Prevalence of Malocclusions in Children and Adolescents in Guinea-Bissau: A Cross-Sectional Observational Preliminar StudyABSTRACT
Objective: To investigate the prevalence of malocclusions in children and adolescents in a population in Guinea-Bissau, Africa.
Material and Methods: The convenience sample comprised 403 individuals of both sexes. Following anamnesis, a clinical examination was conducted to gather occlusion data, including Angle’s molar classification, canine relationship, degree of overjet and overbite, the presence or absence of physiological spaces, and crowding. The data were described using absolute and percentage frequencies and compared using Fisher's exact test or Pearson's chi-square test (p<0.05).
Results: Class I molar relationship was observed in 75.2% of patients, while 18.4% exhibited Class II molar relationship, and 6.5% displayed class III. Concerning the canine relationship, 33% of individuals had a Class I relationship, 19% a Class II relationship, and 3% a Class III relationship. Deep bite was observed in 16% of patients, open bite in 20%, and edge-to-edge relationship in 11%. Furthermore, 48% of the patients presented with diastema, and 34% exhibited dental crowding. No significant difference in occlusion findings was noted between the sexes.
Conclusion: Half of the population examined had some form of malocclusion, with Class I being the most prevalent. Therefore, further occlusal analysis studies in African populations are crucial to contributing significantly to the planning of public policies and the implementation of preventive action.
Keywords:
Epidemiology; Malocclusion; Child; Adolescent
Introduction
Malocclusions are defined as abnormalities in dental arches, in the facial skeleton, or both and may impact the stomatognathic functions, appearance, and self-esteem of affected individuals [1]. Currently classified as the third most significant oral health issue by the WHO, malocclusion is considered a public health concern due to its potential association with functional limitations, pain, and social incapacity, thereby affecting emotional and social well-being and diminishing overall quality of life [2,3].
The etiology of malocclusion can stem from genetic or environmental factors. Hereditary influences play a substantial role in determining tooth size, arch pattern, soft tissue characteristics, certain congenital deformities, and facial asymmetry. Environmental factors such as prenatal influences from maternal diet, metabolism, drug exposure, potential injury or trauma, infections, and birth-related trauma also influence dental alignment. Predisposing factors such as dietary issues, abnormal habits, posture, accidents, and trauma further exacerbate tooth arrangement abnormalities or malocclusion [3].
Conducting epidemiological assessments is crucial for establishing preventive measures against malocclusions. Such assessments provide essential data on occlusal characteristic types and distributions within a population, helping prioritize treatment needs and allocate resources effectively in terms of workforce, skills, agility, and materials. Additionally, assessing malocclusion prevalence across different populations and regions can shed light on genetic and environmental determinants [2]. Therefore, global data availability becomes pivotal for educational and health promotion purposes, guiding health policies towards professional skill development and resource provision for malocclusion prevention and treatment [4].
Guinea Bissau, situated in West Africa with a population of 1,449,230, where 51.6% are women, and 50.2% are young people aged between 15 and 35, faces socioeconomic challenges with a GDP of $1.9 billion and a GDP per capita of $1,164. The country could greatly benefit from efforts aimed at enhancing oral health quality. However, political instability, characterized by frequent changes in health administration, often hinders health improvement endeavors. A precarious health situation further impedes political progress, reducing life expectancy and impacting education access, participation in public life, and economic activities, thus exacerbating poverty. Additionally, political instability weakens productive infrastructure, heightening population vulnerability, particularly in rural areas. Thus, a healthy society is better equipped to demand rights, support development, and hold the government accountable [5,6].
Given these circumstances, this study aims to assess malocclusion prevalence in children and adolescents in Guinea Bissau, aiming to understand its type and distribution within the population to further formulate an educational, preventive, and rehabilitative plan, thereby contributing to the nation's public health policy.
