Prevalence of TMD symptoms in Turkish migrants and re-settlers from the former Soviet Union in comparison to a German group.

OBJECTIVES: The objective of this study was to investigate the prevalence of temporomandibular disorder (TMD) symptoms among Turks and re-settlers with German origin from Russia and to compare those findings with a German group from the same area. METHOD: Sixty-nine Turkish migrants, 50 re-settlers, and 96 Germans were clinically examined according to a short version of the Research Diagnostic Criteria (RDC/TMD) protocol. The subjects participated in a feasibility study of the German National Cohort and were recruited from the study center Heidelberg/Mannheim of the cluster Baden-Württemberg/Saarland. RESULTS: Significant differences emerged between the three ethnic groups for unassisted opening without pain, maximum unassisted opening, and overbite, with highest values for the German group. No significant differences were found for muscle pain on palpation or muscle and joint pain during opening. DISCUSSION: As the authors identified significant differences between the different ethnic groups for metric measurements, it might be beneficial to include questions concerning the ethnicity to the German version of the RDC/TMD for further research, to make the results more comparable.

Pocket depth and bleeding on probing and their associations with dental, lifestyle, socioeconomic and blood variables: a cross-sectional, multicenter feasibility study of the German National Cohort.

BACKGROUND: To investigate the periodontal disease status in a multi-center cross-sectional study in Germany. Associations of dental, socio-economic, blood and biomedical variables with periodontal outcome parameters were evaluated. METHODS: From 4 different centers N = 311 persons were included, drawn randomly from the registration offices. Maximal pocket depth (PD) was used as primary indicator for periodontitis. It was classified as: no/mild ≤3 mm, moderate 4-5 mm, severe ≥6 mm. Associations between socioeconomic (household income, education), lifestyle, and biomedical factors and PD or bleeding on probing (BOP) per site ("Yes"/"No") was analyzed with logistic regression analysis. RESULTS: Mean age of subjects was 46.4 (range 20-77) years. A significantly higher risk of deeper pockets for smokers (OR = 2.4, current vs. never smoker) or persons with higher BMI (OR = 1.6, BMI increase by 5) was found. Severity of periodontitis was significantly associated with caries lesions (p = 0.01), bridges (p < .0001), crowns (p < .0001), leukocytes (p = 0.04), HbA1c (p < .0001) and MCV (p = 0.04). PD was positively correlated with BOP. No significant associations with BOP were found in regression analysis. CONCLUSIONS: Earlier findings for BMI and smoking with severity of PD were confirmed. Dental variables might be influenced by potential confounding factors e.g. dental hygiene. For blood parameters interactions with unknown systemic diseases may exist.

Compression of human primary cementoblasts leads to apoptosis: A possible cause of dental root resorption?

OBJECTIVES: One of the most common side effects of orthodontic treatment is root resorption on the pressure side of tooth movement. This is usually repaired by cementoblasts, but 1-5 % of patients eventually experiences a marked reduction in root length because no repair has occurred. The reason why cementoblasts should lose their repair function in such cases is not well understood. There is evidence from genome-wide expression analysis (Illumina HumanHT-12 v4 Expression BeadChip Kit; > 30,000 genes) that apoptotic processes are upregulated after the compression of cementoblasts, which is particularly true of the pro-apoptotic gene AXUD1. METHODS: Human primary cementoblasts (HPCBs) from two individuals were subjected to compressive loading at 30 g/cm(2) for 1/6/10 h. The cells were then evaluated for apoptosis by flow cytometry, for mRNA expression of putative genes (AXUD1, AXIN1, AXIN2) by quantitative PCR, and for involvement of c-Jun-N-terminal kinases (JNKs) in the regulation of AXUD1 via western blotting. In addition, platelet-derived growth factor receptor-ß (PDGFRß) was selectively inhibited by SU16f to analyze the effect of PDGFRß-dependent signal transduction on AXUD1 and AXIN1 expression. RESULTS: The percentage of apoptotic HPCBs rose after only 6 h of compressive loading, and 18-20 % of cells were apoptotic after 10 h. Microarray data revealed significant upregulation of the pro-apoptotic gene AXUD1 after 6 h and quantitative PCR significant AXUD1 upregulation after 6 and 10 h of compression. AXIN1 and AXIN2 expression in HPCBs was significantly increased after compressive loading. Our tests also revealed that PDGFRß signaling inhibition by SU16f augmented the expression of AXIN1 and AXUD1 in HPCBs under compression. CONCLUSION: Increased apoptosis of compressed HPCBs might help explain why cementoblasts, rather than invariably repairing all cases of root resorption, sometimes allow the original root length to shorten. The pathway hypothesized to lead to cementoblast apoptosis involves PDGF signaling, with this signal transduction's inhibition augmenting the expression of pro-apoptotic genes. Thus activating PDGF signaling may modify the signaling pathway for the apoptosis of cementoblasts, which would reveal a protective role of PDGF for these cells. Further studies are needed to develop strategies of treatment capable of minimizing root resorption.

