上海地区青少年正畸治疗需要的调查研究

目的:调查上海地区青少年人群的正畸治疗需要及自身美学评价。方法:随机抽取上海地区11～13岁青少年686例(男355例,女331例),由正畸专科医师采用正畸治疗需要指数(index of orthodontic treatment need,IOTN)评定受试者正畸治疗需要。IOTN包括学(dental health component,DHC)及美学(aesthetic component,AC)2部分。同时采用IOTN的美学部分让受试者对自身美观程度进行评价(self-perceived aesthetic component,SAC)。采用描述性统计及卡方检验对调查结果进行统计分析。结果:DHC评分显示26.0%的受试者明确需要正畸治疗,19.8%的受试者为临界病例;AC评分显示5.5%的受试者明确需要正畸治疗,31.7%为临界病例;SAC评分显示1.7%的受试者明确需要正畸治疗,6.4%为临界病例。在明确需要正畸治疗的受试者中,最常见的特征是严重接触点异常(>4 mm)。DHC与AC在评价治疗需要时77.8%结果一致,AC与SAC在评价治疗需要时65.0%结果一致。结论:将近一半的青少年人群明确需要正畸治疗或为临界病例,受试者在进行自身美观程度评价有从轻的倾向。     

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 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.     

Orthodontic treatment need in Egyptian schoolchildren

The aim of this study was to assess the orthodontic treatment need and prevalence of malocclusion in 11–15-years-old Egyptian schoolchildren using the Dental Health Component (DHC) and Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). A further aim was to compare the results with those from other populations matched for gender and age. The study followed the World Health Organization recommendations for oral health surveys. The sample comprised 1,464 schoolchildren (720 males and 744 females) who had not undergone orthodontic treatment, divided into two groups: 719 from 11–<13-years-old and 745 from 13–15-years-old, out of a representative sample of the school population of Mansoura Community. The IOTN results were analyzed with regard to gender using the Chi-square test. Orthodontic treatment need, using the DHC, was found in 21.5 per cent of the 11–<13-years-old and in 18.1 per cent of the 13–15-years-old; and with the AC, in 5.1 and 3.7 per cent, respectively. Considering the total sample, 19.8 and 4.4 per cent of the schoolchildren had a definite treatment need according to IOTN DHC and IOTN AC respectively. No gender dependent differences were found. It can be concluded that Egyptian orthodontic treatment need is similar to that reported in most recent studies; with approximately one in five to six children with an orthodontic treatment need.     

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.     

A longitudinal study of orthodontic treatment need in Dunedin schoolchildren

The Index of Orthodontic Treatment Need (IOTN) was used to assess unmet orthodontic treatment need in 152 13-year-old Dunedin schoolchildren, and to compare the findings with those obtained in the same children 3 years previously. The children were randomly selected from Dunedin schools as 10-year-olds, and had not received orthodontic treatment. Approximately 86 percent of the 13-year-old children had "No-little" need for orthodontic treatment when assessed by the child-assessed Aesthetic Component (AC) and the examiner-assessed AC. Slightly less than half the children had "No-little" need for orthodontic treatment when assessed with the Dental Health Component (DHC). More 10- and 13-year-old children "Needed" orthodontic treatment with the DHC than with the AC. Both the examiner-assessed AC and the DHC assessed significantly fewer 13-year-olds as needing orthodontic treatment than the same children as 10-year-olds. Complete agreement between the grades assigned at 10 and 13 years occurred in 30-43 percent of the children and, in the treatment-need categories, between 53 percent (DHC) and 84 percent (child-assessed AC) of the children. The fall in treatment need over the 3-year period may be due to selection bias, over-sensitivity of the IOTN to mixed dentition traits, or both. Although a number of 10-year-old children were assigned different grades as 13-year-olds, many remained within the same treatment category. The apparent stability of the IOTN to assess treatment need in 10- and 13-year-old children is attributed to the grouping of different occlusal traits in the same treatment-need category, and to the small number of treatment-need categories in each component.     

