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 Table of Contents  
ORIGINAL ARTICLE
Year : 2017  |  Volume : 8  |  Issue : 1  |  Page : 5-10

Evaluation of reliability of index of orthodontic treatment need for assessment of orthodontic treatment need


Department of Orthodontics and Dentofacial Orthopedics, Maulana Azad Institute of Dental Sciences, New Delhi, India

Date of Web Publication15-Feb-2017

Correspondence Address:
N Singh
Department of Orthodontics and Dentofacial Orthopedics, Maulana Azad Institute of Dental Sciences, New Delhi - 110 002
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2349-5243.200224

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  Abstract 

Objective: The aim of this study was to evaluate the reliability of index of orthodontic treatment need (IOTN) for assessment of orthodontic treatment need.
Materials and Methods: A total of 106 subjects of aged between 18 and 25 years with no history of orthodontic treatment were selected by the convenience sampling method from the nondental student population of institutions belonging to North Indian population. The expressed demand for orthodontic treatment by the subjects was assessed using questionnaire. The self-perception of the subjects about orthodontic treatment need was done using aesthetic component (AC) of IOTN. The need for orthodontic treatment was evaluated by the investigator using AC and dental health component (DHC) of IOTN and by a panel of orthodontists using subjective assessment of the patient's study models.
Results: Orthodontic treatment need to be determined by the investigator using DHC of IOTN moderately correlated with the demand of orthodontic treatment by the subjects as assessed using subjects response to questionnaires (ρ = 0.627) and orthodontic treatment need to be determined by the opinion of the panel of orthodontists (ρ = 0.598).
Conclusion: DHC of IOTN was found to be reliable for evaluating orthodontic treatment need.

Keywords: Aesthetic component; dental health component; index of orthodontic treatment need.


How to cite this article:
Singh N, Bagga D, Sharma R, Singh R. Evaluation of reliability of index of orthodontic treatment need for assessment of orthodontic treatment need. Int J Orthod Rehabil 2017;8:5-10

How to cite this URL:
Singh N, Bagga D, Sharma R, Singh R. Evaluation of reliability of index of orthodontic treatment need for assessment of orthodontic treatment need. Int J Orthod Rehabil [serial online] 2017 [cited 2019 Sep 21];8:5-10. Available from: http://www.orthodrehab.org/text.asp?2017/8/1/5/200224


  Introduction Top


The demand for orthodontic treatment is complex, subjective, and varies greatly between individuals.[1],[2],[3],[4],[5] Gender, socioeconomic background, and age have been suggested as factors affecting self-perception.

Orthodontic treatment needs can be determined through various occlusal indices. The index of orthodontic treatment need (IOTN),[6] one of the most widely used occlusal indices was introduced as a combination of the standardized continuum of aesthetic need scale [7] and the index used by the Swedish Dental Health Board.[8]

This study was undertaken to evaluate the reliability of IOTN for assessment of orthodontic treatment need in North Indian population.


  Materials and Methods Top


A total of 106 subjects (53 males and 53 females) with no history of previous orthodontic treatment were selected by the convenience sampling method from the nondental student population of institution. They were aged between 18 and 25 years with a mean age of 20.04 ± 1.561 years (mean age of males was 20.53 ± 1.612 years, mean age of females was 19.53 ± 1.353 years). Young adults were chosen for the study because they are capable of expressing their opinion regarding their perception of esthetics. The student population was also chosen because of their easy accessibility in the college. Approval for the study was obtained from the Ethics Committee of the institution. The objectives and protocol of the study were explained to the subjects. Then, consent forms were obtained from participants who agreed to participate in the study.

A brief description about braces and orthodontic treatment were given to the subjects, and they were asked not to consider the cost of treatment while responding the questionnaire so as to remove any bias against treatment due to financial constraints. The expressed demand for orthodontic treatment was evaluated with the responses to the questionnaire by the subjects. The following questionnaire was used which carried responses indicating willingness, unwillingness, or uncertainty (borderline treatment need).

  • Do you need braces?

    No (unwillingness) Yes (willingness)

    Not sure (uncertainty)
  • Are you happy with the arrangement of your front teeth?

    No (willingness) Yes (unwillingness)

    Not sure (uncertainty)
  • Are you happy with the appearance of your own teeth compared to the teeth of your peers?

    No (willingness) Yes (unwillingness)

    Not sure (uncertainty)
  • Do you consider well-aligned teeth important for overall facial appearance?

    No (unwillingness) Yes (willingness)

    Not sure (uncertainty)


The questionnaire was scored in the following manner:

When the number of responses indicating subject's willingness to undergo orthodontic treatment, were more than 2 out of 4, it indicated subject's willingness for orthodontic treatment. When the numbers of responses indicating subject's unwillingness to undergo orthodontic treatment were more than 2 out of 4, it indicated subject's unwillingness for orthodontic treatment. The remaining subjects were categorized as having borderline treatment need.

