pyrig ORIGINALoARTICLE
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No C t fo rP The Relationship of Two Orthodontic Indices, ublicat ion te ss e n c e with Perceptions of Aesthetics, Function, Speech
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and Orthodontic Treatment Need J. Jasmin Winniera/Ullal Anand Nayakb/S. Rupeshc/ Arun Prasad Raod/N. Venugopal Reddye
Purpose: The study was conducted to evaluate the relationship between the Dental Aesthetic Index (DAI) and Index of Orthodontic Treatment Need (IOTN) with subjective perceptions of dental aesthetics, function, speech and orthodontic treatment need. Methods: This is an observational cross-sectional study. The children were assessed using the DAI and IOTN. A questionnaire pertaining to dental aesthetics and function was recorded. Results and conclusions: The aesthetic components of the indices correlated well with aesthetic perceptions of patients, whereas functional components did not have a significant correlation with functional perceptions. The two indices could be used consistently in the present population. Key words: Dental Aesthetic Index, Index of Orthodontic Treatment Need, subjective questionnaire Oral Health Prev Dent 2011; 9: 115-122
T
he nomenclature committee of the American Association of Orthodontics in 1950 defined ‘ideal occlusion’ as ‘basically a myth and a figment of the imagination’. The fact that ideal occlusion does not necessarily occur in all populations suggests that variations from an idealised occlusal scheme are
a
Lecturer, Department of Pedodontics and Preventive Dentistry, Padm Dr DY Patil Dental College and Hospital, Navi Mumbai, Maharashtra, India.
b
Professor, Department of Pedodontics and Preventive Dentistry, Modern Dental College and Research Centre, Indore, Madhya Pradesh, India.
c
Senior Lecturer, Department of Pedodontics and Preventive Dentistry, Pushpagiri College of Dental Sciences, Perunthuruthy, Kerala, India.
d
Professor, Department of Pedodontics and Preventive Dentistry, Rajah Muthiah Dental College and Hospital, Chidambaram, Tamil Nadu, India.
e
Professor and Head, Department of Pedodontics and Preventive Dentistry, Rajah Muthiah Dental College and Hospital, Chidambaram, Tamil Nadu, India.
Correspondence: Dr J. Jasmin Winnier, Department of Pediatric and Preventive Dentistry, Padm. Dr. DY Patil Dental College and Hospital, Nerul, Navi Mumbai – 400706 India. Tel: +91-977-328-4371. Email:
[email protected]
Vol 9, No 2, 2011
Submitted for publication: 11.01.10; accepted for publication: 01.08.10.
quite compatible with normal function and aesthetics (Foley et al, 1996). Aesthetic judgments are usually established on a cultural basis, and thus aesthetically desirable features show immense variations. However, grading dental aesthetics and treatment needs has become necessary for several reasons; hence treatment need indices have been developed. Treatment need indices are used to plan orthodontic treatment in countries where dental health services are subsidised as part of a national health insurance system. Therefore, the use of indices has been limited in countries where publicly funded dental health services are not available (Jarvinen, 2001). However, they are considered essential tools in recording the prevalence and severity of malocclusion in epidemiological studies (Jarvinen, 2001). It has also been reported that a high proportion of referrals of orthodontic patients by general dentists was unnecessary and a number of patients were referred inappropriately. Orthodontic indices serve as important referral guidelines in such cases (O’Brien et al, 1996). While most patients are aware of their malocclusion traits, they do not perceive the need for ortho-
115
n
1
Number of missing visible teeth (incisors, canines and premolars) in the maxillary and mandibular arches
5.76
2
Assessment of crowding in the incisal segments: 0 = no segment crowded, 1 = one segment crowded, 2 = two segments crowded
1.15
1
3
Assessment of spacing in the incisal segments: 0 = no segment spaced, 1 = one segment spaced, 2 = two segments spaced
1.31
1
4
Measurement of any midline diastema in mm
3.13
3
5
Largest anterior irregularity on the maxilla in mm
1.34
1
6
Largest anterior irregularity on the mandible in mm
0.75
1
7
Measurement of anterior maxillary overjet in mm
1.62
2
8
Measurement of anterior mandibular overjet in mm
3.68
4
9
Measurement of vertical anterior open bite in mm
3.69
4
Assessment of anteroposterior molar relation: largest deviation from normal either left or right. 0 = normal, 1 = ½ cusp either mesial or distal, 2 = one full cusp either mesial or distal
2.69
3
Constant
13.36
13
10
