Root surface characteristics of children teeth with periodontal diseases

Dental manifestations of hypophosphatasia: translational and clinical advances

Hypophosphatasia (HPP) is an inherited error in metabolism resulting from loss-of-function variants in the ALPL gene, which encodes tissue-nonspecific alkaline phosphatase (TNAP). TNAP plays a crucial role in biomineralization of bones and teeth, in part by reducing levels of inorganic pyrophosphate (PPi), an inhibitor of biomineralization. HPP onset in childhood contributes to rickets, including growth plate defects and impaired growth. In adulthood, osteomalacia from HPP contributes to increased fracture risk. HPP also affects oral health. The dentoalveolar complex, that is, the tooth and supporting connective tissues of the surrounding periodontia, include 4 unique hard tissues: enamel, dentin, cementum, and alveolar bone, and all can be affected by HPP. Premature tooth loss of fully rooted teeth is pathognomonic for HPP. Patients with HPP often have complex oral health issues that require multidisciplinary dental care, potentially involving general or pediatric dentists, periodontists, prosthodontists, and orthodontists. The scientific literature to date has relatively few reports on dental care of individuals with HPP. Animal models to study HPP included global Alpl knockout mice, Alpl mutation knock-in mice, and mice with tissue-specific conditional Alpl ablation, allowing for new studies on pathological mechanisms and treatment effects in dental and skeletal tissues. Enzyme replacement therapy (ERT) in the form of injected, recombinant mineralized tissue-targeted TNAP has been available for nearly a decade and changed the prognosis for those with HPP. However, effects of ERT on dental tissues remain poorly defined and limitations of the current ERT have prompted exploration of gene therapy approaches to treat HPP. Preclinical gene therapy studies are promising and may contribute to improved oral health in HPP.

Periodontal diseases in Down syndrome during childhood: a scoping review

BACKGROUND

Down syndrome (DS) is a genetic condition that involves the deregulation of immune function and is characterized by a proinflammatory phenotype leading to an impaired response to infections. Periodontitis is a highly prevalent chronic inflammatory disease. It has been shown that adults and teenagers with DS are more susceptible to this disease, but a similar correlation in DS children remains elusive. This systematic scoping review aims to address this knowledge gap by examining periodontitis in DS children, with a secondary objective of elucidating the underlying mechanisms involved.

METHODS

Our primary search was conducted via the PubMed/MEDLINE database and Google Scholar, covering the period from 1951-July 1st, 2024. Primary studies written in English or French were included. The excluded articles were reviews, in vitro or animal studies, studies on teenagers or adults, and studies involving patients with disabilities other than DS. The quality of evidence was assessed via the Newcastle‒Ottawa scale for observational studies and a published tool for evaluating the quality of case reports and case series.

RESULTS

The initial electronic database search yielded a total of 2431 articles. 58 full-text articles, comprising seven cross-sectional studies, 36 case‒control studies, seven cohort studies, and eight case reports and case series, were included in the review. Compared with healthy children or children with disabilities, DS children appear to have more severe periodontal inflammation. However, the evidence is inconclusive regarding the presence of bone loss, with studies divided on this issue. Local risk and etiopathogenetic factors do not seem to play a significant role in increased inflammation. Instead, this difference could be attributed to the general proinflammatory phenotype of children with DS.

CONCLUSIONS

DS children seem to have higher periodontal inflammation than other children, but no periodontal bone loss. Investigating periodontal inflammation in DS children could provide valuable insights into the deregulation of immune function in these patients.