Normative and self-perceived orthodontic treatment need in Nigerian school children

Abstract

Objective. The aim of this study was to assess the normative and self-perceived need for orthodontic treatment in Nigerian children, and to evaluate distribution of orthodontic treatment need according to gender and age. Materials and methods. The sample consisted of 441 randomly selected school children, aged 11–18 years in Benin City, Nigeria. The subjects were further sub-grouped according to gender (229 males and 212 females) and age (246 11–13 years old and 195 14–18 years old). The Dental health Component (DHC) and Aesthetic Component (AC) of Index of Orthodontic Treatment Need (IOTN) were used to assess orthodontic treatment need normatively. Self-perceived need was evaluated by asking the subjects to rate their dental aesthetics on the Aesthetic Component scale of IOTN. Chi-square tests were used to evaluate gender and age differences in distribution of treatment need. Results. A definite need for orthodontic treatment was found among 21.5% (grades 4–5 of DHC) and 6.3% (grades 8–10 of AC) of the subjects; 3.9% of the subjects perceived a definite need for orthodontic treatment (grades 8–10 of AC). There were no statistically significant gender and age differences in distribution of orthodontic treatment need among the subjects (p > 0.05). Conclusion. The study revealed a need for orthodontic treatment in slightly more than one fifth (21.5%) of this sample of Nigerian children. The sample population has a lower need on aesthetic grounds and their normative and self-perceived orthodontic treatment needs were not influenced by gender and age.     

Associations between orthodontic treatment need and oral health‐related quality of life among young adults: does it depend on how you assess them?

Liu Z, McGrath C, Hägg U. Associations between orthodontic treatment need and oral health‐related quality of life among young adults: does it depend on how you assess them? Community Dent Oral Epidemiol 2011; 39: 137–144. © 2011 John Wiley & Sons A/S Abstract – Objective: To determine the association between orthodontic treatment need (OTN) and oral health‐related quality of life (OHRQoL). Methods: A cross‐sectional study involving 273 young adults seeking orthodontic care. OHRQoL was assessed by the short‐form Oral Health Impact Profile (OHIP‐14) and United Kingdom oral health‐related quality of life measure (OHQoL‐UK). Study casts were assessed for OTN by: Dental Aesthetic Index (DAI), Index of Orthodontic Treatment Need (IOTN)‐Aesthetic Component (IOTN‐AC) and Dental Health Component (IOTN‐DHC) and Index of Complexity, Outcome and Need (ICON). Variations in OHIP‐14 and OHQoL‐UK were determined with respect to OTN, and the magnitude of differences was calculated (effect size: ES). Results: There were significant but weak correlations between occlusal indices scores and OHIP‐14 scores (P < 0.05, r < 0.3) and between occlusal indices scores and OHQoL‐UK scores (P < 0.05, r < 0.4). The magnitude of the statistical difference in OHQoL‐UK scores was moderate to large with respect to OTN (ES: 0.36–0.87) and largest when DHC (ES = 0.87) and ICON (ES = 0.74) were used. The magnitude of the statistical difference in OHIP‐14 scores was relatively lower (ES: 0.21–0.69), but also greatest when DHC and ICON were used to determine OTN (ES 0.69 and 0.50, respectively). Conclusion: Orthodontic treatment need was associated with OHRQoL. The magnitude of the statistical difference between those with and without an orthodontic treatment need was larger when OHRQoL was assessed using OHQoL‐UK compared to OHIP‐14. DHC and ICON were more useful indices in identifying greater differences in OHRQoL with respect to orthodontic treatment need.     

A cultural comparison of treatment need

The aims of this study were two-fold. First to compare the perceptions of African dental aesthetics as determined by a panel of black African Senegalese and French Caucasian judges, and second to compare the sensitivity and specificity of both components of the Index of Orthodontic Treatment Need (IOTN) and the Index of Complexity, Outcome and Need (ICON) in relation to the opinions of African and Caucasian judges. Ninety-eight colour digital dental images of black adolescents and adults were scored for attractiveness on a 100 mm visual analogue scale (VAS) by 45 Caucasian and 41 black African judges. In addition the judges were asked to classify the level of treatment need. Both components of the IOTN and ICON were recorded for the 98 cases. The results indicated that Caucasian judges perceived the majority of images to be less attractive than African judges. African and Caucasian judges showed similar levels in the estimation of treatment need. The aesthetic component (AC) of the IOTN and ICON showed similar levels of sensitivity. Taking all factors into account, it would appear that the ICON is marginally better at identifying those individuals who are perceived to need orthodontic treatment.     

The need for treatment and satisfaction with dental appearance among young Finnish adults with and without a history of orthodontic treatment.

