Prevalence of orthodontic treatment needs in permanent dentition in the population of Gulf Cooperation Council countries: A systematic review and meta-analysis of observational studies Shivanna PB, Gopalakrishna VB

REVIEW ARTICLE

Year : 2023 | Volume : 12 | Issue : 1 | Page : 39

Prevalence of orthodontic treatment needs in permanent dentition in the population of Gulf Cooperation Council countries: A systematic review and meta-analysis of observational studies

Praveen B Shivanna¹, Vidyullatha B Gopalakrishna²
¹ Specialist Orthodontist, Bariq Al Ebtesama Dental and Orthodontic Clinic, Riyadh, Saudi Arabia
² Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences; King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia

Date of Submission	29-Dec-2022
Date of Decision	17-Apr-2023
Date of Acceptance	04-May-2023
Date of Web Publication	04-Sep-2023

Correspondence Address:
Praveen B Shivanna
Specialist Orthodontist, Bariq Al Ebtesama Dental and Orthodontic Clinic, Riyadh
Saudi Arabia

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jos.jos_126_22

Abstract

The aim of this systematic review and meta-analysis was to comprehensively analyze the existing information on the prevalence of the need for orthodontic treatment in the permanent dentition stage among populations in Gulf Cooperation Council (GCC) countries. For observational studies in GCC countries, the key terms were electronically searched in Science Direct, PubMed, Embase, Cochrane Reviews, Google Scholar, and Sage databases (1990–2021). The bias risk for the selected studies was evaluated using the modified Strengthening the Reporting of Observational Studies in Epidemiology statement. Thirteen studies reported on the prevalence of orthodontic treatment needs among 33,134 children in GCC countries in permanent dentition with an age range of 11–19 years satisfied the inclusion criteria. Out of the 13 studies, 9 reported on the prevalence of malocclusion, 11 reported on the prevalence of occlusal traits, and 12 reported on the prevalence of orthodontic treatment needs as per the Dental Health Component (DHC) of Index of Orthodontic Treatment Need (IOTN), 4 reported as per both DHC and Aesthetic Component (AC) of IOTN, and 1 reported as per only AC of IOTN. Meta-analysis of the included studies indicated that the pooled malocclusion prevalence rate was 10.60% (confidence interval [CI] 95%: 0.093–0.076) with 8.58% Class I (CI 95%: 0.074–0.188), 2.09% Class II (CI 95%: 0.014–0.058), and 0.93% Class III (CI 95%: 0.005–0.018) malocclusions. The most prevalent type of occlusal trait was spacing (13.10%, CI 95%: 0.018–0.169), followed by crowding (4.96%, CI 95%: 0.017–0.091). The pooled prevalence of borderline and definite needs for orthodontic treatment based on DHC and AC of IOTN was 0.82% (CI 95%: 0.014–0.035), 1.13% (CI 95%: 0.011–0.091), 4.08% (CI 95%: 0.009–0.114), and 2.06% (CI 95%: 0.002–0.048), respectively. The findings were heterogeneous (P < 0.05). These findings indicated that the prevalence of malocclusion and orthodontic treatment needs was not high in the GCC population.

Keywords: GCC countries, malocclusion, occlusal trait, orthodontic treatment need, prevalence

How to cite this article:
Shivanna PB, Gopalakrishna VB. Prevalence of orthodontic treatment needs in permanent dentition in the population of Gulf Cooperation Council countries: A systematic review and meta-analysis of observational studies. J Orthodont Sci 2023;12:39

How to cite this URL:
Shivanna PB, Gopalakrishna VB. Prevalence of orthodontic treatment needs in permanent dentition in the population of Gulf Cooperation Council countries: A systematic review and meta-analysis of observational studies. J Orthodont Sci [serial online] 2023 [cited 2023 Sep 21];12:39. Available from: https://www.jorthodsci.org/text.asp?2023/12/1/39/385063

