) Anterior open bite
4) Congenitally missing maxillary incisors
5) First permanent molar relationship
6) Posterior cross bite
7) Tooth displacement (actual and potential)

• MSE defined and outlined 6 syndromes of
malocclusion:
1) Positive overjet and anterior open bite
2) Positive overjet, positive overbite, distal molar
relationship and posterior crossbite with maxillary
teeth buccal to mandibular teeth.
3) Negative overjet, mesial molar relationship and
posterior crossbite with maxillary teeth lingual to
mandibular teeth
4) Congenitally missing maxillary incisors
5) Tooth displacement
6) Potential tooth displacement

• Despite being a relative comprehensive definition,
there are a few shortcomings of this index, namely:
1) the data is derived from a 12 years old patients
hence might not be valid for deciduous and mixed
dentitions.
2) the score does not reflect all the measurement that
were taken and accumulated and the absence of any
occlusal disorder is not scored as zero.
3) Grainger then revised the MSE index and published
the revised version in 1967 and renamed the index to
Treatment Priority Index (TPI).

Occlusal Index (OI)
(Summers, CJ (June 1971). "The occlusal index: a system for identifying and scoring occlusal
disorders". American Journal of Orthodontics. 59 (6): 552–67).
• Occlusal Index was developed by Summers in his
doctoral dissertation in 1966, and the final paper was
published in 1971.
• Based on Malocclusion Severity Estimate (MSE), OI
attempted to overcome the shortcoming of the MSE.
• Nine characteristics are scored in the occlusal index:
dental age, molar relation, overbite, overjet, posterior
cross-bite, posterior open-bite, tooth displacement
(actual and potential), midline relations, and missing
permanent teeth.

• Summers devised different scoring scheme for
deciduous, mixed and permanent dentition with 6
predefined stages of dental age:
1) Dental age 0 begins at birth, ending with the eruption of first deciduous
tooth.
2) Dental age 1 begins when stage 0 ended, ending with all deciduous teeth
are in occlusion.
3) Dental age 2 begins when stage 1 ended, ends with the eruption of first
permanent tooth.
4) Dental age 3 begins when stage 2 ended and ends with all the permanent
central, lateral incisors and first permanent molar are in occlusion.
5) Dental age 4 begins when stage 3 ended and ends with the eruption of any
permanent canines or premolar.
6) Dental age 5 begins when stage 4 ended and ends with all permanent
canines and premolar are in occlusion.
7) Dental age 6 begins when all permanent canines and premolar are in
occlusion.

Nine characteristics are scored in the occlusal index:
• Molar relation: The scoring of molar relation has the
following propertie:
1. Defined “cut-off” points, where one type of relation
ends and another begins.
2. No classification into Angle Class I, II, or III; Angle’s
classification.
3. The relation of the deciduous second (E) and
permanent first molars (6) is considered for each side.

A. Deciduous teeth
• 1. Mesial: The mesiobuccal cusp of upper E occludes
with the distobuccal cusp of lower E.
• 2. Distal: The mesiobuccal cusp of upper E occludes
with the mesiobuccal cusp of lower E.
B. Permanent teeth
• 1. Mesial: The mesiobuccal cusp of upper 6 occludes
with the distobuccal cusp of lower 6.
• 2. Distal: The mesiobuccal cusp of upper 6 occludes
with the mesiobuccal cusp of lower 6.
61

• Overbite:
1. Positive overbite is scored as the distance the
maxillary central incisor occludes past the
mandibular central incisor, and this distance is
scored in “thirds” of the length of the clinical
crown of the mandibular central incisor.
2. Negative overbite (open-bite) is scored as the
vertical distance from the incisal edge of the
maxillary central incisor to the incisal edge of
the mandibular central incisor in millimeters.

• Overjet:
1) Overjet is scored as the horizontal distance from the
labial surface of the maxillary central incisor to the
labial surface of the mandibular central incisor in
millimeters. The scores may be positive, zero, or
negative.

• Posterior cross-bite (osseous type):

• Posterior open bite:
1) Posterior open-bite is scored as either present or not
present and, if present, as either unilateral or
bilateral. Generally, two or more adjacent posterior
teeth will be in open-bite.

