Indian Journal of Dental Research

: 2015  |  Volume : 26  |  Issue : 4  |  Page : 356--360

Increased overjet is a risk factor for dental trauma in preschool children

Livia Azeredo Alves Antunes1, Isa Fin Gomes2, Mariane Hemerly Almeida2, Erlange Andrade Borges Silva3, Jose De Albuquerque Calasans-Maia1, Leonardo Santos Antunes1,  
1 Department of Specific Formation, Fluminense Federal University, Rio de Janeiro, Brazil
2 School of Dentistry, Fluminense Federal University, Rio de Janeiro, Brazil
3 Nova Friburgo Dental Center, Nova Friburgo, Rio de Janeiro, Brazil

Correspondence Address:
Livia Azeredo Alves Antunes
Department of Specific Formation, Fluminense Federal University, Rio de Janeiro


Context: Traumatic dental injury and malocclusion constitute a public health problem due to their high prevalence. Preventing or detecting such conditions, in any population, is of paramount importance. Aim: Assessing the association of anterior occlusal characteristics and dental trauma in preschool children. Settings and Design: A cross-sectional study was carried out with 2–6-year-old randomly selected by a sample calculation, resulting in 606 subjects Materials and Methods: A questionnaire to collect information about the sample (age, gender, and race) was sent to the children's parents. Two trained and calibrated examiners (Kappa 0.80) evaluated dental trauma according to criteria established by the World Health Organization. The following anterior occlusal characteristics were evaluated: Normal occlusion, anterior open bite, anterior crossbite, increased overjet (categorized as ≥3 mm), and increased overbite (categorized as ≥3 mm). Statistical Analysis Used: The variables associations were assessed (odds ratio, Chi-square test, and logistic regression, P < 0.05) using statistical software (SPSS, version 16.0). Results: Dental trauma was observed in 20.8% and malocclusion in 48.6% of the children. There is an association between malocclusion and dental trauma (P = 0.01). Children with malocclusion have a 64% higher chance of suffering dental trauma. Increased overjet was the type of malocclusion related to a higher rate of tooth fracture (P < 0.01). Subjects with this type of malocclusion suffered tooth fractures three times more often than subjects with other malocclusion types. Conclusions: There was association of dental trauma and malocclusion. Increased overjet was the most common malocclusion related to dental trauma. Preventive strategies are needed to reduce the rate of anterior malocclusion and, consequently, dental trauma in preschool children.

How to cite this article:
Antunes LA, Gomes IF, Almeida MH, Silva EA, Calasans-Maia JD, Antunes LS. Increased overjet is a risk factor for dental trauma in preschool children.Indian J Dent Res 2015;26:356-360

How to cite this URL:
Antunes LA, Gomes IF, Almeida MH, Silva EA, Calasans-Maia JD, Antunes LS. Increased overjet is a risk factor for dental trauma in preschool children. Indian J Dent Res [serial online] 2015 [cited 2020 Apr 3 ];26:356-360
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Full Text

Traumas in primary dentition affects oral health-related quality of life [1] and occur mainly in preschool children because they are in the phase of development and thus experience more falls than other children.[2],[3],[4] Other etiological factors of dental trauma include oral factors and human behavior.[5]

Malocclusion is the inadequate alignment of the dental arches, which can result in changes in masticatory function, poor positioning of the teeth in their osseous bases, and differences in the maxillary development. Therefore, malocclusion is one of the factors predisposing to dental trauma,[6],[7] considered as the third dental public health problem,[8] that also acquires a special character to be, along with caries and oral cancer among the major public health problems worldwide.[9]

According to Bijella et al.,[2] Mestrinho et al.,[3] and Kramer et al.,[10] the relationship between malocclusion and dental trauma involving primary dentition is little discussed. Based on this, the present study was aimed at assessing the association of anterior occlusal characteristics and dental trauma in preschool children.

 Materials and Methods

Ethical approval was obtained from the Local Human Ethics Committee of the Antonio Pedro Hospital of the Federal Fluminense University (CEP/HUAP/UFF CAAE02542412.0.0000.5243). Letters explaining the purpose of the survey were sent to the parents. Informed and written consent was obtained from the parents before their children were recruited to the study.

This cross-sectional study was composed with a sample of 606 children aged from 2 to 6 years old, all attending public preschools in the city of Nova Friburgo, State of Rio de Janeiro, Brazil. The city of Nova Friburgo has 182,082 inhabitants and occupies an area of 933,414 km² divided into eight districts. Its population is predominantly urban (87%).

The subjects included in the sample were invited to participate in the study according to the following inclusion criteria: Children aged from 2 to 6 years old, of either gender; parents who had signed the informed consent and who speak fluent Brazilian Portuguese; and the parents who completed and returned the social determinants questionnaire. Preschoolers undergoing orthodontic treatment, children with special needs (i.e., motor and mental disabilities or some type of syndrome) or with systemic disease, and children who did not allow completion of the dental exams were excluded.

