Etiologic factors of early-onset periodontal disease in Down syndrome

Comparison of the malocclusion and orthodontic treatment needs of Down syndrome and non-syndromic subjects by using the dental aesthetics index

OBJECTIVE

To evaluate the prevalence and significance of the malocclusion traits and orthodontic treatment needs of Down syndrome (DS) subjects with matched non-syndromic (NS) controls.

METHODOLOGY

This cross-sectional study involved 222 subjects (50% DS, 50% NS) who were matched by gender and age. The casts were digitized into three-dimensional images. These images were used alongside the ten occlusal characteristics of the Dental Aesthetic Index (DAI) to determine malocclusion severity and the need for orthodontic treatment.

RESULTS

There were 58 (52.3%) females and 53 (47.7%) males with a mean age of 18.4 ± 8.4 years in both groups. The most common and significant (p < .05) malocclusion traits among the DS subjects were missing teeth (56.2%), incisal spacing segments (73.0%), anterior maxillary irregularity (95.5%), mandibular overjet (36.0%), and full cusp deviation of the molar relationship (61.3%). On the other hand, increased maxillary overjet (69.3%) is a more significant (p < .05) trait amongst NS subjects. There were 85 (76.6%) DS subjects who presented severe malocclusion, which implies a highly orthodontic treatment need (DAI > 30). The DS showed some impact of malocclusion traits components of the DAI.

CONCLUSION

The occurrence of malocclusion was higher in DS, implying a higher need for orthodontic treatments than for NS subjects.

Genetic Susceptibility to Periodontal Disease in Down Syndrome: A Case-Control Study

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis (n = 50) and DS patients with healthy periodontium (n = 36). All samples were genotyped with the “Axiom Spanish Biobank” array, which contains 757,836 markers. An association analysis at the individual marker level using logistic regression, as well as at the gene level applying the sequence kernel association test (SKAT) was performed. The most significant genes were included in a pathway analysis using the free DAVID software. C12orf74 (rs4315121, p = 9.85 × 10⁻⁵, OR = 8.84), LOC101930064 (rs4814890, p = 9.61 × 10⁻⁵, OR = 0.13), KBTBD12 (rs1549874, p = 8.27 × 10⁻⁵, OR = 0.08), PIWIL1 (rs11060842, p = 7.82 × 10⁻⁵, OR = 9.05) and C16orf82 (rs62030877, p = 8.92 × 10⁻⁵, OR = 0.14) showed a higher probability in the individual analysis. The analysis at the gene level highlighted PIWIL, MIR9-2, LHCGR, TPR and BCR. At the signaling pathway level, PI3K-Akt, long-term depression and FoxO achieved nominal significance (p = 1.3 × 10⁻², p = 5.1 × 10⁻³, p = 1.2 × 10⁻², respectively). In summary, various metabolic pathways are involved in the pathogenesis of periodontitis in DS, including PI3K-Akt, which regulates cell proliferation and inflammatory response.

Oral microbiome in down syndrome and its implications on oral health

Introduction: The oral cavity harbors an abundant and diverse microbial community (i.e. the microbiome), whose composition and roles in health and disease have been the focus of intense research. Down syndrome (DS) is associated with particular characteristics in the oral cavity, and with a lower incidence of caries and higher incidence of periodontitis and gingivitis compared to control populations. However, the overall composition of the oral microbiome in DS and how it varies with diverse factors like host age or the pH within the mouth are still poorly understood. Methods: Using a Citizen-Science approach in collaboration with DS associations in Spain, we performed 16S rRNA metabarcoding and high-throughput sequencing, combined with culture and proteomics-based identification of fungi to survey the bacterial and fungal oral microbiome in 27 DS persons (age range 7–55) and control samples matched by geographical distribution, age range, and gender.

Results: We found that DS is associated with low salivary pH and less diverse oral microbiomes, which were characterized by lower levels of Alloprevotella, Atopobium, Candidatus Saccharimonas, and higher amounts of Kingella, Staphylococcus, Gemella, Cardiobacterium, Rothia, Actinobacillus, and greater prevalence of Candida.

Conclusion: Altogether, our study provides a first global snapshot of the oral microbiome in DS. Future studies are required to establish whether the observed differences are related to differential pathology in the oral cavity in DS.

The Dental Needs and Treatment of Patients with Down Syndrome

Down syndrome is a common disorder with many oral conditions and systemic manifestations. Dentists need to take a holistic approach including behavioral, oral, and systemic issues. This review of the literature focuses on oral anomalies, systemic interaction, management, and recommendations.