Bone microRNA-21 as surgical stress parameter is associated with third molar postoperative discomfort.

OBJECTIVE: To evaluate an association between bone levels of inflammation/oxidative stress mediators and postoperative discomfort after third molar conventional or piezosurgery. MATERIAL AND METHODS: Twenty-six subjects with bilaterally impacted mandibular third molars, who underwent either piezo or conventional surgery, were included in a split-mouth design study. MicroRNA-21 (miR-21) expression, interleukin-1 beta (IL-1ß), and vascular endothelial growth factor (VEGF) proteins, as well as superoxide dismutase (SOD) activity in alveolar bone, were evaluated. Pain intensity, the first pain appearance, analgesic first use and total dose taken, trismus, and swelling were clinically recorded. RESULTS: MiR-21 expression was higher while VEGF protein was lower in piezosurgery vs. conventional groups. The differences in IL-1ß protein and SOD activity were not significant between groups. The pain intensity on the first day was significantly decreased in piezosurgery group. The first pain appearance and the first analgesic taken were reported sooner in conventional vs. piezosurgical group. Significantly pronounced trismus on the third day following conventional surgery was found. In conventional group, significantly increased trismus was observed on the third compared to the first postoperative day. MiR-21 showed significant correlation with the first pain appearance. CONCLUSION: Delayed onset of less pronounced postoperative pain after piezosurgical vs. conventional extraction of impacted lower third molar was significantly associated with expression of bone miR-21. CLINICAL RELEVANCE: Alveolar bone miR-21 may reflect surgical stress and is associated with third molar postoperative pain onset.

Which substances loaded onto collagen scaffolds influence oral tissue regeneration?-an overview of the last 15 years.

BACKGROUND: Collagen scaffolds are widely used for guided bone or tissue regeneration. Aiming to enhance their regenerative properties, studies have loaded various substances onto these scaffolds. This review aims to provide an overview of existing literature which conducted in vitro, in vivo, and clinical testing of drug-loaded collagen scaffolds and analyze their outcome of promoting oral regeneration. MATERIALS AND METHODS: PubMed, Scopus, and Ovid Medline® were systematically searched for publications from 2005 to 2019. Journal articles assessing the effect of substances on oral hard or soft tissue regeneration, while using collagen carriers, were screened and qualitatively analyzed. Studies were grouped according to their used substance type-biological medical products, pharmaceuticals, and tissue-, cell-, and matrix-derived products. RESULTS: A total of 77 publications, applying 36 different substances, were included. Collagen scaffolds were demonstrating favorable adsorption behavior and release kinetics which could even be modified. BMP-2 was investigated most frequently, showing positive effects on oral tissue regeneration. BMP-9 showed comparable results at lower concentrations. Also, FGF2 enhanced bone and periodontal healing. Antibiotics improved the scaffold's anti-microbial activity and reduced the penetrability for bacteria. CONCLUSION: Growth factors showed promising results for oral tissue regeneration, while other substances were investigated less frequently. Found effects of investigated substances as well as adsorption and release properties of collagen scaffolds should be considered for further investigation. CLINICAL RELEVANCE: Collagen scaffolds are reliable carriers for any of the applied substances. BMP-2, BMP-9, and FGF2 showed enhanced bone and periodontal healing. Antibiotics improved anti-microbial properties of the scaffolds.

Clinical Factors Affecting the Accuracy of Guided Implant Surgery-A Systematic Review and Meta-analysis.

OBJECTIVES: To systematically review the current dental literature regarding clinical accuracy of guided implant surgery and to analyze the involved clinical factors. MATERIAL AND METHODS: PubMed and Cochrane Central Register of Controlled Trials were searched. Meta-analysis and meta-regression analysis were performed. Clinical studies with the following outcome measurements were included: (1) angle deviation, (2) deviation at the entry point, and (3) deviation at the apex. The involved clinical factors were further evaluated. RESULTS: Fourteen clinical studies from 1951 articles initially identified met the inclusion criteria. Meta-regression analysis revealed a mean deviation at the entry point of 1.25 mm (95% confidence interval [CI]: 1.22-1.29), 1.57 mm (95% CI: 1.53-1.62) at the apex, and 4.1° in angle (95% CI: 3.97-4.23). A statistically significant difference (P < .001) was observed in angular deviations between the maxilla and mandible. Partially guided surgery showed a statistically significant greater deviation in angle (P < .001), at the entry point (P < .001), and at the apex (P < .001) compared with totally guided surgery. The outcome of guided surgery with flapless approach indicated significantly more accuracy in angle (P < .001), at the entry point (P < .001), and at apex (P < .001). Significant differences were observed in angular deviation based on the use of fixation screw (P < .001). CONCLUSIONS: The position of guide, guide fixation, type of guide, and flap approach could influence the accuracy of computer-aided implant surgery. A totally guided system using fixation screws with a flapless protocol demonstrated the greatest accuracy. Future clinical research should use a standardized measurement technique for improved accuracy.