• Tooth displacement:
• The scoring procedures for tooth displacement will be
discussed by dividing the dentitions into the nonmixed
(deciduous and permanent) and mixed dentitions.
• E.g-NONMIXED DENTITIONS: The scoring of tooth
displacement for the nonmixed dentition includes two degrees
of displacementg:
• (1) 1.5 to 2.0 mm. deviation or 35 to 45 degrees of rotation
from normal arch alignment (scored as 1 or single weight) and
• (2) > 2 mm. deviation or > 45 degrees of rotation from normal
arch alignment (scored as 2 or double weight).

• Midline relations:
DIASTEMA: If the incisors are not in occlusion
(dental age III), the observation is not recorded.
• When the diastema equals or exceeds 2 mm., it is
given a weight in the Occlusal index.
JAW DEVIATION: If any central incisor is missing,
the procedure is not recorded. Jaw deviations of 3
mm. or more are given a weight in the occlusal index.

• Missing permanent teeth:
• Only missing maxillary incisor teeth which have not
been replaced by a prosthesis are scored.
• Normally, in a child with at least any four of the
twelve permanent canines or premolars in occlusion
all incisors should be erupted.
• After this stage of dental development, measurement
can be made.
• One simply records the number of missing maxillary
incisors.

• Summers also defined 7 malocclusion
syndromes which includes:

Formula to calculate occlusal index
from syndrome score

Grade Index Scale for Assessment of
Treatment Need (GISATIN)
• Grade Index Scale for assessment of treatment need
(GISATN) was created by Salonen L in 1966.
• GISATN grades the type and severity of the
malocclusion, however, the index doesn't indicate or
describe the damage each type of occlusion can
cause.

Treatment Priority Index (TPI)
(Grainger, R.M. (Dec 1967). "Orthodontic treatment priority index". National Centre
for Health Statistics. 25 (Series 2).
• Treatment priority index (TPI) was created in 1967
by R.M. Grainger in Washington D.C United States.
• Grainger described the index as “a method of
assessing the severity of the most common types of
malocclusion, the degree of handicaps or their
priority of treatment”.

• In the index there are eleven weighed and defined
measurements which are:
1) upper anterior segment overjet,
2) lower anterior segment overjet,
3) overbite of upper anterior over lower anterior,
4) anterior open bite,
5) congenital absence of incisors,
6) distal molar relation,
7) mesial molar relation,
8) posterior crossbite (buccal),
9) posterior crossbite (lingual),
10)tooth displacement,
11)gross anomalies.

• It also includes the seven maloclussion syndromes:
1) maxillary expansion syndrome,
2) overbite,
3) retrognathism,
4) open bite,
5) prognathism,
6) maxillary collapse syndrome and
7) congenitally missing incisors.

• Measurements are assesed with a steel milimeter
ruler.
• After each of the above mentioned components are
measured and scored, the totality of the scores
weights is used to compute the TPI.
• Total scores for the TPI range from 0 to 10 or more.
• Higher score denote more severe malocclusion.
• TPI has been used in national studies of orthodontic
needs in children.
• Mainly used in permanent dentition, inadequate for
deciduous and mixed dentition.

Handicapping Malocclusion
Assessment Record (HMAR)
(Salzmann, J.A. (Oct 1968). Handicapping malocclusions assessment to establish
treatment priority (54th ed.). pp. 749–750).
• Handicapping malocclusion assessment record
(HMAR) was created by Salzmann JA in 1968.
• It was created to establish needs for treatment of
handicapping malocclusion according to severity
presented by magnitude of the score when assessing
the malocclusion.
• The assessment can be made either directly from the
oral cavity or from available casts.

• To make the assessment more accurate an additional
record form is made for direct mouth assessment
which allows the recording and scoring of mandibular
function, facial asymmetry, lower lip malposition in
relation to the maxillary incisor teeth and desirability
of treatment.
• The index has been accepted as a standard by the
Council or Orthodontic Health Care, the Board of
Directors of the American Association due to the easy
use of HMAR.