Material and Methods
Study Design, Setting, and Ethical Aspects
This is a cross-sectional study that employs a quantitative approach guided by the STROBE checklist (https://www.strobe-statement.org/checklists). Prior approval for this project was obtained from the National Health Research Ethics Committee of Guinea-Bissau, regulated by the National Institute of Public Health, with reference number 002/CNES/INASA/2023. All the procedures have been performed as per the ethical guidelines laid down by the Declaration of Helsinki.
Given the country's high illiteracy rates, informed consent procedures involved signed documentation for literate participants, while oral explanations were provided, tailored to the dialects of the ethnic groups involved, for those who were unable to read or write. Consent was verbally obtained from research participants and corroborated by village chiefs (a customary practice in the country) and school principals in the capital.
Potential risks associated with the study included routine dental examinations and potential discomfort stemming from the diagnosis of oral and maxillofacial alterations. However, researchers committed to conducting all examinations in accordance with recommended biosafety protocols for epidemiological surveys and providing requisite dental support. Patients received treatment for oral needs concurrent with examinations, and based on findings, subsequent interventions were implemented within communities.
The study was conducted by a team of Brazilian dentists on a mission across the main government areas in Guinea-Bissau: Gabu (northern region) and Tombali (southern region). The data collection spanned a total of two months, divided across multiple trips conducted between January and May 2023.
Participants
For the sample calculation, this study was based on a study by Jordan et al. [7] conducted in Gambia, which has a population similar in number to Guinea-Bissau (approximately 1.9 million people). Estimations for our study indicated a sample size of 194 individuals per region (Guinea-Bissau has a total of 9 regions) to obtain a sample that would represent the prevalence of the diseases to be studied in these populations with a precision limit of 5% and confidence of 95%. Given the local political instability and the limited access to this study, patients were selected based on a convenience sample. As a preliminar study, this research was performed in the two main regions.
Inclusion criteria involved normosystemic individuals (children and adolescents) aged between 6 and 18, of both sexes, residing within the specified areas, whose guardians consented to participation orally or in writing. Exclusion criteria included the presence of craniofacial anomalies, edentulism, extensive caries affecting occlusal judgment, and total dental agenesis.
Variables, Data Sources/Measurements and Bias Reduction
Data collection commenced with interviews to gather information on sociodemographic data (age, sex) and oral health-related behaviors and habits, including dietary factors. Intraoral examination encompassed the observation of molar relationships, canine keys, vertical occlusion relationships (including deep bite, open bite, and edge-to-edge relationship), as well as the presence of diastemas and crowding. A single chart for occlusal analysis with specific items depending on the child's dentition type was used to identify malocclusion. Occlusal relationships were assessed in centric occlusion or maximum habitual intercuspation, utilizing Angle's classification to analyze occlusion in mixed and permanent dentition.
All clinical examinations were then conducted on benches or improvised stretchers in well-ventilated rooms or outdoor settings, aided by handheld flashlights, with assistance from trained community members. During the clinical examinations, a single community member served as the interpreter, providing consistent support across all populations. The interpreter’s presence facilitated the use of voice commands by the dental team during examinations and enabled the comprehensive collection of data related to diet, habits, and behaviors.
Previous inter-examiner calibration was conducted, with all examiners adhering to SBBrasil 2020 parameters [8], with a kappa coefficient exceeding 80% for inter-examiner calibration and above 90% for intra-examiner calibration.
Statistical Methods
Data analysis involved calculating means and standard deviations. Subsequently, variables were categorized into established disease ranges, and absolute and percentage frequencies were computed for each variable. Chi-square tests or Fisher's exact test were employed to associate sociodemographic variables with variables exhibiting a p-value less than 0.200 subjected to multinomial logistic regression analysis. A 5% confidence level (p<0.05) and a 95% confidence interval were applied. Statistical analyses were conducted using SPSS v20.0 for Windows.