Introduction

Malocclusion is one of the three most frequently occurring oral disorders, apart from caries and periodontal disease. Untreated malocclusion is associated with numerous harmful effects, including impairment in oral functions such as chewing, swallowing, speech, periodontal problems, dental pain, poor functional and aesthetic outcomes, and psychosocial distress.^[1] Malocclusion is any deviation from normal occlusion in the teeth, dental bases, or arches.^[2] Assessment of the need for orthodontic care in a community indicates only the prevalence of different extents of malocclusion, some of which may not require treatment.^[3] However, when normal occlusion undergoes changes that affect an individual's functional and aesthetic aspects, the need for orthodontic care becomes apparent.^[4] Besides, the frequency and distribution of orthodontic treatment care vary depending on the age groups, regions of study subjects, and quality assessment criteria.^[5] Recent years have garnered increasing research attention in evaluating the prevalence and the related requirements for orthodontic treatment,^[6] as comprehensive observational data about the prevalence of the need for orthodontic care have been scant. Several indices have been developed for assessing the need for orthodontic treatment. The Index of Orthodontic Treatment Need (IOTN) by Shaw et al.^[7] is one of the most cited indices as it is user-friendly and reliable.^[8] The IOTN index comprises the Aesthetic Component (AC) and Dental Health Component (DHC). The former is based on perceived dental impairment due to changes in various occlusal traits for the dental health of an individual.^[9] Alternatively, the Dental Aesthetic Index (DAI) combines biological and ACs of occlusion for assessing severity and the need for orthodontic measures.^[10] Thus, evaluation of the prevalence of the need for orthodontic care as per the standard indices seems crucial to obtain information on the occurrence of treatment needs in populations, to establish the significance of treatment, and to target unmet oral needs and accessibility to dental services efficiently.^[11]

The recent growth in Gulf Cooperation Council (GCC) countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates) has generated an increasing population looking for orthodontic treatment, especially in the permanent dentition stage.^[12] However, comprehensive reports have been limited, particularly systematic reviews and meta-analyses, which can offer valuable information regarding the orthodontic treatment needs in GCC countries.^{[12],[13],[14]}

Although the high prevalence of orthodontic anomalies does not necessarily indicate the requirement for orthodontic treatment, a persistent increase in the orthodontic treatment cost in GCC countries seems evident. Thus, further evidence regarding the prevalence of orthodontic anomalies must be gathered to develop a suitable protocol to address various issues related to its treatment. Thus, this study aims to perform a systematic review and meta-analysis to comprehensively analyze and discuss the existing information on the prevalence of the need for orthodontic treatment in GCC countries. The research question to be addressed is: What is the prevalence of orthodontic treatment needs in subjects with permanent dentition in GCC countries?

Methods

Search strategy

A systematic method was followed in this study, which involved searching keyword terms in major databases like Science Direct, PubMed, Embase, Cochrane Reviews, Google Scholar, and Sage, focusing on observational studies related to the prevalence of orthodontic treatment needs in the permanent dentition stage in GCC countries. Studies published in English from 1990 to 2021, with the following search terms, were included: 'Orthodontic treatment needs', 'prevalence', 'permanent dentition', 'orthodontic treatment need index', and 'observational studies'. The Boolean word 'AND' was used. The following search was carried out: ('Orthodontic treatment need') AND ('prevalence') AND ('permanent dentition') AND ('orthodontic treatment need index') AND ('observational studies'). Besides, searching references of the selected studies and manual searching were conducted. The step-wise organization of the search terms yielded 342 articles, of which 336 studies were identified through keyword searches in the databases [Table 1], and six were identified through other sources.

Table 1: Number of hits in the search databases

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Eligibility bases

The selection of the 342 studies was based on the relevance of titles, abstracts, keywords, full-text assessment, and cross-comparison against the following inclusion and exclusion criteria.

Inclusion criteria

Observational studies conducted in one of the six GCC countries that evaluated the prevalence of the need for orthodontic treatment in the permanent dentition stage based on IOTN.
Studies published from 1990–2021 in dental journals.
Studies conducted on subjects aged between 11 and 40 years.
Studies published in English.

Exclusion criteria

Book chapters, literature reviews, records, proceedings, editorials, and duplicate studies.
Studies conducted on individuals with developmental disorders of teeth and craniofacial complex.
Studies conducted on individuals undergoing orthodontic treatment.
Studies conducted on individuals with primary or mixed dentition stages.

The schematic representation for selecting the articles is illustrated in [Figure 1]. The following information was extracted from each selected study: the first author, year of publication, the country where the study was conducted, the total number of samples, age in years, the prevalence of malocclusion, prevalence of occlusal trait, prevalence of orthodontic treatment needs based on components of the IOTN, and conclusive findings. Both components of the IOTN index for orthodontic treatment needs are categorized into three groups (no or slight need, borderline need, and definite need).

