epidemiology of malocclusion

1. EPIDEMIOLOGY
OF
MALOCCLUSION
AND
ORTHODONTIC TREATMENT
NEEDS

2. CONTENTS
1. Introduction
2. Epidemiology-definition, aim and objectives
3. Epidemiology and public health aspects of malocclusion
4. Methods of recording malocclusion for epidemiological
data
5. Factors that contributed to large variations in reporting the
prevalence of malocclusion
6. Ethnic trends in malocclusion prevalence
7. Prevalence of malocclusion in India
8. Prevalence of malocclusion in Indian tribal population
groups
9. Recording the severity of malocclusion :Orthodontic
Indices and the Treatment needs
10. Methods of recording malocclusion
11. Conclusion

3. INTRODUCTION:
• The demand for orthodontic treatment is increasing in most
countries.
• Therefore, rational planning of orthodontic measures on a
population basis is essential in assessing the resources required for
such a service.
• This stresses the importance of epidemiological studies in order to
obtain knowledge about the prevalence of different types of
malocclusions and the need for orthodontic treatment.
• Population- based surveys of dental diseases are a prerequisite for
systematic planning of oral health needs of the society and to
estimate the efficacy of the preventive and therapeutic measures
introduced.

4. Epidemiology
(Epi : among , Demos: People, Logos: Study )
• It is defined as the study of the distribution and determinants
of health-related states or events in specified populations and the
application of this study to control of health problems.
•The scientific study of the spread and control of diseases..
•Epidemiology contributes to the rationale for public health
policies and services and is important for use in their evaluation.

5. Aims of Epidemiology
According to the International Epidemiological Association
(IEA) Epidemiology has three main aims.(IEA). –
a. To describe and analyze diseases occurrence and distribution
in human populations.
b. To identify etiological factors in the pathogenesis of diseases
c. To provide the data essential to the planning, implementation
and evaluation of services for the prevention, control and
treatment of diseases and to the setting up of priorities among
those services.

6. Epidemiology and Public Health Aspects of Malocclusion
• The aim of epidemiologic studies of malocclusion is to describe
and analyze the prevalence and distribution of malocclusion in
various populations, the ultimate goal being to identify etiologic
factors.
• A further aim is to contribute to the solution of the public health
problems concerning assessment of need for orthodontic treatment
and organization of orthodontic services.

7. METHODS OF RECORDING MALOCCLUSION
FOR EPIDEMIOLOGICAL DATA
• Angle’s classification of malocclusion has been used in population
survey to report on the prevalence and distribution of different types
of malocclusion.
• Limitations of Angle’s classification in recording malocclusion –
- Severity of malocclusion can’t be determined
- Does not consider the patient’s profile
- Skeletal relationship
- Intra-examiner and inter-examiner error is usually large.

8. Assessment of Dento-facial Anomalies and status of occlusion was
suggested to be recorded on permanent dentition in three parts :
1. Dental examination : Anomalies of development, congenitally
missing teeth, supernumerary teeth , malformed teeth, impacted ,
missing due to trauma or extraction and retained deciduous teeth.
2. Intra-arch examination: Crowding, spacing, anterior irregularities
and upper midline diastema.
3. Inter-arch examination : Molar relationship, posterior openbite,
crossbite, overjet, overbite, midline deviation, anterior openbite,
and soft tissue impingement.

9. Factors that contributed to large variations in
reporting the prevalence of malocclusion:
1. Lack of demarcation between prevalence of malocclusion in population
Vs frequency distribution of malocclusion among patients visiting
hospitals.
2. Lack of uniform objective criteria in some studies for recording
malocclusion or method of registration of malocclusion.
3. Selection procedure employed in identification of the locations in
population- based studies.
4. Sampling technique
5. Sample size
6. Variation in age group
7. Age group combination
8. Ethnic variations
9. Sex difference
10. Inter-examiner variability
11. Intra-examiner errors

