Lingual bracket transfer accuracy of double vacuum-formed indirect bonding tray using 3D-printed model: an in vivo study.

INTRODUCTION: This study aimed to assess the transfer accuracy of a digital indirect bonding method for lingual brackets using double vacuum-formed trays in vivo. METHODS: Twenty-five patients in need of lingual orthodontic treatment were consecutively recruited. Bracket placement was performed on ideal setups, followed by fabricating indirect bonding trays through vacuum-forming on 3-dimensional printed models. Transfer accuracy was measured at each bracket after superimpositions of postbonding scans and reference data. One-tailed t tests were used to determine whether bracket deviations were within the limit of 0.5 mm and 2° for linear and angular dimensions, respectively. RESULTS: A total of 611 lingual brackets were evaluated. Mean linear transfer errors were 0.06 mm, 0.09 mm, and 0.12 mm, with frequencies of deviations within the 0.5 mm limit of 99.7%, 99.8%, and 98.0% for mesiodistal, buccolingual, and occlusogingival dimensions, respectively. Regarding angular measurements, mean transfer errors were 1.28°, 1.73°, and 2.96°, with frequencies of deviations within the 2° limit of 81.0%, 68.9%, and 51.1% for rotation, tip, and torque, respectively. Mean errors fell within the clinically accepted limits for all linear dimensions and rotation but exceeded the limit for tip and torque. CONCLUSIONS: Lingual bracket indirect bonding using double vacuum-formed trays fabricated on 3-dimensional printed models has high transfer accuracy in the mesiodistal, buccolingual, and occlusogingival dimensions and rotation. However, the transfer of tip and torque is less accurate.

Comparison of In-Hospital Outcomes of Surgical Stabilization of Rib Fractures with Nonsurgical Management: A Multicenter, Prospective, Cohort Study.

Background: Evidence for the efficacy of surgical stabilization of rib fractures in patients with rib fractures is controversial. Objective: We aim to compare the clinical outcomes of surgical rib fixation for rib fracture with non-operative treatment. Methods: Our institutional database from three general hospitals (Viet Duc Hospital, Viet Tiep Friendship Hospital & Cho Ray Hospital) was queried to identify patients with flail chest treated with locked plate fixation between December 2021 and February 2023. A medical record review for demographic, injury, hospital, and surgical data was also retrospectively performed for all patients. Characteristics and outcomes of the patients receiving the surgical rib fixation for rib fracture were compared with those without surgery. Results: A total of 166 patients with thoracic trauma were included. The majority of patients were male, and the age range was from 18 to 80 years old, with a mean age of 51.6 years. 52 (31.3%) underwent surgical stabilization of rib fractures (SSRF). The highest combined injuries were limb injuries, followed by traumatic brain injury, and maxillofacial trauma. While 1 patient died in the non-surgical group, there was no significant difference in the mortality between the two groups. The surgical group had a slightly shorter hospital stay than the non-surgical group (8.6 days vs. 10.0 days, p-value: 0.038). SSRF group tended toward a lower incidence of pneumonia compared to the non-surgical group (SSRF: 3.8% vs. non-surgical: 7%), but this difference was not statistically significant (p-value: 0.426). SSRF group also had a lower incidence of tracheostomy than the non-operative group (SSRF: 0% vs. non-surgical: 1.8%, p-value: 0.337). Conclusion: Operative fixation of a rib fracture in trauma patients resulted in a lower incidence of pneumonia, fewer days of mechanical ventilation, and a shorter hospital stay compared to non-operative treatment group.

Mortality risk factors in patients on waiting list for lung transplantation between 2005 and 2018: A single institutional experience.

BACKGROUND: Lung transplantation is a therapeutic option for patients with end-stage lung disease. However, the increase in organ demand has surpassed the number of donors, with many patients unable to outlive the long waiting period. This study aimed to assess mortality and its risk factors in patients on the waiting list for lung transplantation in a single medical centre. METHODS: All evaluated clinical and laboratory data of the patients with end-stage lung disease assessed for lung transplantation between February 2005 and November 2018 in National Taiwan University Hospital were recorded in the waiting list database. The patients in this study were divided into two groups: survival and death groups. RESULTS: Between February 2005 and November 2018, 169 patients were enrolled in the waiting list. Thirty-one patients were alive and waiting for the chance of lung transplantation, 56 underwent lung transplantation, and 82 died while waiting. The mean age of all patients was 43.7 years, and 91 were women. The mean body mass index (BMI) was 20.3. The most common blood type was type O. All patients were in New York Heart Association (NYHA) class III or IV. After analysis of the two groups, lower BMI presented as a mortality factor. CONCLUSION: This is the first Taiwanese study to describe the mortality factors in patients waiting for lung transplantation. The main factors influencing the survival of these patients were lower BMI, NYHA class IV, and diseases which cause end-stage lung diseases (infection and pulmonary fibrosis).