Little's Irregularity Index (LII)
(Little, Robert M (1975). "The Irregularity Index: A quantitive score of mandibular
anterior alignment". American Journal of Orthodontics.)
• Little irregularity index was first written about in his
published paper The Irregularity Index: a quantitative
score of mandibular anterior alignment.
• The Littles Irregularity index is generally used by
public health sectors and insurance companies to
determine the need for treatment and the severity of
the malocclusion.

• It is said that the method is “simple, reliable and
valid” of which to measure linear displacement of the
tooths contact point.
• The index is used by creating five linear lines of
adjacent contact points starting from mesial of right
canine to mesial of left canine and this is recorded.
• Once this is done the model cast can be ranked on a
scale ranging from 0-10.

WHO/FDI - basic method for
recording of malocclusion
• The WHO/FDI index uses the prevalence of
malocclusion ion and estimates the needs for
treatment of the population by various ways.
• It was developed by the Federation Dentaire
Internationale (FDI) Commission on Classification
and Statistics for Oral Conditions (COCSTOC).
• The aim when creating the index was to allow for a
system in measuring occlusion which can be easily
comparable.

• The five major groups which are recorded are as
follows:
1. Gross Anomalies
2.Dentition: absent teeth, supernumerary teeth,
malformed incisors and exotic eruption
3.Spaced condition: Diastema, Crowding and Spacing
4.Occlusion:
5.Orthodontic treatment need judged subjectively : non
necessary, doubtful and necessary

Dental Aesthetic Index (DAI)
• The aesthetic index created in 1986 by Cons NC and
Jenny J and has been recognised by WHO by which it
was added into the International Collaboration Study
of Oral health Outcomes.
• The index links the aesthetic aspect and the clinical
need plus the patients' perception and combines them
mathematically to produce a single score.

Handicapping Labiollingual Deviation
(HLD) (CalMOD)
(Parker, William S (Aug 1998). "The HLD (CalMod) index and the index question". American
Journal of Orthodontics and Dentofacial Orthopedics. 114: 136.)
• HLD was a suggestion by Dr. Harry L. Draker in
1960 in the published American Journal of
Orthodontics in 1960. It was meant to identify the
most unfavourable looking malocclusion as
handicapping however it completely failed to
recognise patients with a large maxillary protrusion
with fairly even teeth, which would be seen extremely
handicapped by the public.
• The index finally became a law driven modification
of the 1960 suggestion by Dr. Harry L. Draker and
became the HLD (CalMod) Index of California.

• The intent of the HLD (CalMod) index is measuring
the presence or absence, and the degree of the
handicap caused by components of the index and not
to diagnose malocclusion.
• The measurements for the index are made with a
Boley Gauge (or a disposable ruler) scaled in
millimetres. Absence of a condition must be
presented by entering ‘0’.

• These are the various conditions you have to take into
consideration:
1) Cleft palata deformities
2) Deep impinging overbite
3) Cross bite of individual anterior teeth
4) Severe traumatic deviations
5) Overjet greater than 9mm
6) Overjet in mm
7) Overbite in mm
8) Mandibular protrusion in mm
9) Open bite in mm
10) Ectopic eruption
11) Anterior crowding
12) Labiolingual spread
13) Posterior unilateral Crossbite

• Once this is completed and all the checks are done,
the scores are added up.
• If the patient does not score 26 or above they may
still be eligible under the EPSDT (Early and Periodic
Screening, Diagnostic and Treatment) exception, if
medical necessity is documented.

Peer Assessment Rating Index (PAR)
(Richmond, S.; Shaw, W. C.; O'Brien, K. D.; Buchanan, I. B.; Jones, R.; Stephens, C.
D.; Roberts, C. T.; Andrews, M. (April 1992). "The development of the PAR Index
(Peer Assessment Rating): reliability and validity". European Journal of
Orthodontics. 14 (2): 125–139.)
• This index was implemented in 1987 by the British
Orthodontic Standard Working Party after 10
members of this party formulated this index over a
series of 6 meetings.
• The PAR Index has been developed to provide a
single summary score for all the occlusal
anomalies which may be found in a malocclusion.