Tight Placement of Erich Arch Bar While Avoiding Wire Fatigue Failure.

PURPOSE: To determine the number of wire twists needed to acquire ideal Erich arch bar tightness before wire fatigue failure (fracture) in relation to different distances and angles at which different gauge wires are grasped to provide information to improve the efficiency of arch bar application. MATERIALS AND METHODS: This study mimicked surgical placement of arch bars with 24- and 26-gauge wires. The number of twists to tightness and failure was evaluated when the wire distance between the arch bar and wire holder tip changed (5 vs 10 mm) and when the degree at which the wire was held relative to the tooth axis was changed (45° vs 90°). A wire shearing test also was used to investigate the fatigability of wires tightened under these same conditions. Wires twisted to tightness, past tightness, and after shearing test movements were visualized with electron microscopy. RESULTS: For 24-gauge wire held at 5 mm, 2.6 to 2.8 twists were needed for wire tightness, with failure after 1.7 to 1.9 twists past tightness; for 24-gauge wire held at 10 mm, 4.4 to 4.9 twists produced tightness, with failure after 2.3 to 2.9 twists past tightness. For 26-gauge wire held at 5 mm, 3.3 to 3.5 twists provided tightness, with 1.6 to 1.8 twists past tightness causing failure; for 26-gauge wire held at 10 mm, 5.1 to 5.5 twists produced tightness, with 3.1 to 3.7 twists past tightness causing failure. At a 45° angle, the wire tightened with fewer twists and showed more resistance to failure with twists past tightness compared with 90° using 24- and 26-gauge wires. In contrast, 24-gauge wire held at a 5-mm distance showed the opposite result, with decreased resistance to failure at the 45° angle. However, the differences were not statistically meaningful. Scanning election microscopy showed no wire fatigue for either angle for 26-gauge wire held at a 5-mm distance and twisted to tightness. After overtightening and oscillation, the 90° angle trials showed fatigue, whereas the 45° angle trials did not. CONCLUSIONS: Holding a 24-gauge wire at 45° to the tooth axis is recommended owing to fewer twists to tightness and more resistance to failure. A 5-mm grasping distance is recommended for experienced surgeons owing to fewer twists to tightness, whereas a 10-mm grasping distance is recommended for novice surgeons owing to a greater tolerance for over-twisting before failure.

Increasing orthodontic and orthognathic surgery treatment efficiency with a modified surgery-first approach.

This case report describes the treatment of a 33-year-old white man who had a skeletal Class III and dental Class II subdivision malocclusion caused by a retrognathic maxilla, with severe maxillary crowding, a highly placed maxillary left canine, mild mandibular crowding, and a bilateral posterior crossbite. Treatment was performed with a modified surgery-first approach, which included a short presurgical alignment phase for the correction of the significant maxillary crowding while controlling the incisal angulation, followed by LeFort I maxillary advancement surgery. The short presurgical orthodontic phase aimed at eliminating the anterior dental interferences before the maxillary advancement, and the use of the inherent increased bone turnover in the postsurgical phase helped to reduce the total orthodontic treatment time to 12 months. Pleasing esthetic results and a good functional occlusion were achieved.

Treatment duration and factors associated with the surgery-first approach: a two-center study.

BACKGROUND: The aim of this study was to evaluate treatment duration and number of appointments in orthognathic surgery using the surgery-first approach (SFA) and to evaluate the factors associated to these outcomes. METHODS: This was a retrospective chart review of consecutively treated patients with SFA at a University clinic and a private practice setting. Treatment duration, number of appointment, and factors associated to this duration such as patient demographics, type of surgery, use of 3D planning, and treatment center among others were evaluated. Multivariable linear regression models were used to examine the simultaneous association between all predictor variables and outcomes. RESULTS: Median treatment duration for patients undergoing SFA was 9.6 months [6.1 (25 % percentile); 13.4 (75 % percentile)] with a median number of 13.8 appointments [9 (25 % percentile); 17 (75 % percentile)]. Transverse maxillary expansion was associated with longer treatment duration and number of appointments. There was also a significant difference in number of appointments between the two treatment centers. CONCLUSIONS: SFA significantly reduces treatment duration in orthognathic surgery. Transverse expansion is associated with longer treatment duration and number of appointments.

Seven novel probe systems for real-time PCR provide absolute single-base discrimination, higher signaling, and generic components.