The self-perception of the subjects about orthodontic treatment need was done using aesthetic component (AC) of IOTN. The AC of IOTN has ten colored photographs in increasing order of severity of malocclusion with grading from 1 to 10 allocated according to the position photograph. These photographs were presented to the subjects to choose the one with which they could identify themselves on esthetic basis and allocate grades for AC of IOTN. The grades for AC of IOTN were also recorded by the investigator using same photographs (Grades 1–4 represented no need to treatment, 5–7 moderate need, and 8–10 highly needed to treatment).

The need for orthodontic treatment was evaluated by the investigator using dental health component (DHC) of IOTN. There were five grades within the DHC which were grouped the following validation as follows: Grades 1 and 2 as score 1 represents no need for treatment, Grade 3 as score 2 represents borderline treatment need, Grade 4 and 5 as score 3 represents definite treatment need [Table 1].
Table 1: Dental health component of index of orthodontic treatment need

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Dental health component of index of orthodontic treatment need

The study models were given to a panel of orthodontists for subjective evaluation of orthodontic treatment need. The scores given by a panel of orthodontists were as follows No need of treatment as score of 1, borderline treatment need as score of 2, and definite treatment need as score of 3.


  Results Top


On the evaluation of orthodontic treatment need determined by the responses of the subjects to the questionnaires, it was found that a majority (54.7%) of the subjects were willing to undergo orthodontic treatment whereas around quarters (25.5%) were unsure about their orthodontic treatment need. Around one-fifth (19.8%) of subjects expressed no desire for orthodontic treatment. The proportion of males expressing a willingness to undergo orthodontic treatment (73.6%) was more than that of females (35.8%). The proportion of females expressing unwillingness for orthodontic treatment (34.0%) was higher than that of males (5.7%). Thus, it was observed that expression of orthodontic treatment demand was different in males and females [Table 2].
Table 2: Evaluation of orthodontic treatment demand by the subjects using questionnaire

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On the evaluation of orthodontic treatment need determined by self-perception of the subjects using AC of IOTN, it was found that a small proportion 12.6% subjects had a definite need of treatment and 20.4% subjects had a borderline treatment need. A majority (67%) of subjects had no treatment need. A gender-wise comparison of orthodontic treatment needs revealed a significantly higher definite treatment need in males (21.6%) as compared to females (3.8%), whereas females had a significantly higher proportion of subjects with no treatment need (75%) as compared to males (58.8%) [Table 3].
Table 3: Self-perception of orthodontic treatment need evaluated using aesthetic component of index of orthodontic treatment need by the subjects (n=103)

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On the evaluation of orthodontic treatment need determined by the investigator using AC of IOTN, it was found that a small proportion 13.6% subjects had a definite need of treatment and 16.5% subjects had borderline treatment need. A majority (69.9%) of subjects had no treatment need. A gender-wise comparison of orthodontic treatment needs using AC of IOTN revealed a significantly higher definite treatment need in males (23.5%) as compared to females (3.8%). Females had a significantly higher proportion of subjects with no treatment need (78.8%) compared to males (60.8%). The AC of IOTN could not be evaluated for three subjects, either by the investigator or the subjects themselves, as they did not match any photograph of AC [Table 4].
Table 4: Orthodontic treatment need evaluated using aesthetic component of index of orthodontic treatment need by the investigator (n=103)

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On the evaluation of orthodontic treatment need to be determined by the investigator using DHC of IOTN, it was found that 41.5% subjects had definite treatment need and 27.4% subjects had borderline treatment need whereas 31.1% subjects had no treatment need. There was no significant difference in treatment need between males and females when assessed using DHC [Table 5].
Table 5: Orthodontic treatment need evaluated using dental health component of index of orthodontic treatment need

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On the evaluation of orthodontic treatment need to be determined by the opinion of the panel of orthodontists, it was noted that 73.6% subjects had definite treatment need and 16.0% subjects had borderline treatment need whereas 10.4% subjects had no treatment need. Definite treatment needs in males (86.8%) was higher compared to that in females (60.4%). Females with borderline or no treatment need were more as compared to males [Table 6].
Table 6: Subjective evaluation of orthodontic treatment need by a panel of orthodontists

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On evaluation of correlation among different methods, it was found that the demand of orthodontic treatment need by the subjects using questionnaire was moderately correlated with orthodontic treatment need determined by the investigator using DHC of IOTN (ρ = 0.627) and also orthodontic treatment need determined by the subjective evaluation of a panel of orthodontists (ρ = 0.598) [Table 7].
Table 7: Correlation between different evaluation methods (Spearman correlation coefficient “ρ”)

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Orthodontic treatment need to be determined by the investigator using DHC of IOTN and that determined by the subjective evaluation of a panel of orthodontists were also found to be moderately correlated (ρ = 0.525) [Table 7].