• The score provides an estimate of how far a case
deviates from normal alignment and occlusion.
• The difference in scores between the pre- and post-
treatment cases reflects the degree of improvement
and, therefore, the success of treatment.
• The score of zero would indicate good alignment and
higher scores (rarely beyond 50) indicating increased
levels of irregularity.

• Buccal segment
• The recording zone is from the mesial anatomical contact point
of the first permanent molar to the distal anatomical contact
point of the canine.
• Anterior segment.
• The recording zone is from the mesial anatomical contact point
of the canine on one side to the mesial anatomical contact
point of the canine on the opposite side.
• The occlusal features recorded are crowding, spacing, and
impacted teeth. Displacements are recorded as the shortest
distance between contact points of adjacent teeth parallel to the
occlusal plane. The greater the displacement the greater the
PAR score.
• The displacements between first, second, and third molars are
not recorded as these contacts are so broad and are extremely
variable within the normal range.

• An impacted tooth is recorded when the space
for this tooth is less than or equal to 4 mm.
• Impacted canines are recorded in the anterior
segment.
• Scores for the displacements and impactions
are added to give an overall score for each
recording zone.

• If there is potential crowding in the mixed dentition,
average mesio-distal widths are used to calculate the
space deficiency.

• Buccal occlusion
• The buccal occlusion is recorded for both left and right sides.
• The fit of the teeth is scored with respect to the three planes of
space.
• The recording zone is from the canine to the last molar, either
first, second, or third.
• All discrepancies are recorded when the teeth are in occlusion.

• Overjet
• Positive overjet as well as teeth in cross-bite are
recorded.
• The recording zone is from the left to right lateral
incisors.
• The most prominent aspect of any one incisor is
recorded.
• When recording the overjet the ruler is held parallel to
the occlusal plane and radial to the line of the arch.
• It is not uncommon to see two upper laterals in cross-
bite as well as an increased overjet on the central
incisors.
• In this situation if the overjet were 4 mm, the score
would be 3 for the cross-bite and 1 for the positive
overjet (4 in total).

• Overbite
• Records the vertical overlap or open bite of the
anterior teeth.
• Overbite is recorded in relation to the coverage of the
lower incisors or the degree of open bite.
• The recording zone includes the lateral incisors.
• The tooth with the greatest overlap is recorded.

• Centreline
• Records the centreline discrepancy in relation to the
lower central incisors.
• If a lower central incisor has been extracted the
measurement is not recorded.

Index of Orthodontic Treatment Need (IOTN)
(Brook, Peter H.; Shaw, William C. (1989-08-01). "The development of an index of orthodontic
treatment priority". European Journal of Orthodontics. 11 (3): 309–320.)
• The Index of Orthodontic Treatment Need was
developed and tested in 1989 by Brook and Shaw
• The aim of the IOTN is to assess the probable impact
a malocclusion may have on an individual's dental
health and psychosocial wellbeing.
• The index easily identifies the individuals who will
benefit most from orthodontic treatment and assigns
them a treatment priority.
• It comprises two elements: the dental health
component and an aesthetic component.

• For the dental health component (DHC), malocclusion is
categorised into 5 grades based on occlusal characteristics
that could affect the function and longevity of the
dentition.
• Grade 1 (no treatment required)
1. Extremely minor malocclusions, including displacements
less than 1mm.
• Grade 2 (little treatment need)
2.a) Increased Overjet >3.5 mm but ≤6 mm (with competent
lips)
2.b) Reverse overjet greater than 0 mm but ≤1mm
2.c) Anterior or posterior crossbite with ≤1mm discrepancy
between retruded contact position and intercuspal position
2.d) Displacement of teeth >1mm but ≤2mm
2.e) Anterior or posterior open bite >1mm but ≤2mm
2.f) Increased overbite ≥3.5mm (without gingival contact)
2.g) Pre-normal or post-normal occlusions with no other
anomalies. Includes up to half a unit discrepancy

