An insight into four orthodontic treatment need indices

Occlusal indices have been introduced and used to rank or categorize the occlusion. According to Dr. William Shaw and colleagues (1995), there are five types of occlusal indices, diagnostic, epidemiologic, orthodontic treatment need, orthodontic treatment outcome, and treatment complexity indices. Orthodontic treatment need indices are used to rank the malocclusion. They were devised to minimize the subjectivity associated with the diagnosis, referral and complexity assessment of malocclusion. Some are also multifunctional and used to assess the outcome of orthodontic treatment. The overall aim of the present article is to provide an overview on four commonly used American and European orthodontic treatment need indices, review their modifications, advantages, and limitations. These indices are the Index of Orthodontic Treatment Need (IOTN), the Dental Aesthetic Index (DAI), the Handicapping Labio-Lingual Deviation index (HLD), and the Index of Complexity, Outcome and Need (ICON).     

Orthodontic treatment need in a 12-year-old population in the Western Sahara

The aim of this study was to establish orthodontic treatment need according to the Dental Aesthetic Index (DAI) and Aesthetic Component (AC) and Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) and to determine its association with gender among Saharan schoolchildren. The study was carried out in accordance with World Health Organization (WHO) recommendations for oral health surveys at 12 years of age. The sample comprised 248 Sahrawi children (135 girls and 113 boys) living in refugee camps in Tindouf, Algeria. None of the children had previously received any orthodontic treatment. A chi-square test was used to analyse the IOTN results by gender, and a Student's t-test was employed for the DAI results. The mean DAI was 23.32 with a standard deviation of 6.05, 4 percent with a very severe and 9.2 per cent with severe malocclusion. Orthodontic treatment need was 16.1 and 2.0 percent, respectively, according to grades 4 and 5 of the IOTN DHC, 13.7 percent according to the IOTN AC, and 28.6 percent according to the modified IOTN (IOTN DHC grades 4-5 and/or IOTN AC grades 8-10). There were no statistically significant differences by gender. The orthodontic treatment need of Western Saharan schoolchildren is similar to that reported by many recent studies in European and in Sub-Saharan countries.     

基于牙美学指数对青年人群正畸需要的评估

目的：使用牙美学指数评估青年人群的正畸需要,并分析牙外观自我评估值同牙美学指数分值之间的关系。方法：358名大学生参加了牙美学指数检查,同时每位被调查者使用视觉模拟量表对牙外观进行自我评估。对牙美学指数分值和牙外观自我评估进行简单线性相关分析,并基于牙美学指数分组对牙外观自我评估进行秩合检验。结果：37.7%的被调查对象牙美学指数分值≥31,属于需要正畸治疗人群。牙美学指数与牙外观自我评估间呈中度负相关（P〈0.001）,基于牙美学指数分组对牙外观自我评估进行秩合检验表明4组间得分差异有统计学意义（P〈0.001）。结论：本样本中,37.7%的被调查对象需要正畸治疗;牙美学指数与牙外观自我评估呈反向关系。表明牙美学指数可用于青年人群口腔健康相关生活质量的相关研究。     

A comparison of two methods of assessing orthodontic treatment need in the mixed dentition: DAI and IOTN

This paper assesses the unmet orthodontic treatment need in a random sample of 10-year-old schoolchildren, using two indices: the Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN). The DAI scores were adjusted by omitting the missing teeth component of the index because many children were in the mixed dentition with unerupted permanent teeth. Although both indices assessed the same number of children with malocclusions requiring orthodontic treatment, not all were ranked similarly by each index.     