Dental defects in the primary dentition associated with hypophosphatasia from biallelic ALPL mutations

ALPL encodes tissue-nonspecific alkaline phosphatase (TNAP), an enzyme expressed in bone, teeth, liver, and kidney. ALPL loss-of-function mutations cause hypophosphatasia (HPP), an inborn error-of-metabolism that produces skeletal and dental mineralization defects. Case reports describe widely varying dental phenotypes, making it unclear how HPP comparatively affects the three unique dental mineralized tissues: enamel, dentin, and cementum. We hypothesized that HPP affected all dental mineralized tissues and aimed to establish quantitative measurements of dental tissues in a subject with HPP. The female proband was diagnosed with HPP during childhood based on reduced alkaline phosphatase activity (ALP), mild rachitic skeletal effects, and premature primary tooth loss. The diagnosis was subsequently confirmed genetically by the presence of compound heterozygous ALPL mutations (exon 5: c.346G>A, p.A116T; exon 10: c.1077C>G, p.I359M). Dental defects in 8 prematurely exfoliated primary teeth were analyzed by high resolution micro-computed tomography (micro-CT) and histology. Similarities to the Alpl^-/- mouse model of HPP were identified by additional analyses of murine dentoalveolar tissues. Primary teeth from the proband exhibited substantial remaining root structure compared to healthy control teeth. Enamel and dentin densities were not adversely affected in HPP vs. control teeth. However, analysis of discrete dentin regions revealed an approximate 10% reduction in the density of outer mantle dentin of HPP vs. control teeth. All 4 incisors and the molar lacked acellular cementum by micro-CT and histology, but surprisingly, 2 of 3 prematurely exfoliated canines exhibited apparently normal acellular cementum. Based on dentin findings in the proband's teeth, we examined dentoalveolar tissues in a mouse model of HPP, revealing that the delayed initiation of mineralization in the incisor mantle dentin was associated with a broader lack of circumpulpal dentin mineralization. This study describes a quantitative approach to measure effects of HPP on dental tissues. This approach has uncovered a previously unrecognized novel mantle dentin defect in HPP, as well as a surprising and variable cementum phenotype within the teeth from the same HPP subject.

Nonsyndromic localized aggressive periodontitis of primary dentition: A rare case report

Periodontitis is an inflammatory disease of the gingiva and tissues of the periodontium. It is characterized by pocket formation and destruction of supporting alveolar bone. Periodontal diseases of aggressive nature are not very common in children. They are usually associated with systemic conditions. The present case report is of a 5-year-old male child who reported with rapid attachment loss and bony defects of the gingiva and supporting structures. His family and medical history gave no contribution for the diagnosis. Blood investigations did not reveal any abnormality. The microbial examination of culture revealed the presence of periodontal pathogen Aggregatibacter actinomycetemcomitans. The treatment objective in the present case was to prevent the further progress of the condition, restore esthetic and function in the child which would psychologically benefit the child.

Alterações periodontais associadas às doenças sistêmicas em crianças e adolescentes

OBJETIVO: O objetivo deste estuo foi revisar na literatura a inter-relação entre condições sistêmicas e a ocorrência de doenças periodontais em crianças e adolescentes, destacando-se as manifestações periodontais frequentemente encontradas. FONTES DE DADOS: Artigos indexados nas bases de dados Medline, Lilacs e Bibliografia Brasileira em Odontologia, nos últimos 20 anos, além de referências clássicas. As palavraschave utilizadas foram: "doença periodontal", "periodontite", "doenças sistêmicas", "criança" e "adolescente". SÍNTESE DOS DADOS: Doenças sistêmicas como hipofosfatasia, histiocitose X, síndrome de Down, síndrome de Papillon-Lefèvre, síndrome de Ehlers-Danlos, síndrome de Chédiak-Higashi, leucemias, Aids e as deficiências quantitativas e qualitativas dos neutrófilos estão associadas ao aparecimento de alterações periodontais graves em crianças e adolescentes. Os estudos demonstraram a ocorrência de alteração periodontal na forma de periodontite em crianças e adolescentes com doenças sistêmicas, podendo levar à perda precoce de dentes. CONCLUSÕES: A ocorrência de alterações periodontais é observada em crianças e adolescentes com alterações sistêmicas, que manifestam desde inflamação gengival até formas mais destrutivas, como periodontites e perda precoce dos dentes.