Assessments for orthodontic treatment need using AC of IOTN by the investigator, and the subjects were found to be strongly correlated (ρ = 0.950) [Table 7].


  Discussion Top


The results of the present study revealed that a majority of subjects in the study sample were willing to undergo orthodontic treatment. Out of which, the orthodontic treatment demand was expressed by more males than females. This might have been due to the greater severity of malocclusion in the males of our study sample as compared to females as the treatment need was required more in males than females according to the subjective evaluation by the panel of orthodontists. The demand for orthodontic treatment was reported to be influenced by the gender of the patient as has been reported by Roberts et al.[9] and Hedayati et al.,[10] but in their study, a higher proportion of females demanded orthodontic treatment compared to males. In the study by Burden,[11] gender had no influence on the uptake of orthodontic treatment.

Self-perception of orthodontic treatment need by the subjects using stimulus photographs of AC of IOTN revealed that a majority of subjects (67.0%) perceived themselves to be in AC grade 1–4 indicating no treatment need. It could possibly be due to the subjects subconsciously trying to allocate themselves on the attractive side. However, this was in contrast to expressed demand for treatment reflected in the questionnaires responded by the subjects. This disparity of treatment need using AC and expressed demand could be explained by the fact that stimulus photographs of AC of IOTN were a two-dimensional representation of malocclusion in the frontal view. The sagittal or vertical discrepancies of the malocclusion and occlusal traits such as crowding in the lower arch might not be readily appreciated. Evaluation of treatment needs using AC of IOTN by the investigator also placed a majority of subjects in grade 1–4 indicating no treatment need. More males as compared to females were found to be in treatment need as assessed using AC either by the investigator or the subjects.

The correlation of expressed demand for orthodontic treatment by the subjects with self-perception of treatment need by themselves using AC of IOTN was weak (ρ = 0.287). This was in contrast to the findings by Grzywacz [12] and Birkeland et al.[13] who found moderate correlation between expressed demand for orthodontic treatment and self-perception using AC of IOTN.

Three subjects in the present study could not be scored for AC either by the subjects themselves or by the investigator because their malocclusion could not be matched to any of the photographs. Out of these three cases, two had anterior open bite, and one had anterior crossbite. This indicated that AC of IOTN was not sensitive enough to account for all types of malocclusion such as class III, open bite, and crossbite.

There was a strong correlation between perception of orthodontic treatment need as judged by the patient and investigator using AC of IOTN (ρ = 0.95). This was similar to that found by Grzywacz [12] but higher compared to the results of Birkeland et al.[13] and Hedayati et al.[10]

While assessing DHC, the major occlusal traits in the definite treatment need and borderline treatment need groups were increased overjet and displacement. Treatment need was similar in both the sexes when evaluated using DHC of IOTN as reported earlier by Uçüncü and Ertugay [14] and Chew and Aw.[15]

The correlation of orthodontic treatment need using DHC and that using AC of IOTN was mild (ρ = 0.463). Hedayati et al.[10] earlier reported poor correlation (ρ = 0.291) between the two.

The disparity between AC and DHC of IOTN could be explained on the basis that occlusal traits such as crowding in lower arch, increased overjet, missing posterior teeth, and impacted canines could not be visualized on the anterior frontal view photographs of AC which placed them in the “no treatment need” category.

Subjective evaluation by the panel of orthodontists revealed a definite treatment need in 73.6% subjects which was more than that evaluated using DHC of IOTN. This could be due to a tendency among orthodontists to qualify even those cases for treatment which did not have treatment need according to IOTN. The correlation of orthodontic treatment need using DHC with a subjective assessment by the panel of orthodontists was found to be moderate (ρ = 0.525) which was similar to that reported by Grzywacz.[16] The DHC score is based on a grade assigned to the single worst occlusal trait, which makes it an easy and reliable index to use but ignores the cumulative effect of lesser occlusal deviations. As a result, it might underestimate the severity of malocclusion in some individuals. The discrepancy between the orthodontists' opinion and DHC criteria could be mainly attributed to cases of bimaxillary dentoalveolar protrusion with mild or no crowding, displacement of teeth >2 mm to <4 mm, lateral open bite >2 mm to <4 mm, increased and incomplete overbite without gingival or palatal trauma and increased overjet which were placed in the “no treatment” or “borderline treatment” category according to DHC, but the panel of orthodontists placed them under “definite treatment need.”

