A radiation free alternative to CBCT volumetric rendering for soft tissue evaluation / Um método alternativo à TCFC sem radiação ionizante para a avaliação de tecidos moles da face

Objective: The aim of the present study is to evaluate whether a "radiation free" method using 3D facial scan can replace Cone Beam Computed Tomography (CBCT) volumetric rendering of soft tissue of the patient to assess maxillofacial surgery outcomes and compare the reference points and angular measurements of patient facial soft tissue. Material and Methods: Facial soft tissue scan of the patient's face, before and after orthognathic surgery and a CBCT of the skull for volumetric rendering of soft tissues were carried out. The 3D acquisitions were processed using Planmeca ProMax 3D ProFace® software (Planmeca USA, Inc.; Roselle, Illinois, USA). The participant were positioned in a natural position during the skull scannering. Three sagittal angular measurements were performed (Tr-NA, Tr-N-Pg, Ss-N-Pg) and two verticals (Go-N-Me, Tr-Or-Pg) on facial soft tissue scan and on the patient's 3D soft tissue CBCT volumetric rendering. Results: A certain correspondence has been demonstrated between the measurements obtained on the Proface and those on the CBCT. Conclusion: A radiation free method was to be considered an important diagnostic tool that works in conditions of not subjecting the patient to harmful ionizing radiation and it was therefore particularly suitable for growing subjects. The soft tissue analysis based on the realistic facial scan has shown sufficient reliability and reproducibility even if further studies are needed to confirm the research result.(AU)

Objetivo:Avaliar se um método "livre de radiação" usando escaneamento facial 3D pode substituir a renderização volumétrica da tomografia computadorizada de feixe cônico (TCFC) dos tecidos moles do paciente para analisar os resultados da cirurgia maxilofacial e comparar os pontos de referência e medições angulares afim de avaliar a correspondência entre as duas metodologias. Material e Métodos: Foi realizado o escaneamento dos tecidos moles faciais do paciente, antes e depois da cirurgia ortognática e uma tomografia computadorizada de feixe cônico do crânio para renderização volumétrica dos tecidos moles. As aquisições 3D foram processadas usando o software Planmeca ProMax 3D ProFace® (Planmeca USA, Inc.; Roselle, Illinois, USA). O participante foi posicionado em posição natural durante o escaneamento do crânio. Três medições angulares sagitais foram realizadas (Tr-NA, Tr-N-Pg, Ss-N-Pg) e duas verticais (Go-N-Me, Tr-Or-Pg) nas imagens de scaneamento e nas imagens do tecido mole facial da reconstrução tridimensional da TCFC. Resultados: Uma certa correspondência foi demonstrada entre as medidas obtidas no Proface® e aquelas na TCFC. Conclusão: Um método livre de radiação deve ser considerado uma importante ferramenta de diagnóstico que funciona em condições de não submeter o paciente a radiação ionizante nociva e, portanto, é particularmente adequado para indivíduos em crescimento. A análise de tecidos moles com base na varredura facial realista mostrou confiabilidade e reprodutibilidade, porém mais estudos são necessários para confirmar o resultado da pesquisa. (AU)

Validating clinical characteristic of primary failure of eruption (PFE) associated with PTH1R variants.

BACKGROUND: Primary failure of eruption (PFE) is a hereditary condition, and linkage with variants in the PTH1R gene has been demonstrated in many cases. The clinical severity and expression of PFE is variable, and the genotype-phenotype correlation remains elusive. Further, the similarity between some eruption disorders that are not associated with PTH1R alterations is striking. To better understand the genotype-phenotype correlation, we examined the relationship between the eruption phenotype and PTH1R genotype in 44 patients with suspected PFE and 27 unaffected relatives. Sanger sequencing was employed to analyze carefully selected PFE patients. Potential pathogenicity of variants was evaluated against multiple genetic databases for function prediction and frequency information. RESULTS: Mutational analysis of the PTH1R coding sequence revealed 14 different variants in 38 individuals (30 patients and 8 first-degree relatives), 9 exonic and 5 intronic. Their pathogenicity has been reported and compared with the number and severity of clinical signs. In 72.7% of patients with pathogenic variants, five clinical and radiographic criteria have been found: involvement of posterior teeth, involvement of the distal teeth to the most mesial affected, supracrestal presentation, altered vertical growth of the alveolar process and posterior open-bite. In cases with mixed dentition (3), the deciduous molars of the affected quadrant were infraoccluded. DISCUSSION: The probability of an affected patient having a PTH1R variant is greater when five specific clinical characteristics are present. The likelihood of an eruption defect in the absence of specific clinical characteristics is rarely associated with a PTH1R mutation. CONCLUSIONS: We report here that systematic clinical and radiographic observation using a diagnostic rubric is highly valuable in confirming PFE and offers a reliable alternative for accurate diagnosis.

A novel nonsense PTH1R variant shows incomplete penetrance of primary failure of eruption: a case report.

BACKGROUND: Aim of this work was to describe a rare inheritance pattern of Primary Failure of Eruption (PFE) in a small family with incomplete penetrance of PFE and a novel nonsense PTH1R variant. CASE PRESENTATION: The proband, a 26 year-old man with a significant bilateral open-bite, was diagnosed with PFE using clinical and radiographic characteristics. DNA was extracted from the proband and his immediate family using buccal swabs and the entire PTH1R coding sequence was analyzed, revealing a novel heterozygous nonsense variant in exon 7 of PTH1R (c.505G > T). This variant introduces a premature stop codon in position 169, predicted to result in the production of a truncated and non-functional protein. This variant has never been reported in association with PFE and is not present in the Genome Aggregation Database (gnomAD). Interestingly, the c.505G > T variant has also been identified in the unaffected mother of our proband, suggesting incomplete penetrance of PFE. CONCLUSIONS: In this study, we report a new PTH1R variant that segregates in an autosomal dominant pattern and causes PFE with incomplete penetrance. This underlines the diagnostic value of a thorough clinical and genetic analysis of all family members in order to estimate accurate recurrence risks, identify subtle clinical manifestations and provide proper management of PFE patients.

Primary failure of eruption: Clinical and genetic findings in the mixed dentition.

OBJECTIVE: To test the hypothesis that mutations in the parathyroid hormone 1 receptor ( PTH1R) include effects in both primary and permanent teeth. MATERIALS AND METHODS: DNA was extracted from saliva samples of 29 patients (8 familial and 21 sporadic) who presented with clinical evidence of infraoccluded teeth, and their unaffected relatives (N = 22). Sequencing followed by mutational analysis of the coding regions of PTH1R gene was completed for all individuals (N = 29). RESULTS: Eight of 29 cases revealed a heterozygous pathogenic variant in the PTH1R gene; five of eight variants represented distinct mutations based on comparison with the dbSNP, HGMD, and ESP databases. One mutation (c.1765 T>C p.Trp89Arg) was found to segregate within a family (n = 3). In silico analyses for all variants revealed a putative pathogenic effect. A genotype-phenotype correlation was reported as defined by a functional mutation in PTH1R and corresponding effects on one or more posterior teeth only; unilateral or bilateral involvement, infraoccluded primary teeth. CONCLUSIONS: Novel mutations were reported in the PTH1R gene that included PFE-affected primary molars, thus providing the basis for using a genetic diagnostic tool for early diagnosis leading to proper management.