Figure 1: PRISMA representation for step-wise selection of articles

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Bias assessment

After selecting the articles, the methodological quality was assessed using the modified “Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)” statement. Bias risks were evaluated using 12 questions covering 10 domains: study objective, study design, sampling method, sample size, population, inspecting samples method, data collection tools, statistical analysis, way of reporting outcomes, and reporting outcomes based on objectives.^[11] The overall risk of bias for each parameter reported by the selected studies was scored from 0 to 10 points, and studies with a score of less than 8 were removed from the meta-analysis.^[15]

Data analysis

For the meta-analysis, data from the studies that stated similar measurements using appropriate statistical tests were combined after examining sampling considerations, study design, study populations, or missing information in a random-effects model.^[16] The possibility of publication bias across the studies was detected using Egger's test and Begg's rank correlation and visually examined using a funnel plot.^[17],[18] Variation due to statistical heterogeneity among the studies was detected using the Q and I² statistics. I² scores >70% were considered highly heterogenic.^[19] The presence of heterogeneity was visually tested using forest plots. Here, statistical significance was considered at P < 0.05. All analyses were performed using the Jamovi statistical software.

Results

Identification and description of studies

Electronic searches from the databases (Science Direct, PubMed, Embase, Cochrane Reviews, Google Scholar, and Sage) and other sources identified 342 articles [Figure 1]. Of the 342 articles screened, 27 were selected for full-text assessment. A final total of 13 studies (published between 1990 and 2021) were included in the systematic review and meta-analysis based on the inclusion criteria. The description of each study is compiled in [Table 2]. Of the 13 studies, four studies did not report the prevalence of malocclusion data,^{[20],[21],[22],[23]} while two studies did not report the data regarding the prevalence of malocclusion trait.^[24],[25] Besides, 12 studies^{[14],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30]} used the DHC component of IOTN, four studies^{[21],[23],[24],[25]} used both DHC and AC components of IOTN, and one study^[31] used only AC component of IOTN for assessing the need for orthodontic treatment. The total number of participants in the permanent dentition in the included studies was 33,134 children aged 11–19 years. A large proportion of studies were carried out in Saudi Arabia (eight of the total studies included), while three were carried out in Kuwait, one study each in UAE and Oman. However, no studies in Bahrain and Qatar satisfied the inclusion criteria [Table 2].

Table 2: Summary of studies included for the systematic review and meta-analysis

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Quality assessment of selected studies

Assessing the methodological quality of the observational studies is presented in [Table 3]. The modified STROBE criteria summarize an overall good level of evidence obtained from the findings of the selected studies. Based on the modified STROBE statement, four studies obtained a total score of 8,^{[23],[25],[26],[31]} three studies obtained a total score of 9,^{[20],[22],[28]} and six studies had a total score of 10.^{[14],[21],[24],[27],[29],[30]} These scores indicate the acceptable quality of the studies included in this systematic review. Of the 13 studies, nine correctly reported outcome data and the way outcomes should be reported. These studies incorporated all expected outcomes. One study did not provide enough information on the inspecting samples method.^[31] Moreover, five studies did not incorporate the appropriate statistical analysis for the research questions.^{[22],[25],[26],[28],[31]}

Table 3: STROBE criteria for quality assessment of the selected observational studies

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Findings of Meta-Analysis

Prevalence by malocclusion

Around 8520 of the sampled population exhibited malocclusion, with a pooled prevalence of 10.60% (confidence interval [CI] 95%: 0.093–0.076). Seven studies reported the prevalence of Class I malocclusion, while six reported the prevalence of Class II and Class III malocclusions. Based on the pooled results, the highest prevalence of malocclusion in the GCC countries was Class I malocclusion at 8.58% (CI 95%: 0.074–0.188), followed by Class II malocclusion at 2.09% (CI 95%: 0.014–0.058) and Class III malocclusion at 0.93% (CI 95%: 0.005–0.018) [Table 4].