The sample was calculated by estimating the prevalence of dental trauma as 39.1% according to Robson et al.[5] with 5% of error, and 95% of confidence interval. In order to compensate for a possible cluster effect, the sample size was increased by 30% (design effect = 1.3), thus totaling 410 preschoolers. Twenty-five percent more subjects were added to compensate any loss. Thus the sample reached a minimum of 512 subjects. Therefore, 606 children were randomly selected and grouped depending on their age and location of the preschool they attended (18 in urban and 9 in rural areas) to ensure representativeness regarding the original population base.

A questionnaire to collect information about the sample (age, gender, and race) was sent to the children's parents. Once authorized by the parents, the children were submitted to a clinical examination for evaluation of their oral health condition.

The examination was performed by two dental surgeons (LAA and LSA) (inter-examiner kappa = 0.80). All the examinations were performed using a spatula, gauze, disposable gloves, and illumination by a spotlight, with the child laid down on the table while the examiner was seated.

Dental trauma was evaluated according to criteria established by the World Health Organization:[11] 0 = No sign of injury; 1 = treated injury; 2 = enamel fracture only; 3 = enamel and dentine fracture; 4 = pulp involvement (included teeth with color change); 5 = missing tooth due to trauma; 6 = other damage (included teeth with displacement); 9 = excluded tooth. For statistical analyses, code 1, 2, and 3 were grouped in fractures; 4 = pulp involvement; 5 and 6 were grouped in luxations.

Occlusal characteristics of anterior teeth used in this study were: Normal occlusion, anterior open bite, anterior crossbite, increased overjet (categorized as ≥3 mm), and increased overbite (categorized as ≥3 mm).[12]

Overjet was measured to the nearest whole millimeter by use of a periodontal probe from the midpoint of the labial surface of the most anterior lower central incisor to the midpoint of the labial surface of the most anterior upper central incisor, parallel to the occlusal plane. Overbite was assessed on the maxillary right central incisor to the nearest whole millimeter using a periodontal probe. If the right maxillary or mandibular central incisor were missing or fractured, the left central incisors were used. Openbite was the distance in millimeters from the edge of the mandibular central incisor to the edge of the maxillary central incisor with the posterior teeth in occlusion. Crossbite was indicated when there was an abnormal labiolingual relationship of the teeth in the anterior region.

Data were tabulated using statistical software (SPSS (version 11.0, SPSS Inc., Chicago, IL, USA)) at a 5% of significance level. Chi-square test was used to evaluate the hypotheses and aimed at finding a dispersion value for two nominal variables by assessing the possible associations between qualitative variables such as age group, gender, race, school location, and parents' level of schooling. Student's t-test was used for analysis of the mean values. Odds ratio and Chi-square test were also used for assessment of the association between dental trauma and malocclusion. Logistic regression analysis was performed by using age as co-variant to assess increased overjet and type of dental trauma.


Based on the 606 children evaluated, the mean age was 3.50 (SD = 1.12), 415 (68.5%) were Caucasian and 319 (52.6%) were male. The majority of the subjects (425 [70.1%]) lived in an urban area. One hundred and twenty-six (20.8%) cases of dental trauma and 292 (48.6%) cases of malocclusion were observed [Table 1].{Table 1}

Regarding the sample of this study [Table 1], there was no influence of mean age, age group, gender, race, and school location on the children, regardless of the presence of dental traumas (P > 0.05).

There was a statistical difference in the mean age (P < 0.01) and between the age groups (P < 0.01) of subjects with malocclusion. It was observed that malocclusion was more likely to occur in the younger group [Table 1].

As shown in [Table 2], an association between malocclusion and dental trauma (P = 0.01) was observed. Children with malocclusion had a 64% higher chance of suffering dental traumas. Increased overjet was the most common malocclusion related to such events (P < 0.01), with three times higher frequency. [Table 3] shows the multivariate analysis of the type of trauma in which overjet and age are used as co-variates, demonstrating that children with increased overjet have a three times higher chance of suffering a dental fracture.{Table 2}{Table 3}


In the current study, traumatic dental injury was present in 20.8% of the subjects. The prevalence of dental trauma in our subjects is similar to that in the study by Norton and O'Connell.[4] Our prevalence of dental trauma was lower with regard to the studies by Kramer et al.,[10] Granville-Garcia et al.,[13] Robson et al.,[5] and Goettems et al.[6] It was relatively higher than the prevalence reported by Oliveira et al.[14] and de Amorim et al.[15]

The preschool population is more affected because dental trauma occurs as a result of psychomotor sub-development and poor motor abilities, which inhibits the child's ability to make safe and precise movements.[3],[4] However, in the present study, this fact had no influence when age groups of 24–38 months and of 37–72 were compared.

Malocclusion in preschoolers had already been observed in earlier reports,[16],[17],[18] with prevalence as high as that reported in the present study.

