Incidence of Lower Second Permanent Molar Impaction

1988 ◽  
Vol 15 (3) ◽  
pp. 199-203 ◽  
Author(s):  
Ruth Evans
Keyword(s):  
Deciduous Teeth ◽  
Control Group ◽  
Second Molar ◽  
Permanent Molar ◽  
Two Samples ◽  
Orthodontic Patients

The incidence of lower second molar impaction was investigated, comparing the records of two samples of 200 orthodontic patients referred consecutively, in 1976 and 1986. A further study compared 50 cases showing both bilateral and unilateral impactions, with a non-impacted control group. This allowed possible causes of the impactions to be examined, particularly concerning the effect of premature loss of deciduous teeth on the distribution of crowding.

scholarly journals Comparative evaluation of osteogenic differentiation potential of stem cells derived from dental pulp and exfoliated deciduous teeth cultured over granular hydroxyapatite based scaffold

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Manal Nabil Hagar ◽  
Farinawati Yazid ◽  
Nur Atmaliya Luchman ◽  
Shahrul Hisham Zainal Ariffin ◽  
Rohaya Megat Abdul Wahab
Keyword(s):  
Stem Cells ◽  
Osteogenic Differentiation ◽  
Dental Pulp ◽  
3D Culture ◽  
Permanent Teeth ◽  
Deciduous Teeth ◽  
Osteogenic Potential ◽  
Control Group ◽  
Rt Pcr ◽  
Differentiation Potential

Abstract Background Mesenchymal stem cells isolated from the dental pulp of primary and permanent teeth can be differentiated into different cell types including osteoblasts. This study was conducted to compare the morphology and osteogenic potential of stem cells from exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSC) in granular hydroxyapatite scaffold (gHA). Preosteoblast cells (MC3T3-E1) were used as a control group. Methodology The expression of stemness markers for DPSC and SHED was evaluated using reverse transcriptase-polymerase chain reaction (RT-PCR). Alkaline phosphatase assay was used to compare the osteoblastic differentiation of these cells (2D culture). Then, cells were seeded on the scaffold and incubated for 21 days. Morphology assessment using field emission scanning electron microscopy (FESEM) was done while osteogenic differentiation was detected using ALP assay (3D culture). Results The morphology of cells was mononucleated, fibroblast-like shaped cells with extended cytoplasmic projection. In RT-PCR study, DPSC and SHED expressed GAPDH, CD73, CD105, and CD146 while negatively expressed CD11b, CD34 and CD45. FESEM results showed that by day 21, dental stem cells have a round like morphology which is the morphology of osteoblast as compared to day 7. The osteogenic potential using ALP assay was significantly increased (p < 0.01) in SHED as compared to DPSC and MC3T3-E1 in 2D and 3D cultures. Conclusion gHA scaffold is an optimal scaffold as it induced osteogenesis in vitro. Besides, SHED had the highest osteogenic potential making them a preferred candidate for tissue engineering in comparison with DPSC.

scholarly journals Flipping the Script: Measuring Both Performance Validity and Cognitive Ability with the Forced Choice Recognition Trial of the RCFT

2021 ◽  
pp. 003151252110197
Author(s):  
Kaitlyn Abeare ◽  
Kristoffer Romero ◽  
Laura Cutler ◽  
Christina D. Sirianni ◽  
Laszlo A. Erdodi
Keyword(s):  
Cognitive Ability ◽  
Verbal Memory ◽  
Visual Memory ◽  
Large Scale ◽  
Clinical Sample ◽  
Neuropsychological Test ◽  
Forced Choice ◽  
Control Group ◽  
Performance Validity ◽  
Two Samples

