Kolawole and Folayan BMC Oral Health (2019) 19:262 https://doi.org/10.1186/s12903-019-0959-2 RESEARCH ARTICLE Open Access Association between malocclusion, caries and oral hygiene in children 6 to 12 years old resident in suburban Nigeria Kikelomo Adebanke Kolawole* and Morenike Oluwatoyin Folayan Abstract Background: There are conflicting opinions about the contribution of malocclusions to the development of dental caries and periodontal disease. This study’s aim was to determine the association between specific malocclusion traits, caries, oral hygiene and periodontal health for children 6 to 12 years old. Methods: The study was a household survey. The presence of malocclusion traits was assessed in 495 participants. The caries status and severity were assessed with the decayed, missing, and filled teeth (dmft/DMFT) index and the pulpal involvement, ulceration, fistula and abscess (pufa/PUFA) index. The Simplified Oral Hygiene Index (OHI-S) and Gingival Index (GI) were used to assess periodontal health. The association between malocclusion traits, the presence of caries, poor oral hygiene, and poor gingival health were determined with chi square and logistic regression analyses. Statistical significance was inferred at p < 0.05. Results: Seventy-four (14.9%) study participants had caries, with mean (SD) dmft/DMFT scores of 0.27 (0.82) and 0.07 (0.39), respectively, and mean (SD) pufa/PUFA index scores of 0.09 (0.43) and 0.02 (0.20), respectively. The mean (SD) OHI-S score was 1.56 (0.74) and mean (SD) GI score was 0.90 (0.43). Dental Aesthetic Index scores ranged from 13 to 48 with a mean (SD) score of 20.7 (4.57). Significantly greater proportions of participants with crowding (p = 0.026) and buccal crossbite (p = 0.009) had caries. Significantly more children with increased overjet (p = 0.003) and anterior open bite (p = 0.008) had moderate to severe gingivitis. Poor oral hygiene (OR: 1.83; CI: 1.05–3.18 p = 0.033), crowding (OR: 1.97; CI: 1.01–3.49; p = 0.021) and buccal crossbite (OR: 6.57; CI: 1.51–28.51 p = 0.012) significantly increased the odds of having caries. Poor oral hygiene (p < 0.001), increased overjet (p = 0.003), and anterior open bite (p = 0.014) were the only significant traits associated with gingivitis. Conclusions: Crowding and buccal cross bite were associated with caries, whereas increased overjet and anterior open bite were associated with gingivitis. These findings justify the recommendation of orthodontic treatment to improve oral health. Keywords: Malocclusion, Caries, Gingivitis, Periodontal health Background contacts through the face and smile, and perceptions or Untreated malocclusion impacts negatively on the qual- distortions of these media of social contact affect self- ity of life; severe malocclusion often is associated with image and self-esteem negatively [4]. The negative im- functional limitation, pain, and social disability that af- pact of malocclusion on oral health quality of life starts fects the emotional and social well-being of young male to be perceived when children are 11 to 14 years, the age and female adolescents [1, 2]. The psychological impact when they undergo major life changes, and the impact of malocclusion may be strong because of the aesthetic worsens as they grow older [5]. value of the face and smile [3]. Humans make social Evidence on the contribution of malocclusions to the development of dental caries and periodontal health is * Correspondence: [email protected]; [email protected] conflicting. Feldenes et al. [6] found that handicapping Department of Child Dental Health Faculty of Dentistry, Obafemi Awolowo malocclusion, maxillary irregularity, and abnormal molar University, Ile-Ife 220005, Nigeria © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Kolawole and Folayan BMC Oral Health (2019) 19:262 Page 2 of 9 relationship were associated with the occurrence and se- was defined as the biological sex; age was defined as the verity of dental caries. However, Szyszka-Sommerfeld age at last birthday. For children less than a year old, the and Buczkowska-Radlińska [7] reported that the influ- age was defined as the number of months after birth. ence of malocclusion on the development of dental car- Sampling was done with a multi-stage technique ies and periodontal disease was minimal, and Vellappally (Fig. 1), that involved random selection of enumeration et al. [8] found no correlation between the severity of areas within the Local Government Area; selection of malocclusion and dental caries among adolescents. Some every third household on each street; identification of researchers have reported that crowding causes im- eligible individuals within households; and selection of proper contacts between neighboring teeth, making ef- respondents for interview and clinical examination. Only fective oral