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 Table of Contents  
Year : 2022  |  Volume : 29  |  Issue : 3  |  Page : 272-277

The risk factors and pattern of traumatic dental injuries in 10–12-year olds in Kano, Nigeria

1 Department of Child Dental Health, Faculty of Dentistry, Bayero University Kano, Kano, Nigeria
2 Department of Child Dental Health, College of Medicine, University of Lagos, Lagos, Nigeria
3 Department of Child Oral Health, Faculty of Dentistry, University of Ibadan, Ibadan, Nigeria

Date of Submission21-May-2022
Date of Decision19-Jun-2022
Date of Acceptance30-Jun-2022
Date of Web Publication22-Jul-2022

Correspondence Address:
Chizoba Chineme Okolo
Department of Child Dental Health, Faculty of Dentistry, Bayero University Kano, Kano
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/npmj.npmj_145_22

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Background: Traumatic dental injuries (TDIs) rank among the most common conditions in children and adolescents. Nigerian dental trauma data are largely based on studies that were conducted in the southern parts of Nigeria. This study was designed to identify the risk factors and the pattern of TDIs among school-age children in northern Nigeria. Objectives: The objective of the study was to identify the risk factors for and to determine the pattern of dental injuries among 10–12-year-old males in Kano, northern Nigeria. Materials and Methods: Six hundred and ninety-six 10–12-year olds were selected through a multistage sampling of school children, street children and rehabilitated children in Kano and examined for TDIs using the WHO protocols. Data analysis was carried out using SPSS version 20. Statistical significance was considered when P < 0.05. Results: Six hundred and ninety-four 10–12-year olds participated in the study; The prevalence of TDIs was 6.6%. Being a street-child was associated with 30% higher risk for dental injuries (adjusted odds ratio [aOR] = 1.3; 95% confidence interval [CI] = 0.60 - 3.1; P = 0.48), whereas living as a rehabilitated street child (aOR = 0.41; 95% CI = 0.19 - 0.88; P = 0.02) and older age were associated with a reduced risk (aOR = 0.63; 95% CI = 0.39 - 1.01; P = 0.06) to injuries. The most common type of trauma was enamel–dentine injuries or Ellis II, and the most common cause was falls. Street children and low-age groups had more single-tooth injuries (85.7% and 85.0%, respectively). The commonly injured teeth were the maxillary right and left central incisors. Conclusion: Living on the street and young age were associated with the likelihood for injuries in male adolescents in Kano. The maxillary central incisors were the commonly affected teeth.

Keywords: Almajirai, northern Nigeria, school children, street children, traumatic dental injuries

How to cite this article:
Okolo CC, Oredugba FA, Denloye OO, Adeyemo YI. The risk factors and pattern of traumatic dental injuries in 10–12-year olds in Kano, Nigeria. Niger Postgrad Med J 2022;29:272-7

How to cite this URL:
Okolo CC, Oredugba FA, Denloye OO, Adeyemo YI. The risk factors and pattern of traumatic dental injuries in 10–12-year olds in Kano, Nigeria. Niger Postgrad Med J [serial online] 2022 [cited 2022 Nov 29];29:272-7. Available from: https://www.npmj.org/text.asp?2022/29/3/272/351719

  Introduction Top

Traumatic dental injuries (TDIs) constitute one of the most common conditions that affect children and adolescents.[1] They are considered significant public health concerns because of prevalence, cost of treatments and negative impact on the quality of life.[1] They affect children and adolescents unequally, some never get affected, some others may have just a single experience and others may have multiple dental trauma episodes (MDTE).[2]

TDIs typically affect the anterior teeth because of their most prominent position on the face.[2] Several classification systems have been used to describe TDIs according to aetiology, anatomy, pathology, therapeutic considerations or degree of severity.[3] According to the modified Ellis systems (adapted for field surveys), TDIs can be categorised ranging from type I (simple crown fracture with enamel-only involvement) to type V (traumatically avulsed tooth).[4]