Table 4: Pooled prevalence of malocclusion and type of occlusal traits in permanent dentition among the studied population in GCC countries

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Prevalence by type of occlusal trait

The meta-analysis of the types of occlusal traits based on 13 studies revealed the following proportions: spacing 13.10% (CI 95%: 0.018–0.169), crowding 4.96% (CI 95%: 0.017–0.091), transverse occlusal traits (lip incompetence, impeded eruption, contact point discrepancy, displacement, midline diastema) 1.56% (CI 95%: 0.023–0.091), and bite discrepancies (deep bite, open bite, overbite, crossbite, scissor bite) 0.79% (CI 95%: 0.011–0.05) and overjet 0.65% (CI 95%: 0.010–0.028) [Table 4].

Prevalence by orthodontic treatment needs

The meta-analysis showed that the prevalence of no or slight orthodontic treatment needs in samples according to DHC of IOTN was 1.74% (CI 95%: 0.039–0.113), and samples who had definite and borderline orthodontic treatment needs were 1.13% (CI 95%: 0.011–0.091) and 0.82% (CI 95%: 0.014–0.035), respectively [Table 5]. The findings of the present meta-analysis according to AC of IOTN criteria reported that 7.36% (CI 95%: 0.024–0.191) of samples had no or slight orthodontic treatment needs and only 4.08% (CI 95%: 0.009–0.114) and 2.06% (CI 95%: 0.002–0.048) had borderline and definite needs for orthodontic treatment [Table 5].

Table 5: Pooled prevalence of orthodontic treatment needs in permanent dentition in GCC countries

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Heterogeneity and publication bias

The data, including the prevalence of malocclusion, types of occlusal traits, and prevalence of orthodontic treatment needs, were consolidated in a meta-regression random-effects model to identify heterogeneity and publication bias. The Begg's test and Egger's test for publication bias for the prevalence of malocclusion, the prevalence of occlusal traits, and the prevalence of orthodontic treatment needs (I² > 70%; P < 0.001; [Supplementary Table S1]) reported significant heterogeneous findings and a possible suspicion of a publication bias [Supplementary Figure S1], [Supplementary Figure S2], [Supplementary Figure S3], [Supplementary Figure S4], indicating large variability in the results of the pooled studies based on whether the individual studies differed noticeably in the samples included, methods used, age groups, publication year, geographical distribution, and outcomes measured.

Discussion

The present systematic review and meta-analysis combined the results of primary studies, presenting a clear status of the prevalence of malocclusion, types of occlusal traits, and the need for orthodontic treatment in GCC countries based on a random-effects model. The results indicated that a small proportion (10.6%) of the population in GCC countries exhibited at least one type of malocclusion. Compared to the Class II (2.09%) and Class III (0.93%) angle classifications of malocclusion, the Class I (8.58%) angle classification of malocclusion was reported to have the highest estimated prevalence. This result supports the study by Akbari et al.,^[32] where Class I malocclusion was reported to have the highest prevalence among children of Iran, owing to loss of deciduous teeth due to caries at an early age. Besides, this study found a comparatively lower rate of prevalence of Class II and Class III malocclusion, which is consistent with the longitudinal study by Bugaighis,^[33] where Class II (22.4%) and Class III (4.4%) malocclusion among Libyan pre-schoolers exhibited a lower prevalence compared to Class I malocclusion (69.6%). However, a different finding was reported by Shen et al.^[34], which indicated that Class II malocclusion (7.97%) had a lower prevalence compared to Class III malocclusion (12.60%), but the prevalence of Class I malocclusion (26.50%) was highest. This difference in the finding could be due to genetic factors and the pattern of mandibular projection that could increase the prevalence of Class III malocclusion.^[35] Bugaighis^[33] suggested that early recognition of such malocclusions in the deciduous dentition stage may help to prevent a related high prevalence in the permanent dentition stage.

