orthodontic indecis by almuzian

University of Glasgow

Orthodontic Indices

Personal notes

Mohammed Al Muzian

5/2/2013

An Orthodontic index or a malocclusion index can be defined as a means of objectively

assessing occlusal status.

List of contents

Definition

Uses of orthodontic indices

1. Epidemiological

2. Clinical Assessment

3. Uniformity in inter-disciplinary communication and description of a malocclusion

General requirement of an index

Types of indices

1. Classification indices

2. Diagnostic indices

3. Treatment assessment (need, complexity and outcome)

4. Cleft outcomes

5. Oral health indices

Angle’s classification

• Some modification has been added like:

• Advantage

• Drawbacks

Incisor classification

• Some modification has been added like:

Skeletal classification

Index of Orthodontic Treatment Need

1. The aesthetic component

Treatment priority and need according to AC

2. The dental health component

• Treatment priority and need according to DHC

Mohammed Almuzian, University of Glasgow 1

• Advantages

• Disadvantages:

• Reproducibility of the IOTN:

1. Dental Health Component

2. Aesthetic Component:

Missing teeth (5.i, 5.h or 4.h)

Impeded eruption (5.i)

Hypodontia (5.h or 4.h)

Overjet (2.a, 3.a, 4.a, 5.a, 2b, 3b, 4b, 4m,5m)

Crossbite (2.c, 3.c, 4.c)

Displacement of contact points (2.d, 3.d, 4.d)

Overbite and Open bite (2.e/f, 3.e/f, 4.e/f)

Buccal occlusion (2.g)

Submerging teeth (5.S)

Tipped teeth (4.t)

Supernumerary teeth (4.x)

Peer Assessment Rating (PAR)

Reliability

Buccal and anterior segments

Buccal occlusion

Overjets

Overbite

Centrelines

Advantages

Disadvantages

Outcome assessment

Index Of Complexity, Outcome And Need (ICON)


ABO Discrepancy Index (ABO DI)

Disadvantages of ABO DI

Advantages of ABO DI

Handicapping Malocclusion Assessment Record (HMAR)

Irregularity index

Crowding index

The validity of maxillary expansion indices, O'Reilly, 1995

A treatment difficulty index for unerupted maxillary canines

Plaque index

Gingival index

Handicapping Labio-Lingual Deviation (HLD)

Swedish Index (Need For Treatment Index)

Treatment Priority Index (TPI)


Orthodontic Indices

Definition

An Orthodontic index or a malocclusion index can be defined as a means

of objectively assessing occlusal status.

Uses of orthodontic indices

1. Epidemiological

A. determine the prevalence and incidence of occlusal anomalies

B. economic health care resource planning (financially and in terms of

manpower)

C. for academic research

2. Clinical Assessment

A. Classification of malocclusion (Angle classification, incisor classification

by BSI, 1983)

B. Diagnostic (Occlusal index)

C. Treatment Need or priority (e.g. IOTN).

D. Treatment Complexity /difficulty (NB: ICON tries to address

Complexity, Outcome & Need).

E. Treatment Outcome /success (PAR).

3. Uniformity in inter-disciplinary communication and description of a

malocclusion

General requirement of an index

1. Reliable

2. Reproducible : closeness of successive evaluation.


3. Valid : the index should measure what it was intended to measure.

4. Universally acceptable to profession and public

5. Require minimal adjustment.

6. Simple to administer.

7. Cheap .

Types of indices

1. Classification indices

a) Skeletal classification

b) Soft tissue classification

c) Occlusal classification:

Angle’s Classification

Incisor Classification

Canine Classification

2. Diagnostic indices

a) Occlusal index

b) Handicapping Malocclusion Assessment Record (HMAR)

3. Treatment assessment (need, complexity and outcome)

a) IOTN

b) Irregularity Index

c) Peer Assessment Rating (PAR)

d) ICON

4. Cleft outcomes

a) GOSLON Yardstick

b) 5 year Old’s Index

c) Bergalnd index for SABG


d) Kindealan index for SABG

5. Oral health indices

a) Plaque Index

b) CPITN

c) Gingival Index

Angle’s classification

a) This classification is used in orthodontics to assess the anterior posterior

relationship with regards to the lower first permanent molar as a key.

b) Three classes were described by Angle (1899):

Class I (neutrocclusion): when the mesiobuccal cusp of the upper first

permanent molar occlude with the buccal groove of the lower first

permanent molar.