10. ETHNIC TRENDS IN MALOCCLUSION PREVALENCE
 In general, Prevalence of malocclusion :
White > Black Urban children > Rural
 Certain races are know for specific traits of malocclusion:
1. Bimaxillary protrusion – Negroes
2. Skeleletal class III - Polynesians of pukapuka
island and Mongoloids of China, Japan, Taiwan and
Korea
3. Class II is high among - Causasians

11. PREVALENCE OF MALOCCLUSION IN INDIA
Indian population divided into seven ethnic groups based on
Anthropometric measurements and skin color :
1. Indo-Aryans- Eastern Punjab and Kashmir
2. Sytho-Dravidians- Inhabits hilly tracts of Madhaya Pradesh
3. Mangolo-Dravidians- West Bengal and Odisha
4. Mangoloids- Himalayan region, Assam and North-eastern
states.
5. Dravidians-inhabit southern India especially Tamil Nadu,
Andhra, Kerala, southern Bihar and coastal Odisha
6. Aryo-Dravidian-Northern India
7. Turko-Iranians-inhabit Baluchistan and Frontier province

12. Prevalence of Malocclusion in children of Delhi
Age group- 10-13 years
Normal occlusion- 56%
Class I malocclusion -26%
Class II malocclusion-15%
Class III malocclusion-3.0%

13. PREVALENCE OF MALOCCLUSION IN
SOUTHERN INDIAN CITY OF
TRIRUVANANTHAPURAM:
Prevalence of malocclusion-49.2%
Age group- 12-15 years
Class I malocclusion -44%
Class II malocclusion-4.9%
Class III malocclusion-0.3%

14. PREVALENCE OF MALOCCLUSION IN
BANGALORE
•Sample size-1,033 school children
•Age group-5-15years
•Prevalence of malocclusion-51.5%
•Class II malocclusion-4%
•Class III malocclusion-0.9%

15. Ethnic trend in prevalence of type of malocclusion
in India from North to South:
•Prevalence of Class II malocclusion in
•Delhi and Haryana-10-15%
•Bangalore and Thiruvananthapuram - 5%
•Southern population has ethnic affinity for bimaxillary
protrusion

16. EPIDEMIOLOGY OF
MALOCCLUSION
AND
ORTHODONTIC TREATMENT
NEEDS

17. Introduction
Requirements of ideal orthodontic index
Classification
Methods of recording malocclusion
Conclusion
CONTENTS

18. 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
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 occlusion.’
INTRODUCTION

19. WHY RECORDING OF MALOCCLUSION AND ITS
SEVERITY IS REQUIRED ?
1. To document the prevalence of types of malocclusion in
population groups.
2. To document types and severity of different malocclusion
3. Scientific studies to development of malocclusion according to
age
4. Measurement of malocclusion / Traits of occlusion to be used
to objectively quantify outcome of orthodontic treatment.
5. In quality assurance and research.
6. Planning and promoting treatment standards.

20. Requirements of ideal orthodontic index are –
(Jamison H.D. and Mc Millan R.S )
1. Simple, accurate, valid, reliable and reproducible.
2. Index should be Objective in nature and yield quantitative data which
may be analyzed by current statistical methods.
3. Differentiate b/w handicapping and non handicapping malocclusions.
4. Measure degree of handicap.
5. Quick examination.
6. Amenable to modifications.
7. Usable either on patient or on study model.

21. 1. Occlusal Classification
– Angle’s classification by Angle in
1899
– Incisor classification by Ballard and
Wayman, 1964
2. Skeletal classification by
- Houston et al, 1993
3. Malocclusion
- Occlusal index by Summers 1966
- Handicapping Malocclusion
Assessment Record (HMAR) by
Salzmann, 1968
- Index of Treatment Need by Evans and
Shaw 1987
4. Treatment assessment
– Little’s irregularity index by
Little 1975
– Peer Assessment rating by
Richmond et al, 1987
5. Cleft Outcome
– Goslon Yardstick by Mars et al,
1987
– 5Year olds’ Index by Atack et al
,1997
6. Periodontal
– Plaque Index by Silness & Loe ,
1964
– Gingival Index. by Loe & Silness,
1963
Types of Indices ( according to WHO)

