A customized metal guide for controllable modification of anterior teeth contour prior to minimally invasive preparation

ObjectiveOptimal tooth reduction is a key requirement for aesthetics, function, and the longevity of fixed restorations. Research has demonstrated that controlled and conservative tooth preparation is crucial for the long-term success of adhesive restorations. Different techniques of fabricating reduction guides have been previously reported in literature. The present technical note describes the fabrication technique and clinical application of a customized metal preparation reduction guide.Material and methodPatient presented with tilted maxillary left central incisor. The flared-out part of the tooth was modified prior to veneer restoration preparation. Resin pattern reduction guide was fabricated on the diagnostic cast with a window on the tilted mesial portion of the tooth. After intraoral evaluation, resin pattern guide was casted. Metal reduction guide was place intraorally and reduction was provided on the exposed surface of the tooth. After the removal of the tilted portion, a harmonious arch form allowed the clinician to provide adequate evaluation and preparation for veneer restorations.ResultsThe device demonstrated good practical value, allowing for selective and controlled reduction of tooth structure, and definitive protection of adjacent tooth surfaces from iatrogenic damage. The clinical outcome successfully addressed the patient’s restorative and aesthetic needs, and the veneer was stable 2 years postoperatively.ConclusionUse of a metal guide assists clinicians to provide a more predictable reduction of a desired tooth surface, while decreasing the risk of compromising the other/adjacent tooth surfaces.     

Research of connective tissue dysplasia influence on teething

PurposeThis work aimed to study the rate and quality of maturation of the mineral component of retained teeth 3.8, 4.8 and lower jaw fragment of a human in connective tissue dysplasia in different periods of postpartum ontogenesis.MethodsThe study involved 102 men (76 with connective tissue dysplasia and 26 without connective tissue dysplasia) divided into groups by age: 31–40, 41–50, 51–60 years. One tooth 3.8, 4.8 and a fragment of the alveolar part of the lower jaw in the projection of teeth 3.8, 4.8 0.5*0.5 cm in size were extracted from each examinee for medical indications.ResultsLow optical density values are observed at the age of 41–50 years, at the age of 51–60 years, indicating decreased mineral density and the presence of total areas of hypomineralization from the age 31–40 years in connective tissue dysplasia. At the age of 41–50, 51–60 years, at the boundary of connective tissue structures and periosteum, a pronounced sclerosis and deformation of delineation elements were observed; at the age of 31–40 years, the indicated changes were less pronounced. At the age of 31–40 years, the level of bone plate dissection has a local character, after 40 years, it has a generalized character.ConclusionProgressive osteoporosis of the mandible and incomplete amelogenesis are an obstacle to the correct and harmonious teething of the lower wisdom teeth after the age of 30.     

Insights into the pathogenesis of ATP1A1‐related CMT disease using patient‐specific iPSCs

The development of patient‐specific induced pluripotent stem cells (iPSCs) offered interesting insights in modeling the pathogenesis of Charcot‐Marie‐Tooth (CMT) disease and thus we decided to explore the phenotypes of iPSCs derived from a single CMT patient carrying a mutant ATP1A1 allele (p.Pro600Ala). iPSCs clones generated from CMT and control fibroblasts, were induced to differentiate into neural precursors and then into post‐mitotic neurons. Control iPSCs differentiated into neuronal precursors and then into post‐mitotic neurons within 6‐8 days. On the contrary, the differentiation of CMT iPSCs was clearly defective. Electrophysiological properties confirmed that post‐mitotic neurons were less mature compared to the normal counterpart. The impairment of in vitro differentiation of CMT iPSCs only concerned with the neuronal pathway, because they were able to differentiate into mesendodermal cells and other ectodermal derivatives. ATP1A1 was undetectable in the few neuronal cells derived from CMT iPSCs. ATP1A1 gene mutation (p.Pro600Ala), responsible for a form of axonal CMT disease, is associated in vitro with a dramatic alteration of the differentiation of patient‐derived iPSCs into post‐mitotic neurons. Thus, the defect in neuronal cell development might lead in vivo to a decreased number of mature neurons in ATP1A1‐CMT disease.     

Surgical-Periodontal aspects in orthodontic traction of palatally displaced canines: a meta-analysis

The aim was to determine whether there is a difference in the periodontal aspect (gingival recession, probing pocket depth) of the palatally displaced canine (PDC) compared to the contralateral canine. Also, from a surgical perspective, sought to determine whether there is a difference (surgical duration, postoperative pain) between the surgical techniques. The word combinations were adapted for each electronic database: PubMed, LILACS, Scopus, Web of Science, Cochrane Library and gray literature. Studies that met the following criteria were considered eligible: (P) Patients who received orthodontic-surgical treatment for correction of PDC; (I) Performing orthodontic-surgical treatment for traction of the PDC; (C) Comparison of the tractioned canine with its contralateral or between the two techniques; (O) Gingival recession, probing pocket depth, postoperative complications and surgical duration; (S) Randomized and nonrandomized clinical studies or observational studies. The overall prevalence of gingival recession was estimated to be 10.53% [95% CI, 3.87% - 25.59%; I² = 88%]. No statistically significant difference (p > 0.05) was found between the means of the variables gingival recession, probing pocket depth and surgical duration. The evidence suggests that traction of palatally displaced canines can be considered a reliable and acceptable procedure.     

Prognosis and complications of mature teeth after lateral luxation: A systematic review

BackgroundDental trauma injuries are frequent in children and adolescents and can result in a sequela of future complications. Lateral luxation injuries are diagnosed when a tooth becomes displaced in a position other than axial and is often associated with alveolar bone fracture. Although the tooth is not immediately lost, pulp canal obliteration or pulpal necrosis can occur. The objective of this systematic review was to gather existing data on lateral luxation injuries to mature teeth to evaluate their overall prognosis and reported complications.Types of Studies ReviewedThe authors conducted a systematic search of the literature using MEDLINE, PubMed, Embase, and Cochrane databases in February 2019. They hand searched reference lists to identify additional literature. The authors included prospective and retrospective observational studies in the search. They screened a total of 291 articles, downloaded 28 articles, and included 4 articles in the study.ResultsThe most frequent complication reported for mature teeth with lateral luxation was pulpal necrosis (44.2%). Less frequent findings included surface resorption (14.0%), inflammatory resorption (8.5%), pulp canal obliteration (8.1%), and replacement resorption (0.9%). The included studies were cohort studies, which resulted in great heterogeneity, and the authors could not attempt a meta-analysis.Conclusions and Practical ImplicationsA large number of permanent teeth that experience lateral luxation are at risk of developing pulpal necrosis and other complications. Careful follow-up is required for these patients to treat complications as early as possible. Furthermore, the authors of this systematic review emphasize the importance of consistent reporting of dental trauma outcomes.