Orthodontic treatment need of 9, 12 and 15 year-old children according to the Index of Orthodontic Treatment Need and the Dental Aesthetic Index

Objective: To assess the differences in occlusal features in three cohorts at 9, 12 and 15 years of age, and compare orthodontic treatment need measured by the Dental Aesthetic Index (DAI) and Index of Orthodontic Treatment Need (IOTN). Design: Cross-sectional study. Setting: School of Dentistry, University of Valencia. Subjects: A total of 1086 children: 321 aged 9, 397 aged 12 and 368 aged 15. Methods: Children were examined to measure their orthodontic treatment need according to IOTN and DAI. The main outcome measure was orthodontic treatment need according to the DAI and IOTN indices. Results: Overbite and inter-incisal diastema were the occlusal features that presented significant differences between the three groups, diminishing with age. Treatment need according to the IOTN was 15.4% at 9 years, 20.9% at 12 years and 12.8% at 15 years. Treatment need according to DAI was 44.8% at 9 years, 21.7% at 12 years and 14.1% at 15 years. The diagnostic agreement between the two indices on the treatment need by age group was very low at 9 years (Kappa 0.18) and moderate at 12 and 15 years (Kappa 0.451 and 0.405, respectively). Conclusions: Orthodontic treatment need is greater in the mixed dentition and falls slightly as the child grows. The greatest variation in results between 9 and 15 years were found in relation to the DAI, which is consequently not recommended for use in the mixed dentition.     

Assessment of orthodontic treatment needs in Brazilian schoolchildren according to the Dental Aesthetic Index (DAI)

OBJECTIVE: To assess the distribution, prevalence and severity of malocclusion and orthodontic treatment needs in schoolchildren from the northeast of Brazil aged between 13 and 15 years. RESEARCH DESIGN: Cross-sectional study. PARTICIPANTS: A sample of 600 adolescents (264 males and 336 females) randomly selected and representative of schoolchildren living in Recife (Brazil) was obtained from 12 public schools. METHOD: The need for orthodontic treatment was measured using the Dental Aesthetic Index (DAI). RESULTS: Most of the subjects (77%) were deemed to require orthodontic treatment. Only about 5.8% had a handicapping malocclusion that needed mandatory treatment. A severe malocclusion for which treatment was highly desirable was recorded in 47.5% of the adolescents and 23.7% had a definite malocclusion for which treatment was elective. Three main occlusal features were responsible for allocating subjects into the group of "orthodontic treatment required": crowding (47.3%), tooth loss (22.3%) and maxillary overjet of more than 3 mm (21.8%). There were no significant differences (p > 0.05) in mean DAI scores between males and females. CONCLUSIONS: 77% of adolescents from northeast Brazil were in need of orthodontic treatment for dental health reasons. The distribution of DAI scores among Brazilian adolescents is different from that reported in other populations. This study provides baseline data on the need and demand for orthodontic treatment among Brazilian students.     

正畸治疗指数间的一致性研究

目的:观察不同的正畸治疗指数评价正畸治疗需要的一致性。方法:随机选取220副正畸记存模型,采用常用的4种指数评估这些模型是否需要正畸治疗,并对结果的一致性进行分析。结果:不同的指数鉴定出有不同数量的模型需要正畸治疗(31.6%~85.9%),各指数间的判断结果有显著但弱的相关性,各指数间的一致性较低。结论:采用不同的指数会有不完全相同的结果。     

Orthodontic treatment need in Peruvian young adults evaluated through dental aesthetic index

The objectives of this study were to evaluate the frequency and severity of the malocclusion and treatment needs in Peruvian young adults. The second aim was to compare the orthodontic treatment needs according to sex and socio-economic status (SES). This cross-sectional study was conducted at the University Dental Clinic of a private university in Lima, Peru. A total of 267 freshmen (from 16 to 25 years old) were randomly selected from a pool of 780 students. Students wearing an orthodontic appliance or reporting a history of orthodontic treatment were excluded from the study. Clinical examinations were conducted using the Dental Aesthetic Index (DAI). Mann-Whitney and Kruskal-Wallis tests were used to compare the DAI scores according to sex and SES, respectively. The mean DAI score was 28.87 points (IC(95%) 27.77; 29.97, where IC indicates interval of confidence). Around one-third of the sample presented severe or very severe malocclusion, which implies a highly desirable or mandatory orthodontic treatment need. No statistically significant difference was found between the DAI scores according to sex (P = .592) and SES (P = .397). Approximately one-third of the evaluated Peruvian young adults would need orthodontic treatment according to the DAI. In this population, malocclusion was characterized by a relatively high frequency of missing teeth, appreciable dental crowding, and inadequate anteroposterior relationships.     

