Physical Conditions Prevailing in the Nasal and Maxillary Sinus Cavities Based on Numerical Simulation

Background and Objectives: This paper presents a unique study that links the physical conditions in the nasal passage with conditions that favour the development of bacterial strains and the colonization of the mucous membranes of the nose and paranasal sinuses. The physical parameters considered were air flow, pressure, humidity, and temperature. Materials and Methods: Numerical models of the human nose and maxillary sinus were retrospectively reconstructed from CT images of generally healthy young subjects. The state-of-the-art numerical methods and tools were then used to determine the temperature, humidity, airflow velocity, and pressure at specific anatomical locations. Results: The results were compared with optimal conditions for bacterial growth in the nose and sinuses. Conclusions: Temperature, humidity, air velocity, and pressure were shown to play critical roles in the selection and distribution of microorganisms. Furthermore, certain combinations of physical parameters can favour mucosal colonisation by various strains of bacteria.

Bilateral sphenoid sinus mucocele observed in Yaoundé-Cameroon: a case report

A mucocele is a cystic and expansive lesion of the sinus cavities. It is uncommon in the sphenoid sinus and its management is quite challenging especially in low to middle income countries like Cameroon. A 43-years-old female was referred to us by a neurologist for chronic headache and visual disturbances. The pain was unresponsive to analgesics. Physical examination was non-remarkable and a head CT scan realized showed a cyst-like lesion in the sphenoid sinus cavity. Surgical endoscopic treatment was proposed and realized with basic endoscopic instruments, consisting of opening the cavity with drainage of the mucocele. A large opening was made on the anterior wall of the sphenoid sinus, in order to ensure continuous drainage and prevent a recurrence. Sphenoid sinus mucocele is a rare condition, and its diagnosis can be difficult. Confirmation requires specific imaging and treatment is presently well established, but it can be managed with basic tools.

Molecular, Cellular and Pharmaceutical Aspects of Bone Grafting Materials and Membranes During Maxillary Sinus-lift Procedures. Part 1: A General Overview

Sinus augmentation procedure has been demonstrated to be a highly predictable treatment in posterior maxilla atrophy. All the surgical interventions in the maxillary region require deep knowledge of anatomy and possible anatomical variations. In this article, pre-operative and post- operative assessments of sinus cavity as well as novel approaches to deepen our knowledge of the behavior of bone substitute materials are described. The awareness of the patient's morphologic conditions enables exact planning of invasive surgery and aids to avoid complications. Pre- operative radiologic evaluation of the region before sinus lift is advisable both for a planning of the sinus augmentation and for selection and alignment of the optimum placement of implants. On the orthopantomography it is possible to measure the vertical dimension of graft, but not the volume and 3D changes. Cone-beam computed tomography (CBCT) has become the "gold standard" to plan a comprehensive implant treatment and to achieve a post-operative assessment. A computer-aided design/computer-aided manufacturing (CAD/CAM) technique is proposed to produce custom-made block grafts for sinus lift procedure, and a customized cutting guide to accurately place the lateral wall and ease membrane elevation. This procedure allows to reduce intervention time, to precisely adapt the scaffold, to reduce risk of complications and to improve operation quality. Recently, a novel approach has been used to deepen our knowledge of the behavior of BSBs: by means of synchrotron micro-tomography (SCT). It is a 3-D analyzing method, suitable to examine the dynamic and spatial arrangement of regenerative phenomena in complex anatomical structures such as bone, where tissues with several morphologies (alveolar process, unmineralized extracellular matrix, regenerated vessels, etc.) compete to achieve the final goal of bone regeneration.