Biological evaluation of enamel sealants in an organotypic model of the human gingiva.

OBJECTIVES: Various sealant materials have been suggested to decrease decalcification during orthodontic treatment. However, only a few in vitro studies on the cytotoxicity of resinous pit and fissure sealants have been published, and to the best of our knowledge no similar studies are available for the enamel sealants used in orthodontics. Therefore, we aimed to characterize the possible adverse effects of enamel sealants, especially on the gingival epithelium. METHODS: Organotypic cultures of the human gingival mucosa were used to assess the possible impact of six enamel sealants. Differentiation and apoptosis were determined by immunofluorescent staining. The pro-inflammatory cytokines IL-1ß and IL-6 were quantified by ELISA. Cytotoxicity was measured using MTS assays in monolayer cultures of human gingival fibroblasts. Leaching of monomers from enamel sealants was quantified using HPLC. RESULTS: The differentiation of the organotypic gingival mucosa remained unaffected. All under-cured and several standard-cured sealants (Light Bond™ Sealant, Light Bond™ Filled Sealant, and L.E.D. Pro Seal®) significantly induced apoptosis in the organotypic model. Light Bond™ Sealant, Light Bond™ Filled Sealant, and L.E.D. Pro Seal® caused a significant induction of pro-inflammatory cytokines. Reducing curing time had an influence on cytotoxicity in monolayer cultures of primary human oral cells. All resin-based sealants leached monomers. SIGNIFICANCE: Enamel sealants might exert adverse effects on the gingival epithelium. Due to the vicinity of the enamel sealant to the gingival epithelium, and the large surface area of applied sealants, these materials should be carefully applied and sufficiently cured.

Gene expression profile of compressed primary human cementoblasts before and after IL-1ß stimulation.

OBJECTIVES: Root resorptions due to a reduced repair function of cementoblasts are common side effects during orthodontic tooth movement (OTM). The mechanisms, which lead to an impaired cementoblast function, are not fully understood. Therefore, we aimed to investigate changes in the gene expression of cementoblasts during mechanical stimulus under inflammatory conditions. MATERIALS AND METHODS: Human primary cementoblasts (HPCB) were exposed to compression for 6 h or stimulation with IL-1ß for 96 h and subsequent 6 h compression. Genome-wide expression analysis was performed using microarray analysis. Prominent gene expression alterations (COX2, AXUD1, FOSB, CCL2, IFI6, and PTGES) were verified by quantitative RT-PCR (qRT-PCR) in two HPCB populations. A caspase 3/7 activity assay was used to determine caspase-3 and caspase-7 activity in stressed cells. RESULTS: Gene expression cluster analysis revealed apoptosis as an important process induced under both conditions. Apoptosis (pro- and anti-apoptotic) related gene expression was most relevant after pro-inflammatory stimulation and compression. qRT-PCR analysis confirmed significant up-regulation of COX2, AXUD1, and FOSB in both HPCB populations after compression, while selected genes significantly increased after pro-inflammatory stimulation and compression. Compression of cementoblasts increased caspase. The combination of pro-inflammatory stimulation and compression led to a slightly smaller increase of caspase activity. CONCLUSIONS: Gene ontology analysis showed that compressed HPCB up-regulate genes that are associated with apoptosis. Combining compression with a pro-inflammatory stimulus (IL-1ß) augmented the positive regulation of apoptosis-related pathways. The induction of apoptosis related gene expression (pro- and anti-apoptotic genes) in cementoblasts suggests an involvement of apoptosis in cementoblast regulation during OTM. CLINICAL RELEVANCE: As apoptosis is induced in HPCB after compression and inflammation, it is conceivable that HPCB cell death might contribute to root resorptions due to a loss of repair activity of cementoblasts. Further studies should be conducted to clarify the implication of the identified genes on root resorptions in order to develop therapeutic strategies to prevent a shortening of roots.

The management of dental anxiety and impact of psychosomatic factors on dentistry: is recent scientific research translated into German dental practices?

This study investigated the dentists' knowledge about psychosomatic medicine. Anxiolytic techniques, considerations about psychosomatic medicine, and referrals to psychotherapists were examined by a questionnaire. Overall, 65 percent felt negatively affected by patients with dental fear. Few dentists used relaxation techniques and hypnosis. The relationship between psychosomatic factors and pain perception was well known, but not their impact on wound healing. The frequency of continuing education courses correlated with a broader range of treatment techniques and less difficulties in treatment. Research evidence about the impact of psychological factors on dental treatment has not been translated into dental practice.

