Dental Abnormalities in Pediatric Patients Receiving Chemotherapy.

Background: Chemotherapy is a common treatment for pediatric cancer. Although life prognosis is improving because of advances in medical science, it is important to deal with late effects such as dental abnormalities. We investigated the association between dental abnormalities and chemotherapy by age and tooth type. Methods: Among the 568 patients referred to the pediatric dentistry department of our hospital, we selected 32 patients (21 male and 11 female) who received chemotherapy between the ages of 0 and 6 and underwent panoramic examination after the age of 7. We recorded the age of chemotherapy commencement, diagnosis of systemic disease, and dental abnormalities such as congenital absence, microdonts, and short-rooted teeth. Results: Almost half of the patients had dental abnormalities such as congenital absence, microdonts, and short-rooted teeth, but there were no significant differences in the incidence of these abnormalities by age. When we analyzed the incidence of abnormal teeth by tooth type, the incidence of congenital absence was significantly higher in premolars (5.5%) and second molars (3.9%) than in incisor or canine or 1st molar (0.4%) (p < 0.01). The incidence of microdonts was significantly higher in premolars (3.9%) than in incisor or canine or 1st molar (0.2%) and second molars (0.0%) (p < 0.05). Conclusions: Patients who received chemotherapy had a high prevalence of dental abnormalities, and the incidence of abnormalities varied by tooth type. It is important to maintain long-term oral care for patients who have undergone chemotherapy even after the treatment is completed.

Investigation of periodontal disease development and Porphyromonas gulae FimA genotype distribution in small dogs.

In dogs, Porphyromonas gulae is a major periodontal pathogen with 41-kDa proteins polymerizing to form a filamentous structure called fimbriae or pili, termed FimA. FimA is classified into three genotypes: A, B, and C, and there are combinations of types A, B, C, A/B, A/C, B/C, and A/B/C. Periodontal disease is the most common oral disease in small dogs, but the periodontal disease status and P. gulae colonization at each dog age and breed remain unclear. In this study, we stratified 665 small dogs and analyzed the periodontal status and distribution of P. gulae with each FimA genotype. Dogs with periodontal disease and FimA genotype tended to increase with age. The dogs with at least one FimA genotype had significantly more severe periodontal disease compared with P. gulae-negative dogs (P < 0.01). Additionally, periodontal status was significantly associated with specific FimA genotype distribution in Toy Poodles and Chihuahuas (P < 0.05), whereas there was no such association in Dachshunds. These results suggest that the onset of periodontal disease and P. gulae colonization are related and progress with age. The relationship between periodontal disease and FimA genotype may differ depending on the dog breeds.

Inhibitory Effects of Shikonin Dispersion, an Extract of Lithospermum erythrorhizon Encapsulated in ß-1,3-1,6 Glucan, on Streptococcus mutans and Non-Mutans Streptococci.

Shikonin is extracted from the roots of Lithospermum erythrorhizon, and shikonin extracts have been shown to have inhibitory effects on several bacteria. However, shikonin extracts are difficult to formulate because of their poor water solubility. In the present study, we prepared a shikonin dispersion, which was solubilized by the inclusion of ß-1,3-1,6 glucan, and analysed the inhibitory effects of this dispersion on Streptococcus mutans and non-mutans streptococci. The shikonin dispersion showed pronounced anti-S. mutans activity, and inhibited growth of and biofilm formation by this bacterium. The shikonin dispersion also showed antimicrobial and antiproliferative effects against non-mutans streptococci. In addition, a clinical trial was conducted in which 20 subjects were asked to brush their teeth for 1 week using either shikonin dispersion-containing or non-containing toothpaste, respectively. The shikonin-containing toothpaste decreased the number of S. mutans in the oral cavity, while no such effect was observed after the use of the shikonin-free toothpaste. These results suggest that shikonin dispersion has an inhibitory effect on S. mutans and non-mutans streptococci, and toothpaste containing shikonin dispersion may be effective in preventing dental caries.

Inhibitory Effect of Adsorption of Streptococcus mutans onto Scallop-Derived Hydroxyapatite.