Skeletal Class III Malocclusion with Lateral Open Bite and Facial Asymmetry Treated with Asymmetric Lower Molar Extraction and Lingual Appliance: A Case Report.

A skeletal Class III malocclusion with open bite tendency is considered very difficult to treat orthodontically without surgery. This case report describes the lingual orthodontic treatment of an adult skeletal Class III patient with mandibular deviation to the left side, lateral open bite, unilateral posterior crossbite, zero overbite and negative overjet. The lower incisors were already retroclined to compensate with the skeletal discrepancy. The patient was treated by asymmetric molar extraction in the mandibular arch to retract the lower incisors and correct the dental midline, with the help of intermaxillary elastics. Lingual appliance was used with over-torqued lower anterior teeth's brackets to control the torque of mandibular incisors. After a 30-month treatment, satisfactory smile and facial esthetics and good occlusion was achieved. A 12-month follow-up confirmed that the outcome was stable. Asymmetric molar extraction could be a viable option to retract mandibular incisors in Class III malocclusion with lower dental midline deviation.

Perceptions of Dentists and Non-Professionals on Some Dental Factors Affecting Smile Aesthetics: A Study from Vietnam.

Aim: It is important to meet the aesthetic expectation regarding the smile concept of both dentists and non-professionals after treatment is complete. Therefore, the study aims to evaluate the effects of altered displays in incisors, gingival margin, and other smile-related-factors on dentists' vs. non-professionals' aesthetics perceptions. Materials and method: We altered the features of 42 digital smile photographs to generate the changed displays in incisors, gingival margin, and other smile-related-factors. Then, these altered photographs were presented to 51 dentists and 51 non-professionals, and each picture was rated by each participant with a visual analog scale ranging from 0 (very ugly) to 100 (very beautiful). Results: We found that the alterations in incisors, gingival margin, and other factors affected studied groups' aesthetic perception of smile. The ugly smile threshold rated by both groups for crown length of maxillary central incisors was 2.0 mm. This threshold was 2.5mm for dentists, with moving the gingival margin of maxillary lateral incisors to the incisal ridge. The ugly thresholds for other smile-related-factors were different between studied groups; for example, the ugly thresholds for gingival exposure levels were 3 and 4mm for dentists and non-professionals, respectively. Thus, our data indicate that altered displays in incisors, gingival margin, and other smile-related-factors affected perceptions of both studied groups on smile aesthetics, but dentists tended to feel more refined than non-professionals. Dentists and non-professionals had significantly different aesthetic perceptions of the alteration of the gingival exposure level. Conclusion: Both dentists and non-professionals' perceptions should be fully considered during orthodontic and prosthodontic treatment to achieve optimum aesthetic results.

Sensitivity-Based Calibration of the Soil and Water Assessment Tool for Hydrologic Cycle Simulation in the Cong Watershed, Vietnam.

For better water resources management in quality and quantity, an accurate model is needed for simulating the hydrologic cycle and water quality dynamics at a watershed scale. In this study, a semi-distributed hydrologic model, the Soil and Water Assessment Tool (SWAT), was applied for hydrologic cycle assessment in the Cong Watershed, Vietnam. After model-output and accuracy-based sensitivity analyses were conducted without and with observation data, respectively, model parameters were calibrated and validated using meteorological and runoff data observed between 1961 and 1975. Model performance in annual, monthly, and daily flow simulations was assessed using the Nash-Sutcliffe Efficiency coefficient and the coefficient of determination (R²). As a result, the accuracy-based sensitivity analysis better identified the key parameters, as compared to the model output-based sensitivity analysis, resulting in better flow simulations in the Cong River. The calibrated model performed well in hydrologic cycle simulations in the Cong Watershed, suggesting the applicability of the SWAT model.

Analysis of variation and relation of climate, hydrology and water quality in the lower Mekong River.

In order to determine the influence of climate and hydrology on water quality of the lower Mekong River, the long term monitoring data (from 1985 to 2004) of climatic, hydrological and water quality variables were analyzed. In general, water quality was 'good' or 'very good' for most of the investigated water quality parameters including DO, pH, conductivity, nitrate, phosphate and total phosphorus. All climatic and hydrological elements as well as most of the water quality parameters varied seasonally. Throughout the 18-year period, only evaporation, water level and TSS showed a significant pertinent trend. ARIMA models results reveal that among climatic and hydrological paremeters, water quality could be effectively predicted from the data of discharge flow and precipitation. The results showed good R² (≥ 0.7) estimation between predicted and observed values for TSS, alkalinity and conductivity which are the chemically and biologically conservative parameters. For other water quality parameters such as Ca² (+ ), Mg²( +), Si, Cl⁻, NO³â», and SO4²â», the predicting results by ARIMA model were reliable in shorter period than the above three mentioned variables.