Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Skull Neoplasms: Neoplasms of the bony part of the skull.Skull Base Neoplasms: Neoplasms of the base of the skull specifically, differentiated from neoplasms of unspecified sites or bones of the skull (SKULL NEOPLASMS).Skull Fractures: Fractures of the skull which may result from penetrating or nonpenetrating head injuries or rarely BONE DISEASES (see also FRACTURES, SPONTANEOUS). Skull fractures may be classified by location (e.g., SKULL FRACTURE, BASILAR), radiographic appearance (e.g., linear), or based upon cranial integrity (e.g., SKULL FRACTURE, DEPRESSED).Skull Fracture, Depressed: A skull fracture characterized by inward depression of a fragment or section of cranial bone, often compressing the underlying dura mater and brain. Depressed cranial fractures which feature open skin wounds that communicate with skull fragments are referred to as compound depressed skull fractures.Parietal Bone: One of a pair of irregularly shaped quadrilateral bones situated between the FRONTAL BONE and OCCIPITAL BONE, which together form the sides of the CRANIUM.Cranial Sutures: A type of fibrous joint between bones of the head.Craniosynostoses: Premature closure of one or more CRANIAL SUTURES. It often results in plagiocephaly. Craniosynostoses that involve multiple sutures are sometimes associated with congenital syndromes such as ACROCEPHALOSYNDACTYLIA; and CRANIOFACIAL DYSOSTOSIS.Occipital Bone: Part of the back and base of the CRANIUM that encloses the FORAMEN MAGNUM.Dinosaurs: General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.Skull Fracture, Basilar: Fractures which extend through the base of the SKULL, usually involving the PETROUS BONE. Battle's sign (characterized by skin discoloration due to extravasation of blood into the subcutaneous tissue behind the ear and over the mastoid process), CRANIAL NEUROPATHIES, TRAUMATIC; CAROTID-CAVERNOUS SINUS FISTULA; and CEREBROSPINAL FLUID OTORRHEA are relatively frequent sequelae of this condition. (Adams et al., Principles of Neurology, 6th ed, p876)Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Chordoma: A malignant tumor arising from the embryonic remains of the notochord. It is also called chordocarcinoma, chordoepithelioma, and notochordoma. (Dorland, 27th ed)Zygoma: Either of a pair of bones that form the prominent part of the CHEEK and contribute to the ORBIT on each side of the SKULL.Cephalometry: The measurement of the dimensions of the HEAD.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).Temporal Bone: Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).Craniotomy: Any operation on the cranium or incision into the cranium. (Dorland, 28th ed)Cerebrospinal Fluid Rhinorrhea: Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Bite Force: The force applied by the masticatory muscles in dental occlusion.Facial Bones: The facial skeleton, consisting of bones situated between the cranial base and the mandibular region. While some consider the facial bones to comprise the hyoid (HYOID BONE), palatine (HARD PALATE), and zygomatic (ZYGOMA) bones, MANDIBLE, and MAXILLA, others include also the lacrimal and nasal bones, inferior nasal concha, and vomer but exclude the hyoid bone. (Jablonski, Dictionary of Dentistry, 1992, p113)Scalp: The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).Sex Determination by Skeleton: Validation of the sex of an individual by means of the bones of the SKELETON. It is most commonly based on the appearance of the PELVIS; SKULL; STERNUM; and/or long bones.Craniocerebral Trauma: Traumatic injuries involving the cranium and intracranial structures (i.e., BRAIN; CRANIAL NERVES; MENINGES; and other structures). Injuries may be classified by whether or not the skull is penetrated (i.e., penetrating vs. nonpenetrating) or whether there is an associated hemorrhage.Dentition: The teeth collectively in the dental arch. Dentition ordinarily refers to the natural teeth in position in their alveoli. Dentition referring to the deciduous teeth is DENTITION, PRIMARY; to the permanent teeth, DENTITION, PERMANENT. (From Jablonski, Dictionary of Dentistry, 1992)Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Meningioma: A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)Surgical Equipment: Nonexpendable apparatus used during surgical procedures. They are differentiated from SURGICAL INSTRUMENTS, usually hand-held and used in the immediate operative field.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.Foramen Magnum: The large hole at the base of the skull through which the SPINAL CORD passes.Kinesis: Locomotor behavior not involving a steering reaction, but in which there may be a turning random in direction. It includes orthokinesis, the rate of movement and klinokinesis, the amount of turning, which are related to the intensity of stimulation.Mastication: The act and process of chewing and grinding food in the mouth.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.Orbit: Bony cavity that holds the eyeball and its associated tissues and appendages.Head Injuries, Penetrating: Head injuries which feature compromise of the skull and dura mater. These may result from gunshot wounds (WOUNDS, GUNSHOT), stab wounds (WOUNDS, STAB), and other forms of trauma.Petrous Bone: The dense rock-like part of temporal bone that contains the INNER EAR. Petrous bone is located at the base of the skull. Sometimes it is combined with the MASTOID PROCESS and called petromastoid part of temporal bone.Jaw: Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.Plagiocephaly: The condition characterized by uneven or irregular shape of the head often in parallelogram shape with a flat spot on the back or one side of the head. It can either result from the premature CRANIAL SUTURE closure (CRANIOSYNOSTOSIS) or from external forces (NONSYNOSTOTIC PLAGIOCEPHALY).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)Finite Element Analysis: A computer based method of simulating or analyzing the behavior of structures or components.Paleontology: The study of early forms of life through fossil remains.