22. Types of Indices ( According to William Shaw et
al in 1995 )
1. Diagnostic Classification
a. Angle Classification System (1899)
b. Incisal categories of Ballard & Wayman (1964)
c. Five-point system of Ackerman & Proffit (1969)
2. Epidemiologic indices
a. Index of Tooth Position (Massler & Frankel, 1951)
b. Malalignment Index (Van Kirk & Pennel, 1959)
c. Occlusal Feature Index (Poulton & Aaronson, 1961)
d. The Bjork Method (1964)
e. Summers’ Occlusal Index (1966)
f. The FDI method (Baume et al, 1973)
g. Little’s Irregularity Index (1975)

23. •
3. Treatment need ( Treatment priority) indices.
Categorize malocclusion according to levels of treatment needs.
1. Handicapping Labio-lingual Deviation index (HLD) (Draker, 1960)
2. Treatment Priority Index (TPI)- Grainger (1967)
3. Handicapping Malocclusion Assessment Index (HMAR)-Salzmann (1968)
4. Dental Aesthetic Index (DAI) (Cons et al, 1986)
5. Index of Orthodontic treatment Need (IOTN) (Brook & Shaw, 1989)
6. Index of Complexity, Outcome & Need (ICON) (Daniel & Richmond, 2000)
4. Treatment outcome indices:
Assesssment of changes resulting from treatment
Eg 1. Peer Assessment Rating index(1992)
2. Index of Complexity, Outcome & Need (ICON) (2000)
5. Treatment complexity index
1. Index of Complexity, Outcome & Need (ICON) (2000)
2. Index of Orthodontic Treatment Complexity (IOTC) (Liewellyn et al, 2007)

24. Methods of recording
malocclusion
Qualitative Methods Quantitative methods
Qualitative method describes the occlusal
features and provides descriptive
classification of the dentition, however does
not provide any information of the treatment
need and outcome.
Malocclusion symptoms are recorded in
all or none manner as the studies on
epidemiology of malocclusion do not define
the method of measuring the variables.
Quantitative methods quantify the
complexity and severity of the problem rated
in a scale or proportion.
They are used to prioritize the need for
treatment. Their use minimizes the
subjectivity related to the diagnosis, outcome
and complexity assessment of orthodontic
treatment.

25. QUALITATIVE METHODS OF RECORDING AND MEASURING
MALOCCLUSION
Angle
(1899)
Classification of molar relationship devised as a prescription for
treatment
Stallard
(1932)
The general dental status, including some malocclusion
symptoms was recorded.
No definition of various symptoms was specified.
McCall
(1944)
Malocclusion symptoms were recorded include: Molar
relationships, posterior crossbite, anterior crowding, rotated
incisors, excessive overbite, openbite, labial or lingual version,
tooth displacement, constriction of arches.
No definition of these symptoms was specified.
Sclare
(1945)
Specific malocclusion symptoms were recorded, which include
 Angle’s classification,
 arch constriction with incisor crowding,
arch constriction without incisor crowding,
superior protrusion with incisor crowding,
superior protrusion without incisor crowding
labial prominence of canines, Lingually placed incisors,
rotated incisors, crossbite, openbite and closebite
No definition of these symptoms was specified.
Symptoms were recorded in an ‘all-or-none’ manner.