TDI affects between 7.9% and 18.8% of Nigerian adolescents and between 8.6% and 35% of adolescents worldwide.[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15] Boys, children in low-age groups, children with increased overjet with lip incompetence and children with visual and motor impairments are at an increased risk of dental injuries.[6],[14],[15] Other studies also identified social class, type of school, the summer season and participation in contact sports as factors that also increase the risk of TDIs in adolescents.[15],[16]

Almajirai, or male street children, make up a large proportion of the school-age population in northern Nigeria, but have previously been omitted from studies involving children.[17] Daily, 13 million Almajirai, aged 5–15-years old, roam the streets of northern Nigeria's largest towns, separated from their nuclear families.[18] The Federal Government constructed a few modern Almajirai schools to readapt some Almajirai, believing that the Almajiranci system provided a detrimental psychosocial environment for pupils.[19] Living with non-nuclear family members and paternal abuse are regarded as examples of adverse psychosocial environment for children.[20]

Oral health data are most useful when it is age specific. The age of 12 years is a WHO index monitoring age for oral conditions; by this age, children should have completed primary school and fully transitioned to permanent dentitions.[21] The age of 10 years represents the late mixed dentition stage that also carries dental information of disease experience to the primary and young permanent teeth. Young adolescents are in such a critical stage of development that TDIs can cause far-reaching aesthetic, emotional and functional issues.[22] Treatment for TDIs, which range from simple restorations to full-mouth prosthetic replacements, significantly improves quality of life.[23],[24]

Majority of Nigeria's TDI data originated from studies conducted in southern Nigeria.[5],[6],[7],[8],[9],[10],[11],[25] Northern Nigeria is quite distinct from the south in terms of geography, genetic profile, ethnicity and culture, to name a few.[26],[27] TDI studies in northern Nigeria would provide the necessary data that will facilitate the understanding of the scope of the problem. The studies would also guide future children and adolescent health policy formulation in the region. The goal of this study was to identify the risk factors for dental trauma and describe the pattern of dental trauma among 10–12-year olds in Kano, Nigeria.

  Materials and Methods Top

Study design

A cross-sectional survey was conducted on 10–12-year olds who resided in Kano state, Nigeria, between March 2020 and January 2021.

Ethical issues

Before the study, ethical approval was obtained from the Health and Ethics Committee of the Kano State Ministry of Health, Kano, via MOH/Off/797/T. I/1774 dated 4 November, 2019. Permission from school heads, parents and Mallams was sought and obtained before the commencement of the study.

Letters containing consent forms were sent to all parents and guardians of the school children explaining the objectives, characteristics and importance of the study in the local language. Within each school, the study was conducted only on children whose parents or caretakers signed and returned the consent form and whose children gave their assent to participate in the study.

Sample size determination

Sample size was determined using data from a similar study in Ibadan, Nigeria.[8] We fixed type I error at 5% allowable error and 95% confidence interval (CI) with an 18.8% of prevalence using the formula for descriptive cross-sectional studies:[28]


n = Minimum sample size

Z = Standard normal deviate at 95% CI = 1.96

p = Prevalence of dental trauma from a previous study = 18.8%[26]

e = The degree of precision (5%).

The minimum sample size (including provision for non-response) was determined to be 258 children.

Selection criteria

  • Inclusion criteria: School-aged boys between 10 and 12 years old, who were willing to participate in the study
  • Exclusion criteria: Mentally retarded children, children with congenital anodontia and children who were undertaking orthodontic treatments.

Calibration of the examiner

A single examiner conducted all the examinations. The investigator was trained to diagnose dental trauma using the modified Ellis classification by a specialist paediatric dentist in children who visited the Paediatric Dentistry Clinic of the Aminu Kano Teaching Hospital, Kano, for 3 months. The intra- and inter-examiner reliability was calculated on 30 randomly selected children. The examination had kappa statistics of 0.90 for intra- and inter-examiner reliability, indicating a good degree of conformity.