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.Paleopathology: The study of disease in prehistoric times as revealed in bones, mummies, and archaeologic artifacts.Anatomy, Comparative: The comparative study of animal structure with regard to homologous organs or parts. (Stedman, 25th ed)Acrocephalosyndactylia: Congenital craniostenosis with syndactyly.Craniofacial Abnormalities: Congenital structural deformities, malformations, or other abnormalities of the cranium and facial bones.Dura Mater: The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.Mastoid: The posterior part of the temporal bone. It is a projection of the petrous bone.Cranial Fossa, Posterior: The infratentorial compartment that contains the CEREBELLUM and BRAIN STEM. It is formed by the posterior third of the superior surface of the body of the sphenoid (SPHENOID BONE), by the occipital, the petrous, and mastoid portions of the TEMPORAL BONE, and the posterior inferior angle of the PARIETAL BONE.Tooth: One of a set of bone-like structures in the mouth used for biting and chewing.Meningeal Neoplasms: Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.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.Imaging, Three-Dimensional: The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.Masticatory Muscles: Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)Alligators and Crocodiles: Large, long-tailed reptiles, including caimans, of the order Loricata.Craniofacial Dysostosis: Autosomal dominant CRANIOSYNOSTOSIS with shallow ORBITS; EXOPHTHALMOS; and maxillary hypoplasia.Cranial Nerve Diseases: Disorders of one or more of the twelve cranial nerves. With the exception of the optic and olfactory nerves, this includes disorders of the brain stem nuclei from which the cranial nerves originate or terminate.Head: The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.Neurosurgical Procedures: Surgery performed on the nervous system or its parts.Palate, Hard: The anteriorly located rigid section of the PALATE.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Encephalocele: Brain tissue herniation through a congenital or acquired defect in the skull. The majority of congenital encephaloceles occur in the occipital or frontal regions. Clinical features include a protuberant mass that may be pulsatile. The quantity and location of protruding neural tissue determines the type and degree of neurologic deficit. Visual defects, psychomotor developmental delay, and persistent motor deficits frequently occur.Hyperostosis: Increase in the mass of bone per unit volume.Cerebrospinal Fluid Otorrhea: Discharge of cerebrospinal fluid through the external auditory meatus or through the eustachian tube into the nasopharynx. This is usually associated with CRANIOCEREBRAL TRAUMA (e.g., SKULL FRACTURE involving the TEMPORAL BONE;), NEUROSURGICAL PROCEDURES; or other conditions, but may rarely occur spontaneously. (From Am J Otol 1995 Nov;16(6):765-71)Body Weights and Measures: Measurements of the height, weight, length, area, etc., of the human and animal body or its parts.Osteitis Deformans: A disease marked by repeated episodes of increased bone resorption followed by excessive attempts at repair, resulting in weakened, deformed bones of increased mass. The resultant architecture of the bone assumes a mosaic pattern in which the fibers take on a haphazard pattern instead of the normal parallel symmetry.Traction: The pull on a limb or a part thereof. Skin traction (indirect traction) is applied by using a bandage to pull on the skin and fascia where light traction is required. Skeletal traction (direct traction), however, uses pins or wires inserted through bone and is attached to weights, pulleys, and ropes. (From Blauvelt & Nelson, A Manual of Orthopaedic Terminology, 5th ed)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).Head Injuries, Closed: Traumatic injuries to the cranium where the integrity of the skull is not compromised and no bone fragments or other objects penetrate the skull and dura mater. This frequently results in mechanical injury being transmitted to intracranial structures which may produce traumatic brain injuries, hemorrhage, or cranial nerve injury. (From Rowland, Merritt's Textbook of Neurology, 9th ed, p417)Maxilla: One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the ORBIT, and contains the MAXILLARY SINUS.Skeleton: The rigid framework of connected bones that gives form to the body, protects and supports its soft organs and tissues, and provides attachments for MUSCLES.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.Bone Diseases: Diseases of BONES.Meninges: The three membranes that cover the BRAIN and the SPINAL CORD. They are the dura mater, the arachnoid, and the pia mater.Mummies: Bodies preserved either by the ancient Egyptian technique or due to chance under favorable climatic conditions.LizardsParanasal 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.Microsurgery: The performance of surgical procedures with the aid of a microscope.Nasal Bone: Either one of the two small elongated rectangular bones that together form the bridge 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.Beak: In some animals, the jaws together with their horny covering. The beak usually refers to the bill of birds in which the whole varies greatly in form according of the food and habits of the bird. While the beak refers most commonly to birds, the anatomical counterpart is found also in the turtle, squid, and octopus. (From Webster, 3d ed & Storer, et al., General Zoology, 6th ed, p491, 755)Neuronavigation: Intraoperative computer-assisted 3D navigation and guidance system generally used in neurosurgery for tracking surgical tools and localize them with respect to the patient's 3D anatomy. The pre-operative diagnostic scan is used as a reference and is transferred onto the operative field during surgery.Reconstructive Surgical Procedures: Procedures used to reconstruct, restore, or improve defective, damaged, or missing structures.Atlanto-Occipital Joint: The point of articulation between the OCCIPITAL BONE and the CERVICAL ATLAS.Famous PersonsHistory, Ancient: The period of history before 500 of the common era.