Quantifying the potential of morphological parameters for human dental identification: part 2-selecting the strongest identifiers in mandibular permanent teeth.

The current study aimed to select the best dental morphological identifiers for human identification. Sixty-two panoramic radiographs were collected retrospectively, in which six measurements were performed on all seven mandibular left permanent teeth: tooth length (TL), crown length (CL), root length (RL), crown width (CW), cervical width (CEJW), and root width (RW). Nine length-width ratios were then calculated using these measurements. Three groups of statistics were considered: (1) inter-observer reliability quantified by intra-class correlation (ICC); (2) mean "potential set"; and (3) Spearman correlation. A step-by-step cascade was then established based on selected parameters. In a univariate approach, the following parameters were the best identifiers: TL/CW for tooth 36 (ICC 0.82; mean potential set 13.7%), TL/CEJW for tooth 35 (ICC 0.87; mean potential set 15.2%), and TL/RW for tooth 32 (ICC 0.89; mean potential set 16.0%). The correlations between these three parameters ranged from 0.24 to 0.47. In a multivariate approach, the following parameters had the best identifying capacity: all parameters combined for tooth 31 (mean potential set 8.1%), for tooth 35 (mean potential set 11.9%), and for tooth 32 (mean potential set 16.3%). In conclusion, a single ratio in a specific tooth narrows down the potential set of matches, but the mean potential set remains relatively large. Combining all ratios of a single specific tooth increases the certainty of the match. In particular, tooth 31 was the strongest identifier.

Osteogenic properties of bioactive titanium in inflammatory environment.

OBJECTIVES: It is very important that the effects of surface modified titanium on osteogenic differentiation of bone marrow mesenchymal stem cells in the process of bone regeneration. The bio-function of modified titanium could be affected by the inflammatory micro-environment. The aim of this study was to investigate the effects of modified titanium on osteogenic differentiation in the inflammatory conditions and the osteogenic properties of the modified titanium dental implant in vivo. METHODS: The medical pure titanium metals (PT-Ti) subjected to Anodic Oxidation (AO-Ti), Sand Blasting/acid etching (SLA-Ti) and Plasma-sprayed HA coating (HA coating-Ti) were used for regulating the osteogenic properties of MSCs in the normal and inflammatory conditions. RESULTS: The amount of the MSCs in the inflammatory environment were more similar to that in the non-inflammatory environment after cultured on AO-Ti samples for 7D. However, the proliferation of the MSCs was obviously inhibited on the other groups in the inflammatory condition. The morphology of MSC cells on the modified titanium surface was affected in the inflammatory conditions and the AO-Ti was more conducive to maintain the skeletal morphology of MSCs. The results of osteogenic related proteins expression showed that the amount of BMP-2 on AO-Ti group was the highest in the inflammatory conditions, and followed the order of AO-Ti > HA coating-Ti > SLA-Ti > PT-Ti. What's more, the AO-Ti samples were more beneficial to promote the expression of osteogenic genes ALP, OCN, COL-I and Runx2 in the inflammatory conditions. The results of osteogenic properties in vivo showed that the gingival depth of the AO-Ti group was smaller than that on the other groups. Some new bone could be observed around the AO-Ti implant at two weeks. The bone binding rates on AO-Ti group was the highest of 81.3% after implanted for one year. SIGNIFICANCE: The AO-Ti was beneficial to osteogenic differentiation than other modified titanium metals in inflammatory condition. The anodic oxidation is an effective surface modification method on titanium to promote bone regeneration.

Efficacy and safety of Runzao Zhiyang capsule for chronic urticaria: a systematic review and meta-analysis of randomized controlled trials.

