Prevalence and impact of infant oral mutilation on dental occlusion and oral health-related quality of life among Kenyan adolescents from Maasai Mara.

BACKGROUND: Infant Oral Mutilation (IOM) includes germectomy and early extraction of primary and permanent incisors and canines, primarily in the lower jaw. The aim of the present study was to examine the prevalence and impact of IOM, involving the removal of mandibular permanent incisors and/or canines, on dental occlusion and Oral Health-Related Quality of Life (OHRQoL) among Kenyan adolescents from Maasai Mara. METHODS: In a cross-sectional study, 284 adolescents (14-18 yrs. of age) participated in an oral examination and an interview, using a structured questionnaire on age, gender, medical history, and IOM practice. For the analysis of the dental occlusion, participants with IOM, in terms of absence of two or more permanent teeth in the mandibular incisor and/or canine tooth segments (IOM group), were compared to participants who had all six incisors and canines present in the oral cavity (control group). OHRQoL was assessed using child perception questionnaire (CPQ11-14). RESULTS: The majority of the participants (61%) had been exposed to IOM, among whom 164 (95%) had absence of two mandibular central incisors. More individuals in the IOM group had maxillary overjet exceeding 5 mm than in the control group (50.9% vs. 20%, p <  0.001). Nineteen (11%) subjects in the IOM group had mesial occlusion in contrast to none in the control group (p <  0.001). The mean and median total CPQ scores and the mean and median CPQ domain scores were low in both groups with no significant differences between the groups. CONCLUSIONS: Approximately two-thirds of the study population presented with IOM, with the majority of them missing two mandibular permanent central incisors. Although some participants with IOM had substantial maxillary overjet and mesial occlusion, only few of them showed substantial effect on their OHRQoL.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures.

BACKGROUND: A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. METHODS: A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. RESULTS AND CONCLUSIONS: The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.

Prevalence of JP2 and Non-JP2 Genotypes of Aggregatibacter actinomycetemcomitans and Oral Hygiene Practice of Kenyan Adolescents in Maasai Mara.

Aggregatibacter actinomycetemcomitans is implicated in the etiology of periodontitis that affects adolescents. The monitoring and mapping of the geographic dissemination pattern of JP2 and non-JP2 genotypes of A. actinomycetemcomitans are of interest. In Africa, the highly leukotoxic JP2 genotype is known to be prevalent, particularly in north-west Africa. The aims of this study were to determine the prevalence of JP2 and non-JP2 genotypes and investigate the oral hygiene practices among adolescents living in Maasai Mara, Kenya. A total of 284 adolescents (mean age: 15.0 yrs; SD 1.1) were interviewed regarding their age, gender, medical history, and oral hygiene practice, and the number of teeth present was recorded. One subgingival pooled plaque sample from all the first molars of each participant was analyzed by conventional PCR. The mean number of permanent teeth present was 27.9 (SD: 2.0; range: 22-32; 95% CI: 27.7-28.1). Sixteen (5.6%) and two (0.7%) adolescents were positive for non-JP2 and JP2 genotypes, respectively. For the vast majority of the adolescents, the use of a toothbrush (99.3%) and toothpaste (80.1%), as well as some kind of toothpick (>60.2%), were part of their oral hygiene practice, with dental floss (0.4%) and/or mouth rinses (0.4%) rarely being used. We have, for the first time, identified Kenyan adolescents colonized with the JP2 genotype. The prevalence of the JP2 genotype of A. actinomycetemcomitans is low, a possible indicator that it spreading through human migration from North and West Africa to East Africa is a rare occasion.

Transcriptomic analysis of three Veillonella spp. present in carious dentine and in the saliva of caries-free individuals.

Veillonella spp. are predominant bacteria found in all oral biofilms. In this study, a metatranscriptomic approach was used to investigate the gene expression levels of three oral Veillonella spp. (V. parvula, V. dispar and V. atypica) in whole stimulated saliva from caries-free volunteers and in carious lesions (n = 11 for each group). In the lesions the greatest proportion of reads were assigned to V. parvula and genes with the highest level of expression in carious samples were those coding for membrane transport systems. All three Veillonella spp. increased expression of genes involved in the catabolism of lactate and succinate, notably the alpha- and beta-subunits of L(+)-tartrate dehydratase (EC 4.2.1.32). There was also significantly increased expression of histidine biosynthesis pathway in V. parvula, suggesting higher intra-cellular levels of histidine that could provide intra-cellular buffering capacity and, therefore, assist survival in the acidic environment. Various other systems such as potassium uptake systems were also up regulated that may aid in the survival and proliferation of V. parvula in carious lesions.