26. Fisk
(1960)
Dental age was used for grouping patients.
Three planes of space were considered:
1.Anteroposterior relationship: Angle’s classification, anterior
crossbite, overjet (mm), negative overjet (mm).
2.Transverse relationship:Posterior crossbite(maxillary teeth biting
buccally or lingually)
3. Vertical relationship: Openbite (mm), overbite (mm)
Additional measurement include labiolingual spread (Draker 1960),
Spacing, therapeutic extractions, postnatal defects, congenital
defects, mutilation, congenital absence., supernumerary teeth.
Bjork,
Krebs,
and
Solow
(1964)
Objective registration of malocclusion symptoms based on detailed
definitions. Data obtained could be analysed by computers.
Three parts:
1. Anomalies of dentition: tooth anomalies, abnormal eruption,
malalignment of individual teeth.
2. Occlusal anomalies : deviation in the positional relationship
between upper and lower dental arches in saggital, vertical and
transverse planes.
3. Deviation in space conditions : spacing or crowding

27. Proffit and
Ackerman
(1973)
5-step procedure of assessing malocclusion (no definite creteria for
assessment was given) :
1. Alignment: Ideal, crowing, spacing, mutilated
2. Profile: Mandibular prominence mandibular recession, lip profile
realted to nose and chin (Convex, straight and concave )
3. Cross-bite : Relationship of dental arches in transverse plane, as
indicated by buccolingual relationship of posterior teeth.
4. Angle classification : Relationship of dental arches in sagittal plane.
5. Bite depth : Relationship of dental arches in vertical plane,as
indicated by presence or absence of anterior openbite, deepbite,
posterior open-bite and posterior collapse bite.
WHO/FDI
(1979)
Five major group of items were recorded ( with well-defined recording
criteria) :
1. Gross anomalies
2. Dentition: Absence teeth, supernumary, malformed incisor, ectopic
eruption
3. Space conditions: Diastema, crowding and spacing
4. Occlusion:
a) Incisor segment: Maxillary and mandibular overjet, crossbite,
overbite, openbite and midline shift
b) Lateral segment : Anteroposterior relations, openbite, posterior
crossbite.
5. Orthodontic treatment need judged subjectively : Not necessary,
doubtful, necessary, urgent

28. Kinaan
and
Bruke
(1981)
Five features of occlusion measured:
1. Overjet (mm)
2. Overbite(mm)
3. Posterior crossbite (number of teeth in crossbite ,unilateral ,
or bilateral)
4. Buccal segment crowding or spacing (mm)
5. Incisal segment alignment (classified as acceptable, crowded,
spaced, displaced, or rotated, following defines criteria)

29. QUANTITATIVE METHODS OF RECORDING
MALOCCLUSION
I. HANDICAPPING LABIO-LINGUAL DEVIATION
INDEX: (HARRY L DRAKER-1960):
• The HLD index was proposed to select subjects with severe or
handicapping malocclusion and dento-facial anomalies.
•To measure the presence or absence and the degree of handicap
caused by the components of index.
•Applicable only to the permanent dentition.
•It was the first orthodontic index designed to meet the
administrative needs of program planners.

30. •Method: 3 planes commonly used for orthodontic orientation i.e. the sagittal plane,
the Frankfort horizontal plane and the orbital plane.
•
•HLD index is based on seven components
•Measurements was made with Boley gauge scaled in mm.
1. Condition #1-Cleft Palate: This is describes as malocclusions resulting from serious
structural deformities involving growth and development of maxilla and mandible.
Presence is indicated by an ‘X’ in recording chart.
2. Condition #2-Traumatic Deviations: Indicated by an ‘X’ in recording chart
3. Condition # 3 – Overjet- Measurement can be applied to a single protruding tooth as well
as to the whole arch.
4. Condition # 4- Overbite: Reverse overbite should also be measured and recorded.
5. Condition #5- Mandibular Protrusion: Measured from labial of lower incisor to labial of
upper incisor.
6. Condition #6- Openbite: measured from edge to edge in mm .
7. Condition #7-Labio-lingual spread- The boley gauge is used to determine the extent of
deviations from normal arch.
Total distance between the most protruded and lingually displaced anterior is measured
.

31.  In case of multiple anterior crowding, all deviation
from normal arch should be measured for
labio-lingual spread, but only the most severe
individual measurement should be entered on
index—done to give the patient the benefit of
greatest deviation.

