Radiographical Measurements of Overeruption in Unopposed Posterior Teeth Among Selected Population of Saudi Arabia

The suspended replacement of extracted teeth may disrupt the structural integrity of the whole dental arch, particularly in posterior maxillary or mandibular tooth/teeth. This phenomenon often has consequences of masticatory deficiency and temporomandibular joint disorders. This work aims to assess and measure the overeruption of posterior teeth from panoramic radiographs (OPGs) and its relation to gender, age, tooth type, arch, sides, and cause of tooth loss. A total of 100 OPGs were included in this in vitro study. The level of posterior overeruption was measured in mm using the panoramic digital radiograph machine and its software systems. Other variables such as gender, tooth/teeth involved, arches, and side were considered. All parameter values were inputted to a software program and assessed. P value < 0.05 was considered as statistically significant. Males accounted for 63% of the OPGs. Age groups 18–30 and 31–45 years had the highest frequency and percentage (34%). Approximately 74% of the patients got their tooth/teeth extracted 4–6 years ago. The 0.7–1.2 mm overeruption subgroup had the highest proportion of 41%. The rate of overeruption in mandibular molars was 36%, which was the highest among the subgroups. Males had higher percentage than females in ≥60 and 31–45 age groups (84.65% and 76.5%, respectively), 4–6 years post-extraction time (85.7%), with significant differences, also, mandibular molars (85.0%) and mandibular arches (74.3%) were the higher among males. The highest level of overeruption was 0.7–1.2 mm, and mandibular molars were the most affected type. Significant differences between genders were detected in age groups, years after tooth loss, and arch side but not in cause of tooth loss, supra-erupted tooth type, and arch type parameters.

Survival of Fiber-Reinforced Composite Resin Post-Restored vs. Cast Post-and-Core-Restored Teeth: A Retrospective Clinical Study

Objective: The question of whether classic cast post-and-core (CPC) or fiber-reinforced composite resin posts (FRCP) are the best clinical decision has still not been fully solved. Materials and Methods: One hundred and sixty-two teeth were restored with FRCP, and 162 CPC restored teeth were included in this study with a matched-pair design. In a primary analysis, the survival rates after one year (primary endpoint) were compared. The additional analysis included an evaluation of tooth- and construction-specific variables and an illustration of the survival up to 60 months via Kaplan-Meier curves. Results: FRCP showed lower failure risk considering the definitive prosthetic restoration and tooth type compared to CPC restored teeth. In total, 17 failures were observed in the FRCP group and 35 failures in the CPC group. A 60-month survival rate of 79.3% for FRCP and 64.5% for CPC was observed. Teeth serving as abutments for telescopic dentures were more likely to be affected by failure compared to teeth restored with single crowns. Conclusion: Within the limitations of this study, the FRCP showed a lower failure risk compared to the CPC, considering the definitive prosthetic restoration and tooth type within the observation period.

MITOL-mediated DRP1 ubiquitylation and degradation promotes mitochondrial hyperfusion in CMT2A-linked MFN2 mutant

Mutations in Mitofusin2 (MFN2), associated with the pathology of the debilitating neuropathy, Charcot-Marie-Tooth type 2A (CMT2A) are known to alter mitochondrial morphology. One such abundant MFN2 mutant, R364W results in the generation of elongated, interconnected mitochondria. However, the mechanism leading to this mitochondrial aberration remains poorly understood. Here we show that mitochondrial hyperfusion in the presence of R364W-MFN2 is due to increased degradation of DRP1. The Ubiquitin E3 ligase MITOL is known to ubiquitylate both MFN2 and DRP1. Interaction with and its subsequent ubiquitylation by MITOL is stronger in presence of WT-MFN2 than R364W-MFN2. This differential interaction of MITOL with MFN2 in the presence of R364W-MFN2 renders the ligase more available for DRP1 ubiquitylation. Multimonoubiquitylation and proteasomal degradation of DRP1 in R364W-MFN2 cells in the presence of MITOL eventually leads to mitochondrial hyperfusion. Here we provide a mechanistic insight into mitochondrial hyperfusion, while also reporting that MFN2 can indirectly modulate DRP1 – an effect not shown before.