IL-1ß and compressive forces lead to a significant induction of RANKL-expression in primary human cementoblasts.

AIM: The aim of this study was to investigate the response of primary human cementoblasts to conditions as they occur on the pressure side during orthodontic tooth movement. METHODS: In our previous study, the cementoblasts were characterized using markers for osteoblastogenic differentiation and the cementoblast-specific marker CEMP-1. Initially, primary human cementoblasts were compressed for 1 h, 4 h, and 6 h (30 g/cm(2)). In the second experiment, the cementoblasts were stimulated with interleukin (IL)-1ß for 24 h and for 96 h with 1 ng/ml and 10 ng/ml and subsequently compressed for 1 h and 6 h. Changes in mRNA expression for receptor activator of NF-κB (RANK), RANK ligand (RANKL), osteoprotegerin (OPG), and cyclooxygenase-2 (COX-2) were measured by quantitative real-time polymerase chain reaction (RT-PCR). RANK and RANKL were also examined by immunocytochemical staining at the protein level. RESULTS: Compression (30 g/cm(2)) led to a significant increase in RANKL expression after 6 h. OPG expression in compressed cementoblasts was significantly reduced after 1 h. RANK remained unchanged during the course of the experiment. Stimulation with IL-1ß induced RANKL and OPG expression. However, IL-1ß-dependent induction of RANKL was more prominent than the induction of OPG, leading to a (significant) increase in the RANKL/OPG ratios. The expression of RANK remained unchanged after 24 h of stimulation with IL-1ß and decreased significantly after 96 h. Compression of the prestimulated cells resulted in a further increase in RANKL expression significant after 6 h. OPG and RANK expression remained unchanged compared to the unstimulated sample. COX-2 increased significantly after both compression and stimulation with IL-1ß. Combined stimulation and compression resulted in a significant further increase after 6 h compared to IL-1ß stimulation alone. CONCLUSION: Primary human cementoblasts in vitro express increased levels of RANKL, in particular during the combination of inflammation and compression. The increase in RANKL expression is not compensated by an increase in OPG expression. The induction of RANKL expression was associated with a significant increase in COX-2 expression. Since RANKL attracts osteoclasts, its increase might be associated with the progression of root resorption. The in vitro alterations in cementoblasts we observed may be indicators of cellular mechanisms that lead to the increased root resorption during orthodontic treatment.

Dental fear in children and adolescents: a comparison of forms of anxiety management practised by general and paediatric dentists.

BACKGROUND. About 11% of children and adolescents suffer from dental fear. These young people run an increasing risk of undergoing more invasive treatments. AIM. We researched the management of dental anxiety in young patients by general and paediatric dentists as well as by trained and untrained dentists. DESIGN. Eight hundred dentists in Germany were interviewed via e-mail regarding their experience, treatment techniques, information material and complications during the treatment of fearful children. We also examined how difficult dentists judge the treatment of anxious children and how often they participate in continuing education courses. RESULTS. Paediatric dentists applied a greater spectrum of management techniques than general dentists. They used more often psychotherapeutic interventions and anxiety assessment questionnaires. Dentists who frequently attend in continuing education courses judged the treatment to be less difficult and also used psychotherapeutic interventions more often. CONCLUSIONS. German paediatric dentists and dentists who take continuing education courses utilise a broader range of techniques to manage dental anxiety. They may be eminently suited to treat children with severe forms of anxiety. Therefore, dentists who treat young patients should participate in education programmes so as to reduce both the anxiety of their patients and their own anxiety.

Strain-dependent up-regulation of ephrin-B2 protein in periodontal ligament fibroblasts contributes to osteogenesis during tooth movement.

During orthodontic tooth movement, the application of adequate orthodontic forces allows teeth to be moved through the alveolar bone. These forces are transmitted through the periodontal ligaments (PDL) to the supporting alveolar bone and lead to deposition or resorption of bone, depending on whether the tissues are exposed to a tensile or compressive mechanical strain. Fibroblasts within the PDL (PDLF) are considered to be mechanoresponsive. The transduction mechanisms from mechanical loading of the PDLF to the initiation of bone remodeling are not clearly understood. Recently, members of the ephrin/Eph family have been shown to be involved in the regulation of bone homeostasis. For the first time, we demonstrate that PDLF exposed to tensile strain induce the expression of ephrin-B2 via a FAK-, Ras-, ERK1/2-, and SP1-dependent pathway. Osteoblasts of the alveolar bone stimulated with ephrin-B2 increased their osteoblastogenic gene expression and showed functional signs of osteoblastic differentiation. In a physiological setting, ephrin-B2-EphB4 signaling between PDLF and osteoblasts of the alveolar bone might contribute to osteogenesis at tension sites during orthodontic tooth movement.