In our study, we observed that younger children (24–36 months old) had a higher percentage of malocclusion compared to older ones (37–72 months old). This finding can be explained by the fact that younger children have nonnutritive suction habits. Eliminating these habits, as older children often have, is related to the correction of malocclusions and consequently to the decrease in the possibility of dental trauma, since the predisposing factor is eliminated.

Although the current study found no statistical relationship regarding dental trauma in older children (37–72 months old), the older children displayed a greater number of trauma compared to the younger ones (24–36 months old), thus agreeing with Osuji [19] and disagreeing with Jesus et al.[20] and de Amorim et al.[15]

Although there was no statistical relation found in this study, children who had increased overbite, openbite, and crossbite presented dental trauma. Bonini et al.,[21] de Amorim et al.[15] and Goettems et al.[7] found an association between increased overbite and dental trauma. The association between anterior openbite and dental trauma was found in studies by Oliveira et al.[14] and Bonini et al.[21] However, in neither the study by Goettens et al.[7] nor in our study was such an association found. With regard to the anterior crossbite, the study by Goettens et al.[7] found no association with dental trauma, corroborating with our findings.

Oliveira et al.,[14] Bonini et al.,[21] and de Amorim et al.[15] reported a statistically significant relationship between increased overjet and dental trauma. This finding was also reported in the current work. As we found in this study, children with malocclusion have a 64% chance of suffering dental traumas. In addition, it was found that dental traumas, such as tooth fractures, are three times more likely when the child has an increased overjet, in accordance with the findings of Artun et al.[22] and Bauss et al.[23] Since this association has been observed, one can see the need for studies on prevention and treatment of malocclusion, as well as for health care policies to include corrective services for malocclusions. Educative campaigns would be convenient to guide and reduce harmful habits, since these can lead to malocclusion (e.g., increased overjet). This might minimize the prevalence of dental traumas.

The traumatic dental injury is related to a high prevalence in the primary dentition.[5],[6],[10],[13] In the present study, the most common type of trauma was small dental fractures. However, in the literature, it is postulated that luxations are more frequent in the primary dentition due the bone resilience and porous characteristics at the stage of primary dentition. Also, bone spaces that include the germs of permanent teeth also dissipate the impact, avoiding dental fracture.[24] Cross-sectional studies about dental trauma prevalence commonly investigate cases those only the trauma sequels are still present. In these studies, the trauma in support tissue is underreported. So, traumatic dental injury can be misdiagnosed as occurred in our study. This could be the reason why the cases of teeth fracture were much more frequent than those of teeth luxation in this study."

Many factors, such as human behaviors (risk-taking children, children being bullied, emotionally stressful conditions, obesity, and attention-deficit hyperactivity disorder), were found to increase the risk for traumatic dental injuries.[5] The study of Glendor [5] also describes oral factors, such increased overjet with a protrusion, as a risk factor. The traumatic dental injury frequently results in time and cost consequences. Early prevention, acting on any risk factor and dental trauma, can reduce these consequences. Knowledge of spent time and costs on dental trauma has been given little attention,[24] especially regarding the prevention of malocclusion (i.e., increased overjet) and the reduction of spent resources that it can offer. So, we suggest future studies on this theme. Future studies should be done to find out what strategies for oral health promotion are more efficient in preventing anterior malocclusion since this will consequently reduce the prevalence of dental trauma.

Dental trauma in children is often related to esthetical, psychological, social, and therapeutic problems.[1] Therefore, more effort to promote health and implement preventive strategies are needed to reduce the rate of dental traumas in preschool children. These strategies could have a favorable impact on the consequences of lesions in primary teeth, particularly in the permanent successors, and on general health as well.[21]

In Brazil, there is a lack of specialized centers for the treatment of dental trauma and malocclusion. Because a significant part of the population depends exclusively on the public healthcare system, it is expected that many patients with malocclusion and dental traumas will not be treated. In this way, the epidemiological survey in this study was important to characterise the sample so that educational programs can be guided and developed to prevent dental trauma and malocclusion, mainly targeting people who are in constant contact with younger children (e.g., teachers and caregivers). Also, services for interception and correction of malocclusion, as well as the implementation of reference centers for dental traumas for this part of the population, should be developed.

The sample used in the present study is representative for the 2–6-year-old population who was enrolled in public preschools of the city of Nova Friburgo. This sample consists of children with primary dentition only, all belonging to low social classes lacking healthcare services. Therefore, it is suggested that the same area be mapped regarding other ages and social groups, including private preschools and children with permanent dentition, in order to evaluate whether the scenario remains the same or changes.


We are indebted to the participants of the study. Sarah Vinski revised the text for grammar and style.

Financial support and sponsorship

FAPERJ E-26/111.020/2013 (LAA) and E-26/010.001900/2014 (LAA).

Conflicts of interest

There are no conflicts of interest.


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