Primary failure of tooth eruption associated with secondarily inflamed dental follicle: inflammatory follicular cyst?

Epigenetic markers of tooth eruption - DNA methylation and histone acetylation

The present study aimed to evaluate whether epigenetic markers are expressed in the dental follicles surrounding ectopically erupting teeth. Twenty-one dental follicles were collected in 20 adolescent children through surgical exposure of ectopic teeth. The epigenetic modifications of DNA methylation and histone acetylation were evaluated by immunohistochemistry. The results showed cells positive for DNA-methyltransferase 1 (DNMT1), DNA methyltransferase 3 beta (DNMT3B), ten-eleven translocation-2 (TET2), acetyl-histone H3 (AcH3), acetyl-histone H4 (AcH4), 5-methylcytosine (5mC), and 5-hydroxymethylcytosine (5hmC) were present in all the samples. The levels of epigenetic markers representing active chromatin (5hmC, AcH3, AcH4, and TET2) were statistically significantly higher than those of markers representing inactive chromatin (5mC, DNMT3B, DNMT1). In conclusion, follicles in ectopic teeth display major epigenetic modifications. In the follicles, epigenetic markers associated with the activation of bone-related genes are more abundant than markers associated with the inactivation of bone-related genes.

Conservative Approach of a Dentigerous Cyst

Dentigerous cysts (DC) are the most common odontogenic cystic lesions of inflammatory origin occurring in children. These lesions can be treated by enucleation with or without related impacted teeth or marsupialization/decompression. The latter procedures have been used successfully for many years, but decompression is increasingly recommended in children because of its good outcomes and the preservation of the developing tooth. This conservative surgical technic allows simultaneously the normal eruption of the involved permanent teeth and the ossification of the bony defect. The present report describes an 8-year-old female patient with an inflammatory DC associated with an endodontically treated primary molar accidentally discovered on panoramic radiograph. Decompression of the cyst was performed, by means of a removable space maintainer acting as an acrylic obturator after removal of teeth 83 and 84. Ten months after the decompression procedure, a complete resolution and regression of the cystic lesion with full spontaneous eruption of the premolar were observed.

Success in Conservative Treatment of an Inflammatory Follicular Cyst: A 5-year Follow-up

The inflammatory follicular cysts are cystic lesions associated with non-erupted permanent teeth and involve devitalized deciduous teeth. Products resulting from the necrotic pulp of deciduous teeth stimulate crown hood growth of successor permanent tooth radiographically shown as a unilocular, radiolucent area, associated with an impacted permanent crown. Treatment based on cyst decompression and maintenance of the deciduous tooth is a conservative approach to space maintenance. This case report describes the diagnosis, treatment, and post-surgery follow-up after 5 years of an extensive inflammatory follicular cyst in the mandible, in the region of tooth 75, with marsupialization being the method of treatment and emphasizing the importance of clinical and radiographic follow-up. How to cite this article: de Oliveira GAA, Limongi MC, Garcia HS, et al. Success in Conservative Treatment of an Inflammatory Follicular Cyst: A 5-year Follow-up. Int J Clin Pediatr Dent 2021;14(2):327-330.

KMT2C, a histone methyltransferase, is mutated in a family segregating non-syndromic primary failure of tooth eruption

Primary failure of tooth eruption (PFE) is a rare odontogenic defect and is characterized by failure of eruption of one or more permanent teeth. The aim of the study is to identify the genetic defect in a family with seven affected individuals segregating autosomal dominant non-syndromic PFE. Whole genome single-nucleotide polymorphism (SNP) genotyping was performed. SNP genotypes were analysed by DominantMapper and multiple shared haplotypes were detected on different chromosomes. Four individuals, including three affected, were exome sequenced. Variants were annotated and data were analysed while considering candidate chromosomal regions. Initial analysis of variants obtained by whole exome sequencing identified damaging variants in C15orf40, EPB41L4A, TMEM232, KMT2C, and FBXW10 genes. Sanger sequencing of all family members confirmed segregation of splice acceptor site variant (c.1013-2 A > G) in the KMT2C gene with the phenotype. KMT2C is considered as a potential candidate gene based on segregation analysis, the absence of variant in the variation databases, the presence of variant in the shared identical by descent (IBD) region and in silico pathogenicity prediction. KMT2C is a histone methyltransferase and recently the role of another member of this family (KMT2D) has been implicated in tooth development. Moreover, protein structures of KMT2C and KMT2D are highly similar. In conclusion, we have identified that the KMT2C gene mutation causes familial non-syndromic PFE. These findings suggest the involvement of KMT2C in the physiological eruption of permanent teeth.

Inflammatory follicular cysts associated to necrotic primary teeth

BACKGROUND

Cysts are pathological cavities lined by epithelium and supported by connective tissue, containing fluid or semi-fluid substances and presenting developmental or inflammatory origins.