Results
A total of 403 patients were included in this study, and no patient was excluded or withdrawn from the study. A similar proportion of females and males was observed. Class I molar relationship was observed in the majority of patients, with a significant proportion exhibiting malocclusion. Class II molar relationship was noted in a smaller percentage of patients, while a smaller group exhibited Class III. Additionally, a majority of patients demonstrated a canine key, with most classified as Class I, followed by smaller percentages of Class II and Class III. However, in a notable portion of patients, the canine key assessment was hindered by exfoliation or early loss of deciduous canines (Table 1).
Vertical occlusion analysis revealed the presence of deep bite, open bite, and an edge-to-edge relationship in a smaller percentage of the participants (less than 25%). The majority of patients exhibited a normal vertical relationship (Table 1). Diastemas were observed in nearly half of the patients, with a significant portion occurring in one arch and a smaller percentage in both arches. Furthermore, a notable percentage of patients displayed dental crowding, with a portion exhibiting crowding in one arch and a smaller group in both arches (Table 1).
The majority of patients assessed exhibited a Class I molar relationship, with smaller proportions showing Class II and Class III relationships, irrespective of sex. Similarly, among those with a canine key, the majority had a Class I key, followed by smaller groups with Class II and Class III keys, regardless of sex. Statistical analysis revealed no significant differences in either molar relationship or canine key between the sexes (Table 2).
Vertical occlusion analysis revealed that a significant proportion of patients exhibited variations in this parameter, with both females and males affected by deep bite, open bite, and edge-to-edge relationships. No statistically significant difference in vertical relationships was observed between the sexes (Table 2).
The distribution between females and males was nearly equal regarding diastemas and dental crowding. The majority of patients were affected by at least one of them in one arch; a smaller proportion was affected by both arches, irrespective of sex. Thus, no significant difference in the presence of diastemas or dental crowding was observed between the sexes (Table 2).
To explore the association between occlusion prevalence and deleterious habits and feeding patterns, a specific investigation was conducted in the Gabu region due to communication challenges in other areas. This segment involved 156 children affiliated with an NGO, enabling better communication with parents through a questionnaire.
No statistically significant relationship was found between the patients' occlusal patterns and observed deleterious habits (bottle, pacifier, and finger) (p>0.05) (Table 3).
Regarding feeding habits, a higher percentage of patients with Class I canines reported exclusive breastfeeding between 6 months and 2 years of age, while a greater proportion of patients with Class II canines indicated a combination of breastfeeding and supplementation during this period. This feeding pattern from 6 months to 2 years of age demonstrated a statistically significant relationship with the canine classification observed in the patients (p<0.05) (Table 4). However, no significant association was found between occlusal patterns and eating habits during other periods (p>0.05) (Table 4).
Discussion
This preliminar population-based study represents the first comprehensive investigation into the prevalence of malocclusion among children and adolescents in Guinea Bissau. The majority of participants exhibited a Class I molar relationship and a canine key, with malocclusion observed in a significant proportion. Vertical occlusion analysis revealed a normal vertical relationship in most patients, with a smaller percentage showing deep bite, open bite, or edge-to-edge relationships. Diastemas and dental crowding were also common, with no significant gender differences observed in these occlusal parameters. The investigation into deleterious habits revealed a significant relationship between feeding patterns, specifically exclusive breastfeeding, and the Class I of canines. These findings highlight the prevalence of malocclusion in the population and suggest a potential link between early feeding habits and canine classification while also emphasizing the limited impact of deleterious habits on occlusal outcomes.
As noted by Lombardo et al. [9], understanding the prevalence of malocclusions provides invaluable insight for orthodontists and pediatric dentists, guiding their clinical focus and specialty practices. The data obtained herein serves as a cornerstone, initiating and directing research of a broader scope aimed at enhancing epidemiological understanding across the African continent, thereby contributing to the advancement of oral health. However, this study has limitations, such as the sample may not be representative of the broader population since it’s a pilot study composed of a convenience sample. Also, the cross-sectional design limits the ability to establish causal relationships, and measurement error in diagnosing occlusal features, such as malocclusion and dental crowding, may further impact the precision of the results. This may either overestimate or underestimate the observed associations, particularly with feeding habits and occlusal patterns.