In this study we attempted to replicate the classification accuracy of the newly introduced Forced Choice Recognition trial (FCR) of the Rey Complex Figure Test (RCFT) in a clinical sample. We administered the RCFT FCR and the earlier Yes/No Recognition trial from the RCFT to 52 clinically referred patients as part of a comprehensive neuropsychological test battery and incentivized a separate control group of 83 university students to perform well on these measures. We then computed the classification accuracies of both measures against criterion performance validity tests (PVTs) and compared results between the two samples. At previously published validity cutoffs (≤16 & ≤17), the RCFT FCR remained specific (.84–1.00) to psychometrically defined non-credible responding. Simultaneously, the RCFT FCR was more sensitive to examinees’ natural variability in visual-perceptual and verbal memory skills than the Yes/No Recognition trial. Even after being reduced to a seven-point scale (18-24) by the validity cutoffs, both RCFT recognition scores continued to provide clinically useful information on visual memory. This is the first study to validate the RCFT FCR as a PVT in a clinical sample. Our data also support its use for measuring cognitive ability. Replication studies with more diverse samples and different criterion measures are still needed before large-scale clinical application of this scale.

scholarly journals Endodontic treatment of a mandibular hypertaurodontic second molar

2015 ◽  
Vol 63 (2) ◽  
pp. 203-206
Author(s):  
Emmanuel João Nogueira Leal SILVA ◽  
Plínio Mendes SENNA ◽  
Tauby de Souza COUTINHO FILHO ◽  
Renato Liess KREBS
Keyword(s):  
Anatomical Variations ◽  
Endodontic Treatment ◽  
Study Objective ◽  
Second Molar ◽  
Clinically Normal ◽  
Permanent Molar ◽  
Root Sheath ◽  
Molar Teeth ◽  
Root Canal System ◽  
Apical Displacement

Taurodontism is the consequence of a developmental disorder in which the invagination of Hertwig's epithelial root sheath doesn't occur at a proper level. As a result, the pulp body and the chamber of a multi-root tooth, usually permanent molar teeth, are enlarged by the apical displacement of the pulp floor. Despite its clinically normal appearance, the morphological variation of this tooth can be diagnosed by a routine radiographic exam that shows enlarged apico-occlusal pulp chamber and short roots. Due to these anatomical variations, endodontic treatment of a taurodontic element is a clinical challenge given the complexity of localization and instrumentation of the root canal system. According to the degree of displacement of the pulp floor, taurodontism can be classified as: hypotaurodontism, mesotaurodontism and hypertaurodontism. This study objective is to report a clinical case of a patient who was submitted to endodontic treatment of the second inferior molar affected by hypertaurodontism.

scholarly journals Hydroxyl and calcium ions diffusion from endodontic materials through roots of primary teeth - in vitro study

2005 ◽  
Vol 13 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Ana Cristina Gerent Petry Nunes ◽  
Maria José de Carvalho Rocha
Keyword(s):  
In Vitro Study ◽  
Deciduous Teeth ◽  
Control Group ◽  
Apical Surface ◽  
Working Length ◽  
Group A ◽  
Periapical Healing ◽  
Materials Used ◽  
Spectrometer Data

The purpose of this research was to evaluate the diffusion of calcium (Ca+2) and hydroxyl (OH-) ions from materials with a calcium hydroxide base - Ca(OH)2 through the intact roots of deciduous teeth. This diffusion of ions is important for periapical healing. Forty-six deciduous teeth were selected and instrumented to their working length with #40 files. The teeth were washed during cleaning and shaping with a 1% sodium hypochlorite (NaOCl) solution. The canals were dried with paper points. The teeth were divided into 4 groups based on the sealer type, with 10 specimens in each group. A fifth group of 6 teeth without sealer constituted the control group. The materials used as sealers were: Ca(OH)2 paste associated to propylene glycol (CaPE) thickened at the proportion of 2:1 w/v; UFSC (Federal University of Santa Catarina) paste - a mixture of 0.3g of zinc oxide with 0.3g of Ca(OH)2 with 0.2ml of olive oil 1:1 w/w; Vitapex® and Sealapex®. The coronal access was sealed with a glass ionomer after the root had been filled with each sealer. A one-third apical surface and foramen was hard-pressed with Araldite®. The teeth were stored individually in flasks containing saline solution at 37ºC and 100% humidity. The OH- and Ca+2 ions diffusion levels were determined using a pH meter and an atomic absorption spectrometer. Data were collected at 48 hours and at intervals of 7, 30, 45 and 60 days. Statistical analysis was performed using ANOVA to compare groups. In the pH evaluation, the CaPE group presented the largest OH- ions diffusion, which peaked at sixty days (p=0.0309), when compared to the other groups (p<0.0001). In relation to amount of Ca+2 ions released, the CaPE paste showed the best results, followed by the UFSC's paste. These results suggest that the CaPE paste was the material that allowed the highest diffusion of OH- and Ca+2 ions.