In the present study, the maximum treatment need was assessed by the panel of orthodontists while minimum treatment need was assessed using AC.

The moderate correlation of DHC with demand for orthodontic treatment expressed by the subjects and orthodontists' opinion of treatment need make it a reliable way to assess treatment need.


  Conclusion Top


The following conclusions were drawn from the study:

  1. Assessments for orthodontic treatment need using AC of IOTN by the investigator, and the subjects were found to be strongly correlated (ρ = 0.950)
  2. Maximum treatment need was assessed by the subjective evaluation of a panel of orthodontists while minimum treatment need was assessed by AC of IOTN
  3. Self-perception of orthodontic treatment need by the subjects using AC of IOTN correlated weakly with the expressed demand of orthodontic treatment by the subjects indicating failure of AC of IOTN to identify all cases with orthodontic treatment need
  4. Orthodontic treatment need was more in males than that in females as assessed by expressed demand for orthodontic treatment by the subjects, AC of IOTN, as well as opinion of the panel of orthodontists whereas there was no genderwise difference in treatment, need assessed by DHC of IOTN
  5. Orthodontic treatment needs assessed by DHC of IOTN correlated moderately with expressed demand of orthodontic treatment by the subjects and orthodontic treatment need assessed by the subjective evaluation of a panel of orthodontists thereby making it a reliable tool for evaluating orthodontic treatment need.


Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Shue-Te Yeh M, Koochek AR, Vlaskalic V, Boyd R, Richmond S. The relationship of 2 professional occlusal indexes with patients' perceptions of aesthetics, function, speech, and orthodontic treatment need. Am J Orthod Dentofacial Orthop 2000;118:421-8.  Back to cited text no. 1
    
2.
Mandall NA, Wright J, Conboy FM, O'Brien KD. The relationship between normative orthodontic treatment need and measures of consumer perception. Community Dent Health 2001;18:3-6.  Back to cited text no. 2
    
3.
Hunt O, Hepper P, Johnston C, Stevenson M, Burden D. The aesthetic component of the index of orthodontic treatment need validated against lay opinion. Eur J Orthod 2002;24:53-9.  Back to cited text no. 3
    
4.
Hamdan AM. The relationship between patient, parent and clinician perceived need and normative orthodontic treatment need. Eur J Orthod 2004;26:265-71.  Back to cited text no. 4
    
5.
Johansson AM, Follin ME. Evaluation of the aesthetic component of the index of orthodontic treatment need by Swedish orthodontists. Eur J Orthod 2005;27:160-6.  Back to cited text no. 5
    
6.
Brook PH, Shaw WC. The development of an index of orthodontic treatment priority. Eur J Orthod 1989;11:309-20.  Back to cited text no. 6
    
7.
Evans R, Shaw W. Preliminary evaluation of an illustrated scale for rating dental attractiveness. Eur J Orthod 1987;9:314-8.  Back to cited text no. 7
    
8.
Linder-Aronson S. Orthodontics in the Swedish public dental health service. Trans Eur Orthod Soc 1974:233-40.  Back to cited text no. 8
    
9.
Roberts EE, Beales JG, Dixon L, Willcocks AJ, Willmot DR. The orthodontic condition and treatment status of a sample of 14-year-old children in North Derbyshire. Community Dent Health 1989;6:249-56.  Back to cited text no. 9
    
10.
Hedayati Z, Fattahi HR, Jahromi SB. The use of index of orthodontic treatment need in an Iranian population. J Indian Soc Pedod Prev Dent 2007;25:10-4.  Back to cited text no. 10
[PUBMED]  Medknow Journal  
11.
Burden DJ. The influence of social class, gender, and peers on the uptake of orthodontic treatment. Eur J Orthod 1995;17:199-203.  Back to cited text no. 11
    
12.
Grzywacz I. The value of the aesthetic component of the index of orthodontic treatment need in the assessment of subjective orthodontic treatment need. Eur J Orthod 2003;25:57-63.  Back to cited text no. 12
    
13.
Birkeland K, Boe OE, 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.  Back to cited text no. 13
    
14.
Uçüncü N, Ertugay E. The use of the index of orthodontic treatment need (IOTN) in a school population and referred population. J Orthod 2001;28:45-52.  Back to cited text no. 14
    
15.
Chew MT, Aw AK. Appropriateness of orthodontic referrals: Self-perceived and normative treatment needs of patients referred for orthodontic consultation. Community Dent Oral Epidemiol 2002;30:449-54.  Back to cited text no. 15
    
16.
Grzywacz I. Orthodontic treatment needs and indications assessed with IONT. Ann Acad Med Stetin 2004;50:115-22.  Back to cited text no. 16
    



 
 
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  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]



 

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