Periodontal Probing of Dental Furcations Compared With Diagnosis by Low‐Dose Computed Tomography: A Case Series

Background: Therapeutic decisions in periodontal surgery are based on the accurate diagnosis of the furcation. Clinical probing is the basic diagnostic tool; however, the accuracy of clinical probing to distinguish Class II and Class III furcation defects is unknown. Therefore, this study compares clinical probing diagnoses to those of computed tomography (CT). Methods: Seventy‐five patients with severe periodontal disease were enrolled in this case series study. A total of 582 furcation sites in molars were assigned for the diagnosis of Class II and Class III furcation defects by clinical probing. Diagnosis based on CT served as a reference. Results: The degree of furcation involvement on clinical findings was confirmed in 57% of the sites, whereas 20% were overestimated and 23% were underestimated compared with the radiologic analysis. Only 32% of Class III furcations in the CT scan were detected clinically. The best correlation of CT scan and clinical probing was found at buccal furcation sites in the mandible, with a κ‐coefficient of 0.52, and buccal furcation sites in the maxilla, κ = 0.38. The κ‐coefficient was 0.35 for lingual furcations, 0.29 for mesial furcations, and 0.27 for distal furcations, showing weaker correlations. Conclusions: CT scans offer more detailed information on furcation involvement than clinical probing. Especially before surgical treatment, three‐dimensional radiographic imaging can be a useful tool to assess the degree of furcation involvement and optimize treatment decisions.     

Limited value of routine microalbuminuria assessment in multi-ethnic obese children

Background

To determine the prevalence of microalbuminuria and its association with cardiometabolic risk factors in a multi-ethnic cohort of overweight and obese children.

Case-Diagnosis/Treatment

A retrospective analysis of prospectively collected data was performed using data from 408 overweight and obese children (age 3–19 years). In addition to administering an oral glucose tolerance test, we measured anthropometric variables, plasma lipid levels, alanine aminotransferase and the urinary albumin/creatinine ratio (ACR). Microalbuminuria was defined as an ACR of between 2.5 and 25 mg/mmol in boys and 3.5 and 25 mg/mmol in girls. In total, only 11 (2.7 %) of the children analyzed presented with microalbuminuria, with no differences between ethnic groups, sex or in the prevalence of hypertension compared to the children with normoalbuminuria. After adjustment for confounders, the body mass index Z-score tended to be different between the group with microalbuminuria versus that without (3.6 vs. 3.2, respectively; P?=?0.054). ACR was not associated with hypertension, impaired glucose tolerance, high triglycerides or low high-density lipoprotein-cholesterol.

Conclusions

In a large multi-ethnic cohort of overweight and obese children, we found a low prevalence of microalbuminuria (11 children, 2.7 %), and in this small number of individuals, we found no association with any of the cardiometabolic risk factors assessed. Therefore, our data do not support the routine measurement of microalbuminuria in asymptomatic overweight and obese children and adolescents.     

Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation

Background

Osteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue.

Materials and methods

One gram each of either a porous beta-tricalcium phosphate (β-TCP) or an hydroxyapatite/silicon dioxide (HA/SiO₂)-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix.

Results

Both materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points.

Conclusions

This study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.     

Impact of a prior medical degree on students' dental school performance in Innsbruck, Austria

The purpose of this study was to identify the performance differences between two groups of Austrian dental students (one with a prior medical degree and one without a medical degree) during their dental school training and final dental licensure examination. A specific aim was to determine if having a medical degree is a predictive factor for dental students' scores on the Austrian Dental Admission Test (Austrian DAT), performance in the dental clinic, and scores on final exam. The study consisted of a retrospective analysis of 122 students (thirty-nine with a medical degree and eighty-three without a medical degree) who were enrolled in the Dental Clinic at Innsbruck Medical University, Innsbruck, Austria, between 2001 and 2006. Three performance categories were considered: Austrian DAT results, clinical performance after the first clinical year in dental school, and performance on the final dental licensure examination. Information on students' age, gender, and previous medical degree was collected from official records. Analyses with student's t-test and Pearson's chi-square test revealed that the students with a medical degree had significantly higher Austrian DAT total test scores, grade point averages after the first clinical year, and scores on the final exam. Additionally, those students had significantly better performance on the final exam in prosthodontics and oral and maxillofacial surgery. The linear regression analysis showed that a medical degree had an independent effect on average scores on the final exam, age, and Austrian DAT test scores, while gender showed no statistically significant effect. Overall, the study found that dental students with a prior medical degree had significantly higher Austrian DAT total test scores and performed significantly better in the first clinical year and on the final exam than those without a prior medical degree.     

Direct binding of GABAA receptor β2 and β3 subunits to gephyrin

GABAergic transmission is essential to brain function, and a large repertoire of GABA type A receptor (GABA_AR) subunits is at a neuron's disposition to serve this function. The glycine receptor (GlyR)‐associated protein gephyrin has been shown to be essential for the clustering of a subset of GABA_AR. Despite recent progress in the field of gephyrin‐dependent mechanisms of postsynaptic GABA_AR stabilisation, the role of gephyrin in synaptic GABA_AR localisation has remained a complex matter with many open questions. Here, we analysed comparatively the interaction of purified rat gephyrin and mouse brain gephyrin with the large cytoplasmic loops of GABA_AR α1, α2, β2 and β3 subunits. Binding affinities were determined using surface plasmon resonance spectroscopy, and showed an ~ 20‐fold lower affinity of the β2 loop to gephyrin as compared to the GlyR β loop–gephyrin interaction. We also probed in vivo binding in primary cortical neurons by the well‐established use of chimaeras of GlyR α1 that harbour respective gephyrin‐binding motifs derived from the different GABA_AR subunits. These studies identify a novel gephyrin‐binding motif in GABA_AR β2 and β3 large cytoplasmic loops.