Class II (distocclusion/ Post-Normal): when the mesiobuccal cusp of the

upper permanent first molar at least one cusp width mesial to Class I (Full

unit class II).

Class III (mesiocclusion/ Pre-normal): when the mesiobuccal cusp of the

upper permanent first molar at least one cusp width distal to Class I (Full

unit Class III).

Some modification has been added like:

Class II subdivision: when there is a Cl1 on one side and Cl2 on

the other side

Class III subdivision: when there is a Cl1 on one side and Cl3

on the other side

1/2, 1/3, 1/4 unit Class II and Class III are also used now.


Advantage

Simple

Widely accepted

Reliable and reproducible

Drawbacks

Cannot used in primary dentition

Not distinguish between dental and skeletal problems

Only consider problem in AP direction

Consider the 6s as fixed point which are not in reality and can be affected

by environmental factors.

Cannot used when 6s extracted

Incisor classification

By British standard institutes (1983)

It is based on the relationship between the lower incisor edges and the

upper central incisors’ cingulum plateau.

According to the definition of these classes as follows:

A. Class I: the lower incisor edges occlude with or lie immediately below the

cingulum plateau of the upper incisors.

B. Class II: the lower incisor edges occlude or lie posterior to the cingulum

plateau of the upper incisors. Two divisions of this class were described:

Division 1: the upper incisors are proclined with an increased overjet.

Division 2: all the upper incisors or just the centrals are retroclined. The

laterals may be proclined. The overjet is decreased but may be increased.

C. Class III: the lower incisor edges occlude or lie anterior to the cingulum

plateau of the upper incisors. Overjet is usually reduced or reversed.


Some modification has been added like:

Class II subdivision: one incisor in CLII and other side CLI

Class II indefinite when one incisor retroclined and the other is

proclined (Gravely)

Class II intermediate when the incisor retroclined or upright and

the OJ 5-7 mm (Stephen and William, 1993).

Skeletal classification

1. Skeletal classification is obtained from lateral cephalometric radiograph

to support the clinical findings.

2. Three skeletal classes were described using cephalometric points and

angular measurements:

Class I: lower dental base is related to the upper dental base (ANB= 2-

4˚).

Class II: lower dental base is retruded relative to the upper dental base

(ANB> 4˚)

Class III: lower dental base is protruded relative to the upper dental base

(ANB <2˚).

Wits appraisal and Balllard conversion can be used in a similar way to

ANB.

Index of Orthodontic Treatment Need This was developed by Brooke and Shaw in 1989.

Specific ruler had been developed to make the procedure easy.

IOTN in general is composed of two components:


1. The aesthetic component

a) This was developed by Evans and Shaw (1987). It was originally called

the SCAN (Standardised Continuum of Aesthetic Need). A lay panel was

used.

b) It is a ranking system (1-10) using coloured photographs which can be

said to assess dental attractiveness.

c) Number 1 is the most attractive while number 10 is the least attractive.

Rating is allocated to the clinician and sometime to the patient for overall

attractiveness compared with the photo and not specific morphological

similarity to the photo.

d) The NHS does recognise that some children need and benefit from

orthodontic treatment on the basis of poor aesthetics. The Aesthetic

Component of the IOTN is a scale of 10 colour photographs showing

different levels of dental attractiveness. The grading is made by the

orthodontist matching the patient to these photographs. The photographs

were arranged in order by a panel of lay persons.

e) Within the NHS if a patient in Dental Health category 3 has an Aesthetic

Component rating of 6 or more NHS treatment is permissible.

f) Monochromic photographs are used for dental cast assessments.

g) It has been reported that monochromic photographs have advantage

that raters are not influenced by oral hygiene, gingival condition, or

poor colour matching in anterior restorations . the black and white is

used to rate the SM. (Woolass and Shaw, 1987).

Treatment priority and need according to AC

1. Grades 1 - 3 No/slight need for treatment

2. Grades 4 mild

3. Grades 5 6 7 borderline need for treatment


4. Grades 8 9 10 Definite need for orthodontic treatment

2. The dental health component

a) This was developed based on the index used by the Swedish Dental

Board. It consists of 14 qualifiers and 5 grades, grade 1 representing little

or no need for treatment and grade 5 representing great need of treatment.

