The three-dimensional finite volume model of the lower central incisor with bracket and archwire.

<p>The peri-bracket sites were divided as extending 2 mm around the bracket base. Occlusal regions along the bracket (BO), gingival region along the bracket (BG), left region along the bracket (BL) and right region along the bracket (BR).</p

Mean numbers of total colony-forming units (CFU), with a logarithmic scale, at T0, T1 and T2.

<p>Four peri-bracket sites includes: occlusal regions along the bracket (BO), gingival region along the bracket (BG), left region along the bracket (BL) and right region along the bracket (BR).</p

Longitudinal changes in periodontal measurements of bonded teeth.

<p>Longitudinal changes in periodontal measurements of bonded teeth.</p

Salivary velocity distribution on lower central incisor.

<p>The salivary velocity distribution were displayed when (a) the saliva was flowing gingivally at T1; (b) the saliva flowing occlusally at T1; (c) the saliva flowing gingivally at T2; (d) the saliva flowing occlusally at T2. The red enclosed area illustrated the low velocity areas, and the arrow indicates the direction of saliva flow.</p

Average salivary velocity of peri-bracket sites at T1 and T2.

<p>Occlusal regions along the bracket (BO), gingival region along the bracket (BG), left region along the bracket (BL) and right region along the bracket (BR).</p

Amount of total bacteria colony-forming units (CFU) per site at T1 and T2.

<p>The first part displays the averages per site, the second part the differences between the sites with the corresponding <i>P</i>-values.</p

Salivary velocity contour on lower central incisor.

<p>The salivary velocity contour were displayed when (a) the saliva flowed gingivally at T1; (b) the saliva flowed occlusally at T1; (c) the saliva flowed gingivally at T2; (d) the saliva flowed occlusally at T2. The bottom figures demonstrated the routes of salivary flow in the gingival region along the bracket (BG). The red enclosed area illustrated the vortex areas, and the arrow indicated the direction of saliva flow.</p

Comprehensive Analysis of Mandibular Residual Asymmetry after Bilateral Sagittal Split Ramus Osteotomy Correction of Menton Point Deviation

<div><p>Purpose</p><p>Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement.</p><p>Patients and Methods</p><p>A retrospective cohort study was conducted at the Hospital of Stomatology, Sun Yat-sen University (China) of patients with pure hemi-mandibular elongation (HE) from September 2010 through May 2014. Mandibular models were reconstructed from CBCT images of patients with pre-surgical orthodontic treatment. After mandibular de-rotation and midline alignment with virtual BSSRO, the elongation hemi-mandible was virtually mirrored along the facial sagittal plane. The residual asymmetry, defined as the superimposition and boolean operation of the mirrored elongation side on the normal side, was calculated, including the volumetric differences and the length of transversal and vertical asymmetry discrepancy. For more specific evaluation, both sides of the hemi-mandible were divided into the symphysis and parasymphysis (SP), mandibular body (MB), and mandibular angle (MA) regions. Other clinical variables include deviation of Me point, dental midline and molar relationship. The measurement of volumetric discrepancy between the two sides of post-surgical hemi-mandible were also calculated to verify the availability of virtual surgery. Paired t-tests were computed and the <i>P</i> value was set at .05.</p><p>Results</p><p>This study included 45 patients. The volume differences were 407.8±64.8 mm³, 2139.1±72.5 mm³, and 422.5±36.9 mm³; residual average transversal discrepancy, 1.9 mm, 1.0 mm, and 2.2 mm; average vertical discrepancy, 1.1 mm, 2.2 mm, and 2.2 mm (before virtual surgery). The post-surgical volumetric measurement showed no statistical differences between bilateral mandibular regions.</p><p>Conclusions</p><p>Mandibular asymmetry persists after Me point correction. A 3D quantification of mandibular residual asymmetry after Me point correction and mandible de-rotation with virtual BSSRO sets up a true reference mirror plane for comprehensive asymmetry assessment of bilateral mandibular structure, thereby providing an accurate guidance for orthognathic surgical planning.</p></div

Two-Dimensional Ultrathin MXene Ceramic Nanosheets for Photothermal Conversion

Ceramic biomaterials have been investigated for several decades, but their potential biomedical applications in cancer therapy have been paid much less attentions, mainly due to their lack of related material functionality for combating the cancer. In this work, we report, for the first time, that MAX ceramic biomaterials exhibit the unique functionality for the photothermal ablation of cancer upon being exfoliated into ultrathin nanosheets within atomic thickness (MXene). As a paradigm, biocompatible Ti₃C₂ nanosheets (MXenes) were successfully synthesized based on a two-step exfoliation strategy of MAX phase Ti₃AlC₂ by the combined HF etching and TPAOH intercalation. Especially, the high photothermal-conversion efficiency and <i>in vitro</i>/<i>in vivo</i> photothermal ablation of tumor of Ti₃C₂ nanosheets (MXenes) were revealed and demonstrated, not only in the intravenous administration of soybean phospholipid modified Ti₃C₂ nanosheets but also in the localized intratumoral implantation of a phase-changeable PLGA/Ti₃C₂ organic–inorganic hybrid. This work promises the great potential of Ti₃C₂ nanosheets (MXenes) as a novel ceramic photothermal agent used for cancer therapy and may arouse much interest in exploring MXene-based ceramic biomaterials to benefit the biomedical applications

A Two-Dimensional Biodegradable Niobium Carbide (MXene) for Photothermal Tumor Eradication in NIR‑I and NIR-II Biowindows

Conventionally, ceramics-based materials, fabricated by high-temperature solid-phase reaction and sintering, are preferred as bone scaffolds in hard-tissue engineering because of their tunable biocompatibility and mechanical properties. However, their possible biomedical applications have rarely been considered, especially the cancer phototherapeutic applications in both the first and second near-infrared light (NIR-I and NIR-II) biowindows. In this work, we explore, for the first time as far as we know, a novel kind of 2D niobium carbide (Nb₂C), MXene, with highly efficient in vivo photothermal ablation of mouse tumor xenografts in both NIR-I and NIR-II windows. The 2D Nb₂C nanosheets (NSs) were fabricated by a facile and scalable two-step liquid exfoliation method combining stepwise delamination and intercalation procedures. The ultrathin, lateral-nanosized Nb₂C NSs exhibited extraordinarily high photothermal conversion efficiency (36.4% at NIR-I and 45.65% at NIR-II), as well as high photothermal stability. The Nb₂C NSs intrinsically feature unique enzyme-responsive biodegradability to human myeloperoxidase, low phototoxicity, and high biocompatibility. Especially, these surface-engineered Nb₂C NSs present highly efficient in vivo photothermal ablation and eradication of tumor in both NIR-I and NIR-II biowindows. This work significantly broadens the application prospects of 2D MXenes by rationally designing their compositions and exploring related physiochemical properties, especially on phototherapy of cancer