A Novel Mutation (D395A) in Valosin-Containing Protein Gene Is Associated With Early Onset Frontotemporal Dementia in an Italian Family

Inclusion body myopathy (IBM) with Paget’s disease of bone (PDB) and/or frontotemporal dementia (FTD) (IBMPFD) was recently identified as rare autosomal dominant disorder due to mutations in VCP gene. However, VCP mutations have also been documented in patients with amyotrophic lateral sclerosis (ALS), Charcot-Marie-Tooth type 2 (CMT2) disease, and hereditary spastic paraplegia (HSP), underlining the heterogeneity of the phenotypes due to VCP mutations. In this study, we reported a novel missense heterozygous variant c.1184A &gt; C (p.D395A) in exon 10 of VCP gene identified in three patients (two sisters and one brother) belonging to an Italian family. The patients underwent a detailed clinical evaluation including medical history, neurological examination, and neuropsychological assessment. Brain’s morphologic and functional analysis was also performed. The whole picture was consistent with the criteria of behavioral variant frontotemporal dementia (bvFTD) without IBM and PBD. Our report confirms the high degree of heterogeneity of VCP disease. A VCP analysis should be considered for the genetic screening of familial bvFTD with an early onset also in absence of IBM or PDB signs.

Design and performance testing of areca nut thresher machine using solid triangle spike tooth type

Technology for handling agricultural products from areca nut has received less attention. However, the economic potential of the areca nut is comparable to that of other palm trees. Threshing areca nut from the bunch is one of the procedures that must be completed to obtain high-quality betel nut. Therefore, this research aims to design and test an areca nut threshing machine that uses a solid triangle spike-type threshing tooth. This study uses an experimental manufacturing method in the workshop and laboratory testing. A detailed engineering drawing of areca nut thresher machine is a guide in carrying out the manufacturer. The influence of rotational speed on the threshing shaft (34 rpm, 42 rpm, and 50 rpm) was investigated to determine the machinery’s performance (percentage of threshing results, engine capacity, and fuel consumption). This study indicates that the areca thresher machine has been successfully designed with a diesel motor driving source of 6.5 hp, 2200 rpm. Applied a rotational speed of 50 rpm will give the best percentage of threshing products. The increase in rotational speed applied to the threshing machine will be in line with the rise in the engine capacity. In addition, the fuel consumption of a diesel engine from this thresher machine is 0.039 l/hr.

Assessment of dens invaginatus and its characteristics in maxillary anterior teeth using cone-beam computed tomography

This cone-beam computed tomographic (CBCT) study aimed to evaluate the prevalence of dens invaginatus (DI) and its characteristics in maxillary anterior teeth in a Saudi population. A total of 505 CBCT scans were evaluated, including a total of 2790 maxillary anterior teeth. The patients’ demographic data, including age and sex, were recorded. The presence of DI and the related characteristics including bilateral occurrence; DI type according to Oehlers classification; and presence of periapical radiolucency, open apex, and/or nearby impacted teeth were analyzed. The associations between DI and the other factors were analyzed using the chi-square and fisher exact tests. DI was detected in 7.3% of the patients and 1.6% of the teeth examined. Most of the DI-affected teeth were maxillary lateral incisors (76.1%), followed by mesiodens (19.6%) and maxillary central incisors (4.3%), while no DI was observed in the maxillary canines. Bilateral DI was found in 24.3% of the affected patients. Oehlers type I DI was the most frequent (80%). Periapical radiolucencies, open apices, and nearby impacted teeth were observed in 10.9%, 4.3%, and 30% of the invaginated teeth, respectively. DI was significantly associated with tooth type (P < 0.0001) but not with sex (P > 0.05). Although most of the DI cases are limited to the crown, CBCT imaging is essential for DI evaluation and management.