32. Handicapping Labio-lingual deviation index scoring:
Condition observed HLD score
1. Cleft palate Score X, no further
score
2. Severe traumatic deviations Score X, no further
score
3. Overjet in mm mm
4. Overbite in mm mm
5. Mandibular protrusion in mm (mm) x 5
6.Open bite in mm (mm) x 4
7. Ectopic eruption, anteriors only each tooth (count) x 3
Anterior crowing
Maxilla- 1
Mandible- 1
Maximum for anterior crowding - 2
(0, 1 or 2) x 5
labiolingual spread in mm mm
Posterior unilateral crossbite (must involve 2 or more 4
adjacent teeth, one of which must be a molar)

33. A score of 13 (tentative) and over constitutes a ‘physical handicap’
Following codes are used in HLD index:
O Condition absent
X Condition present
M Mixed dentition
A Clinical approved
D Clinical disapproval
Demerits- The distribution of HLDI scores in the two groups were
found to be largely overlapping, which indicated that the HLDI was
unable to distinguish the so-called handicapping malocclusion.

34. II. Index of Orthodontic Treatment Needs (IOTN)
by Brook &Shaw - 1987
Index of orthodontic treatment needs attempts to rank malocclusion
based on the level of treatment needed on treatment priority.
The index intends to identify people who would most likely benefit
from orthodontic treatment.
The 2 Components:
• Dental Health Component(DHC): derived from occlusion and
alignment – Dental casts.
• Aesthetic Component(AC): Derived from comparison of dental
appearance to standard photographs. – direct examination

35. DENTAL HEALTH COMPONENT (DHC)
Based on index of Swedish Medical Health Board and
involves aspects of the occlusion that might impair the health
and function of the dentition.
This is categorized in 5 grades ranging from 1 (no treatment
need ) to 5 (great need).
The dentition is assessed systematically, thus ensuring that
all relevant occlusion anomalies are recorded.
If two or more occlusal anomalies are of the same DHC
grade, the most severe one is scored.

36. Hierarchical scale:
Missing teeth (including aplasia, displaced and impacted teeth)
Overjets (including reverse sagittal overjets)
Crossbite
Displacement
Overbites (including open bites)
Grade 1 No treatment need
Grade 2
Minor anomaly, no treatment
need
Grade 3 Borderline treatment need
Grade 4 Treatment need
Grade 5 Treatment need
Mnemonic acronym: MOCDO
Mnemonic acronym: MOCDO

37. GRADES
Grade 1 (no treatment need)
Extremely minor malocclusion including contact point displacement.
Grade 2 (Mild/little need)
2.a) Increased overjet >3.5mm < 6 mm with competent lips
2.b) reverse overjet >0 mm < 1 mm
2.c) anterior or posterior crossbite < 1 mm discrepency
2.d) anterior or posterior open bite 1 mm < 2 mm.
2.e) increased overbite > 3.5 mm but with no gingival contact.
2.f) contact point displacement 1 mm < 2 mm.
2.g) pre normal or post normal occlusion with no other abnormalities.

38. Grade 3(moderate/borderline need)
3.a) Same as grade 2 with incompetent lips
3.b) reverse overjet >1 mm < 3.5 mm
3.c) anterior or posterior crossbite >1mm < 2 mm
3.d) contact point displacement > 2 mm < 4 mm.
3.e) lateral or anterior open bite > 2 mm < 4 mm
3.f) Deep overbite on gingival and palatal tissues but no trauma

39. Grade 4(severe/need treatment)
4.a) Less extensive hypodontia (less than or equal to one tooth per
quadrant)
4.b) increased over jet > 6 mm < 9 mm
4.c) reverse over jet >3.5 mm with no speech or masticatory
difficulty.
4.d) anterior or posterior crossbite with > 2 mm discrepancy.
4.e) posterior lingual crossbite with no functional occlusal contact in
one or both buccal segments.
4.f) severe contact point displacement > 4 mm.
4.g) extreme openbite > 4mm
4.h) partially erupted, impacted tipped teeth.
4.i) increased overbite with palatal trauma.
4.j) presence of supernumerary teeth.