The aim of this investigation was to evaluate orthodontic treatment need and patient satisfaction among young adults living in a city where free-of-charge orthodontic treatment was provided. A total of 281 18- to 19-year-old subjects randomly selected from the population register of the city of Vantaa took part in the study. The drop-out rate was 30%. Treatment need was clinically assessed according to the Index of Orthodontic Treatment Need (IOTN), consisting of a Dental Health Component (DHC) and an Aesthetic Component (AC). Information on previous orthodontic treatment was based on the patient records. Satisfaction of the subjects with their dental appearance and with the orthodontic treatment received was obtained using a questionnaire. The rate of orthodontic treatment among the subjects was 46% (54% for the females and 37% for the males, p < 0.05). 4% had discontinued treatment. A definite need for treatment (DHC 4 to 5/AC 8 to 10) was assessed in 15% of the subjects, and borderline/moderate need (DHC 3/AC 5 to 7) in 36%. No difference in IOTN scores between the treated and untreated subjects was found. Females had significantly more often no treatment need (DHC 1 to 2/AC 1 to 4) compared with males (p < 0.05). The majority of subjects (89%) reported that they were very or quite satisfied with their dental appearance. The odds of being satisfied were significantly higher for the treated subjects (OR = 2.71, p < 0.05) and lower for those at the non-attractive end of the AC scale (OR = 0.14, p < 0.01). Neither gender nor DHC grade significantly affected the odds of being satisfied among the subjects. The results indicate that the majority of young adults in this study were satisfied with their dental appearance regardless of objective treatment need of various degrees. The high treatment rate in relation to unnoticed treatment need calls for reevaluation of priorities in patient selection.     

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.     

Agreement between normative and perceived orthodontic need amongst deprived multiethnic school children in London

The Index of Orthodontic Treatment Need (IOTN) has been used in dental epidemiology and to prioritize orthodontic treatment. The aim of this paper was to use the aesthetic component (AC) of the IOTN to measure agreement between normative and perceived orthodontic need amongst school children. Three hundred and seventy-eight children aged 11-14 years, enrolled in London UK state schools participated in this survey. The study focused on three ethnic groups: white, black and South Asian. Townsend deprivation scores suggested that the children were from areas of high socio-economic deprivation. Logistic regression analysis was carried out for agreement between normative and perceived need at each threshold value. Perceived need for braces, ethnic background, social class and hours of television viewing were significant variables. Black pupils were significantly less likely to concur on normative and perceived need scores, tending to perceive less need for treatment than did the dentist. Subjects from lower social classes were significantly more likely to concur on normative and perceived need scores. In conclusion, the study showed that using the IOTN AC at various points along the scale, different influences play a significant role in agreement/disagreement between normative and perceived needs, indicating that patient-clinician agreement regards orthodontic treatment is sensitive to several cultural factors.     

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.     

Orthodontic treatment needs in Caribbean dental clinics

This study was undertaken to determine the normative and perceived orthodontic treatment need of patients in Trinidad, a Caribbean island. The study sample comprised 30 child dental health clinic patients, 30 of their accompanying parents, and 52 adult patients from other University of the West Indies clinics and the Dental Hospital in Mount Hope, Trinidad. Two clinicians used the Dental Health Component of the Index of Orthodontic Treatment Need (IOTN) to assess normative need, and the patient's perceived needs were assessed using the Aesthetic Component (AC) of the IOTN and the Oral Aesthetic Subjective Impact Scale (OASIS). Fisher's exact test was used to determine the differences between the subgroups of the sample for both normative and perceptive treatment need. Association between normative need and perception assessment measures was tested using Spearman's correlation coefficient. Two-thirds of the sample of 112 subjects were female and each subgroup had a similar gender distribution. The results also indicate that approximately four out of five Trinidadians have a great (or very great) orthodontic treatment need. The perception of orthodontic treatment need differed significantly (P < 0.05) from normative need in this sample and this was seen more clearly when the OASIS was used.     

Orthodontic treatment need and demand in 12-14-year-old north Jordanian school children

This study was undertaken to assess the need and demand for orthodontic treatment among 12-14-year-old north Jordanian school children. In total, 1002 students randomly selected to represent five geographical areas of Irbid were examined. The examinations were carried out twice, first on the pupils in the school premises and then using study models taken from each student. The dental health (DHC) and aesthetic (AC) components of the Index of Orthodontic Treatment Need (IOTN) were used as an assessment measure of the need for orthodontic treatment. The demand for orthodontic treatment was measured by asking the students 'if it was necessary, would they like to have their teeth straightened by an orthodontist'. The results showed that approximately one-third (34 per cent) of the children examined had a definite need for orthodontic treatment. Within this group, 73.5 per cent were in need of orthodontic treatment according to the DHC, 23.5 per cent had both DHC and AC great need scores, and 3 per cent were in need according to the AC only. Severe contact point displacement of more than 4 mm was the most common occlusal feature in the definite treatment need group, followed by impeded eruption of teeth, hypoplasia of a single tooth and increased overjet of more than 6 mm but less than or equal to 9 mm. The demand for orthodontic treatment among the students was 49 per cent. Approximately half of them (54 per cent) had a definite need for orthodontic treatment. This study provides baseline data on the need and demand for orthodontic treatment among a Jordanian population, which is important for planning public orthodontic and dental services.     