Study sampling

The study participants were selected using a multistage systematic sampling technique. In the first stage, the Tarauni Local Government was randomly selected. In the second stage, from a list of Almajiri and public primary schools and the schools' attendance register obtained from the Kano State Qur'anic and Islamiyya Schools Board and the State Universal Basic Education Board Kano, respectively, schools were randomly selected from across the different wards within the local government. In the third stage, children were consecutively recruited into the study until the sample size was reached.

Data collection

An interviewer-administered questionnaire and clinical examinations were used to collect data. The questionnaire requested information regarding the patient's age, type of school and nature of injury.

Clinical examination

Clinical examinations were conducted in a suitable classroom using a mouth mirror and probe under natural light similar to the protocol reported by Kirthiga et al.[29] A visual clinical examination of all anterior teeth (central incisors, lateral incisors and canines), using a sterile dental mirror and Williams probe, was used to diagnose TDI. To classify dental injuries, the modified version of the Ellis fracture system was used.

Statistical analysis

Descriptive summary statistics was obtained for all independent variables. Difference in proportion was tested using the Chi-square test. Analysis was performed using SPSS version 21 (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY, USA: IBM Corp.). Statistical significance was considered when P < 0.05. The potential predictors of TDIs were evaluated using logistic regression. To identify the independent impact of each variable and avoid potential confounding effects, odds ratios were calculated and adjusted for significantly related factors.

  Results Top

Six hundred and ninety-four adolescents participated in the study; the prevalence of TDIs among the study participants was 6.6%, with that for the Almajirai and non-Almajirai being 8.7% and 4.3%, respectively. The odds for traumatic injuries were increased by 30% for the Almajirai, although this was not statically significant (P = 0.48) [Table 1].
Table 1: Distribution of traumatic dental injuries in the study participants

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The prevalence of traumatic injuries in the modern and traditional Almajirai was 5.6% and 12.5%, respectively. The odds for traumatic injuries were reduced to 41% in the modern Almajirai with a statistically significant level of difference with respect to the traditional Almajirai (P = 0.02). The prevalence of dental trauma decreased with increasing age, at 12%, 5.9% and 4.3% at ages 10, 11 and 12 years, respectively; however, the trend was not statically significant [Table 1].

Of the injured teeth affected, 68.4% occurred in the Almajirai and 31.6% occurred in the non-Almajirai. The most common type of trauma that affected the study population was Ellis II injuries. Ellis Class II injuries occurred more in the traditional Almajirai, and Class I injuries occurred more in the modern Almajirai and non-Almajirai [Table 2].
Table 2: Distribution of the types of dental trauma in the study population

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The most common cause of injury among the adolescents was “fall.” The traditional Almajirai group alone reported injuries from road traffic accidents in addition to other causes [Table 3].
Table 3: Causes of dental injuries in study participants

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The highest number of injured teeth per child was 5 [Figure 1]. Traditional Almajirai had more single-tooth injuries (85.7%), while the non-Almajirai and modern Almajirai had comparatively higher multiple teeth injuries (21.4% and 18.2%, respectively). The low-age groups had comparatively more single-tooth injuries (85.0%), while the old-age groups had more multiple teeth trauma (21.4%) [Table 4].
Figure 1: Distribution of the number of teeth with dental trauma

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Table 4: Comparing single with multiple dental trauma episodes

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The commonly injured teeth were teeth 11, 21, 12, 41 and 22 (the maxillary right and left central incisors, the maxillary right lateral incisors, the mandibular right central incisors and the maxillary left lateral incisors, respectively) [Figure 2].
Figure 2: Frequency of dental trauma on the anterior teeth

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  Discussion Top

This study found out that the prevalence of dental trauma is low and that living in adverse psychosocial environments, type of school and age were risk factors for TDIs for school-aged children in Kano State. The prevalence of dental trauma in the study population was lower than the reported values for their Nigerian and international contemporaries.[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16] The finding of this study supports the observation of Dacosta, who reported that the skeletal profile of northern Nigerian adolescents favoured a reduced likelihood for dental trauma.[30]