dontic treatment to the same extent as dentists or orthodontists (Hamdan, 2004). On the other hand, some patients are so deeply concerned about minor irregularities that it may affect their self-confidence and self-esteem (Shaw et al, 1995). Indices help in grading patients’ dental traits in such a way that they will have a realistic understanding of their dental aesthetic status. It is the responsibility of the practitioner to ensure that every patient is aware of the risks and stability of treatment. The applicability of an index in a population depends upon how well the index correlates with the patients’ view of their dental aesthetic and functional needs. In order to examine this, two indices were used in this study: the Dental Aesthetic Index (DAI) (Cons et al, 1986) and the Index of Orthodontic Treatment Need (IOTN) (Brook and Shaw, 1989). A questionnaire was also included which contained questions regarding the individuals’ perception of dental aesthetics and their need for orthodontic treatment. Questions regarding problems encountered with biting, chewing and speech were included to assess the functional aspects of occlusion (Yeh et al, 2000).
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Actual weights
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DAI components
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Number
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Table 1 Dental Aesthetic Index
pyrig No Co t fo rP ub lica Rounded weights tio n te s6s e n c e
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Winnier et al
MATERIALS AND METHODS An observational cross-sectional study was conducted to assess the relationship of DAI and IOTN with patients’ perceptions of aesthetics, function, speech, and orthodontic treatment need. The study was conducted in schoolchildren in Chidambaram, Tamil Nadu, India. One hundred fifty-two children between the ages 10 and 12 years were included in the study, of which 82 were female and 70 were male subjects. Children with mental or physical impairment, or who had a history of, currently ongoing, or planned orthodontic treatment at the time of study were excluded. All subjects were first assessed using the DAI (Table 1). All 10 components of the DAI were measured according to WHO guidelines. The measured components of the DAI were multiplied by their respective regression coefficient (weights), the products were added, and the constant number 13 was added to the total to give the total DAI score. The treatment need according to the scores was divided into the following categories:
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pyr Co etigal No Winnier t fo rP ub lica tio n te ss e n c e
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Fig 1 AC – IOTN.
Fig 2 Representative AC in the studied population.
r 25 and below: normal or minor malocclusion with no or slight treatment need. r 26 to 30: definite malocclusion; elective treatment. r 31 to 35: severe malocclusion; treatment highly desirable. r 36 and more: handicapping malocclusion; treatment mandatory.
then independently scored each child for aesthetic component (E-AC). This was done on an individual basis and the child was not informed of his/her score. An aesthetic component rating was allocated for the overall dental attractiveness rather than specific morphological similarity to the photographs. The value arrived at gave an indication of the patient’s treatment need on the ground of aesthetic impairment. Ten dental photographs of subjects who closely resembled the AC photographs given by Brook and Shaw (1989) were also made, which represented irregularities in the present population (Fig 2). The subjects were then grouped according to the following treatment need categories:
Then, all subjects were evaluated with the IOTN. This index has two components: the aesthetic component (AC) and the dental health component (DHC). The AC is a rating scale of dental attractiveness comprising 10 numbered dental colour photographs (Fig 1). To make assessment more reliable, a lip retractor and a mirror were employed. The child was asked the following question: ‘Here are a series of 10 photos showing a range of dental attractiveness, number 1 is the most and number 10 is the least attractive arrangement of teeth. Where would you put your teeth on this scale?’ The photograph that the child selected gave the child’s rating of his/her aesthetic component (C-AC). The examiner
Vol 9, No 2, 2011
r Grade 1–2: No need for treatment r Grade 3–4: Slight need for treatment r Grade 5–7: Moderate/borderline need for treatment r Grade 8–10: Great need for treatment.
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Table 2 Dental health component of IOTN
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Extremely minor malocclusions including displacements less than 1 mm.
