Longitudinal evaluation of the Treatment Priority Index (TPI)

Nature and severity of dental malocclusion in children suffering from transfusion-dependent (-thalassemia major

Objective:

To evaluate the prevalence and severity of malocclusion in children suffering from β-thalassemia and to assess orthodontic treatment need using Grainger’s Treatment Priority Index (TPI) and index of orthodontic treatment need (IOTN)-dental health component (DHC).

Methods:

A cross-sectional study was conducted on 200 transfusion-dependent children diagnosed with homozygous β-thalassemia and 200 healthy school children aged 11-17 years. The TPI and IOTN-DHC data was recorded for both groups. Total TPI score for each subject was calculated and graded according to malocclusion severity estimate (MSE). Independent sample t-test was used to compare mean TPI scores, overjet and overbite between thalassemic and healthy children. Chi-square test was used to compare the frequency of IOTN-DHC grades, Angle’s classification, and MSE grades between thalassemic and healthy children.

Results:

The most prevalent malocclusion was Class I in normal children (67.5%) and Class II in thalassemic children (59%). The mean overjet and overbite were significantly (p<0.001) greater in thalassemic children than in healthy children. Severe tooth displacements were 3.5 times greater in thalassemic children, compared to controls. A greater proportion of thalassemic children were in IOTN grades 3 and 4, compared to the controls (p<0.001). MSE grades 4 and 5 were significantly (p<0.001) more prevalent in thalassemic children, compared to the controls.

Conclusion:

There is a high prevalence of Angle’s Class II malocclusion in thalassemic children. Majority of these children are categorized in higher grades of IOTN-DHC and TPI-MSE, showing a great severity of malocclusion and high orthodontic treatment needs.

Prevalence of malocclusion and assessment of treatment needs in β-thalassemia major children

Background

The objective of this study is to evaluate the prevalence of malocclusion and treatment needs in transfusion dependent β-thalassemia major children.

Methods

One hundred transfusion dependent β-thalassemia major children visiting the Department of Pediatrics were selected randomly and evaluated for malocclusion with Angle’s classification and Dewey’s modification. The orthodontic treatment needs were also assessed using Grainger’s treatment priority index (TPI). The orthodontic treatment needs were compared to normal children.

Results

The assessment of treatment needs revealed a higher prevalence of handicapping and severely handicapping malocclusion in thalassemic children compared to normal children. The thalassemic patients were found to show significantly more Angle’s Class II malocclusion (55 % vs. 15.7 %) when compared to normal children.

Conclusions

The higher prevalence of Angle’s Class II malocclusion and definitive malocclusion in thalassemic children indicates the importance of preventive orthodontic procedures and efforts towards providing orthodontic treatment to these children.

The relationship of orthodontic treatment need with periodontal status, dental caries, and sociodemographic factors

The aim of this study was to determine the relationship of orthodontic malocclusion with periodontal status, dental caries, and sociodemographic status. Our study population consisted of a sample of 836 school children (384 male and 452 female, aged 11-14 years). Four experienced orthodontists and two experienced periodontists performed the clinical examinations. The Treatment Priority Index (TPI), Community Periodontal Index of Treatment Needs (CPITN), decayed, missing, filled teeth (DMFT) scores, and a questionnaire that surveyed socio-demographic status of students were used. Spearman's rank correlation coefficients were used to measure the association between variables. TPI scores showed that 36.4% of the students had normal occlusion, while 41.2% had slight, 15.7% had definite, 4% had severe, and 2.7% had very severe malocclusion. TPI values did not show any significant differences between pupils in different age, gender, socioeconomic status groups, and CPITN scores, whereas there was a significant relationship between TPI and DMFT scores. The orthodontic treatment need was not significantly correlated with CPITN or socio-demographic status; however, the correlation coefficient showed a significant relationship between TPI and DMFT scores.

An Overview of Orthodontic Indices

Analysis of prevalence of various types of malocclusion is an important aspect of today's evidence-based dentistry. Orthodontic indices are a tool in the hands of an epidemiologist to analyze the prevalence and severity of various kinds of malocclusion. The aim of this article is to look into the various qualitative and quantitative methods of grading and assessing malocclusion and their evolution over the years along with their advantages and limitations have also been analyzed. The article also compares the commonly used indices—DAI and IOTN.

How to cite this article

Agarwal A, Mathur R. An Overview of Orthodontic Indices. World J Dent 2012;3(1):77-86.