The current study also corroborates the findings of Nagarajappa et al.[15] and Kumar and Dixit,[16] who observed that the type of school a child attends significantly affected his/her odds for traumatic injuries; Ogordi et al. however did not observe a significant difference despite acknowledging that there was a relationship between school type and the incidence of dental trauma.[5] Private school children and those from higher socioeconomic groups have disproportionately higher risk for trauma according to Nagarajappa et al.[15] and Nicolau et al.[20] This they believed was due to their access to high-risk sport and play equipment (bicycles, roller skates, etc.). The present study, however, found a significantly higher risk among the Almajirai over their non-Almajirai peers, similar to the conclusions of Ayebameru et al. who reported that street life increased the chances of dental injuries for adolescents.[8]

The current study found an inverse relationship between age and the occurrence of dental injuries, as well as a linear relationship between age and MDTE. TDIs become less common as a child grows older and attains adequate motor coordination.[2] The several single-trauma episodes that occur in the earlier years account for the MDTE observed later in life.[20]

More maxillary teeth were more associated with traumatic injuries in our study than mandibular teeth, in keeping with previously documented pattern of anterior dental injuries.[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16] This is due to the maxillary teeth's susceptible position in respect to the face, as well as their central and relatively proclined posture, which makes them more vulnerable to direct assault.[1],[2] Furthermore, because the upper jaw is fixed to the skull, it is inflexible, whereas the lower jaw, as a flexible portion, tends to lessen the impact forces exerted on the lower anterior teeth as a result of movement.[4]

The commonest type of injury in our study was enamel fracture. This observation is similar to that of other authors,[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16] but different to that of Rajab et al.[31] who reported that enamel and dentin fractures were the commonest. The discrepancy with the proportion and types of fractures seen in our study could be attributed to the criteria used and the location of the assessment, i.e., the hospital versus the field.

Falls were shown to be the most common cause of injury in this study and is supported by the account of other researchers.[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16] Boys' engagement in contact sports and physical combats has been linked to a higher prevalence of dental injuries.[8],[14],[15] Contact sports and fights in addition to immediately inflicting tooth trauma also cause falls and, as a result, injuries. The features of street life may have created the ideal conditions for the severity of injuries seen in this study.[20],[21] In the current study, a few children were unable to recall the cause of their injuries. While this could be related to short-term memory issues in childhood, the dentist is expected to be on the alert for signs of child abuse.[29]

Before this study, none of the study participants had sought or received any type of treatment; this is consistent with the observations of Taiwo and Jalo.[10] While this could be due to a lack of knowledge about dental treatments, it also underscores the poor health-seeking behaviour frequently associated with the lower social classes and underdeveloped countries.[32],[33] Treatment rates after TDIs are low in developed countries although they are lower in developing countries.[10] Dental injuries have better outcomes when the general public is informed on the first-aid measures and the importance of seeking immediate treatment.[23],[33] This emphasises the critical role that parents and teachers can play in TDI prevention and management.[34] Despite the fact that dental procedures are considered expensive, the availability of social health programmes have been linked with increased service utilisations.[35]

The prevalence of uncomplicated fractures in this cohort may have also contributed to the lack of interest in seeking treatment. Because uncomplicated fractures are accompanied with minor discomforts, parents and their wards may have thought that they were minor and unworthy of the cost and efforts to acquire competent care. This perception is supported by another study that reported that uncomplicated fractures have no substantial negative impact on the oral health-related quality of life.[36] However, there were a few cases in this study of advanced dental injuries: complicated fractures, non-vital and avulsed teeth, which had also not been treated.

This study had a few limitations: first, the conclusions were based primarily on data collected from male adolescents; this is due to the Almajirai being exclusively male. Second, while cross-sectional studies provide information on association between risk factors and outcomes, they cannot infer causation. In the future, longitudinal study designs are recommended for similar studies to establish causation between risk factors and outcome.

  Conclusion Top

The prevalence of TDIs among 10–12-year olds in Kano was low, and living as an Almajirai or street child and being young were associated with increased risks. In addition, there was a significant level of unmet treatment need in the population.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3], [Table 4]


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