scholarly journals Stem Cells from Human Exfoliated Deciduous Teeth (SHED) Differentiate in vivo and Promote Facial Nerve Regeneration

2018 ◽  
Vol 28 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Larissa Vilela Pereira ◽  
Ricardo Ferreira Bento ◽  
Dayane B. Cruz ◽  
Cláudia Marchi ◽  
Raquel Salomone ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Schwann Cell ◽  
Facial Nerve ◽  
Deciduous Teeth ◽  
Control Group ◽  
Cell Marker ◽  
Mandibular Branch ◽  
Human Exfoliated Deciduous Teeth

Post-traumatic lesions with transection of the facial nerve present limited functional outcome even after repair by gold-standard microsurgical techniques. Stem cell engraftment combined with surgical repair has been reported as a beneficial alternative. However, the best association between the source of stem cell and the nature of conduit, as well as the long-term postoperative cell viability are still matters of debate. We aimed to assess the functional and morphological effects of stem cells from human exfoliated deciduous teeth (SHED) in polyglycolic acid tube (PGAt) combined with autografting of rat facial nerve on repair after neurotmesis. The mandibular branch of rat facial nerve submitted to neurotmesis was repaired by autograft and PGAt filled with purified basement membrane matrix with or without SHED. Outcome variables were compound muscle action potential (CMAP) and axon morphometric. Animals from the SHED group had mean CMAP amplitudes and mean axonal diameters significantly higher than the control group ( p < 0.001). Mean axonal densities were significantly higher in the control group ( p = 0.004). The engrafted nerve segment resected 6 weeks after surgery presented cells of human origin that were positive for the Schwann cell marker (S100), indicating viability of transplanted SHED and a Schwann cell-like phenotype. We conclude that regeneration of the mandibular branch of the rat facial nerve was improved by SHED within PGAt. The stem cells integrated and remained viable in the neural tissue for 6 weeks since transplantation, and positive labeling for S100 Schwann-cell marker suggests cells initiated in vivo differentiation.

scholarly journals Team Resilience Training in the Workplace: E-Learning Adaptation, Measurement Model, and Two Pilot Studies (Preprint)

2017 ◽  
Author(s):  
Joel B Bennett ◽  
Michael Neeper ◽  
Brittany D Linde ◽  
Gale M Lucas ◽  
Lindsay Simone
Keyword(s):  
Intervention Group ◽  
Measurement Model ◽  
Control Group ◽  
Pilot Studies ◽  
Working Model ◽  
Team Resilience ◽  
Two Samples ◽  
Program Efficacy ◽  
E Learning ◽  
The Individual

BACKGROUND The majority of resilience interventions focus on the individual. Workplace resilience is a growing field of research. Given the ever-increasing interconnectedness in businesses, teamwork is a guarantee. There is also growing recognition that resilience functions at the team level. OBJECTIVE The objective of our work was to address three shortcomings in the study of workplace resilience interventions: lack of interventions focusing on group-level or team resilience, the need for brief interventions, and the need for more theoretical precision in intervention studies. METHODS The authors took an established evidence-based program (Team Resilience) and modified it based on these needs. A working model for brief intervention evaluation distinguishes outcomes that are proximal (perceptions that the program improved resilience) and distal (dispositional resilience). A total of 7 hypotheses tested the model and program efficacy. RESULTS Two samples (n=118 and n=181) of engineering firms received the Web-based training and provided immediate reactions in a posttest-only design. The second sample also included a control condition (n=201). The findings support the model and program efficacy. For example, workplace resilience was greater in the intervention group than in the control group. Other findings suggest social dissemination effects, equal outcomes for employees at different stress levels, and greater benefit for females. CONCLUSIONS This preliminary research provides evidence for the capabilities of e-learning modules to effectively promote workplace resilience and a working model of team resilience.