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Grade 1 (None) 1
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Winnier et al
Grade 2 (Little) A
Increased overjet greater than 3.5 mm but less than or equal to 6 mm with competent lips.
B
Reverse overjet greater than 0 mm but less than or equal to 1mm.
C
Anterior or posterior cross bite with less than or equal to 1 mm discrepancy between retruded contact position and intercuspal position.
D
Displacement of teeth greater than 1 mm but less than or equal to 2 mm.
E
Anterior or posterior open bite greater than 1mm but less than or equal to 2 mm.
F
Increased overbite greater than or equal to 3.5 mm without gingival contact.
G
Pre-normal or post-normal occlusion with no other anomalies. Includes up to half a unit discrepancy.
Grade 3 (Moderate) A
Increased overjet greater than 3.5 mm but less than or equal to 6 mm with incompetent lips.
B
Reverse overjet greater than 1 mm but less than or equal to 3.5 mm.
C
Anterior or posterior crossbite with greater than 1 mm but less than or equal to 2 mm discrepancy between retruded contact position and intercuspal position.
D
Displacement of teeth greater than 2 mm but less than or equal to 4 mm.
E
Lateral or anterior openbite greater than 2 mm but less than or equal to 4 mm.
F
Increased or complete overbite without gingival or palatal trauma.
Grade 4 (Great) A
Increased overjet greater than 6 mm but less than or equal to 9 mm.
B
Reverse overjet greater than 3.5 mm with no masticatory or speech difficulties.
C
Anterior or posterior crossbite with greater than 2 mm discrepancy between retruded contact position and intercuspal position.
D
Severe displacements of teeth greater than 4 mm.
E
Extreme lateral or anterior open bite greater than 4 mm.
F
Increased or complete overbite with gingival or palatal trauma.
H
Less extensive hypodontia requiring pre-restorative orthodontics or orthodontic space closure to obviate need for prosthesis.
L
Posterior lingual cross bite with no functional occlusal contact in one or both buccal segments.
T
Partially erupted teeth, tipped and impacted against adjacent teeth.
X
Supplemental teeth.
Grade 5 (Very great) A
Increased overjet greater than 9 mm.
H
Extensive hypodontia with restorative implications (more than one tooth missing in one quadrant) requiring pre-restorative orthodontics.
I
Impeded eruption of teeth (with the exception of third molars) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth and any pathological cause.
M
Reverse overjet greater than 3.5 mm with reported masticatory and speech difficulty.
P
Defects of cleft lip and palate.
S
Submerged deciduous teeth.
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CAC – IOTN
EAC – IOTN
No
%
No
%
No
%
A
69
45.4
70
46
43
28.3
83
54.6
B
45
29.6
58
38.2
70
46.1
54
35.5
C
26
17.1
16
10.5
33
21.7
13
8.6
D
12
7.9
8
5.3
6
3.9
2
1.3
SQ Q1 (Appearance) Q2 (Biting /chewing) Q3 (Speech)
Grade Grade Grade Grade
Answer 2, no. and %
Answer 3, no. and %
Answer 4, no. and %
Answer 5, no. and %
33 21.7
32 21.1
39 25.7
11 7.2
37 24.3
Score
1 0.7
3 2
16 10.5
3 2
129 84.9
0
1 0.7
14 9.2
2 1.3
135 88.8
1–2: No/slight need for treatment. 3: Borderline need for treatment. 4: Orthodontic treatment desirable. 5: Orthodontic treatment mandatory.
When assessment for both the indices was completed, the subjects were asked to answer the following questions. 1. How satisfied are you with the appearance of your teeth? Not satisfied/satisfied/very satisfied 2. Do you have difficulty in biting or chewing food? Great difficulty/some difficulty/no problems 3. Do you have difficulty in speaking? Great difficulty/some difficulty/no problems 4. Do you think you need orthodontic treatment?