Intra- and inter-examiner reliability of intraoral malocclusion assessment

Malocclusion assessment methods are based on measurements of study casts, which requires that impressions be taken. In addition to being costly and time consuming, this process can be unpleasant for children. Therefore, the aim of this study was to evaluate intra- and inter-examiner reliability of intraoral score measurements to determine malocclusion severity in the permanent dentition. The research was a part of a longitudinal study from which a cohort of 92 children (39 boys, 53 girls), with a mean age of 14.8 years (standard deviation = 0.18), were randomly selected and classified into severity grades based on total malocclusion score. Subsequently, 12 children were randomly selected for a reliability study to assess intra-examiner reliability of malocclusion trait measurements. Nine subjects gave informed consent to participate in the study. Quantitative registrations of space and occlusal anomalies were performed intraorally by five examiners, on two occasions with a 1-month interval between the two measurements. Intra- and inter-examiner reliability was determined using intraclass correlation coefficients (ICCs). Overall classification into severity grades, based on total malocclusion score, showed almost perfect intra-examiner reliability for all examiners (ICC = 0.97-0.99); inter-examiner ICC was almost perfect (0.97). Near perfect intra-examiner reliability was determined for eight occlusal trait measurements (ICC = 0.89-1.0); substantial reliability for midline deviation (ICC = 0.68), overbite (ICC = 0.78), but large variability for space condition assessment (ICC = 0.42-0.52). Inter-examiner reliability was almost perfect for the eight traits (ICC = 0.81-1.0); substantial reliability for midline deviation (ICC = 0.65), and axial tooth inclination (ICC = 0.75), but large variability for space condition assessment (ICC = 0.13-0.26). Intra- and inter-examiner malocclusion assessment, recorded and measured intraorally to determine malocclusion severity scores in 14-year old children, is reliable. It is therefore proposed as the method of choice to be used not only in epidemiological studies and screening but also in clinical orthodontic assessment.

Prevalência de maloclusão e sua associação com alterações funcionais do sistema estomatognático entre escolares

Esta pesquisa objetivou estimar a prevalência de maloclusões entre escolares com 12 anos de idade do Município de Camaragibe, Pernambuco, Brasil. As maloclusões foram estratificadas em função do grau de severidade, analisando-se, ainda, a sua associação com as alterações das seguintes funções: fonoarticulação, respiração e deglutição. A oclusão foi avaliada por intermédio do Treatment Priotiy Index (TPI) e as referidas funções por meio de critérios utilizados na rotina clínica fonoaudiológica por um único examinador calibrado (valores de kappa variáveis entre 0,64 e 1,00). Os escolares foram selecionados randomicamente em 11 escolas públicas. Dos 173 sorteados, 82,1% apresentaram maloclusão (IC95%: 76,4-87,8), sendo 38,2% consideradas manifestações menores de maloclusões; 20,8% maloclusões definidas; 13,3% maloclusões severas; e 9,8% maloclusões muito severas. Conclui-se que há uma alta demanda reprimida por tratamentos ortodônticos e que quanto maior a severidade das maloclusões maior é a possibilidade de associação com alterações funcionais, fato que deve ser levado em consideração no planejamento de serviços públicos destinados aos referidos agravos.

Occlusal and cephalometric Class II Division 1 malocclusion severity in patients treated with and without extraction of 2 maxillary premolars

INTRODUCTION

The purpose of this study was to compare the initial occlusal and cephalometric severity of Class II Division 1 malocclusion patients treated with and without extraction of 2 maxillary premolars.

METHODS

Dental study models and cephalograms of 62 patients were selected. Those in group 1 (n = 42) were treated without extractions, and those in group 2 (n = 20) were treated with 2 maxillary premolar extractions. Grainger's treatment priority index (TPI) was used to assess the final and the initial occlusal status of each subject. Variables such as overjet and overbite were also evaluated. Independent t tests were used to compare the occlusal variables at the posttreatment stage, the occlusal and cephalometric variables at the pretreatment stage, and the improvement in TPI values between the groups.

RESULTS

Patients treated with 2 maxillary premolar extractions had greater initial occlusal TPI values, overjets, cephalometric apical base anteroposterior discrepancies, maxillary incisor protrusions, and anteroposterior molar discrepancies than those treated without extractions.

CONCLUSIONS

For patients with more severe anteroposterior discrepancies, an extraction plan provides more effective treatment with less need for patient compliance.