scholarly journals Research Regarding Physical Testing in the Military Pentathlon at the 50 M Race with Obstacles

2019 ◽  
Vol 24 (1) ◽  
pp. 29-37
Author(s):  
Ioan Sabin Sopa ◽  
Marcel Pomohaci
Keyword(s):  
Research Methods ◽  
Statistical Significance ◽  
Control Group ◽  
Military Students ◽  
Physical Test ◽  
Two Samples ◽  
Physical Testing ◽  
Experiment Method ◽  
The Military

Abstract The research started from the necessity of finding new ways to physical test the military students that are part of the military pentathlon 50 m race with obstacles team. The research methods used was the experiment method, using two groups: the first group was the control group and the second the experiment group. The experiment consisted in testing the students at: 50 m speed running, 800 m resistance running, push-ups, and specific testing like: 50 m swimming with obstacles, 8 km run in varied terrain. The results of our investigation showed that calculation of the statistical significance of the differences between the averages of the two samples showed significant values at p>0.05, n-1, at the following parameters: running 800 m (t = 2.71> 2.13 - p = 0.05); push-ups (t = 3.01> 2.95 - p = 0.05); freestyle swimming 50m (t = 2.81> 2.13 - p = 0.05).

scholarly journals Prevalence and Pattern of Canine Impaction and Its Associated Anomalies among Orthodontic Patients Attending Tertiary Care Dental Hospital in Kathmandu

2020 ◽  
Vol 10 (1) ◽  
pp. 6-10
Author(s):  
Anshu Piya ◽  
Bikash Veer Shrestha ◽  
Anju Khapung ◽  
Prakash Bhattarai
Keyword(s):  
Root Resorption ◽  
Tertiary Care ◽  
Anterior Segment ◽  
Deciduous Teeth ◽  
Dental Anomalies ◽  
Impacted Tooth ◽  
Impacted Canines ◽  
Dental Hospital ◽  
Orthodontic Patients ◽  
And Function

Introduction: Permanent canines are considered as the cornerstone of mouth. Canines are important for esthetics and function as they are located in the anterior segment of the mouth and help in tearing of food. An impacted tooth is that tooth that cannot or will not erupt into its normal functional occlusion due to some circumstances. Those impacted tooth are considered pathologic as they might lead to various problems like resorption of roots of adjacent teeth, cystic formation, and infection with partial eruption leading to pain and trismus. Materials & Method: All the patients (550) being treated in department of Orthodontics in Nepal Medical College from January 2017 to December 2019 were included in the study. Patients aged 13-30 years were included in the study. Clinical examinations and panoramic radiographs of patients were taken. Anterior occlusal view was done in those patients having canine impaction to determine the patterns of impaction. Data was processed in SPSS version 16.0. Result: Among 550 orthodontic patients, 31 patients were found to have canine impaction. Among them 18 (58.1%) were females and 13 (41.9%) were males. The overall prevalence of canine impaction was found to be 5.6%. Various dental anomalies were observed in the participants’ radiographs, the most common being the retained deciduous teeth (54.8%) followed by dilacerations of adjacent teeth (51.6%). Peg shaped lateral incisors and root resorption of adjacent tooth were almost equal (22.6%) with least being the odontomas and other impacted teeth. Conclusion: The prevalence of canine impaction in tertiary care dental hospital in Kathmandu was found to be 5.6%. Patients with impacted canines also had other dental anomalies. Knowing the prevalence of impacted canines, will encourage the community to be aware about canine impaction and educate the population about the clinical implications and the importance of performing preventive and interceptive procedures.