Vol 9, No 2, 2011
Table 4a Subjective questionnaire (SQ) – need for orthodontic treatment
Answer 1, no. and %
The subjects were then assessed using the dental health component of the IOTN (Table 2). The most severe trait identified was the basis for grading the individuals for treatment. Multiple minor variations could not be added together to give the individual a higher grade. The treatment need is divided into the following categories: r r r r
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Table 4 Subjective questionnaire (SQ)
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Treatment Need
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Table 3 Treatment needs according to the indices
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pyr Co etigal No Winnier t fo rP ub lica DHC tio n te % No ss e n c e
Number by gender Female
Male
yes
45
31
no
35
41
Total number
80
72
The answers to the first three questions were recorded on a 5-point Likert scale. The last question was recorded as a yes or no response.
Statistical evaluation All data were entered into a database on Microsoft Excel and analysed using SPSS software with the Spearman rank correlation coefficient to assess the relation between the indices and the questionnaire.
RESULTS According to the DAI, C-AC, DHC and E-AC, the treatment need of the present population was 25%, 15.8%, 9.9% and 25.6%, respectively (Table 3). When the question regarding appearance was asked, 42.8% were not satisfied with their dental appearance, 2.7% had difficulty in biting or chewing, and 0.7% reported difficulty in speech. 50% of the children felt they needed orthodontic treatment, of which 45 were female and 31 were male (Tables 4 and 4a).
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Q3
-0.217 ** 0.007 152
-0.022 0.786 152
-0.042 0.607 152
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Q2
n
Q1
ot
Subjective Questionnaire
DAI correlation coefficient Significance (2-tailed) N
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Table 5 DAI and SQ
pyrig No Co t fo rP ub lica tio n te Q4 ss e n c e 0.221 ** 0.006 152
** Correlation is significant at 0.01 level (2 tailed)
Table 6 IOTN and SQ Subjective Questionnaire
Spearman’s rho C-AC correlation coefficient Significance (2-tailed) N DHC correlation coefficient Significance (2.tailed) N
Q1: App
Q2: B/C
Q3: speech
Q4: need
-9.247** 0.002 152
0.208* 0.010 152
0.041 0.615 152
0.148 0.068 152
-.219** 0.007 152
0.082 0.315 152
0.034 0.675 152
0.226** -0.005 152
** Correlation is significant at 0.01 level (2 tailed)
Table 7 E-AC and DAI Dental Aesthetic Index
Total
1
2
3
4
E-AC 1, 2 (no need)
Count % of total
34 22.4%
8 5.3%
1 0.7%
43 28.3%
3, 4 (slight need)
Count % of total
32 21.1%
28 18.4%
8 5.3%
2 1.3%
70 46.1%
5 to 7 (borderline)
Count % of total
2 1.3%
8 5.3%
17 11.2%
6 3.9%
33 21.7%
8 to 10 (great need)
Count % of total
1 0.7%
1 0.7%
4 2.6%
6 3.9%
Total
Count % of total
69 45.4%
45 29.6%
12 7.9%
152 100%
26 17.1%
Table 7a Symmetric measures
Measure of agreement Kappa N of valid cases
Value
Asymp. Std. Errora
Approx. Tb
Approx. Sig
0.347 152
0.057
6.900
0.000
a Not b
assuming null hypothesis Using the asymptotic error assuming null hypothesis
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The age of children included in the study was 10 to 12 years. The rationale for studying children of this age group was both biological and psychological. Biologically, any screening method should be done at the optimum treating age, which is the mixed dentition period of dental development (Cooper et al, 2000). Psychologically, according to the level of cognitive development at this age, children should be able to interpret and answer questions by themselves (Birkeland, 1996). Children who are currently undergoing or have already had orthodontic treatment were excluded to eliminate bias in answering questions regarding dental appearance and need for orthodontic treatment. This also avoids confusion in the selection of aesthetic component photographs by the child. The indices used in the present study were the DAI and IOTN. Both contained aesthetic and functional criteria, and both incorporated patient’s perceptions in the index. They were simple and easy to use. The DAI can be recorded intaorally without the use of radiographs in about 2 minutes (Cooper et al, 2000). The time taken to record the IOTN was 1 minute. However, if several minor traits required examination, identifying the most severe and allocating a grade took 3 minutes (Shaw et al, 1991). The cut-off point of any treatment need index is the value below which there is no definite need for the treatment of malocclusion. The cut off point recommended for the DAI is 31 (Beglin et al, 2001). For the IOTN, DHC grades 4 and 5 and AC photographs 6 to 10 are recommended (Abdullah and
n
DISCUSSION
Q ui
The Spearman rank correlation was used to assess the relationship between the indices and the questionnaire. There was a strong negative correlation between DAI and the question regarding appearance of teeth. A strong positive correlation was present between DAI and the need for orthodontic treatment as perceived by the patients (Table 5). There was a strong negative correlation between the IOTN components and the question regarding appearance of teeth. A strong positive correlation was present between DHC and need for orthodontic treatment as perceived by the patients (Table 6). The relationship between DAI and E-AC was assessed using kappa statistics. There was a 54.6% agreement between DAI and E-AC. This relationship was statistically significant (K = 0.347; P < 0.001) (Tables 7 and 7a).