儿童错畸形对其父母生活质量的影响

目的:研究儿童的错(牙合)畸形对其父母生活质量的影响和两者间的关系.方法:从正畸科临床就诊病人中选择155名儿童患者,对其错(牙合)畸形的严重程度采用常用的正畸治疗需要指数(IOTN-AC和DHC、ICON和DAI)进行评估;另外,儿童的家长填写一份关于儿童口腔健康对父母生活质量影响的问卷(family impact scale-FIS).结果:儿童的错(牙合)畸形会影响父母的生活质量,包括日常活动和家长情绪;需要正畸治疗的儿童的FIS分数明显高于不需要正畸治疗者.统计效应最小0.07、最大0.42.多元回归结果显示FIS分数与是否需要正畸治疗、儿童性别、家长文化程度、家长性别没有关系.结论:儿童错(牙合)畸形会影响家长的生活质量,但受影响程度与儿童错(牙合)畸形的严重程度相关性不大.     

Perceived aesthetic impact of malocclusion and oral self-perceptions in 14-15-year-old Asian and Caucasian children in greater Manchester

The aims of this study were to evaluate (i) the effect of ethnicity, social deprivation, and normative orthodontic treatment need on orthodontic aesthetic self-perception, self-perceived need for orthodontic treatment, and oral aesthetic impact of malocclusion; (ii) the effect of ethnicity, social deprivation, and gender on perceived orthodontic treatment need and use of orthodontic services; (iii) the influence of perceived oral aesthetic impact of malocclusion on perceived need and wish for orthodontic treatment; and (iv) whether orthodontic treatment experience influences perceived oral aesthetic impact of malocclusion. A stratified, random sample of 434 14-15-year-old children from schools in Manchester, UK, was obtained. Information was collected on orthodontic aesthetic self-perception and orthodontic treatment experience using a questionnaire. The former data were combined to form an Oral Aesthetic Subjective Impact Scale (OASIS). Normative orthodontic treatment need was measured with the Index of Orthodontic Treatment Need (IOTN). Children with higher clinical need for orthodontic treatment perceived themselves as worse off than their peers with lower need. More socially deprived children or those with high IOTN aesthetic component (AC) scores had a higher (i.e. more negative) aesthetic impact (OASIS) score. Asians and females had higher IOTN dental health component (DHC) scores, but a better aesthetic appearance than Caucasians and males. More deprived children were less likely to have received orthodontic treatment. Despite this, OASIS scores were similar between treated and untreated children. Untreated children who wished for orthodontic treatment had higher IOTN AC and OASIS scores.     

Malocclusions and orthodontic treatment needs in a group of Spanish adolescents using the Dental Aesthetic Index

OBJECTIVE: To evaluate the prevalence of malocclusion and orthodontic treatment need among Spanish adolescents and compare with other populations. METHODS: The study sample comprised 744 schoolchildren from urban and rural populations in Granada province (Southern Spain), aged from 14-20 years, who had received no orthodontic treatment. The measurement instrument was the Dental Aesthetic Index (DAI). RESULTS: The mean DAI score of the whole series was 25.6 (SD, 7.94). The distribution of the four DAI grades was: DAI 1, no anomaly or malocclusion, 58.6%; DAI 2, definite malocclusion, 20.3%; DAI 3, severe malocclusion, 11.2%; DAI 4, very severe or disabling malocclusion, 9.9%. There were no statistically significant differences in DAI score between genders or those in rural vs. urban residence, but a significant difference was found between social classes, with subjects of low social class presenting the worst scores (p<0.05). CONCLUSION: The distribution of DAI scores among Spanish adolescents is similar to that reported in other populations.     