Hydroxyapatite adsorbs various substances, but little is known about the effects on oral bacteria of adsorption onto hydroxyapatite derived from scallop shells. In the present study, we analyzed the effects of adsorption of Streptococcus mutans onto scallop-derived hydroxyapatite. When scallop-derived hydroxyapatite was mixed with S. mutans, a high proportion of the bacterial cells adsorbed onto the hydroxyapatite in a time-dependent manner. An RNA sequencing analysis of S. mutans adsorbed onto hydroxyapatite showed that the upregulation of genes resulted in abnormalities in pathways involved in glycogen and histidine metabolism and biosynthesis compared with cells in the absence of hydroxyapatite. S. mutans adsorbed onto hydroxyapatite was not killed, but the growth of the bacteria was inhibited. Electron microscopy showed morphological changes in S. mutans cells adsorbed onto hydroxyapatite. Our results suggest that hydroxyapatite derived from scallop shells showed a high adsorption ability for S. mutans. This hydroxyapatite also caused changes in gene expression related to the metabolic and biosynthetic processes, including the glycogen and histidine of S. mutans, which may result in a morphological change in the surface layer and the inhibition of the growth of the bacteria.

Five-Year Follow-Up of a Child with Non-Syndromic Oligodontia from before the Primary Dentition Stage: A Case Report.

BACKGROUND: Congenital absence of teeth is a major dental abnormality in pediatric dentistry and the absence of six or more teeth is defined as oligodontia. Few reports of patients with non-syndromic oligodontia without systemic disease have continued dental follow-up from an early age. METHODS: We performed the five-year follow-up from before the eruption of the primary dentition of a Japanese child with non-syndromic oligodontia and analyzed changes in dental arch growth. RESULTS: At the oral examination at the age of 1 year and 2 months, eight primary incisors were congenitally absent. Therefore, we made dentures for the patient at the age of 3 years and 4 months. From the age of 5 years and 1 month, the child received articulation training for dysarthria from a speech therapist to improve the function and appearance of the oral cavity. Measurement of the patient's dental models revealed a particularly narrow dental arch, especially between the primary canines. CONCLUSIONS: Our findings highlight the importance of treatment for patients with non-syndromic oligodontia from an early age by multiple medical professionals, recognizing that the missing teeth affect the growth of the maxillofacial region.

A Third Supernumerary Tooth Occurring in the Same Region: A Case Report.

The presence of a supernumerary tooth is one of the most common dental anomalies, and surgical treatment is often required to address this anomaly. Moreover, it may lead to malocclusion, and long-term follow-up is important to monitor its status. A 4-year-and-11-month-old boy was referred to our hospital for dental caries treatment. At 5 years and 5 months of age, a radiographic examination showed a supernumerary tooth (first supernumerary tooth) near the permanent maxillary left central incisor, and it was extracted 6 months later. Eighteen months after the extraction of the first supernumerary tooth, a new supernumerary tooth (second supernumerary tooth) was detected in the same region, which was extracted when the patient was aged seven years and seven months. Seven months later, another supernumerary tooth (third supernumerary tooth) was detected and extracted immediately. However, the permanent maxillary left central incisor did not erupt spontaneously even after 6 months. Therefore, surgical exposure was performed, and the central incisor erupted into the oral cavity. This report describes our experience with this patient with three metachronous supernumerary teeth and their management until the eruption of the permanent tooth. This report highlights the importance of long-term follow-up after supernumerary tooth extraction until the permanent teeth in that region have erupted completely.

Fusion of a Tooth with a Supernumerary Tooth: A Case Report and Literature Review of 35 Cases.

Tooth fusion is a dental anomaly with a prevalence of 0.1% in permanent dentition. The aim of this paper is to present the occurrence, region of fusion, and prognosis of fused tooth which is a very rare case in the literature. The authors present a very rare case with a maxillary right lateral incisor fused to a supernumerary tooth on the palatal side. The eruption was delayed, but eruption occurred naturally at 9 years and 6 months. However, cone-beam computed tomography at 11 years and 6 months revealed it was diagnosed as a fused tooth. The authors undertook a literature review over the past 10 years and found 30 articles about fused teeth between permanent teeth and supernumerary teeth. It was more common in males than females and there were no differences depending on the occurrence. Mesiodistal fusion was more common in the incisor region, while labiopalatal fusion was more common in the molar region. Most cases required dental treatment with a surgical approach, root canal treatment, or orthodontic treatment. The present study highlights the importance of long-term follow-up and suggests the region of fusion and prognosis of the fused tooth may vary depending on the occurrence.