We have developed novel probe systems for real-time PCR that provide higher specificity, greater sensitivity, and lower cost relative to dual-labeled probes. The seven DNA Detection Switch (DDS)-probe systems reported here employ two interacting polynucleotide components: a fluorescently labeled probe and a quencher antiprobe. High-fidelity detection is achieved with three DDS designs: two internal probes (internal DDS and Flip probes) and a primer probe (ZIPR probe), wherein each probe is combined with a carefully engineered, slightly mismatched, error-checking antiprobe. The antiprobe blocks off-target detection over a wide range of temperatures and facilitates multiplexing. Other designs (Universal probe, Half-Universal probe, and MacMan probe) use generic components that enable low-cost detection. Finally, single-molecule G-Force probes employ guanine-mediated fluorescent quenching by forming a hairpin between adjacent C-rich and G-rich sequences. Examples provided show how these probe technologies discriminate drug-resistant Mycobacterium tuberculosis mutants, Escherichia coli O157:H7, oncogenic EGFR deletion mutations, hepatitis B virus, influenza A/B strains, and single-nucleotide polymorphisms in the human VKORC1 gene.

The relationship between implant stability and bone health markers in post-menopausal women with bisphosphonate exposure.

OBJECTIVES: The authors assessed the relationship between implant stability and bone turnover markers in patients with and without a history of bisphosphonate (BP) exposure for treatment of osteopenia/osteoporosis. MATERIALS AND METHODS: One dental implant site was evaluated in 58 post-menopausal women with a spectrum of bone health in a "best practice" prospective cohort study. Each site had a previous or simultaneous bone augmentation procedure. BP exposure at enrollment was categorized as "never" or "past/current" exposure. Implant stability was assessed by resonance frequency analysis (RFA ISQ) at surgery and 8 weeks post-implant. Bone turnover markers, C-telopeptide collagen crosslinks (sCTX) and procollagen -1 N-terminal telopeptide (P1NP), were measured pre-treatment, 1, and 8 weeks following implant surgery. RESULTS: Mean age was 62.4 ± 6.8 years; 66 % were osteopenic/osteoporotic. Average RFA ISQ at placement for all participants was 63.5 ± 11.3, at 8 weeks post-surgery 74.2 ± 9.4 (p < 0.01). Among "past/current" BP users, there was a significant negative correlation between RFA ISQ values at 8 weeks post-implant placement and sCTX and P1NP values at 1 week (ρ = -.65 and ρ = -.55, respectively; p < 0.01) and 8 weeks (ρ = -.64 and ρ = -.52, respectively; p < 0.05). CONCLUSION: RFA ISQ values increased between implant placement and 8 weeks post-surgery demonstrating successful osseointegration. Lower bone turnover was associated with better implant stability among patients with a history of BP exposure. CLINICAL RELEVANCE: Further investigation of the relationship between BP exposure and implant stability is warranted in a larger population, as results may strongly impact on clinical practice decisions.

Three-dimensional cone-beam computed tomography-based virtual treatment planning and fabrication of a surgical splint for asymmetric patients: surgery first approach.

Virtual 3-dimensional planning in orthognathic surgery allows for a detailed visualization and analysis of skeletal and dental deformities, especially in patients with asymmetries. This approach also eliminates conventional stone model surgery through computer-aided fabrication of surgical stents. This article presents a new approach with 3-dimensional cone-beam computed tomography-based treatment planning for the surgical correction of facial asymmetry in conjunction with the surgery first approach. Good esthetic and occlusal outcomes were obtained for 2 patients after orthognathic surgery and orthodontic treatment with a short total treatment time.

Bone quality evaluation: comparison of cone beam computed tomography and subjective surgical assessment.

PURPOSE: To examine the relationship between dental cone beam computed tomography (CBCT) gray scale values and Hounsfield units (HU), and whether the gray values of edentulous sites correlate with the subjective clinical bone quality assessed at surgery. MATERIALS AND METHODS: Two radiographic phantoms containing varying concentrations of either dipotassium hydrogen phosphate or calcium hydroxyapatite (HA) were imaged using multislice CT or CBCT. Reconstructed DICOM data were analyzed to examine the relationship between CBCT gray values and HU. Presurgical CBCT scans from 52 patients who underwent implant placement in the posterior sextants were used. The gray values of the edentulous implant sites were measured and compared with the subjective bone quality assessed at surgery. RESULTS: There was a strong correlation between CBCT gray values and HU. CBCT gray values increased linearly with increasing calcium HA or bone equivalent density material. CBCT gray values measured at edentulous implant sites ranged from -455 to 642, with a trend of decreasing gray values with bone quality type. The median gray values for the four subjective bone types were: 362 (type 1), 214 (type 2), 76 (type 3), and -454 (type 4). CONCLUSIONS: CBCT gray values can be used to infer bone density and may provide a valuable aid to predict bone quality at potential implant sites.

