Computer-Assisted Preoperative Simulation and Augmented Reality for Extraction of Impacted Supernumerary Teeth: A Clinical Case Report of Two Cases.

Delayed eruption, malocclusion, poor oral hygiene, and formation of follicular cysts are some complications associated with an impacted supernumerary tooth (ST). Although surgical extraction is one of the methods to prevent these complications, it can also lead to fractured roots or has a risk of permanent injury to young teeth and gingiva. Recently, computer-assisted preoperative simulation has been helpful in planning the surgery for precise extraction of impacted ST guided with 3-dimensional images. Herein, we present 2 cases of extraction of severely impacted ST guided by preoperative computer-assisted simulation and intraoperative augmented reality. While being minimally invasive, the augmented reality-guided system can precisely highlight the tooth position. The therapeutic aspects of these procedures have also been discussed.

Nutritional condition in the dry period is related to the incidence of postpartum subclinical endometritis in dairy cattle.

OBJECTIVE: Endometritis is a major disease, that causes infertility in cattle, and is usually categorized as clinical or subclinical endometritis (SCE). The nutritional condition during the dry period is important for recovery after the last stage of the lactation period, and for postpartum production and reproduction. This study aimed to clarify the relationship between nutritional and metabolic characteristics in the dry period, and the risk of postpartum SCE. METHODS: Multiparous Holstein dairy cows (n = 25, raised in a tied stall) were used. Endometrial cytological analysis was performed around 30 days post-partum, with 5% to 14% polymorphonuclear (PMN) as a cut-off point to define SCE. Serum levels of glucose, non-esterified fatty acids, ß-hydroxybutyric acid (BHBA), blood urea nitrogen, total cholesterol, aspartate aminotransferase, γ-glutamyl transpeptidase, calcium, phosphorus, and magnesium were measured in the cows at the dry period to evaluate energy status, protein metabolism, and mineral metabolism. RESULTS: The incidence of SCE in the cows was 60.0% (n = 15/25) and the mean PMN% in postpartum cows diagnosed as SCE was 8.05%±2.6%. Overall, 17 and 8 samples were collected from the cows in the far-off and close-up periods, respectively. The serum concentration of BHBA in the far-off period and serum glucose concentration in the closeup period were correlated with postpartum PMN% (r = 0.62, p<0.01; r = -0.74, p<0.05, respectively). Serum levels of calcium and magnesium in the dry period were associated with the incidence of postpartum SCE (healthy vs SCE cows, p<0.05). CONCLUSION: Blood levels of glucose, BHBA, calcium, and magnesium in dry periods could be useful parameters for predicting the risk of postpartum SCE. The present study also suggests that management in the close-up period is essential for promoting recovery from calving fatigue.

Solution-mediated nanometric growth of α-Fe2O3 with electrocatalytic activity for water oxidation.

This paper describes a simple, low-temperature, and environmentally friendly aqueous route for the layer-by-layer nanometric growth of crystalline α-Fe2O3. The formation mechanism involves alternative sequences of the electrostatic adsorption of Fe2+ ions on the surface and the subsequent onsite oxidation to Fe3+. A combination analysis of X-ray diffraction, scanning electron microscopy, UV-Vis spectroscopy, and X-ray photoelectron spectroscopy revealed that α-Fe2O3 is directly formed without post-growth annealing via designed chemical reactions with a growth rate of ca. 1.7 nm per deposition cycle. The obtained α-Fe2O3 layer exhibits electrocatalytic activity for water oxidation and, at the same time, insignificant photo-electrocatalytic response, indicating its defective nature. The electrocatalytic activity was tailored by annealing up to 500 °C in air, where thermal diffusion of Sn4+ into the α-Fe2O3 lattice from the substrate probably provides an increased electrical conductivity. The subsequent surface-modification with Ni(OH)2 lowers the overpotential (250 mV at 0.5 mA cm-2) in a 1 M KOH solution. These findings open direct growth pathways to functional metal oxide nanolayers via liquid phase atomic layer deposition.

Computer-assisted preoperative simulation for positioning and fixation of plate in 2-stage procedure combining maxillary advancement by distraction technique and mandibular setback surgery.

INTRODUCTION: Computer-assisted preoperative simulation surgery is employed to plan and interact with the 3D images during the orthognathic procedure. It is useful for positioning and fixation of maxilla by a plate. We report a case of maxillary retrusion by a bilateral cleft lip and palate, in which a 2-stage orthognathic procedure (maxillary advancement by distraction technique and mandibular setback surgery) was performed following a computer-assisted preoperative simulation planning to achieve the positioning and fixation of the plate. A high accuracy was achieved in the present case. PRESENTATION OF CASE: A 21-year-old male patient presented to our department with a complaint of maxillary retrusion following bilateral cleft lip and palate. Computer-assisted preoperative simulation with 2-stage orthognathic procedure using distraction technique and mandibular setback surgery was planned. DISCUSSION: The preoperative planning of the procedure resulted in good aesthetic outcomes. The error of the maxillary position was less than 1mm. CONCLUSION: The implementation of the computer-assisted preoperative simulation for the positioning and fixation of plate in 2-stage orthognathic procedure using distraction technique and mandibular setback surgery yielded good results.

Computer-assisted preoperative simulation for positioning of plate fixation in Lefort I osteotomy: A case report.

Computed tomography images are used for three-dimensional planning in orthognathic surgery. This facilitates the actual surgery by simulating the surgical scenario. We performed a computer-assisted virtual orthognathic surgical procedure using optically scanned three-dimensional (3D) data and real computed tomography data on a personal computer. It helped maxillary bone movement and positioning and the titanium plate temporary fixation and positioning. This simulated the surgical procedure, which made the procedure easy, and we could perform precise actual surgery and could forecast the postsurgery outcome. This simulation method promises great potential in orthognathic surgery to help surgeons plan and perform operative procedures more precisely.