Ruler is used for measurement.

b) It assesses few points in order as follows (MOCDO): Missing teeth,

Overjets, Crossbites, Displacements, and Overbites.

c) Only the highest scoring trait need be recorded, as this determine the

grading for the patient.

Treatment priority and need according to DHC

1. Grades 1 & 2 No need for orthodontic treatment

2. Grade 3 Borderline need for treatment

3. Grades 4 & 5 Definite need for treatment

Advantages

1. Valid

2. Reproducible

3. Acceptable to clinician


4. Easy and quick to apply

5. Can be used directly on patients or on dental casts

6. Yield quantitative data which can be analyzed.

Disadvantages:

1. Crowding represented a problem in recording when the patient is in the

mixed dentition.

2. The AC has no side view rating or class III malocclusion.

3. Objective index

4. No representation of aesthetic or skeletal relationship

5. No assessment of crowding which relies on displacement only

NB:

Complexity can be defined as "intricate or complicated".

Difficulty is defined as "needing much effort and skill"

Severity is how far a malocclusion deviates from normal.

Reproducibility of the IOTN:

1. Dental Health Component

In the study of Brook and Shaw in 1989 they have shown that the

reproducibility of this component is very good.

They also found that the common trait causing disagreement in

descending order of frequency were; crowding, increased overjet,

crossbites, and overbites.


2. Aesthetic Component:

High level of agreement found between patients, parents and

orthodontists when grading a patient (Evans and Shaw, 1987).

This was supported with the results that suggested that the

correlation coefficients of this component were reasonably high

(Brook and Shaw, 1989).


In order to memorize them use this acronym

1) Grade 1=D

2) Grade 2= ABCDEFG

3) Grade 3= ABCDEF

4) Grade 4= ABCDEF+LHM+TX

5) Grade= SIMPHA

Missing teeth (5.i, 5.h or 4.h)

Missing teeth relates to: impacted, impeded eruption, hypodontia.

Impeded eruption (5.i)

If a tooth is out of the line of the arch and erupted it would be considered

(ectopic)

The tooth is considered impeded or impacted if the space remaining for

an erupted tooth is less than or equal to 4mm and the angulation is not

favorable (horizontal directed not vertical)

In the mixed dentition, the distance from the mesial contact point of the

first permanent molar to distal contact point of the lateral incisor is less

than 18 mm or 17 mm in the upper and lower dental arches respectively,

then the canine is considered impacted.

Hypodontia (5.h or 4.h)

Where there is extensive hypodontia (more than one tooth missing in

each quadrant) requiring either space closure or pre-restorative

orthodontics the grade would be 5h.

When there is only one tooth missing per quadrant the score would be 4h

Hypodontia is counted if the space will be address orthodontically (open

or close not to accept)


Overjet (2.a, 3.a, 4.a, 5.a, 2b, 3b, 4b, 4m,5m)

The overjet

It is measured using the ruler held parallel to the occlusal plane and radial

to the line of the arch

The overjet is recorded to the labial aspect of the incisal edge of the most

prominent incisor (lateral or central incisors). If the incisor falls on the

ruler line the lower grade is allocated.

A reverse overjet

It is recorded when ALL four incisors are in lingual occlusion.

If the reverse overjet is greater than 1 mm it is important to investigate

whether the individual has masticatory or speech (M&S) difficulties.

There are several methods of investigation but a simple approach is to ask

the individual to count from 60-70 noting any difficulty in pronunciation.

In addition, any signs and symptoms of mandibular dysfunction should be

checked.

Crossbite (2.c, 3.c, 4.c)

An anterior crossbite is when 1, 2 or 3 incisors (BUT) not all of them

are in lingual occlusion.

A posterior crossbite is recorded when the posterior tooth or teeth are

cusp to cusp or in full crossbite in a buccal or lingual perspective.


The grade recorded depends on the severity of discrepancy between

retruded contact position (RCP) and intercuspal position (IP).

The greater the discrepancy between RCP an IP, the higher the grade

Scissor bite always has a grade of 4L

Displacement of contact points (2.d, 3.d, 4.d)

The contact point displacement is measured between anatomical contact

points where teeth deviate from the line of the arch. Only the worst

displacement is recorded

Vertical displacements from the occlusal plane are not recorded.

Spacing is not generally recorded in the Dental Health Component. But if

spacing is associated with a tooth or teeth deviating from the line of the

arch, the contact point displacement is recorded.

Displacements between deciduous and permanent teeth are not recorded.

