Vascular Structures of the Lateral Wall of the Maxillary Sinus: A Vascular Labeling Technique.

PURPOSE: Sinus floor augmentation is a common procedure in implant dentistry. However, several intraoperative complications can occur during this procedure, such as bleeding from the lateral wall of the maxillary sinus. The aim of this study was to describe the vascular structures of the lateral wall of the maxillary sinus using a vascular labeling technique. MATERIALS AND METHODS: Ten cadaveric specimens were prepared by the vascular labeling technique. Liquid latex was injected into the large vessels of the head, and the lateral wall of the maxillary sinus was exposed by dissection. The diameter of the vessels and their distance from the alveolar ridge (AR) were recorded. RESULTS: Blood vessels could be observed in all the dissected specimens (100%). The mean distance from the lower edge of the blood vessels to the AR was 18.5 mm (SD 3.31 mm). CONCLUSIONS: The vascular labeling technique detects maxillary sinus vessels in a predictable and effective way. These structures are clinically relevant because they are located in the area where the lateral window is usually created in sinus augmentation procedures and can cause profuse bleeding.

Three-Stage Power Supply System Model for a Wearable IoT Device for COVID-19 Patients.

During the current crisis caused by the COVID-19 pandemic, Wearable IoT (WIoT) health devices have become essential resources for remote monitoring of the main physiological signs affected by this disease. As well as sensors, microprocessor, and wireless communication elements are widely studied, the power supply unit has the same importance for the WIoT technology, since the autonomy of the system between recharges is of great importance. This letter presents the design of the power supply system of a WIoT device capable of monitoring oxygen saturation and body temperature, sending the collected data to an IoT platform. The supply system is based on a three-stage block consisting of a rechargeable battery, battery charge controller, and dc voltage converter. The power supply system is designed and implemented as a prototype in order to test performance and efficiency. The results show that the designed block provides a stable supply voltage avoiding energy losses, which makes it an efficient and rapidly developing system.

Vascular labeling of the head and neck vessels: Technique, advantages and limitations.

BACKGROUND: Vascular staining techniques have been used to describe the vascular structures of several anatomic areas. However, few reports have described this procedure in the head and neck region. This paper describes a head and neck vascular labeling procedure, and describes some of the technical complications that may occur. MATERIAL AND METHODS: Fifteen specimen cadaver heads were prepared. After drying the vascular system, the internal carotid arteries were ligated and a solution with latex and a gelling agent was injected into the internal carotid arteries and external jugular veins. Two different colors were employed to differentiate arteries from veins. A total of 60ml latex was injected into each blood vessel. Subsequently, the specimens were refrigerated at 5°C for a minimum of 24 hours. Finally, a dissection was performed to identify the venous and arterial systems of the maxillofacial region. RESULTS: In most specimens, correct identification of the vascular structures (lingual artery, pterigoyd plexus, and the major palatal arteries, among others) was possible. However, in three heads a major technical problem occurred (the latex remained liquid), making the dissection unfeasible. Other minor complications such as latex obstruction due to the presence of atheromas were found in two further specimens. CONCLUSIONS: The vascular labeling technique is a predictable, effective and simple method for analyzing the vascular system of the maxillofacial area in cadaveric studies, including vessels of reduced diameter or with an intraosseous course. This procedure can be especially useful to teach vascular anatomy to dental students and postgraduate residents. Key words:Blood vessels, vascular casting, vascular labeling, head and neck arteries, carotid arteries, jugular veins.