pyr Co etigal No Winnier t fo r P exRock, 2001). The two components are mutually ub lica clusive and the component showing greatest need tio takes priority (Beglin et al, 2001). n te ss e nthe It was found that as DAI scores increased, ce subjects were less satisfied with their dental appearance. A significant correlation was also present between the DAI and a patient’s desire to undergo orthodontic treatment. No significant relation was present between DAI and speech, biting or chewing problems. These findings are in agreement with the study by Onyeaso et al (2003), but in contradiction to the study by Yeh et al (2000). As the AC photograph number increased, the patients were less satisfied with their dental appearance. A moderately significant relationship between AC and the question regarding biting and chewing, and no relationship between AC and speech were observed. These are in contradiction to a previous study (Yeh et al, 2000). The differences are probably due to the fact that, in the study by Yeh et al (2009), subjects who were seeking orthodontic treatment were selected, whereas in the present study, the subjects were from the general population. As DHC scores increased, the patients were less satisfied with their dental appearance and their need for treatment also increased. In the present study, it was noted that, according to the E-AC, 25.4% of the children belonged to borderline or great need for treatment, whereas according to the C-AC only 15.8% of the subjects fell into the same category. These findings agree with other authors, who have stated that children are usually less critical about their dental appearance than is the dentist (Birkeland et al, 1996; Shaw et al, 1991; Evans and Shaw, 1987; Grzywacz, 2003; Holmes, 1992). However, the E-AC was more closely related to the objective assessment with DAI. This relationship was statistically significant. Thus, in the present population, a combination of DAI and AC rating scales appear to reasonably assess the patients’ perceptions of their dental status and thereby give the care provider insight into the patient’s expectations. Such significant relationships were not noted when functional aspects of malocclusion were considered. Other factors which affect patients’ views are socioeconomic and sociocultural background, cost and availability of treatment, rural, urban variations etc. Further studies that also take these factors into consideration are warranted.
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1. Abdullah MSB, Rock WP. Assessment of orthodontic treatment need in 5112 Malaysian using Index of orthodontic treatment need and Dental aesthetic index indices. Community Dent Oral Epidemiol 2001;18:242-248. 2. Beglin FM, Firestone AR, Vig KW, Beck FM, Kuthy RA, Wade D. A comparison of the reliability and validity of 3 occlusal indexes of orthodontic treatment need. Am J Orthod Dentofacial Orthop 2001;120:240-246. 3. Birkeland K, Boe OK, Wisth PJ. Orthodontic concern among 11 year old children and their parents compared with orthodontic treatment need assessed by Index of orthodontic treatment need. Am J Orthod Dentofacial Orthop 1996;110:197-205. 4. Brook PH, Shaw WC. The development of an index of orthodontic treatment priority. Eur J Orthod 1989;11:309-320.
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1. The DAI correlates well with the aesthetic perceptions of the present population, but not the functional criteria. 2. The AC – IOTN correlates well with the aesthetic perceptions of the present population and correlates moderately with a patient’s difficulty in biting or chewing. 3. Although DHC is used to assess dental healthrelated factors, it did not have a significant relationship with questions pertaining to the dental health of the patient. 4. E-AC: The subjective assessment by the examiner had a significant relationship with the objective assessment of malocclusion as assessed with the DAI.
5.
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CONCLUSIONS
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