Contact point displacements due to rotated teeth (generally lower 2nd

premolars) are not recorded.

However, if the rotation results in a discrepancy between retruded contact

position (RCP) and intercuspal position (IP) as a direct result of occlusal

interference then a crossbite is recorded according to the severity of the

discrepancy between IP and RCP.


Overbite and Open bite (2.e/f, 3.e/f, 4.e/f)

Overbite and open bite relates to any of the lateral or central incisors.

The largest vertical discrepancy is recorded.

It is also important to note if there is any gingival or palatal trauma as a

result of the deep overbite

Other like acronym GTSX as below

Buccal occlusion (2.g)

The buccal occlusion is assessed irrespective whether the teeth

interdigitate in Angle's Class I, II or III.

Submerging teeth (5.S)

Submerging teeth are not generally recorded unless only two cusps

remain visible and/or the adjacent teeth are severely tipped towards each

other and closely approximated.


Tipped teeth (4.t)

When a tooth has erupted and is tipped against an adjacent tooth,

resulting in food packing it may require orthodontic treatment to upright

and level to eliminate the problem

Supernumerary teeth (4.x)

It is graded ONLY if a supernumerary tooth requires extraction followed

by orthodontic alignment and/or space closure

PEER ASSESSMENT RATING (PAR)

This index was developed by Richmond et al. (1992). It was formulated

over a series of six meetings in 1987 with a group of 10 experienced

orthodontists.

This index was developed to record the malocclusion at any stage of

treatment.

The concept is to assign a score to various occlusal traits which make

up a malocclusion.

The individual scores are summed to obtain an overall total, representing

the degree a case deviates from normal alignment and occlusion.

Study models used with a specifically designed ruler for this index. The

ruler has all the information summarized which makes measurement

quick and easy to perform.

The score zero indicates good alignment and higher scores (rarely beyond

50) indicates increased levels of irregularity.

The difference between the pretreatment and posttreatment scores

represent the degree of improvement as a result of orthodontic

intervention and active treatment.


There are 11 components of the PAR index:

1. Upper anterior segment

2. Lower anterior segment

3. Upper right segment

4. Upper left segment

5. Lower right segment

6. Lower left segment

7. Right buccal occlusion

8. Left buccal occlusion

9. Overjet

10.Overbite

11.Centrelines

Each dental arch is divided into three recording segments left and right

buccal segments and the anterior segments.

Reliability

It has been reported that the PAR index has an excellent reliability within

intra and inter-examiner agreement (Richmond et al., 1992).

Buccal and anterior segments

o Buccal segments start from the mesial anatomical contact point of the

first permanent molar to the distal anatomical contact point of the canine.

o Anterior segments starts 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.

o The occlusal features recorded are crowding, spacing, and impacted teeth.

o Displacements are recorded at the shortest distance between contact

points of adjacent teeth parallel to the occlusal plane with the exception

of the displacements that are present between the first, second and third


molars. This is because of the fact that the contact points are very broad

and are extremely variable within the normal range.

o In case of potential crowding in the mixed dentition, average mesio-distal

widths are used to calculate the space deficiency. Impacted teeth are

recorded when the space available for the tooth is equal or less than 4

mm.

o Displaced contact points due to poor restoration are not recorded and the

same for contact points between deciduous teeth.

o Orthodontic extraction spaces are not recorded

o Spacing in the anterior segment resulting from extraction, agenesis or

avulsion of incisors or cuspids is recorded as follows:

- If closing space the space is recorded

- If opening space and restore it, the space is not recorded unless it is less

than or equal to 4 mm

PAR Score Amount of teeth

displacement0 0 mm – 1mm

1 1.1 mm – 2mm

2 2.1 mm – 4mm

3 4.1 mm- 8mm

4 Greater than 8mm

5 Impacted teeth

Mixed dentition crowding assessment using average mesio-

distal widthUpper

Canine 8mm Total 22mm

Impaction < = 18mm 1st

Premolar

7mm


2nd

Premolar

7mm

Lower

Canine 7mm Total 21mm

Impaction < = 17mm 1st

Premolar

7mm

2nd

Premolar

7mm

Buccal occlusion

oThis is recorded for both right and left sides in occlusion in three

dimensions. A-P, vertical and transverse.

oThe recorded zone is from the canine and to the last molar whether this

was the first, second or third molar.

oTemporary developmental stages and submerging deciduous teeth are

excluded.