hygiene difficult. The difficulty with cleaning one child per household was selected for study participa- of crowded teeth increases plaque accumulation and tion. A structured questionnaire was used for collection predisposes to the development of dental caries and of data about the child from the mothers. Where periodontal disease [6, 9]. mothers were unavailable, fathers completed the ques- Helm and Petersen [10] controlled for the effect of sex tionnaires. The questionnaire collected details on the and social group, and found that crowding, extreme child’s socio-demographic characteristics (age, sex, and maxillary overjet, and cross-bite increase the risk for socio-economic status), oral habits, and caries preven- periodontal disease in the maxilla. Ngom et al. [11] also tion habits. All study participants had oral examination reported that malocclusion was a risk factor for peri- performed on the same day. odontal disease. A prior study conducted in this study environment found a weak relationship between mal- Malocclusion occlusion, lip competence and gingival health [12]. A Children were examined in their homes under natural cause and effect relationship could not be established light while sitting on a chair. The occlusal features of between malocclusion and gingivitis, however. each child were assessed in the antero-posterior, trans- van Gastel et al. [13] reviewed the literature on the im- verse and vertical planes of space. The presence of indi- pact of orthodontic appliances used for the treatment of vidual malocclusion traits, i.e., crowding, spacing, malocclusion on periodontal health. They found contra- increased overjet, reverse overjet, anterior open bite, in- dictory findings in the review, which they attributed partly creased overbite, buccal and lingual crossbite were docu- due to the selection of materials for review and differences mented. Malocclusion was assessed with the dental in the research methods employed. The literature, how- aesthetic index (DAI), described by Cons et al. [21] ever, is consistent in the view that untreated malocclusion Scores for each of the 10 morphologic characteristics worsens the oral health-related quality of life [5]. Un- assessed by the DAI, i.e., number of missing visible teeth, treated malocclusion increases the risk for caries [6], poor crowding and spacing in the incisal segments, midline oral hygiene and poor gingival health [9], thereby causing diastema, anterior irregularity in the maxillary and man- pain and functional limitation. As with malocclusion [14], dibular arches, anterior maxillary overjet and mandibular the quality of life is affected by caries [15], poor oral hy- overjet, vertical anterior open bite and the antero- giene [16], and poor gingival health [17]. posterior molar relationships, were determined. The For this study, we examined the association between values obtained were multiplied with the appropriate malocclusion traits, caries, oral hygiene and gingival weighting factor, summed, and added to a constant value health for children 6 to 12 years old. It was important to of 13 to get the DAI score. The DAI scores were graded identify the further possible impact of malocclusion on into four groups based on pre-defined DAI scores [21] the oral health of children and adolescents with mixed 13–25, Grade 1 (normal or minor malocclusions, with dentition. slight or no treatment need); scores 26–30, Grade 2 (def- inite malocclusions, with treatment considered elective); Methods scores 31–35, Grade 3 (severe malocclusions, with treat- This is a secondary analysis of data generated to deter- ment highly desirable); and scores 36 and higher, Grade mine the association between oral habits, caries [18], and 4 (very severe or disabling malocclusions, with treatment periodontal health [19]. The study was a household survey considered mandatory). of children resident in Ife Central Local Government Area of Osun State, a suburban area in Nigeria. The data were Caries collected in the months of August and September 2013. The caries status was assessed with the decayed, missing, The study methodology has been extensively described and filled teeth/decayed, missing, and filled teeth (dmft/ by Folayan et al. [20] and Kolawole et al. [18]. Children DMFT) index [22]. Caries severity was evaluated with 6 months to 12 years of age whose parents consented to the pufa/PUFA index [23]. Caries status was further di- their participation in study were recruited. Child’s sex vided into caries present or absent. Kolawole and Folayan BMC Oral Health (2019) 19:262 Page 3 of 9 Fig. 1 Flowchart of sampling conducted for the primary study and the data extracted for this study Oral hygiene hygiene was further dichotomized into good oral hygiene Oral hygiene status of participants was evaluated with and fair/poor oral hygiene.