Community Environmental Monitoring Program: a case study of public education and involvement in radiological monitoring.

The public's trust in the source of information about radiation is a key element of its acceptance. The public tends to trust two groups where risk communication is concerned: (1) scientists with expertise who are viewed as acting independently; and (2) friends, family, and other close associates who are viewed as sharing the same interests and concern, even if they have less knowledge of the subject. The Community Environmental Monitoring Program (CEMP) bridges both of these groups by having members of the public help operate and communicate results of a network of 29 radiation monitoring stations around the Nevada National Security Site (NNSS), formerly known as the Nevada Test Site (NTS), the principal continental location where the United States conducted nuclear tests. The CEMP stations, spread across a 160,000 km area, help provide evidence to the public that no releases of radiation of health concern are occurring from the NNSS to public receptors. The stations provide continuous measurements of gamma radiation and collect air particulate samples that are analyzed for radioactivity and meteorological measurements that aid in interpreting variations in background radiation. A public website (http://cemp.dri.edu) provides data for most instruments. Twenty-three of the 29 stations upload their data in near-real time to a public website as well as to digital readout displays at the stations, both of which are key elements in the CEMP's transparency. The remaining six stations upload their data hourly. Public stakeholders who are direct participants provide the most significant element of the CEMP. The "Community Environmental Monitors," who are residents of towns where the stations are located, are part of the chain-of-custody for the air samples, perform minor station maintenance, and most significantly in terms of trust, serve as lay experts on issues concerning the NNSS and on ionizing radiation and nuclear technologies in general. The CEMP meets nearly all of the principles for stakeholder engagement identified by the International Radiation Protection Association.

Botulinum neurotoxin type A-ABO (Dysport): clinical indications and practice guide.

The key points to remember about abobotulinumtoxinA are as follows: BoNTA-ABO (abobotulinumtoxinA [Dysport]; Medicis Aesthetics, Scottsdale, AZ) and BoNTA-ONA (onabotulinumtoxin A [Botox Cosmetic]; Allergan, Irvine, CA) are both derivatives of botulinum toxin A produced from different strains of the bacterium Clostridium botulinum through proprietary manufacturing processes, and both are approved by the US Food and Drug Administration (FDA). BoNTA-ABO and BoNTA-ONA, which are both type A botulinum toxins, should be further differentiated from Myobloc (Solstice Neurosciences, San Francisco, CA), which is the only FDA-approved type B botulinum toxin. BoNTA-ABO, as with other derivatives of botulinum toxin, produces a chemodenervation of the muscle by preventing the release and binding of acetylcholine at the neuromuscular endplate. The paralytic effect of BoNTA-ABO, as with other derivatives of botulinum toxin, produces a relaxation of the underlying muscle with the associated benefit of reducing dynamic rhytids of the overlying skin. BoNTA-ABO units are not interchangeable with BoNTA-ONA units. An understanding of the proper dosing and familiarity with the use of either botulinum toxin in aesthetic applications is required to produce results that are both safe and consistent. Spread of the toxin is dependent on solution volume and injection technique (physically pushing the toxin from the area of injection). Diffusion of the toxin is largely dependent on toxin dose and receptor concentration; unbound toxin moves down a concentration gradient. Beyond the treatment of glabellar rhytids, there are few, if any, randomized, double blind, placebo-controlled studies on the aesthetic uses of BoNTA-ABO. This guide summarizes what is known and serves as a basis for clinical use and continued understanding.

A new technique for characterizing the efficacy of fugitive dust suppressants.

The Portable In-Situ Wind Erosion Laboratory (PI-SWERL) instrument was evaluated for testing the effectiveness of dust suppressants for a range of native and constructed soils. The PM10 (particles with diameter < or = 10 microm) emissions from dust suppressant-treated and untreated soil surfaces were measured periodically over 14 months. No statistically significant differences were found among soil surfaces treated with three dilution mixtures of the dust suppressant. The temporal variation of PM10 emissions from treated and untreated plots for native and constructed soil textures indicated that: (1) reductions of PM10 emissions by the dust suppressant were significant within 2-3 months after the application and diminished substantially thereafter, (2) decomposition of the protective treated layer resulted in high PM10 emissions for longer environmental exposure times, and (3) emissions from untreated soil surfaces declined over time because of the formation of a natural crust. These results demonstrated that the PI-SWERL can provide qualitative and quantitative information on PM10 emissions for a range of soil textures and can be used to estimate the effectiveness of dust suppressants exposed to actual environmental (i.e., weather and solar radiation) conditions over long periods of time.