Background: Chronic urticaria (CU) is a commonly seen skin disorder featured by recurring wheals, with or without angioedema, lasting for at least 6 weeks. Runzao Zhiyang capsule (RZC) has been widely applied to treat patients with CU. This study is aimed at systematically evaluating the efficacy and safety of RZC in treating CU. Materials and Methods: Randomized controlled trials (RCTs) of RZC on treating CU from Chinese and English databases were searched. Data were collected by two independent researchers. The Cochrane Collaboration tool was adopted for evaluating the risk of bias. The meta-analysis was performed with Review Manager 5.3 software. Sensitivity analysis and publication bias assessment were conducted by Stata 14.0 software. Results: Totally 27 studies were included in the analysis, involving 2,703 patients. The pooled results showed that compared with second-generation H1-antihistamines (sgAHs) therapy alone, RZC combined with sgAHs is more effective in improving the total effective rate (RR = 1.32, 95% CI: 1.25 to 1.39, p < 0.00001), the quality of life measured by Dermatology Life Quality Index (DLQI) (MD = -2.63, 95% CI: -3.68 to -1.58, p < 0.00001) and the serum IFN-γ level (SMD = 3.10, 95% CI: 1.58 to 4.62, p < 0.0001), and reducing the recurrence rate (RR = 0.39, 95% CI: 0.27 to 0.55, p < 0.00001), the serum total IgE level (SMD = -2.44, 95% CI: -3.51 to -1.38, p < 0.00001), the serum IL-4 level (SMD = -2.96, 95% CI: -4.10 to -1.83, p < 0.00001), and the incidence of adverse events including dizziness, fatigue, dry mouth, and constipation (RR = 0.53, 95% CI: 0.33 to 0.85, p = 0.009; RR = 0.46, 95% CI: 0.26 to 0.84, p = 0.01; RR = 0.57, 95% CI: 0.34 to 0.95, p = 0.03; RR = 0.24, 95% CI: 0.07 to 0.85, p = 0.03). Conclusion: The current evidence indicates that RZC may be an efficient therapeutic regimen in patients with CU. Nevertheless, owing to the suboptimal quality of the included studies, more large-scale, well-designed RCTs are required to verify the obtained findings. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/; Identifier: CRD42022313177.

Simultaneous correction of bilateral temporomandibular joint ankylosis with mandibular micrognathia using internal distraction osteogenesis and 3-dimensional craniomaxillofacial models.

PURPOSE: The present study evaluated the simultaneous correction of bilateral temporomandibular joint ankylosis with mandibular micrognathia using internal distraction osteogenesis (DO) with the help of a 3-dimensional craniomaxillofacial model technique. MATERIALS AND METHODS: A total of 16 patients (age 18 to 43 years) with bilateral temporomandibular joint ankylosis and mandibular micrognathia were included in the present study. Obstructive sleep apnea and hypopnea syndrome was diagnosed in all patients preoperatively. Three-dimensional craniomaxillofacial models of the 16 patients were constructed using computed tomography and a rapid prototype technique. Simulation surgery and individual internal DO was performed on the models. The treatment included simultaneous DO of the mandibular body and transport DO for temporomandibular joint arthroplasty. The distraction was started on the seventh day after surgery. The distraction rate was 0.8 mm/day. The patients began active mouth opening postoperatively. Distracters were kept in place for 4 months after distraction completion and then removed. Polysomnography, cephalometry, and computed tomography were performed at 6 months postoperatively. RESULTS: The obstructive sleep apnea and hypopnea syndrome was cured, and the micrognathia was corrected in all patients. The average mouth opening increased from 4.6 mm preoperatively to 33.5 mm postoperatively. The average range of the sella-nasion-supramental angle increased from 68.7 degrees preoperatively to 77.6 degrees postoperatively. Bone formation in the distraction gaps was observed. The follow-up period was 29.7 months (range 6 to 52). No complications or recurrence of temporomandibular joint ankylosis or micrognathia occurred in any patient during the follow-up period. CONCLUSIONS: Bilateral temporomandibular joint ankylosis accompanied by mandibular micrognathia and obstructive sleep apnea and hypopnea syndrome can be corrected effectively by simultaneous internal DO. The application of preoperative simulation surgery using 3-dimensional craniomaxillofacial model has many advantages for planning the surgical method and precise operation. Our preliminary results have shown that it is a safe, effective, and feasible technique.

Thecodont tooth attachment and replacement in bolosaurid parareptiles.