Class II treatment success rate in 2- and 4-premolar extraction protocols

This study compared the occlusal success rate of Class II orthodontic treatment results with either 2- or 4-premolar extraction protocols. Group 1 comprised dental study models of 81 patients treated with 2 premolar extractions, and group 2 comprised dental study models of 50 patients treated with 4 premolar extractions. The initial mean ages of the groups were 13.9 and 12.9 years, respectively. Grainger's treatment priority index (TPI) was used to assess the initial and final occlusal status of each patient. Individual variables, such as maxillary canine anteroposterior positioning, overjet, and overbite improvements were also evaluated. Independent t tests were used to compare the variables at the pretreatment and posttreatment stages and their improvement between the groups. The results showed a statistically significant difference in most of the variables and in their improvement at the end of treatment between the groups. The variables showed a better dental relationship in group 1, and the improvements in group 1 were larger than in group 2. Treatment of Class II malocclusion with 2 premolar extractions gives a better occlusal success rate than treatment with 4 premolar extractions.

Class II subdivision treatment success rate with symmetric and asymmetric extraction protocols

The purpose of this study was to compare the success rates of Class II subdivision malocclusion patients treated with either symmetric or asymmetric extractions. The sample consisted of 51 patients with Class II subdivision malocclusion. The patients were divided into 2 groups. Group 1 included 28 patients who were treated with 4 premolar extractions. The 23 patients in group 2 were treated with 3 premolar extractions (2 maxillary premolars and 1 mandibular premolar on the Class I side). The initial and final study models were evaluated by means of Grainger's treatment priority index (TPI). Individual evaluations of improvements in maxillary-to-mandibular dental midline deviation, overjet, and overbite were also made. The final mean TPI and the mean improvement in TPI and in the other variables of each group were compared with independent t tests. The results showed a statistically significant difference only for the improvement in maxillary-to-mandibular dental midline deviation of the groups. The 3-premolar-extraction group had a greater improvement of the initial interdental midline deviation. There is a tendency for a slightly better treatment success rate when Class II subdivision patients are treated with asymmetric extraction of 3 premolars, compared with extraction of 4 premolars.

Comparative radiographic evaluation of the alveolar bone crest after orthodontic treatment

This study evaluated and compared the heights of the alveolar bone crests (AC) among orthodontic patients treated with either the simplified standard edgewise technique (group 1, n = 30), the edgewise straight-wire system (group 2, n = 30), or bioefficient therapy (group 3, n = 26). These 3 groups were compared with an untreated control group (group 4, n = 30). A comparison by sex of AC height was also conducted. The first premolars were extracted in every treated patient, and measurements were performed on bitewing radiographs taken after a mean posttreatment period of 2.17 years. The distances from the AC to the cementoenamel junction (CEJ) on the mesial and distal surfaces of the first molars and second premolars and on the distal surface of the canines were measured; the larger the distance, the greater the alveolar bone loss. The data were analyzed by 1-way analysis of variance and the Newman-Keuls test (P <.05) for comparison among the groups. Sex differences of the AC height were evaluated with the t test. All treated groups had larger, statistically significant CEJ-AC distances than the untreated group, primarily at the extraction areas. There were no consistent statistically significant differences in the areas among the treated groups. Mean distances of the CEJ-AC in boys were larger than or similar to those in girls. The patients in the treated groups showed a greater number of proximal surfaces with statistically significant differences between sexes, compared with the control subjects.

Indexes for orthodontic treatment need

Orthodontic treatment need indexes are used extensively in Northern Europe, especially in selecting patients for treatment in public orthodontic health services and in determining the level of third party copayment. This article describes certain treatment need indexes and their uses in everyday practice. The reliability and validity of indexes are discussed.

Recording and measuring malocclusion: a review of the literature

The methods of recording and measuring malocclusion can be broadly divided into two types: qualitative and quantitative. Among the qualitative methods of recording malocclusion, Angle's method of classifying malocclusion with or without modifications is probably the most widely used. The "WHO/FDI Basic Method for Recording of Malocclusion" was published in 1979 to establish an assessment format to determine the prevalence of malocclusion and to estimate treatment needs of a population. Among the many occlusion indices developed by various research workers, the occlusal index developed by Summers appeared to have the least amount of bias, is best correlated with clinical standards and has the highest validity during time. More recently, methods have also been developed to enable assessment of treatment need according to grade index scales. However, experience in using these methods is still very limited.