Longitudinal study of patients with TMJ dysfunction by tomographic examination: Condylar position and clinical sign

For patients with TMJ dysfunction, operators often change the condylar position by various methods. The aim of this study is to investigate how much the changes with time of condylar positions are related to the changes of clinical signs. The subjects were 584 joints of 127 patients with TMJ dysfunction to whom the serial lateral TMJ tomography was performed more than twice. In the most of cases where the condylar position had moved downward, inter-incisal distance had increased and TMJ noise had ameliorated. Furthermore, in many cases where the condylar position had moved forward, the amelioration of the TMJ pain was observed. It was considered that those ameliorations occurred because the positional relationship between the condylar head and the articular disk or posterior attachment had been improved.     

Five-year changes in periodontal parameters after apical surgery

Introduction

Most clinical studies on the outcome of apical surgery concentrate on periapical healing based on radiographic and clinical characteristics (signs and symptoms). This study focuses on long-term changes in periodontal parameters after apical surgery.

Methods

Periodontal parameters (ie, probing depth [PD], level of gingival margin [GM], and calculated clinical attachment level [CAL]) were collected at baseline and at 1 and 5 years after apical surgery. Changes in PD, GM, and CAL were calculated over time and were also evaluated in relation to patient-, tooth-, and treatment-related covariables.

Results

One hundred eighty-six of 242 initially identified teeth could be evaluated. Significant changes in GM and CAL were observed at facial sites during the first year after surgery (mean recession of GM was 0.29 mm, mean CAL loss was 0.20 mm), but none of the periodontal parameters significantly changed between 1 and 5 years after apical surgery. With regard to covariables, the type of incision technique was found to be the major factor affecting changes in GM and CAL between baseline and 1 year after surgery. Age, smoking, and type of periapical healing were the variables influencing the periodontal parameters over the longer observation period of up to 5 years.

Conclusions

Patients should be informed about possible changes in periodontal parameters (gingival recession and loss of attachment) after apical surgery. The surgery itself appears to account for changes observed during the first year, whereas patient- and healing-related factors seem to affect periodontal changes seen thereafter.     

Exploring bacterial diversity of endodontic microbiota by cloning and sequencing 16S rRNA

Introduction

The characterization of microbial communities infecting the endodontic system in each clinical condition may help on the establishment of a correct prognosis and distinct strategies of treatment. The purpose of this study was to determine the bacterial diversity in primary endodontic infections by 16S ribosomal-RNA (rRNA) sequence analysis.

Methods

Samples from root canals of untreated asymptomatic teeth (n = 12) exhibiting periapical lesions were obtained, 16S rRNA bacterial genomic libraries were constructed and sequenced, and bacterial diversity was estimated.

Results

A total of 489 clones were analyzed (mean, 40.7 ± 8.0 clones per sample). Seventy phylotypes were identified of which six were novel phylotypes belonging to the family Ruminococcaceae. The mean number of taxa per canal was 10.0, ranging from 3 to 21 per sample; 65.7% of the cloned sequences represented phylotypes for which no cultivated isolates have been reported. The most prevalent taxa were Atopobium rimae (50.0%), Dialister invisus, Prevotella oris, Pseudoramibacter alactolyticus, and Tannerella forsythia (33.3%).

Conclusions

Although several key species predominate in endodontic samples of asymptomatic cases with periapical lesions, the primary endodontic infection is characterized by a wide bacterial diversity, which is mostly represented by members of the phylum Firmicutes belonging to the class Clostridia followed by the phylum Bacteroidetes.     

Development of temporomandibular disorder symptoms: a 3-year cohort study of university students

The aims of this study were to examine the incidence of temporomandibular disorders (TMDs) over a 3-year period and to evaluate the risk of self-reported TMDs among university students in Japan. The study population comprised 2374 university students examined at the start of their undergraduate course and 492 students re-examined after 3 years using questionnaires on symptoms of TMD and experiences of jaw injury, stress, orthodontic treatment and parafunctional habits. Cumulative incidence (%) and relative risks were calculated overall. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the degree of risks of these variables for symptoms of TMDs using logistic regression. Results of logistic regression analysis showed that male subjects with experience of jaw injury had a 3·54 (CI=1·45-8·68, P<0·01)-fold higher risk of temporomandibular joint (TMJ) pain than that for those who did not. Female subjects who reported experiencing stress and bruxism had 10·56 (CI=1·28-87·54, P<0·05)- and 5·00 (CI=1·21-20·71, P<0·05)-fold higher risks of TMJ sound, respectively, than the risk for female subjects who had not experienced stress or bruxism. The results indicated that experiences of jaw injury, stress and bruxism were significantly associated with increased risks of development of TMJ disorders in a 3-year cohort.     

Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs

Objectives: The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N‐methyl‐2‐pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. Materials and methods: In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were bilaterally extracted creating two bony defects on each site. A total of 20 dental implants were inserted and allocated to four different treatment modalities within each dog: PLGA/NMP membrane only (Test 1), PLGA/NMP membrane with DBBM (Test 2), RCM only (negative control), and RCM with DBBM (positive control). A histomorphometric analysis was performed 12 weeks after implantation. For statistical analysis, a Friedman test and subsequently a Wilcoxon signed ranks test were applied. Results: In four out of five PLGA/NMP membrane‐treated defects, the membranes had broken into pieces without the support of DBBM. This led to a worse outcome than in the RCM group. In combination with DBBM, both membranes revealed similar amounts of area of bone regeneration and bone‐to‐implant contact without significant differences. On the level of the third implant thread, the PLGA/NMP membrane induced more horizontal bone formation beyond the graft than the RCM. Conclusion: The newly developed PLGA/NMP membrane performs equally well as the RCM when applied in combination with DBBM. Without bone substitute material, the PLGA/NMP membrane performed worse than the RCM in challenging defects, and therefore, a combination with a bone substitute material is recommended. To cite this article:
Jung RE, Kokovic V, Jurisic M, Yaman D, Subramani K, Weber FE. Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs.
Clin. Oral Impl. Res. 22 , 2011; 802–807
doi: 10.1111/j.1600‐0501.2010.02068.x     

Inverted U-Shaped Associations between Glycemic Indices and Serum Uric Acid Levels in the General Chinese Population: Findings from the China Cardiometabolic Disease and Cancer Cohort (4C) Study

Objective The relationship between serum uric acid(SUA)levels and glycemic indices,including plasma glucose(FPG),2-hour postload glucose(2 h-PG),and glycated hemoglobin(HbA1 c),remains inconclusive.We aimed to explore the associations between glycemic indices and SUA levels in the general Chinese population.Methods The current study was a cross-sectional analysis using the first follow-up survey data from The China Cardiometabolic Disease and Cancer Cohort Study.A total of 105,922 community-dwelling adults aged≥40 years underwent the oral glucose tolerance test and uric acid assessment.The nonlinear relationships between glycemic indices and SUA levels were explored using generalized additive models.Results A total of 30,941 men and 62,361 women were eligible for the current analysis.Generalized additive models verified the inverted U-shaped association between glycemic indices and SUA levels,but with different inflection points in men and women.The thresholds for FPG,2 h-PG,and HbA1 c for men and women were 6.5/8.0 mmol/L,11.0/14.0 mmol/L,and 6.1/6.5,respectively(SUA levels increased with increasing glycemic indices before the inflection points and then eventually decreased with further increases in the glycemic indices).Conclusion An inverted U-shaped association was observed between major glycemic indices and uric acid levels in both sexes,while the inflection points were reached earlier in men than in women.     

Combined Effect of Smoking and Obesity on Coronary Heart Disease Mortality in Male Veterans: A 30-year Cohort Study

Objective Evidence is lacking regarding the combined effects of smoking and obesity on mortality from coronary heart disease in male veterans.This study aimed to explore the combined effect of smoking and obesity on coronary heart disease mortality in male veterans in China.Methods A cohort of 1,268 male veterans from 22 veteran centers in Xi’an(Shaanxi Province,China)were followed up once every 2 years from February 1,1987 to October 30,2016.The endpoint was death from any cause.The hazard ratio(HR)of each risk factor and the 95%confidence interval(CI)were calculated using a multivariate Cox proportional hazard model.Results The total follow-up was 24394.21 person-years;each subject was followed up for a mean duration of 19.24 years.By the end of the study,of the 1,268 veterans,889 had died,363 were alive,and 16 were lost to follow-up.Cox regression analysis results revealed that current smoking(HR:1.552,95%CI:1.074–2.243),obesity(HR:1.625,95%CI:1.024–2.581),and the combined effect of the two factors(HR:2.828,95%CI:1.520–5.262)were associated with coronary heart disease mortality.Conclusion Our results suggest that obese veterans who smoke might be an important target population for coronary heart disease mortality control.     

Millard法和Tennison法修复单侧完全性唇裂316例比较研究

目的:通过两种不同的方法修复单侧完全性唇裂,比较其结果并基于不同唇裂形态学变化选择最优手术方法。方法:316例单侧完全性唇裂患者随机分为两组。每一组分别为158例患儿,分别采用Millard法和Tennison法行首次唇裂修复。术前唇鼻软组织测量并记录。通过白唇卷、唇红缘、丘比特弓、唇高、鼻孔对称性、鼻翼穹隆外观以及鼻翼基脚位置术后评估分析。结果:采用Preson-χ2检验分析关联性和线性趋势对两组患者进行比较。结果显示,Millard法在鼻孔对称性和鼻翼形态方面效果显著(P=0.004,P=0.002),而Tennison法则在恢复唇高方面效果较为突出(P=0.003)。一种特殊的方法能很好的适用于某些唇裂解剖类型的观点在统计上不被证实。结论:某些术前唇裂解剖特点使得手术者选择一种特殊手术方法,但本研究发现这种特殊的手术方法本质上与其他方法是一样的。单一的手术修复方法并不能达到理想的美学和功能结果,而缝合技术与皮肤切口设计同样重要。