• Grade 3 (borderline/moderate need)
3.a) Increased overjet >3.5mm but ≤6mm
(incompetent lips)
3.b) Reverse overjet greater than 1 mm but ≤3.5mm
3.c) Anterior or posterior crossbites with >1mm but
≤2mm discrepancy between the retruded contact
position and intercuspal position
3.d) Displacement of teeth >2mm but ≤4mm
3.e) Lateral or anterior open bite >2mm but ≤4mm
3.f) Increased and incomplete overbite without
gingival or palatal trauma

• Grade 4 (treatment required)
4.a) Increased overjet >6mm but ≤9mm
4.b) Reverse overjet >3.5mm with no masticatory or
speech difficulties
4.c) Anterior or posterior crossbites with >2mm
discrepancy between the retruded contact position and
intercuspal position
4.d) Severe displacements of teeth >4
4.e) Extreme lateral or anterior open bites >4mm

4.f) Increased and complete overbite with gingival or
palatal trauma
4.g) Less extensive hypodontia requiring pre-restorative
orthodontics or orthodontic space closure to obviate
the need for a prosthesis
4.h) Posterior lingual crossbite with no functional
occlusal contact in one or more buccal segments
4.i) Reverse overjet >1mm but <3.5mm with recorded
masticatory and speech difficulties
4.j) Partially erupted teeth, tipped and impacted against
adjacent teeth
4.k) Existing supernumerary teeth

• Grade 5 (treatment required)
5.a) Increased overjet >9mm
5.h) Extensive hypodontia with restorative implications
(more than one tooth missing in any quadrant
requiring pre-restorative orthodontics)
5.i) Impeded eruption of teeth (apart from 3rd molars)
due to crowding, displacement, the presence of
supernumerary teeth, retained deciduous teeth, and
any pathological cause
5.m) Reverse overjet >3.5mm with reported masticatory
and speech difficulties
5.p) Defects of cleft lip and palate
5.s) Submerged deciduous teeth

• A Standardized Continuum Aesthetic Need(SCAN)
scale was used for the development of aesthetic
component.
• A scale of 10 standardised colour photographs showing
decreasing levels of dental attractiveness is used.
• The pictures are compared to the patient's teeth, when
viewed in occlusion from the anterior aspect, by an
orthodontist who will score accordingly.
• The scores are categorised according to treatment need:
1) Score 1 or 2 – no need
2) Score 3 or 4 – slight need
3) Score 5, 6, or 7 – moderate/borderline
4) Score 8, 9, or 10 – definite need

Memorandum of Orthodontic Screen and
Indication for Orthodontic Treatment
("Danish National Board of Health". Memorandum of orthodontic screening and
indications for orthodontic treatment. 1990.)
• This index was implemented in 1990 by Danish
national board of health.
• In 1990 a Danish system was introduced based on
health risks related to malocclusion, where it
describes possible damages and problems arising
from untreated malocclusion which allows for the
identification of treatment need.
• This mandate introduced a descriptive index that is
more valid from a biological view, using qualitative
analysis instead of a quantitative.

Ideal Tooth Relationship Index
(Haeger, Robert S; Schneider, Bernard J; Begole, Ellen A (1992-05-01). "A static
occlusal analysis based on ideal interarch and intraarch relationships". American
Journal of Orthodontics and Dentofacial Orthopedics. 101 (5): 459–464.)
• The ITRI was established in 1992 by Haeger which
utilises both intra-arch and inter-arch relationships to
generate index scores to compare the entire dentitions
occlusion.
• This index is of use as it divides the arches into
segments which would result in a more accurate
outcome.

• This index evaluates tooth relationships from a
morphological perspective which has been of use
when evaluating the results of orthodontic treatment,
post-treatment stability, settling, relapse and different
orthodontic treatment modalities.
• The ITRI can allow for comparisons to be made in an
objective and quantitative manner that allows for
statistical analysis of orthodontic outcomes.