PAR

Score

Buccal Occlusion discrepancy

Vertical

0 No discrepancy in intercuspation

1 Lateral open bite on at least 2 teeth greater

than 2 mm

Antero-posterio

0 Good interdigitation (Cl I, Cl II or Cl III)

1 Less than ½ unit discrepancy

2 ½ a unit discrepancy (cusp to cusp) or more


Transverse

0 No crossbites

1 Crossbite tendency

2 Single tooth in crossbite

3 More than 1 tooth in crossbite

4 More than 1 tooth in scissor bite

Overjets

o The recording zone starts from the distal anatomical contact point of the

lateral incisor on one side to the distal anatomical contact point of the

lateral incisor on the other side.

o The most prominent aspect of any one incisor is recorded with a ruler

held parallel to the occlusal plane.

o Overjets and crossbites are recorded here. The sum of the two scores is

the total score for this component. If there is a positive overjet and

incisors or canines in crossbite the scores should be added together

Overjet component

measurementsOverjet

0 0-3 mm

1 3.1- 5mm

2 5.1- 7mm

3 7.1- 9mm

4 Greater than 9mm

Anterior crossbites

0 No discrepancy


1 One or more teeth edge to

edge

2 One single tooth in

crossbite

3 Two teeth in crossbite

4 More than two teeth in

crossbite

Overbite

oThe vertical overlap or open bite of the anterior teeth is recorded.

oThe tooth with the greatest overlap is recorded.

oIf OB and AOB are present, then they should be added.

Overbite component measurementsOpen bite

0 No open bite

1 Openbite less than and equal to 1mm

2 Openbite 1.1 mm – 2 mm

3 Openbite 2.1 mm- 3 mm

4 Open bite greater than or equal 4mm

Overbite

0 Less than or equal to 1/3 coverage of the lower incisor

1 Greater than 1/3, but less than 2/3 coverage of the

lower incisor

2 Greater than 2/3 coverage of the lower incisor

3 Greater than or equal to full tooth coverage.

Centrelines

o Records the centreline discrepancy in relation to the lower central incisor.


o If a lower incisor has been extracted the measurement is not recorded.

PAR Score Centrelines discrepancy assessment0 Coincident and up to ¼ lower incisor

width

1 ¼ to ½ lower incisor width

2 Greater than ½ lower incisor width

Advantages

1) Reliable.

2) Easy and quick considering the PAR ruler is used.

3) May be used for all types of malocclusion, treatment modalities, and

extraction / non-extraction cases.

4) The score provides an estimate of how far a case deviates from the

normal

5) Good tool in measuring the perceived degree of improvement and

therefore the success of treatment. Thus, it is an indicator for clinical

performance

NB: OJ multiplied by 6, OB by 2 and ML by 4, Zero weighing for

displacements

Disadvantages

1. It is not an index of treatment need.

2. It provides a single summary score for all the occlusal

anomalies. Thus, it is insensitive and can misjudge

individual patient need. Therefore, it is better to weigh each

malocclusion individually.


3. The reliability of the upper left and right segments was

found to be low and this was referred to the fact that the

upper teeth varies in size. The larger teeth cause a broader

contact points which makes inaccurate recording of the

scores (Richmond et al. 1992).

4. Hamdan and Rock (1999) suggested the limitation of PAR

index to be:

Overjet high weighing

Overbite low weighing

Outcome assessment

There are basically three methods of assessing outcome using the PAR

Index.

o The first is to record the reduction in PAR score. 22 point reduction

indicates great improvement.

o The second method is to calculate the percentage change. A percentage

improvement of greater than 70% can be considered as a good standard of

orthodontic treatment. While, 30-70% reduction represents an

improvement. Less than 30% reduction is either considered as becoming

worse or no improvement.

o The final method of assessment is to use the graph (nomogram)

INDEX OF COMPLEXITY, OUTCOME AND NEED (ICON)

This is the first index based on an international orthodontic opinion.

