Paranasal Sinuses: Air-filled spaces located within the bones around the NASAL CAVITY. They are extensions of the nasal cavity and lined by the ciliated NASAL MUCOSA. Each sinus is named for the cranial bone in which it is located, such as the ETHMOID SINUS; the FRONTAL SINUS; the MAXILLARY SINUS; and the SPHENOID SINUS.Paranasal Sinus Neoplasms: Tumors or cancer of the PARANASAL SINUSES.Paranasal Sinus Diseases: Diseases affecting or involving the PARANASAL SINUSES and generally manifesting as inflammation, abscesses, cysts, or tumors.Maxillary Sinus Neoplasms: Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.Maxillary Sinus: The air space located in the body of the MAXILLARY BONE near each cheek. Each maxillary sinus communicates with the middle passage (meatus) of the NASAL CAVITY on the same side.Frontal Sinus: One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the FRONTAL BONE in the forehead.Ethmoid Sinus: The numerous (6-12) small thin-walled spaces or air cells in the ETHMOID BONE located between the eyes. These air cells form an ethmoidal labyrinth.Sinusitis: Inflammation of the NASAL MUCOSA in one or more of the PARANASAL SINUSES.Nose Neoplasms: Tumors or cancer of the NOSE.Nasal Cavity: The proximal portion of the respiratory passages on either side of the NASAL SEPTUM. Nasal cavities, extending from the nares to the NASOPHARYNX, are lined with ciliated NASAL MUCOSA.Sphenoid Sinus: One of the paired air spaces located in the body of the SPHENOID BONE behind the ETHMOID BONE in the middle of the skull. Sphenoid sinus communicates with the posterosuperior part of NASAL CAVITY on the same side.Mucocele: A retention cyst of the salivary gland, lacrimal sac, paranasal sinuses, appendix, or gallbladder. (Stedman, 26th ed)Turbinates: The scroll-like bony plates with curved margins on the lateral wall of the NASAL CAVITY. Turbinates, also called nasal concha, increase the surface area of nasal cavity thus providing a mechanism for rapid warming and humidification of air as it passes to the lung.Nasal Polyps: Focal accumulations of EDEMA fluid in the NASAL MUCOSA accompanied by HYPERPLASIA of the associated submucosal connective tissue. Polyps may be NEOPLASMS, foci of INFLAMMATION, degenerative lesions, or malformations.Nasal Septum: The partition separating the two NASAL CAVITIES in the midplane. It is formed by the SEPTAL NASAL CARTILAGE, parts of skull bones (ETHMOID BONE; VOMER), and membranous parts.Otorhinolaryngologic Surgical Procedures: Surgery performed on the ear and its parts, the nose and nasal cavity, or the throat, including surgery of the adenoids, tonsils, pharynx, and trachea.Osteoma: A benign tumor composed of bone tissue or a hard tumor of bonelike structure developing on a bone (homoplastic osteoma) or on other structures (heteroplastic osteoma). (From Dorland, 27th ed)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Ethmoid Bone: A light and spongy (pneumatized) bone that lies between the orbital part of FRONTAL BONE and the anterior of SPHENOID BONE. Ethmoid bone separates the ORBIT from the ETHMOID SINUS. It consists of a horizontal plate, a perpendicular plate, and two lateral labyrinths.Sphenoid Sinusitis: Inflammation of the NASAL MUCOSA in the SPHENOID SINUS. Isolated sphenoid sinusitis is uncommon. It usually occurs in conjunction with other paranasal sinusitis.Rhinitis: Inflammation of the NASAL MUCOSA, the mucous membrane lining the NASAL CAVITIES.Rhinometry, Acoustic: Diagnostic measurement of the nose and its cavity through acoustic reflections. Used to measure nasal anatomical landmarks, nasal septal deviation, and nasal airway changes in response to allergen provocation tests (NASAL PROVOCATION TESTS).Frontal Sinusitis: Inflammation of the NASAL MUCOSA in the FRONTAL SINUS. In many cases, it is caused by an infection of the bacteria STREPTOCOCCUS PNEUMONIAE or HAEMOPHILUS INFLUENZAE.Epistaxis: Bleeding from the nose.Nose Diseases: Disorders of the nose, general or unspecified.Orbital Neoplasms: Neoplasms of the bony orbit and contents except the eyeball.Exophthalmos: Abnormal protrusion of both eyes; may be caused by endocrine gland malfunction, malignancy, injury, or paralysis of the extrinsic muscles of the eye.Orbit: Bony cavity that holds the eyeball and its associated tissues and appendages.Nose Deformities, Acquired: Abnormalities of the nose acquired after birth from injury or disease.Esthesioneuroblastoma, Olfactory: A malignant olfactory neuroblastoma arising from the olfactory epithelium of the superior nasal cavity and cribriform plate. It is uncommon (3% of nasal tumors) and rarely is associated with the production of excess hormones (e.g., SIADH, Cushing Syndrome). It has a high propensity for multiple local recurrences and bony metastases. (From Holland et al., Cancer Medicine, 3rd ed, p1245; J Laryngol Otol 1998 Jul;112(7):628-33)Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Ethmoid Sinusitis: Inflammation of the NASAL MUCOSA in the ETHMOID SINUS. It may present itself as an acute (infectious) or chronic (allergic) condition.Cranial Sinuses: Large endothelium-lined venous channels situated between the two layers of DURA MATER, the endosteal and the meningeal layers. They are devoid of valves and are parts of the venous system