Need for Orthodontic Treatment Index (NOTI)
(Stenvik, A.; Espeland, L.; Berset, G. P.; Eriksen, H. M.; Zachrisson, B. U. (December
1996). "Need and desire for orthodontic (re-)treatment in 35-year-old
Norwegians". Journal of Orofacial Orthopedics. 57 (6): 334–342.)
• This index was first described and implemented in
1992 by Espeland LV et al and is also known as the
Norwegian Orthodontic Treatment Index.
• This index is used by the Norwegian health insurance
system and due to this it is designed for allocation of
public subsidies of treatment expenses, and the
amount of reimbursement which is related to the
category of treatment need. It classifies malocclusions
into four categories based on the necessity of the
treatment need.

Risk of Malocclusion Assessment
(ROMA)
• This is a tool used to assess treatment need in young
patients by evaluating malocclusion problems in
growing children, assuming that some aspects may
change under positive or negative effects of
craniofacial development.
• It was published for use in 1998 by Russo et al.

• This index illustrates the need for orthodontic
intervention and is used to establish a relationship
between the registered onset of orthodontic treatment
and disorders inhibiting growth of facial and alveolar
bones, and the development of the dentition along
with the IOTN index.
• This index can be used in exchange for the IOTN
scale as it is quick and easy to apply as a screening
test to decide whether and when to refer patients to
specialist orthodontists.

Index of Complexity, Outcome and
Need (ICON)
(Daniels, C.; Richmond, S. (June 2000). "The development of the index of complexity,
outcome and need (ICON)". Journal of Orthodontics. 27 (2): 149–162.)
• This index was produced in 2000 by Charles Daniels
and Stephen Richmond in Cardiff and has been
investigated to illustrate that it can be used to replace
the PAR and IOTN scale as a means of determining
need and outcome of orthodontic treatment.

• This index measures the following to produce a
scoring system:
1) Dental aesthetics as measured by the aesthetic
component of the IOTN
2) The presence of a crossbite
3) Anterior vertical relationship as measured by PAR
4) Upper arch crowding/spacing on a 5-point scale
5) Buccal segment Antero-posterior relationship as
measured by PAR.
• The measurements are added together to produce a
score which can be interpreted by score ranges that
give need for treatment, complexity and degree of
improvement.

Baby-ROMA
(Grippaudo, C.; Paolantonio, E. G.; Pantanali, F.; Antonini, G.; Deli, R. (December
2014). "Early orthodontic treatment: a new index to assess the risk of malocclusion in
primary dentition". European Journal of Paediatric Dentistry. 15 (4): 401–406.)
• This was established in 2014 by Grippaudo et al for
use in assessing the risks/benefits of early orthodontic
therapies in the primary dentition.
• It is a paediatric type version of the ROMA scale. It
measures occlusal parameters, skeletal and functional
factors that may represent negative risks for a
physiological development of the orofacial region,
and indicates the need for preventative or
interceptions orthodontic treatment using a score
scale.

• This index was designed as it has been observed that
some of the malocclusion signs observed in the
primary dentition can deteriorate with growth while
others remain the same over time and others can even
improve.
• This index is therefore used to classify the
malocclusions observed at an early stage on a risk-
based scale.

Aesthetic Based Orthodontic Indexes
(Borzabadi-Farahani, A. (November 2012). "A review of the evidence supporting the
aesthetic orthodontic treatment need indices". Progress in Orthodontics. 13 (3): 304–
313.)
• Assessment of the aesthetics is mostly subjective and
any orthodontic index which has an aesthetic
component can reduce the objectivity of the index in
determining the need for treatment and theoretically
not suitable for assessing orthodontic treatment need
in a research setting or resource allocation.

EVALUATION OF INDICES
• The reproducibility or reliability of an index is the
ability to produce the same score or measurement
when one or more examiners measure the same case
at the same or at a different time.
• The validity of an index can be defined as its ability
to accurately measure what it purports to measure.

• Bias, or systemic error of an index or measurement is
the magnitude and direction of its tendency to
measure something other than what was intended.
• The score of an unbiased index should accurately
reflect the intended characteristics.
• For malocclusion indices, severity of malocclusion
and the priority for treatment based on need would be
the intended characteristics.
• An index could be precise but biased.
• In such a case, the score will be reproducible but not
an accurate portrayal of the occlusion.