Orthodontic treatment need in French schoolchildren: an epidemiological study using the Index of Orthodontic Treatment Need

This survey was undertaken to assess the orthodontic treatment need in a sample of 9- to 12-year-old French children (mean age: 9.77 years; standard deviation: 0.84) attending 12 different schools in the same geographic area of Ile de France. Two examiners used the Index of Orthodontic Treatment Need (IOTN) in order to estimate treatment need. Five hundred and eleven children (268 males, 243 females) who had not previously received orthodontic treatment were examined. Two examiners, who had been previously trained in the use of occlusal indices, screened all the schoolchildren. No radiographs, study casts, or previously written records of the children were used; the IOTN was calculated from direct examination. Qualitative data were analysed using the chi-square test to determine differences in treatment need between subgroups of subjects, and kappa("kappa") statistics to analyse the findings. A correlation coefficient was used to compare professional assessments. Twenty-one per cent of the children presented an objective need for orthodontic treatment, 28 per cent had crowding, 28 per cent an increased overjet, and 15 per cent an increased overbite. The dental health component (DHC) of the IOTN was found to be reliable and simple to use. The malocclusion status of French schoolchildren was lower than that recorded in epidemiological studies of European children.     

Assessing malocclusion--the time factor.

Abstract

Assessment of occlusal status for orthodontic purposes may be undertaken by subjective assessment or by means of an index of occlusion. The assessment method should be reproducible and should achieve the intended outcomes. This study investigated another possible modifying factor--performance over time. Photographs and dental casts of 45 subjects at 12 years of age were compared with follow-up records at 16 years of age. No orthodontic intervention had occurred during the 4 years. Subjective severity assessments and Aesthetic Component (AC) scores of the Index of Treatment Need (IOTN) for first and second series records were made by four orthodontists. Scores of the Dental Aesthetic Index (DAI) and Dental Health Component (DHC) of the IOTN were made by one of the authors. Implications for hypothetical decisions to treat were considered. There was a significant reduction in the subjective severity and DAI scores across the whole sample and in the mixed dentition subgroup. There was a non-significant reduction in the AC (IOTN) scores across the whole samples, but there was a significant reduction in the AC (IOTN) scores in the mixed dentition subgroup. The DHC (IOTN) categorisations proved to be more stable over the period of study.     

Effectiveness of training dental students in two occlusal indices

The purpose of this study was to evaluate the ability of students in a U.S. dental school to learn and apply two indices of orthodontic need: the Index of Orthodontic Treatment Need (IOTN) and the Index of Complexity, Outcome, and Need (ICON). Dental students were randomly selected and separated into three groups: control, IOTN, and ICON. Each evaluated thirty casts that had previously been evaluated by a panel of thirteen orthodontists to develop a gold standard of orthodontic treatment need for these casts. Students re-evaluated the same thirty casts after IOTN and ICON training for their own group, while the control group did not receive any training. Logistic regression of pre- and post-training agreement with the gold standard was calculated for each group to create a clear quadratic relationship. Significant differences were not found between pre- and post-training evaluation for either the IOTN or the ICON groups as compared to the control. However, the IOTN group did show more improvement when compared with the ICON group. This study demonstrates that the use of the IOTN index improved assessment in predoctoral dental students to determine orthodontic treatment need.     

Research methods in dentistry 10. Assessment of orthodontic treatment need

Approximately one third of the Dutch population has an objective need for orthodontic treatment. Yet, patients mostly seek treatment because of aesthetic reasons. Recent social developments and the increased attention for aesthetics ask for ways to objectively measure treatment need. This is not only important because of the risks of orthodontic treatment, but also because of financial reasons. In this article indices to verify treatment need, i.e. the Index for Orthodontic Treatment Need (IOTN), de Dental Aesthetic Index (DAI) en de Index of Complexity, Outcome and Need (ICON), are discussed. All three indices seem to lead to a reduction of treatment need, especially in borderline cases. They can serve as 'neutral' instruments to discuss treatment need with patients and as instruments to allocate financial resources for orthodontic care.     

IOTN (DHC): is it supported by evidence?

The strength of the evidence linking some common malocclusion traits (which are used as the basis for IOTN classification) with dental disease is reviewed. It is concluded that IOTN is not a reliable predictor of the potential impact of malocclusion on future dental health, and that alternative indices, which place greater emphasis on the aesthetic impairment and take account of patient perceptions, are more appropriate for assessing an individual's orthodontic treatment need. CLINICAL RELEVANCE: IOTN is likely to assume greater significance with the advent of the new GDS/PDS regulations pertaining to orthodontics. However, all practitioners, including those who commission specialist services, should be aware of its limitations, especially in relation to the Dental Health Component.     