of dura mater. Major cranial sinuses include a postero-superior group (such as superior sagittal, inferior sagittal, straight, transverse, and occipital) and an antero-inferior group (such as cavernous, petrosal, and basilar plexus).Orbital Diseases: Diseases of the bony orbit and contents except the eyeball.Nasal Obstruction: Any hindrance to the passage of air into and out of the nose. The obstruction may be unilateral or bilateral, and may involve any part of the NASAL CAVITY.Tampons, Surgical: Plugs or cylinders made of cotton, sponge, or other absorbent material. They are used in surgery to absorb fluids such as blood or drainage.Kartagener Syndrome: An autosomal recessive disorder characterized by a triad of DEXTROCARDIA; INFERTILITY; and SINUSITIS. The syndrome is caused by mutations of DYNEIN genes encoding motility proteins which are components of sperm tails, and CILIA in the respiratory and the reproductive tracts.Cranial Fossa, Middle: The compartment containing the anterior extremities and half the inferior surface of the temporal lobes (TEMPORAL LOBE) of the cerebral hemispheres. Lying posterior and inferior to the anterior cranial fossa (CRANIAL FOSSA, ANTERIOR), it is formed by part of the TEMPORAL BONE and SPHENOID BONE. It is separated from the posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) by crests formed by the superior borders of the petrous parts of the temporal bones.Skull Base Neoplasms: Neoplasms of the base of the skull specifically, differentiated from neoplasms of unspecified sites or bones of the skull (SKULL NEOPLASMS).Maxillary Fractures: Fractures of the upper jaw.Cavernous Sinus: An irregularly shaped venous space in the dura mater at either side of the sphenoid bone.Sinus of Valsalva: The dilatation of the aortic wall behind each of the cusps of the aortic valve.Papilloma, Inverted: A mucosal tumor of the urinary bladder or nasal cavity in which proliferating epithelium is invaginated beneath the surface and is more smoothly rounded than in other papillomas. (Stedman, 25th ed)Maxillary Sinusitis: Inflammation of the NASAL MUCOSA in the MAXILLARY SINUS. In many cases, it is caused by an infection of the bacteria HAEMOPHILUS INFLUENZAE; STREPTOCOCCUS PNEUMONIAE; or STAPHYLOCOCCUS AUREUS.Levocardia: Congenital abnormalities in which the HEART is in the normal position (levocardia) in the left side of the chest but some or all of the THORAX or ABDOMEN viscera are transposed laterally (SITUS INVERSUS). It is also known as situs inversus with levocardia, or isolated levocardia. This condition is often associated with severe heart defects and splenic abnormalities such as asplenia or polysplenia.Nose: A part of the upper respiratory tract. It contains the organ of SMELL. The term includes the external nose, the nasal cavity, and the PARANASAL SINUSES.Nasal Sprays: Pharmacologic agents delivered into the nostrils in the form of a mist or spray.Carotid Sinus: The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.Nasal Mucosa: The mucous lining of the NASAL CAVITY, including lining of the nostril (vestibule) and the OLFACTORY MUCOSA. Nasal mucosa consists of ciliated cells, GOBLET CELLS, brush cells, small granule cells, basal cells (STEM CELLS) and glands containing both mucous and serous cells.Wood: A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.Anatomy: A branch of biology dealing with the structure of organisms.Sphenoid Bone: An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Mucormycosis: Infection in humans and animals caused by any fungus in the order Mucorales (e.g., Absidia, Mucor, Rhizopus etc.) There are many clinical types associated with infection of the central nervous system, lung, gastrointestinal tract, skin, orbit and paranasal sinuses. In humans, it usually occurs as an opportunistic infection in patients with a chronic debilitating disease, particularly uncontrolled diabetes, or who are receiving immunosuppressive agents. (From Dorland, 28th ed)Coronary Sinus: A short vein that collects about two thirds of the venous blood from the MYOCARDIUM and drains into the RIGHT ATRIUM. Coronary sinus, normally located between the LEFT ATRIUM and LEFT VENTRICLE on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures.Sinus Thrombosis, Intracranial: Formation or presence of a blood clot (THROMBUS) in the CRANIAL SINUSES, large endothelium-lined venous channels situated within the SKULL. Intracranial sinuses, also called cranial venous sinuses, include the superior sagittal, cavernous, lateral, petrous sinuses, and many others. Cranial sinus thrombosis can lead to severe HEADACHE; SEIZURE; and other neurological defects.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Sick Sinus Syndrome: A condition caused by dysfunctions related to the SINOATRIAL NODE including impulse generation (CARDIAC SINUS ARREST) and impulse conduction (SINOATRIAL EXIT BLOCK). It is characterized by persistent BRADYCARDIA, chronic ATRIAL FIBRILLATION, and failure to resume sinus rhythm following CARDIOVERSION. This syndrome can be congenital or acquired, particularly after surgical correction for heart defects.Aspergillosis: Infections with fungi of the genus ASPERGILLUS.Exhalation: The act of BREATHING out.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.