• Weights were first introduced to put different
emphasis on various measurements.
• Only the OI had developed different scoring schemes
and scoring forms for patients in different stages of
dental development, i.e, deciduous dentition, mixed
dentition, and permanent dentition.
• Later, weighting systems were also included in the
OI, the TPI, and the HMAR.

• Hermanson and Grewe tested the precision and bias
of five malocclusion indices including the HMAR,
the OI, the TPI, and two other indices.
• Their results showed that only the OI and the TPI
demonstrated nonsignificant interexaminer variability
at the 1% level, and that the most precise and
unbiased index would be the OI or the TPI.

• Grewe and Hagan compared the HMAR, the OI, and
the TPI for precision and bias when used in the same
population.
• The results showed that all three indices were highly
reproducible.
• When bias or systematic error was evaluated, the
results indicated that the OI described the clinical
standard most accurately.
• Therefore, of the three indices tested in the study, no
one index can be selected over the others with regard
to precision, but the OI would be the index of choice,
with regard to having the least amount of bias.

• Summers tested the validity of three indices: The
CHAMPUS index, the HMAR, and the OI.
• The OI was found to be the most valid among the
three indices.
• When validity during time was tested, decreased
scores were noted in the CHAMPUS index and the
HMAR but not in the OI.

• Gray and Demirjian compared the reproducibility and
accuracy of four indices: the HLDI, the TPI, the OI,
and the HMAR.
• The results showed that all methods were highly
reproducible but the OI had the best correlation with
the clinical standard, which was determined by
subjective assessment of orthodontists.
• The HLDI was found by Gray and Demirjian to
identify only the very worst cases and tended to lump
all the others into a common pool.
• Therefore it was unacceptable for overall field use.

• The TPI and the OI were very highly correlated and
had some common characteristics.
• Both needed very close and careful examination as
subjective decisions were required in deciding
whether the molar relationship is distal or mesial by
half a cusp or more than half a cusp on each side.
• A certain degree of subjective judgement was also
involved in determining whether some teeth were
rotated by 35° to 45° or more than 45°, and in
determining displacement by 1.5 to 2 mm or more
than 2 mm.

• Hence it required a well trained person to make
accurate decisions because mistakes made would be
serious due to the large differences in weighting
factors influencing the decisions made.
• The OI, when compared with the TPI, was slightly
more complicated to use and would require even
more calculations and clerical time.

• The HMAR correlates fairly well with the standard
but not as closely as the TPI or the OI.
• However, it had advantages as well.
• Subjective decisions were not as critical as the TPI or
the OI, because only full-cusp discrepancies were
noted.

• If errors were made, they were not usually serious
because the weighting system applied was only to the
anterior segment and mostly for esthetics.
• Recording and calculation of the index was also
simpler and required less time.
• In conclusion, The Summers occlusal index appear to
have the least amount of bias has the highest validity
during time and is best correlated with clinical
standards.

• Yet it still has short comings.
• Elderton and Clark pointed out that OI needs to be
refined to allow scoring when first permanent molars
are lost or drifted because difficulty and mistakes in
measuring the malocclusion would arise in these
situations.

• Tang and Wei used the OI to assess treatment
effectiveness of orthodontic appliances and thought
that the OI is not ideal because it does not take into
account residual or extraction spaces, nor does it
measure mesiodistal or buccolingual tooth
inclinations.
• Further research would therefore be needed to
develop better indices or to refine the present indices
so that they can be more universally accepted.

CONCLUSION
• A good method of recording or measuring
malocclusion is important for documentation of the
prevalence and severity of malocclusion in population
groups.
• This kind of data is not only important for the
epidemiologist, but also for those who plan for the
provision of orthodontic treatment in a community or
for the training of orthodontic specialists.

• If the method is universally accepted and applied,
data collected from different population groups can
be compared.
• McLain and Proffit "occlusal problems cannot be
defined solely in physical terms."
• They say that the psychosocial consequences due to
unacceptable dental esthetics may be as serious, or
even more serious, than the biologic problems.

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