This index comprised of an assessment of:

Score 0 1 2 3 4 5

1) Aesthetic 1-10 as judged


using IOTN

AC

2) Upper arch

crowding

Only the

highest trait

either spacing

or crowding

Less than

2mm

2.1-

5mm

5.1-

9mm

9.1-

13mm

13.1-

17m

m

More

than

17mm

or

impacte

d teeth

3) Upper spacing Up to

2mm

2.1-

5mm

5.1-

9mm

More

than

9mm

4) Crossbite Transverse

relationship of

cusp to cusp or

worse

No

crossbites

Cross

bite

present

5) Incisor open bite Only the

highest trait

either openbite

or overbite

Complete

bite

Less

than

1mm

1.1-

2mm

2.1-

4mm

More

than

4mm

6) Incisor overbite Lower incisor

coverage

Up to 1/3

tooth

1/3- 2/3

coverag

e

2/3 up

to full

covered

Fully

covere

d

7) Buccal segment

anterioposterior

Left and right

added together

Cusp to

embrasure

relationshi

p only, Cl

I, II, III

Any

cusp

relation

up to

but not

includin

Cusp to

cusp

relation

ship


g cusp

to cusp

ABO Discrepancy Index (ABO DI)

The elements which make up the ABO Discrepancy Index are

measurements of:

1. Overjet and anterior cross bite

2. overbite and anterior open bite and lateral open bite,

3. crowding,

4. buccal occlusion,

5. lingual posterior crossbite and buccal posterior crossbite,


6. ANB angle and SN-Go-Gn and lower incisor to GoGn angle.

7. An additional category designated "other" is available so that other

conditions which may affect or add to complexity of treatment may be

scored.

OVERJET: Overjet is scored as the distance between the incisal edge of

the most forward positioned maxillary incisor and the most forward

positioned mandibular incisor. For overjets of 0 mm. (edge to edge), 1

point is scored; for overjets of 0 to 3 mm., no points are scored; for 3.1 - 5

mm., 2 points are scored; for 5.1 - 7 mm., 3 points are scored; for 7.1 - 9

mm., 4 points are scored and if over 9 mm., 5 points are scored. If there is

a negative overjet (anterior crossbite), the score is recorded as 1 point per

mm. per anterior tooth in crossbite.

OVERBITE: For overbites of up to 3 mm. no points are scored. If the

overbite is between 3.1 to 5 mm. 2 points are scored; if between 5.1 to 7

mm. 3 points are scored. If the lower incisors are impinging on the palatal

tissue (100% overbite), then 5 points are scored.

ANTERIOR OPEN BITE: If the maxillary and mandibular incisors are

in an edge to edge relationship (overbite = 0), then 1 point is scored. For

each millimeter of open bite, 2 points are scored for each maxillary tooth

involved from canine to canine. No points are scored for the maxillary

canines if they are blocked out of the arch to the labial.

LATERAL OPEN BITE: For each maxillary tooth (from the first

premolar to third molar) in an open bite relationship with the lower arch,

2 points are scored per mm. of open bite for each tooth.

CROWDING: When scoring crowding, the most crowded dental arch is

considered. From 1 to 3 mm. one point is scored; from 3.1 - 5 mm. 2


points are scored; from 5.1 - 7 mm. 4 points are scored. If the crowding is

greater than 7 mm. 7 points are scored.

OCCLUSION: When scoring occlusion, the Angle classification is used.

If the mesiobuccal cusp of the maxillary first molar occludes with the

buccal groove of the mandibular first molar or anywhere between the

buccal groove and the mesiobuccal cusp (cusp to cusp or end on), no

points are scored. If the occlusal relationship is end on (cusp to cusp)

class II or III, then 2 points are scored per side. If the relationship is a full

class II or III, then 4 points are scored per side. If the relationship is

greater or beyond class II or III, then 1 additional point is scored per mm.

for each side.

LINGUAL POSTERIOR CROSSBITE: For each maxillary posterior

tooth in lingual crossbite (from the first premolar to the third molar), 1

point is scored.

BUCCAL POSTERIOR CROSSBITE: For each maxillary posterior

tooth (from the first premolar to the third molar) in complete buccal

crossbite, 2 points are scored.

CEPHALOMETRICS: If the ANB angle is greater than 5.5 degrees or

less than -1.5 degrees, 4 points are scored. For each additional degree

above or below these values, an additional point is scored.

If the SN-Go-Gn angle is between 27 and 37 degrees, zero points are

scored.

If the SN-Go-Gn angle is greater than 37 degrees, then 2 points are scored

for each additional degree above 37.


If the SN-Go-Gn angle is less than 27 degrees, then 1 point is scored for

each additional degree below 27.

If the lower incisor to GoGn angle is greater than 98 degrees, then 1 point

is scored for each additional degree above 98.