40. Grade 5(extreme/need treatment)
5.a) Impacted eruption of teeth(except third molars) due to crowding,
displacement, the presence of supernumerary, retained deciduous and
pathological causes
5.b) extensive hypodontia
5.c) increased overjet > 9 mm
5.d) reverse overjet > 3.5 mm with reported masticatory and speech
problems
5.e) submerged deciduous teeth

41. ASTHETIC COMPONENT
10 front viewing photographs illustrating varying degree of
Occlusion (serves as a scale) attractive and unattractive occlusion or
casts viewed from front.
The grade awarded is for overall dental attractiveness rather than
specific morphological similarity to the photographs.
The rating is based on matching the dental appearance of the
patient with one of the photographs by an orthodontist or non
professional
No profile views are included
Photographs are arranged from number 1(most attractive) to
number 10(most non attractive)

42. The patient score is based on matching his/her photograph with
that of reference photographs.
Rating is allocated for overall dental attractiveness rather than
specific morphologic similarities to the photographs.
 The value arrived gives an indication of the patient's treatment
need on the grounds of esthetic impairment, and by inference
reflects the socio-psychologic need for orthodontic treatment

44. MODIFICATION S OF IOTN
Modifications were introduced in 1993
The Dental health component and aesthetic component were modified to improve
the reliability of these components.
In the dental health component DHC, the 5 grades were reduced to 3
Grade 1,2….. No treatment need
Grade 3……. Borderline
Grade 4,5….. Treatment need
In the Aesthetic component AC the 10 point scale was reduced to 3 point scale
1. Photographs 1-4…. No treatment need
2. Photograph 5-7….. Borderline need
3. Photograph 8-10…. Definite need
These modifications were accepted and are used in British standards for
Orthodontic treatment

45. ADVANTAGES:
•Valid and reliable.
•Simple, quick and satisfactory reproducible method for recording orthodontic
treatment needs in epidemiological surveys.
LIMITATIONS
• In aesthetic component ,Class III not considered.
•Facial profile not considered.
•Class I bimaxillary protrusion not considered
•All the children with cleft lip and palate are grade 5,i.e. the most severe
malocclusion irrespective of type and severity of defect.

46. III. Peer Assessment Rating Index (PAR index)
by Richmond et al., 1987
Developed at the Manchester university.
 Its developed mainly to assess effectiveness of Orthodontic
treatment.
 Scores are assigned to various occlusal traits that make up a
malocclusion.
The individual scores are summed & the total represents the
degree to which a case deviates from normal alignment
&occlusion.
Improvement in the PAR index can be assessed with either the
point reduction in the weighted PAR score or percentage
reduction.

47. 5 components Weighting
1. Upper & lower anterior segment x1
2. Left and right buccal segments x1
3. Over jet x6
4. Overbite x2
5. Centerlines - x4
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 treatment.

48. The PAR (Peer Assessment Rating) index
1.Contact point displacement score
The contact point displacement in the upper and lower anterior segments is recorded as the
shortest distance between contact points of adjacent teeth measured parallel to the occlusal
plane.
0 0–1 mm
1 1.1–2 mm
2 2.1–4 mm
3 4.1–8 mm
4 >8 mm
5 impacted teeth
2. Buccal occlusal assessment
a. Antero-posterior
0 Good interdigitation
1 <1/2 unit from full interdigitation
2 Half a unit
b.Vertical
0 No open bite
1 Lateral open bite on at least 2 teeth >2 mm
c.Transverse
0 No crossbite
1 Crossbite tendency
2 Single tooth in crossbite
3 >1 tooth in crossbite
4 >1 tooth in scissors bite
3.Overjet assessment
a.Overjet
0 0–3 mm
1 3.1–5 mm
2 5.1–7 mm
3 7.1–9 mm
4 >9 mm
b.Anterior crossbite
1 No crossbite
2 > teeth egde to edge
3 one single tooth in crossbite
4 Two teeth in crossbite
5 >2 teeth in crossbite