Permian bolosaurid parareptiles are well-known for having complex tooth crowns and complete tooth rows in the jaws, in contrast to the comparatively simple teeth and frequent replacement gaps in all other Paleozoic amniotes. Analysis of the specialized dentition of the bolosaurid parareptiles Bolosaurus from North America and Belebey from Russia, utilizing a combination of histological and tomographic data, reveals unusual patterns of tooth development and replacement. The data confirm that bolosaurid teeth have thecodont implantation with deep roots, the oldest known such example among amniotes, and independently evolved among much younger archosauromorphs (including dinosaurs and crocodilians) and among synapsids (including mammals). High-resolution CT scans were able to detect the density boundary between the alveolar bone and the jawbone, as confirmed by histology, and revealed the location and size of developing replacement teeth in the pulp cavity of functional teeth. Evidence provided by the paratype dentary of Belebey chengi indicates that replacement teeth are present along the whole tooth row at slightly different stages of development, with the ontogenetically more developed teeth anteriorly, suggesting that tooth replacement was highly synchronized. CT data also show tooth replacement is directly related to the presence of lingual pits in the jaw, and that migration of tooth buds occurs initially close to these resorption pits to a position immediately below the functional tooth within its pulp cavity. The size and complex shape of the replacement teeth in the holotype of Bolosaurus grandis indicate that the replacement teeth can develop within the pulp cavity to an advanced stage while the previous generation remains functional for an extended time, reminiscent of the condition seen in other amniotes with occluding dentitions, including mammals.

Placement of Teflon Sponges in Microvascular Decompression Procedure for Treatment of Hemifacial Spasm.

Background Hemifacial spasm (HFS) is generally treated by microvascular decompression (MVD). Inadequate separation of vessel and nerve or adhesive inflammation surrounding the nerve root may cause recurrence. Objective To explore a method to reduce the incidence of adhesions and to ensure sufficient separation of the offending vessel and nerve during MVD. Methods Fifty-one patients diagnosed with HFS were studied. During the MVD procedure, Teflon sponges were placed between the offending vessels and medulla oblongata to push compressing vessels away from the facial nerve without contacting the nerve. Results Our method of placement of the Teflon sponge effectively shifts the compressing artery and ensures that both the Teflon sponge and offending vessels do not contact the root exit zone. This method also ensures that the Teflon sponge is fixed in place. Conclusion The technique described for the treatment of HFS provides an effective, safe, and durable resolution to patient symptoms that minimizes surgical complications and may be useful in treating HFS.

[Reconstruction and measurement of a digital dental model using grating projection and reverse engineering].

OBJECTIVE: This work lays the foundation for establishing a digital model database with normal occlusion. A digital dental cast is acquired through grating projection, and model features are measured through reverse engineering. METHODS: The grating projection system controlled by a computer was projected onto the surface of a normal dental model. Three-dimensional contour data were obtained through multi-angle shooting. A three-dimensional model was constructed, and the model features were analyzed by using reverse engineering. The digital model was compared with the plaster model to determine the accuracy of the measurement system. RESULTS: The structure of three-dimensional reconstruction model was clear. The digital models of two measurements exhibited no significant difference (P > 0.05). When digital and plaster models were measured, we found that the crown length and arch width were not statistically different (P > 0.05), whereas the difference between the crown width and arch length was statistically significant (P < 0.05). CONCLUSION: The reconstruction of a digital model by using the grating projection technique and reverse engineering can be used for dental model measurement in clinic al and scientific research and can provide a scientific method for establishing a digital model database with normal occlusion.

Synthesis and characterization of novel blood-compatible soluble chemically cross-linked polyurethanes with excellent mechanical performance for biomedical applications.

A controlled cross-linking polymerization system was designed, and soluble chemically cross-linked polyurethane was synthesized using laurylamine, n-octylamine, n-pentylamine, and ethylenediamine chain extenders. The mechanical analysis showed that the polyurethane materials synthesized in this paper have very excellent mechanical properties with a breaking elongation of 1914% and a tensile strength of 4303 N/cm(2). Such good mechanical properties must enable it to have good longevity when used as biomaterials. The polyurethane materials with n-pentylamine and n-octylamine chain extenders show reduced platelet adhesion than that with an ethylenediamine chain extender after sustaining 200 000 times of load cycles, indicating that polyurethanes introduced with an alkyl side chain onto the hard segments keep good antithrombogenic properties after sustaining load cycles. This might be because the hard segments are shielded by the alkyl side chain when the micro-phase-separation structure is destroyed in the repeated deformation of the polyurethane materials. The present investigation reveals that the influence of introducing long alkyl side chains into the backbone of the polyurethane macromolecule has been shown to reduce platelet deposition and to enhance in vitro albumin adsorption. However, in this paper, it has been observed that the polyurethane material introduced with a proper-length alkyl side chain onto the hard segment has the best antithrombogenic properties after the fatigue test.