OTHER: At the discretion of the examiner an additional 2 points may be

awarded for each of the following conditions:

Missing teeth (except for third molars)

Supernumerary teeth

Impactions (except for third molars)

Ectopic eruption

Anomalies of tooth size and shape

Dental midline discrepancies greater than 3 mm.

Skeletal asymmetries (involving dental compensation for case

completion)

Disadvantages of ABO DI

Complicated

Time consuming

Relies on cephs, expensive, time consuming, irradiation, reproducibility

Reproducibility

Advantages of ABO DI

o Detailed/comprehensive

o Measures case complexity-link this to who should treat the case, and case

suitability for examinations, remember that difficulty is elusive and

subjective.


HANDICAPPING MALOCCLUSION ASSESSMENT RECORD

(HMAR)

The purpose of the HMAR form is to provide a means for establishing

priority for treatment dentofacial deformity constitute a hazard to the

maintenance of oral health and interfere with the well-being of the child

by adversely affecting dentofacial aesthetics, mandibular function or

speech (Salzmann, 1968).

The HMAR is used to:

Inter and intra-arch relationships are looked at.

1. Intra-arch deviations include:

Missing teeth

Crowding

Rotations

Spacing

2. Inter-arch relationships include:

Overjet

Crossbite

Overbite

Openbite

Molar and canine relationships

IRREGULARITY INDEX

Developed by Little (1975).

It assess the irregularity of the lower labial segment by measuring the

linear displacement of the contact points in mm (from the mesial contact


point of the canine on one side to the mesial contact point of the canine

on the other hand side)

The sum of these 5 displacments representing the relative degree of

anterior irregularity.

Crowding index

In occlusal view, the CI was determined by measuring the available

horizontal space parallel to the occlusal plane, between the least displaced

interproximal contact points. The actual width of the corresponding tooth

was then deducted from the available space to give a resultant amount of

crowding (positive measure) or spacing (negative measure) for each tooth

The validity of maxillary expansion indices, O'Reilly, 1995

1) In 1909, Pont (overestimate) described a method which assumed a

constant relationship between the sum of the maxillary incisor widths

(SI=Sum of Incisors) and the width of the dental arch in an ideal

uncrowded dentition. The formula was then transposed to allow arch

width prediction: Required inter-premolar width = SI/ 0.80 Required

inter-molar width = SI/0.6


2) McNamara (overestimate) proposed a simple rule of thumb indicating an

ideal average Intermolar width in males of 37 mm and in females of 36

mm

3) Schwarz's analysis (accurate) was calculated with the appropriate

formula as described by Schwarz. In narrow faces, the first inter-premolar

width is SI + 6 mm while the intermolar width is SI + 12 mm; in the

average face the widths are SI + 7 mm and SI + 14 mm; in broad faces

they are SI + 8 mm and SI + 16 mm respectively.

A treatment difficulty index for unerupted maxillary canines, Pitt,

Hamdan and Rock, 2006

The prognosis for alignment of an impacted maxillary canine is affected

by several factors (McSherry, 1996):

1. Horizontal position

2. Age of patient.

3. Vertical height.

4. Bucco-palatal position.

5. Angulation to midline.

6. Rotation.

7. Coincidence of arch midlines.

8. Alignment and spacing of the upper labial segment.

9. Condition of primary canine.

10. Missing teeth.

Result of this study, Difficulty score in order: (ACRONYM HAV

BARMA CM)

Plaque index

Records levels of supragingival plaque present


Subjective scoring:

o 0= no plaque at gingival margin

o 1= initial deposite of plaque at gingival margin (not visible to the eye)

o 2= plaque at the gingival margin (visible to the eye)

o 3= heavy plaque accumulation on tooth

Gingival index

o 0= healthy

o 1= mild inflammation, slight change in colour.

o 2= moderate inflammation, redness, moderate glazing, bleeding on

pressure.

o 3= severe inflammation, redness, hyperplasia, tendency for spontaneous

bleeding.

Recommends scoring of 6 teeth which are: 6 2 | 4

4 | 2 6

Four values per tooth recorded; buccal, lingual, mesial and distal.

Further reading if you like the indecis!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

• HANDICAPPING LABIO-LINGUAL DEVIATION (HLD)

• SWEDISH INDEX (NEED FOR TREATMENT INDEX)

• TREATMENT PRIORITY INDEX (TPI)


orthodontic indecis by almuzian

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