Is the Child Perceptions Questionnaire for 11–14 year olds sensitive to clinical and self‐perceived variations in orthodontic status?

OBJECTIVES: To assess the association between scores on the Child Perceptions Questionnaire for 11-14 year olds (CPQ11-14) and clinical and self-perceived measures of malocclusion. METHODS: Children were recruited from an orthodontic clinic just prior to starting orthodontic treatment. They completed a copy of the CPQ11-14 and a short questionnaire concerning their feelings about the condition of their teeth. Study models were taken and rated according to the Dental Aesthetic Index (DAI) and the Peer Assessment Rating (PAR) index by two sets of three examiners. Intra and inter-rater reliabilities for the two sets of examiners ranged from 0.80 to 0.99. CPQ11-14 scores were calculated for the full 35-item version and for 16 and 8-item short forms by summing the item response codes. The association between these scores, the DAI and PAR ratings and self-perceived measures of malocclusion were examined using appropriate parametric and nonparametric tests. RESULTS: Complete data were collected for 141 children, 63 boys and 78 girls. The mean age was 12.5 (SD = 1.0). DAI scores ranged from 17.0 to 58.0 with a mean of 35.0 (SD = 8.0). The distribution of subjects across the four severity categories was minor/none - 6.6%, definite - 35.2%, severe - 15.6% and handicapping 42.6%. PAR scores ranged from 8.0 to 66.0 with a mean of 31.4 (SD = 11.1). Eight percent had scores of 50 or above indicating marked deviation from an ideal occlusion. Both the long and the short forms of the CPQ11-14 identified substantial variability in the impacts of malocclusion. Correlations between CPQ11-14 scores and the orthodontic indices ranged from 0.26 to 0.31 (P < 0.01). There was a clear gradient in CPQ11-14 scores across four categories of the PAR based on quartiles. The gradient across the DAI categories was less clear. There were significant associations between all CPQ11-14 scores and the children's self-ratings of oral health, ratings of the extent to which the condition of the teeth affected life overall and expressions of happiness with the appearance and arrangement of the teeth. CONCLUSION: The results provide some evidence of the validity of the CPQ11-14 when used with children needing orthodontic treatment. However, because clinical samples are biased the study needs to be repeated in different treatment settings in order to confirm the utility of the measure.     

Establishing malocclusion severity levels on the Dental Aesthetic Index (DAI) scale

The Dental Aesthetic Index (DAI) is an orthodontic index based on socially defined aesthetic standards. It is useful in both epidemiological surveys to identify unmet need for orthodontic treatment and as a screening device to determine priority for subsidized orthodontic treatment. An earlier study established the score of 36 on the DAI scale to identify handicapping malocclusions. The purpose of the present study was to determine decision points on the DAI scale that identify malocclusion severity levels less severe than handicapping. Two sources of data were used: 1) The frequency distribution of DAI scores on a probability sample of 1306 study models representing the untreated occlusions found in half a million adolescents. 2) The per cent distribution of US youths aged 12–17 by specified case severity reported in an assessment of the occlusion of youths? by the National Center for Health Statistics (NCHS). The decision points separating specific case severities on the DAI scale were determined by relating the proportions of the NCHS population with specified case severities to the cumulative percentages of the frequency distribution of DAI scores on the 1306 models. The NCHS report found 45.8 per cent of the sample to have normal or minor malocclusion with no need or slight need for treatment. DAI scores 25 and below corresponded to that proportion of the sample. The NCHS report found 25.2 per cent of the sample to have definite malocclusion with treatment being elective. DAI scores between 26 and 30 corresponded to that proportion of the sample. The NCHS report found 13 per cent of the population to have severe malocclusion with treatment highly desirable. Fifteen per cent were included in this category. DAI scores 31 to 35 corresponded to that proportion of the sample.