The most common occlusal trait was reported to be spacing, followed by crowding, which is consistent with a previous study by Bahadure et al.,^[36] where spacing (64.7%) and crowding (27.1%) were observed among Indian children. Spacing, including the physiological, developmental, and primate spacing, indicates an accurate alignment of the permanent teeth^[37],[38]; thus, early detection and treatment are not indispensable in such cases. Developmental and primate spacing increase with the child's growth and expansion of the alveolar processes.^[39] Crowding occurs mainly due to the modern diet in the deciduous dentition stage, which subsequently contributes to the discrepancy between the jaw and teeth in the permanent dentition^[40]; thus, early detection and treatment are crucial to enhance the proportion between the jaw and teeth.^[41] A similar finding was reported by Abu Alhaija and Qudeimat,^[42] where spacing in the maxilla (61.8%) and mandible (61.1%) of primary dentition was the most prevalent among Jordanian pre-schoolers. Previous studies reported deep bite and spacing as common occlusal traits.^[34],[43] Shen et al.^[34] reported spacing (28.34%) to be the second most prevalent occlusal trait after the deep bite (33.66%). These values were more than those reported in this study, possibly due to sampling error owing to the small sample size and differences in dentition stages. Besides, the lower prevalence of bite discrepancies (deep bite, open bite, overbite, crossbite, scissor bite) and overjet in this study could be due to the temporary occurrence of these traits during the transition from primary dentition to the permanent dentition stage and natural correction over time as a result of the vertical growth of the mandible, upward, and backward and the complete venting of permanent molars, as supported by a previous study by Baccetti et al.^[44] Also, the lower prevalence of overbite could be influenced by genetic and environmental factors,^[45] while self-correction of anterior crossbite during the transition from the deciduous to permanent dentition stage was observed.^[46] Similarly, early recognition and treatment decrease the long-term effects of crossbite in permanent dentition.^[34] Compared to the relative prevalence of increased overjet reported in the previous studies^[34],[47], which ranges between 10.16% and 40.8%, the prevalence rate in this study was the lowest. This could be due to the alleviation of overjet from the deciduous to permanent dentition stage.^[40]

This study found a rather low prevalence of definite and borderline needs for orthodontic treatment based on the DHC of IOTN, compared to those reported in Spanish, Italian, and Serbian school students (27.3%, 27.4%, and 21.8%).^{[48],[49],[50]} According to the results of AC of IOTN, the prevalence of a definite need for orthodontic treatment in this study was similar to the previous studies that reported self-perceived orthodontic treatment needs among school children in London which was 2%,^[51] 4.4% in Spain,^[48] and 4.8% in Iran.^[11] The epidemiological assessment of malocclusion requires precise information about orthodontic treatment needs, which can be helpful in policy-making and resource planning for oral healthcare systems. The IOTN is useful for gathering objective and subjective information for epidemiological purposes and establishing priorities for administrative purposes.

Limitations

Although this study offered some significant findings, these were not without some limitations and scope for further research.

The present review included cross-sectional studies, which unavoidably restricted the estimation of the prevalence of orthodontic treatment needs due to the use of different research methods, tools, and self-perceived judgments. Thus, longitudinal studies assessing the prevalence of orthodontic treatment needs in GCC countries are suggested.
The insufficient number of studies conducted in GCC countries that met the inclusion criteria restricted the accurate representation of the population. Also, a lack of enough studies was observed in Oman and the UAE, and no studies were observed in Bahrain and Qatar that satisfied the inclusion criteria. Thus, more epidemiologic studies on the prevalence of orthodontic treatment needs are suggested to be carried out in the GCC countries.
The significant heterogeneity observed among the included studies, which might be due to differences in age groups, ethnic groups, analyzed traits, and genetic and environmental factors, limited the determination of the influence of variables on pooled prevalence.^[52]
The methodological quality of the selected studies was a concern. Despite that, some of the studies mentioned the study question and sample size; these studies needed to wholly inspect the sampling method and the data collection, which might have led to biased evaluations of prevalence.
Only a few studies reported the prevalence of orthodontic treatment needs as per the AC criteria of IOTN. Thus, future studies descriptively assessing the prevalence of orthodontic treatment needs are suggested for epidemiological surveys.

Conclusion

This systematic review and meta-analysis identified 13 studies that estimated the prevalence of malocclusion, occlusal traits, and orthodontic treatment needs in the permanent dentition stage. This study observed that the prevalence of Class I malocclusion was highest, and Class III malocclusion was lowest in the studied populations. Moreover, the analysis of the occlusal traits revealed that spacing was most prevalent in the permanent dentition in the studied population, followed by crowding and other transverse traits (i.e., impeded eruption, contact point discrepancy, displacement, and midline diastema), vertical traits (deep bite, open bite, and overbite), and overjet. Furthermore, in this study, the majority of the population in GCC countries were categorized in no or slight need for orthodontic treatment as per DHC and AC criteria of IOTN. However, nearly 1.13% and 2.06% of the population have a definite need for orthodontic treatment. Thus, it calls for policymakers in GCC countries' attention to implement policies that recognize the importance of early preventive orthodontic treatment measures leading to improved oral health of subjects with permanent dentition.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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