scholarly journals Association between arch perimeter management and the occurrence of mandibular second molar eruption disturbances:

2021 ◽  
Author(s):  
Lucas Garcia Santana ◽  
Kimberlly Avelar ◽  
Leandro Silva Marques
Keyword(s):  
Randomized Clinical Trials ◽  
Treatment Time ◽  
Risk Of Bias ◽  
Second Molar ◽  
Mandibular Arch ◽  
Assessment Development ◽  
Permanent Molar ◽  
High Prevalence ◽  
Mandibular Second Molar ◽  
Meta Analyses

ABSTRACT Objectives To investigate the association between the management of mandibular arch perimeter during development of the dentition and its effects on second permanent molar (M2) eruption. Materials and Methods Seven electronic databases were searched without restrictions up to June 2020. Assessment was performed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool for non-randomized clinical trials (non-RCT). Odds ratio (OR) with 95% confidence intervals was calculated from random-effects meta-analyses. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the certainty of the evidence. Results Five non-RCTs, with serious to moderate risk of bias, were included. A low certainty of evidence indicated that individuals undergoing mandibular arch perimeter management by controlling the position of the first molar had a high prevalence of M2 eruption difficulties. The odds of eruption disorders was 7.5 times higher (OR: 7.57, [3.72, 15.41], P &lt; .001) in treated individuals. Subgroup analysis revealed that appliances that increased the arch perimeter lead to a greater chance of eruption disorders compared to appliances that only maintained the perimeter. The predictive factors for the M2 eruption difficulty were its previous mesioangulation in relation to the first molar (&gt;24°) and the treatment time (&gt;2 years). Conclusions Mandibular arch perimeter management during development of the dentition leads to an increase in the occurrence of M2 eruption difficulties. The identification of possible risk factors as well as the choice of the appropriate appliance type and the monitoring of these individuals seems to be essential to avoid undesirable effects with this therapy.

scholarly journals Evaluation of dental age and associated developmental anomalies in subjects with impacted mandibular canines

2014 ◽  
Vol 85 (4) ◽  
pp. 638-644 ◽  
Author(s):  
Shikha Jain ◽  
K Sadashiva Shetty ◽  
Shweta Jain ◽  
Sachin Jain ◽  
A.T. Prakash ◽  
...  
Keyword(s):  
Null Hypothesis ◽  
Close Association ◽  
Statistical Significance ◽  
Reference Sample ◽  
Dental Development ◽  
Control Group ◽  
Dental Age ◽  
Odds Ratios ◽  
Developmental Anomalies ◽  
Orthodontic Patients

ABSTRACT Objectives:  To assess the null hypothesis that there is no difference in the rate of dental development and the occurrence of selected developmental anomalies related to shape, number, structure, and position of teeth between subjects with impacted mandibular canines and those with normally erupted canines. Materials and Methods:  Pretreatment records of 42 subjects diagnosed with mandibular canines impaction (impaction group: IG) were compared with those of 84 subjects serving as a control reference sample (control group: CG). Independent t-tests were used to compare mean dental ages between the groups. Intergroup differences in distribution of subjects based on the rate of dental development and occurrence of selected dental anomalies were assessed using χ2 tests. Odds of late, normal, and early developers and various categories of developmental anomalies between the IG and the CG were evaluated in terms of odds ratios. Results:  Mean dental age for the IG was lower than that for the CG in general. Specifically, this was true for girls (P &lt; .05). Differences in the distribution of the subjects based on the rate of dental development and occurrence of positional anomalies also reached statistical significance (P &lt; .05). The IG showed a higher frequency of late developers and positional anomalies compared with controls (odds ratios 3.00 and 2.82, respectively; P &lt; .05). Conclusions:  The null hypothesis was rejected. We identified close association of female subjects in the IG with retarded dental development compared with the female orthodontic patients. Increased frequency of positional developmental anomalies was also remarkable in the IG.

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