Influence of Root Canal Fillings on Alveolar Bone Crest Level—An Observational Cross Sectional CBCT Analysis

The aim of this study was to compare the alveolar bone crest (ABC) level of root canal filled (RCF) teeth without apical periodontitis with corresponding non-filled teeth in the same individual using three-dimensionally cone-beam computed tomography (CBCT) data. Two hundred and thirty-five matching pairs of RCF teeth and corresponding teeth without RCF were selected from a pool of 580 random CBCT-images (voxel size 160–200 µm). Teeth with apical periodontitis, perio-endodontic lesions or surgical endodontic treatment were excluded. The distance between the cemento–enamel-junction (CEJ) and the ABC was assessed centrally mesial, distal, palatal/lingual and buccal at each tooth (∑1880 measuring points) in a standardized manner. Topographic, gender, and age-related relationships were also noted. Data were analyzed using the Kruskal–Wallis-test. The ABC-level between RCF teeth (2.64 ± 1.25 mm) and teeth without RCF (2.61 ± 1.16 mm) did not differ significantly (p > 0.05). No differences concerning localization (maxilla/mandible, tooth type) and gender (p > 0.05) occurred. Overall, ABC-level in the maxilla (2.74 ± 1.48 mm) was significantly lower (p < 0.001) compared to mandibular teeth (2.50 ± 1.41 mm). Patients >41 years had significantly lower ABC-levels than younger patients (p < 0.05). Men showed a reduced bone level compared to women (p < 0.05). In conclusion, RCF teeth are identical to their non-RCF counterparts, at least in terms of crestal bone level, regardless of the location or type of tooth and the gender of the patient. Thus, root canal treatment is an essential pillar for long-term tooth preservation.

Evaluation of Quality of Root Canal Fillings Performed by Undergraduate Students of a Brazilian University / Avaliação da qualidade da obturação do canal radicular realizada por estudantes de graduação de uma Universidade brasileira

The aim of this study was to evaluate the quality of root canal filling performed by undergraduate students at the Federal University of Espirito Santo (UFES). A total of 368 periapical radiographs of endodontic treatment performed by undergraduate students between 2012 and 2014 was assessment. The quality of root canal filling was based on two criteria: length of root canal filling and adequate density of the obturation. Root canal fillings were considered adequate if had no voids and were located at 0-2 mm below the radiographic apex. Statistical analysis was conducted using chi-square tests, with a 5% significance level. In 93.8% of the cases the root canal filling was considered adequate. The density of the obturation was considered inadequate in 3% of the cases. When the length of root canal filling was observed, 1.2% of cases were considered as over-filled and 2.2% were considered under-filled. Non-significant differences were observed among the tooth type (incisive, canines and pre-molars) and the quality of root canal filling. Most of root canal filling performed by undergraduate students at the UFES were considered adequate, regardless of tooth type.

Longevity of Crown Margin Repairs Using Glass Ionomer Cement: A Retrospective Study

Clinical Relevance Repairing defective crown margins can extend the functional life of existing crowns. SUMMARY Objective: The objective of this study was to determine the survival time of crown margin repairs (CMRs) with glass ionomer and resin-modified glass ionomer cements on permanent teeth using electronic dental record (EDR) data. Methods: We queried a database of EDR (axiUm; Exan Group, Coquitlam, BC, Canada) in the Indiana University School of Dentistry (IUSD), Indianapolis, IN, USA, for records of patients who underwent CMRs of permanent teeth at the Graduate Operative Dentistry Clinic. Two examiners developed guidelines for reviewing the records and manually reviewed the clinical notes of patient records to confirm for CMRs. Only records that were confirmed with the presence of CMRs were retained in the final dataset for survival analysis. Survival time was calculated by Kaplan-Meier statistics, and a Cox proportional hazards model was performed to assess the influence of age, gender, and tooth type on survival time (a&lt;0.05). Results: A total of 214 teeth (115 patients) with CMR were evaluated. Patient average age was 69.4 ± 11.7 years old. Posterior teeth accounted for 78.5% (n=168) of teeth treated. CMRs using glass ionomer cements had a 5-year survival rate of 62.9% and an annual failure rate (AFR) of 8.9%. Cox proportional-hazards model revealed that none of the factors examined (age, gender, tooth type) affected time to failure. Conclusion: The results indicate the potential of CMRs for extending the functional life of crowns with defective margins, thus reducing provider and patient burden of replacing an indirect restoration. We recommend future studies with a larger population who received CMR to extend the generalizability of our findings and to determine the influence of factors such as caries risk and severity of defects on survival time.