The relationship between patient, parent and clinician perceived need and normative orthodontic treatment need

The aim of the present study was to compare patient, parent and clinician perceived need for orthodontic treatment in relation to normative orthodontic treatment need as measured by the Index of Orthodontic Treatment Need (IOTN). A prospective cross-sectional study was designed to address this aim. The sample comprised 103 patients attending the 'new' patient clinic at the Jordan University Hospital. The patients' mean age was 15.3 years (standard deviation 3.8 years); 33 per cent were males and 67 per cent females. One clinician scored the patients' normative orthodontic treatment need using the IOTN, then determined perceived need using a 10 cm visual analogue scale (VAS). The subjects then assessed their own perceived need and aesthetic component (AC) score and the parents carried out similar assessments for their children. All scoring was carried out blind. The parents had the highest average perceived need scores, followed by patient and clinician scores (6.6, 6.1 and 5.4 cm, respectively). A significant difference was found between the parents and the clinician (P < 0.05). When the relationship between perceived need and clinician-measured normative orthodontic treatment need was investigated, significant differences were found with the dental health component (DHC) for all three groups (P < 0.05). Differences between AC and perceived need scores were also significant for the patients and parents, but not for the clinician (P > 0.05). The present study has shown that perceptions of orthodontic treatment need are multifactorial and influenced by elements other than health measures of normative orthodontic treatment need and perceptions of aesthetics.     

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.     

Measuring failure of orthodontic treatment: a comparison of outcome indicators

OBJECTIVE: To compare treatment failure rates on a sample of completed and discontinued orthodontic treatment cases as measured by PAR, IOTN and ICON to determine whether the use of a sole index would suffice. SUBJECTS AND METHOD: All patients completing or discontinuing orthodontic treatment in the hospital orthodontic departments in the Northern Region during two calendar months were identified and pre and post-treatment models were analysed. PAR scores, IOTN (DHC and AC) and ICON were recorded. RESULTS: One-hundred-and-forty-five cases were identified and 15 had incomplete records on the day of analysis. The final sample was therefore 130. The overall treatment discontinuation rate of these 130 patients was 24.6%. The treatment failure rate with respect to occlusal improvement varied from 3.1% when measured by PAR and 10.0% using ICON. With respect to residual need it varied from 0.77 to 20.1% with respect to IOTN depending on the criteria examined. The residual treatment need with respect to ICON was 17.2%. CONCLUSIONS: Different occlusal indices give differing failure rates when used on the same patients with ICON being the most critical index. We felt that ICON was the most valid with respect to identifying treatment failure. Its use would enable international comparison of results.     

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.     

The reliability and validity of the Index of Complexity, Outcome and Need for determining treatment need in Dutch orthodontic practice

The Index of Complexity, Outcome and Need (ICON), based on international opinion, has been proposed as a multipurpose occlusal index. The aim of this study was to validate the ICON for treatment need in the Netherlands by relating it to Dutch orthodontic opinion. Furthermore, the reliability of this index was explored, for both a calibrated orthodontist and non-calibrated orthodontists. A sample of 102 patients was chosen which represented the actual distribution of severity of malocclusion experienced by orthodontists in every day practice. The ICON was scored, based on complete patients records of those 102 patients, by an examiner calibrated in the use of this index. The results were compared with the opinion about treatment need of seven Dutch orthodontists - the 'gold standard'. Nine non-calibrated orthodontists also scored the ICON for 49 patients. The intra-examiner agreement of both the non-calibrated and the calibrated orthodontists was moderate to high [0.52-0.86 and 0.89, respectively, measured with the Intraclass Correlation Coefficient (ICC)]. The inter-examiner agreement of the ICON score of the nine orthodontists was moderate measured with the single estimate of the ICC (0.60), and high measured with the average estimate (0.93). Spearman's correlation coefficient between the ICON score (calibrated) and the gold standard was sufficient: 0.78. The sensitivity and specificity were 1 and 0.36, respectively. The best compromise between sensitivity and specificity was at a cut-off point of 52, instead of the international ICON cut-off point of 43. There was a significant difference in ICON score between the non-calibrated orthodontists and the calibrated orthodontist, mainly based on the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). It can be concluded that the ICON needs to be adjusted when used to determine treatment need in the Dutch orthodontic population.