CASE REPORT

This study aimed to evaluate a case series of inflammatory follicular cysts in children to clarify their nomenclature, diagnosis, clinical implications and treatment outcomes. Prevalence, aetio-pathogenesis, clinical, radiographic and microscopic findings, treatments and sequelae of this condition were assessed by using the records of patients treated between 2000 and 2015. Data were analysed and presented descriptively.

FOLLOW-UP

This was performed periodically for 2 years to monitor lesion regression and complete eruption of impacted permanent teeth. All of the involved permanent teeth erupted naturally. Twelve cases of asymptomatic lesions with volumetric bone expansion were identified through radiographic findings or delayed tooth eruption in patients aged between 8 and 14 years. After establishing the diagnosis of inflammatory follicular cyst, necrotic primary teeth extraction was followed by decompression of the cystic lesions.

CONCLUSIONS

The investigated cases were consistent with inflammatory follicular cyst diagnoses. The proposed treatment was considered to be appropriate, that was revealed by the maintenance of the permanent teeth involved during the patients follow-up.

[Innovations in diagnosis and treatment about a case of primary failure eruption linked to a PTHR1 gene mutation]

Primary failure of eruption is a rare condition marked by non-eruption of the posterior teeth due to mutation of a gene responsible for tooth eruption. Today, this anomaly can be detected early using innovative 3D-imaging techniques. Genetic and histologic testing will confirm the diagnosis and unfavorable prognosis. Alveolar growth must be followed in other areas too in order to avoid structural and functional asymmetry. An analysis of the diagnostic and therapeutic options using bone-borne anchorage is presented via the long-term monitoring of a female patient presenting primary failure of eruption linked to mutation of the PTHR1 gene.

Incidência de anormalidades histológicas em tecido correspondente ao espaço pericoronário de terceiros molares inclusos e semi-inclusos

INTRODUÇÃO: O Folículo Pericoronário envolve a coroa do germe dental durante seu desenvolvimento. Quando o dente permanece incluso, alterações do folículo podem originar doenças, como cistos e tumores odontogênicos. OBJETIVO: Analisar as alterações histológicas no tecido mole circundante a terceiros molares inclusos e semi-inclusos, independentemente de alterações patológicas aparentes em suas radiografias correspondentes, além de relacionar o diagnóstico histológico com o diagnóstico radiográfico dos casos. MATERIAL E MÉTODO: A partir de terceiros molares extraídos de 26 pacientes, foram analisados espécimes histológicos de folículos pericoronários por dois examinadores calibrados. O diagnóstico histopatológico obtido foi relacionado ao radiográfico, sendo este realizado por meio de radiografias periapicais e, quando necessário, complementado por radiografias panorâmicas. RESULTADO: Dos 37 folículos pericoronários avaliados, 30% mostraram alterações histológicas compatíveis com cistos dentígeros; 51% eram folículos normais, e 19% continham apenas fragmentos de mucosa. Radiograficamente, 100% dos casos demonstraram características de folículos sem alterações. CONCLUSÃO: Esses dados exemplificam que anormalidades podem estar presentes nos tecidos pericoronários sem que haja evidências clínicas e radiográficas. O exame histopatológico provê um diagnóstico mais preciso e deve ser considerado para a construção do diagnóstico definitivo.

Infected orthokeratinized odontogenic cyst: a rare cause of facial cellulitis

Orthokeratinized odontogenic cysts (OOCs) are relatively uncommon developmental cysts lined with orthokeratinized epithelium consisting of a prominent granular layer and a basal layer of low cuboidal flattened cells that show no tendency for nuclear palisading. These cysts have been considered a distinct entity from odontogenic keratocysts since they exhibit a less aggressive behavior and a very low rate of recurrence. Developmental odontogenic cysts can become infected but serious complications, such as potentially life-threatening cellulitis, are rare. This report describes a rare case of facial cellulitis secondary to an infected OOC located in the mandible of a 27-year-old man. The relevant literature about the clinical-pathological features of OOC is reviewed.

Odontogenic cysts: analysis of 680 cases in Brazil

The purpose of this study was to evaluate the prevalence of 680 odontogenic cysts diagnosed in Porto Alegre, RS, Brazil, and to compare results with findings in the literature. Data of odontogenic cysts diagnosed from 1985 to 2005 were collected from the files of the Oral Pathology Laboratory of Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil, and entered in a standardized form for later comparisons. The most prevalent odontogenic cysts were radicular (72.50%), dentigerous (22.20%) and residual (4.26%) cysts. The mandible of white patients was the anatomic site and ethnic group most frequently affected by this disease. Four of the six types of cysts were more frequent in the second and fourth decades of life, and no significant differences were found between sexes in the diagnosis of odontogenic cysts. In conclusion, the prevalence of odontogenic cysts was similar to that reported in the literature, which shows that inflammatory cysts are the most frequent.