Existing literature highlights that Angle Class I malocclusion typically manifests with a normal anteroposterior relationship in the molars, often accompanied by dental and/or skeletal alterations in the vertical or transverse planes, representing the most prevalent form [10]. However, its prevalence varies globally, as evidenced by diverse studies [9,11]. Our study mirrors this global trend, revealing a predominant distribution of Class I malocclusions (59.8%), followed by Class II (18.4%) and Class III (6.5%). This pattern aligns with findings from other studies, such as Rebelo Vieira et al. [12] in Brazil and Londono et al. [13] in Turkey, underscoring its consistency across diverse populations.
In assessing the vertical plane of malocclusions, our study identified open bite as the most prevalent anomaly (20%), followed by deep bite (16%) and edge-to-edge bite (11%). Past research, including studies by Perrotta et al. [14] and Yin et al. [15], suggests genetic and environmental influences on the occurrence of these anomalies, with factors like mouth breathing, prolonged sucking habits, tongue interposition, and onicofagia contributing to their prevalence. Interestingly, our study found no statistically significant difference in vertical relationships between genders or correlations with deleterious habits, in contrast to prior research [16], emphasizing the multifactorial nature of malocclusions.
Space discrepancies, particularly diastemas and crowding, were prevalent in our study, echoing findings from other African populations. Some examples include studies with children in Nigeria [17,18] and Ghana [16]. However, no statistical difference was observed between genders or arches, diverging from some prior studies [19,20] that evidenced a higher prevalence in the upper arch. Conversely, studies from different populations, such as Albanian children [20], have reported varying prevalence rates [21,22] that might indicate potential racial and environmental influences.
Deleterious oral habits, such as digital sucking, pacifier use, tongue projection, atypical swallowing, onicofagia, and mouth breathing [23], have been linked to increased malocclusion prevalence due to their potential impact on bone growth, dental positioning, respiratory function, and speech, potentially serving as etiological factors in malocclusions. However, our study did not find a positive correlation between these factors and malocclusion prevalence, contrasting with other findings [24].
Regarding feeding patterns, our study revealed that 57.7% of patients with Class I canines were exclusively breastfed between 6 months and 2 years of age, whereas 84.2% of those with Class II canines were breastfed and supplemented during this period. Consequently, the feeding pattern during this critical developmental stage showed a statistically significant relationship with the canine ratio observed in the patients. This finding is supported by studies that highlight the repercussions of not breastfeeding on children [25], leading to the establishment of non-nutritive sucking habits that may predispose them to malocclusions. Similarly, Abate et al. [26] posit that breastfeeding fosters a favorable occlusal relationship. Thus, our results underscore the importance of breastfeeding in promoting proper occlusal development, aligning with existing literature emphasizing its benefits for the stomatognathic system.
The variability in prevalence observed in our study suggests a discernible racial pattern, hinting at genetic factors as potential determinants. However, environmental and cultural influences can also significantly impact the prevalence of dental alterations and, consequently, malocclusions. Thus, there remains a pressing need for a more comprehensive occlusal analysis of the population, coupled with broader investigations into environmental factors. Additionally, enhancing tools to mitigate language barriers is crucial to facilitating preventive and interventional studies, which hold immense value for public health, particularly in underdeveloped countries.
Conclusion
Class I malocclusion emerged as the predominant condition among the study population, with a significant portion exhibiting some form of vertical malocclusion and dental misalignment. This underscores the importance of conducting larger-scale epidemiological investigations within African populations. Such endeavors are essential for informing the development of targeted public policies aimed at facilitating preventive and interceptive orthodontic interventions.
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Financial Support
None.
Data Availability
The data used to support the findings of this study can be made available upon request to the corresponding author.
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Academic Editor:
Alessandro Leite Cavalcanti