49. 4. Overbite assessment
1)Open bite
0 No open bite
1 Open bite <1 mm
2 Open bite 1.1–2 mm
3 Open bite 2.1–3 mm
4 Open bite > 4 mm
2)Overbite
0 - < 1/3 coverage of the lower incisor
1 - >1/3 but <2/3 coverage of the lower incisor
2 - > 2/3 coverage of the lower incisor
3 - Greater or equal to full tooth coverage
5.Centreline assessment
0 - Coincident and up to 1/4 lower incisor
width
1 - 1/4–1/2 lower incisor width
2 - >1/2 lower incisor width

50. Change expressed as:
Reduction in weighted PAR score : 22 point reduction – Greatly improved
% reduction in weighted PAR score:
< 30% reduction – worse/ no better
> 30% reduction – Improved.

51. Advantages
Allows rapid recordings and is therefore suitable for routine quality
evaluation in a clinic.
 Serve as a basis for long-term follow-up and further analysis of the
causes of relapse
Limitations-
Several aspects of orthodontic treatment quality are not taken into
consideration, such as the patient´s own assessment of his treatment need
and the treatment result, the duration of treatment and various side
effects, for instance.
The index does not reflect all details of morphological change.
 Facial profiles not considered Eg. Bimaxillary protrusion

52. IV. TREATMENT PRIORITY INDEX (TPI)
(GRAINGER-1967)
•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.
The prerequisites for determining a handicap were defined by Grainger as
follows:
(1) unacceptable esthetics,
(2) significant reduction in masticatory function,
(3) traumatic condition predisposing to tissue destruction,
(4) speech impairment,
(5) unstable occlusion and
(6) gross or traumatic defects.

53. Eleven weighted & defined measurements:
1. Upper Anterior Segment Overjet
2. Lower Anterior Segment Overjet
3. Overbite Of Upper Anterior Over Lower Anterior
4. Anterior Openbite
5. Congenitally Absence Of Incisors
6. Distal Molar Relation
7. Mesial Molar Relation
8. Post.Crossbite (maxillary Teeth Buccal To Normal)
9. Post.Crossbite (maxillary Teeth Lingual To Normal)
10. Tooth Displacement
11. Gross Anomalies

54. Malocclusion Syndromes
1. Maxillary Expansion Syndrome
2. Overbite
3. Retrognathism
4. Openbite
5. Prognathism
6. Maxillary Collapse Syndrome
7. Congenitally Missing Incisor

55. 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 serves as a guide for epidemiological surveys of populations
as well as an instrument for screening.
 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 children aged b/w 6-11 yrs in year
1967

56. A few manifestations of malocclusion, such as midline diastema and
slight asymmetry, were rejected as being of little public health
significance.
It is inadequate for assessing the occlusion of the deciduous or
mixed dentition.
 As there is no "mixed dentition analysis" it is invalid to measure
potential tooth displacement.

57. CONCLUSION
• The main purpose of the indices is to interpret malocclusion severity objectively in
terms of treatment priority. Fundamentally, the index scores are based on clinical
estimations of the severity of the various traits. In other words, the scores are
assigned according to clinical concepts of the adverse effects of the traits on facial
appearance, function, and oral health. Thus, the objectivity involved in such
interpretations would seem to be questionable.
• Once the basic needs for caries control in a child population have been met, the
problems of organizing orthodontic care comes into focus. Traditionally, the
responsibility for initiating orthodontic measures and the economic burden of the
treatment have rested mainly with the patients, or rather with their parents. Thus, the
provision of orthodontic treatment has often been determined by the incidental
educational and socio-economic level of the family, instead of the severity of the
patient's malocclusion