Dental Articulators: Mechanical devices that simulate the temporomandibular joints and jaws to which maxillary and mandibular casts are attached. The entire assembly attempts to reproduce the movements of the mandible and the various tooth-to-tooth relationships that accompany those movements.Jaw Relation Record: A registration of any positional relationship of the mandible in reference to the maxillae. These records may be any of the many vertical, horizontal, or orientation relations. (Jablonski, Illustrated Dictionary of Dentistry)Dental Occlusion, Centric: Contact between opposing teeth during a person's habitual bite.Speech Articulation Tests: Tests of accuracy in pronouncing speech sounds, e.g., Iowa Pressure Articulation Test, Deep Test of Articulation, Templin-Darley Tests of Articulation, Goldman-Fristoe Test of Articulation, Screening Speech Articulation Test, Arizona Articulation Proficiency Scale.Dental Models: Presentation devices used for patient education and technique training in dentistry.Dental Care: The total of dental diagnostic, preventive, and restorative services provided to meet the needs of a patient (from Illustrated Dictionary of Dentistry, 1982).Dental Occlusion: The relationship of all the components of the masticatory system in normal function. It has special reference to the position and contact of the maxillary and mandibular teeth for the highest efficiency during the excursive movements of the jaw that are essential for mastication. (From Jablonski, Dictionary of Dentistry, 1992, p556, p472)Centric Relation: The location of the maxillary and the mandibular condyles when they are in their most posterior and superior positions in their fossae of the temporomandibular joint.Lip: Either of the two fleshy, full-blooded margins of the mouth.Jaw: Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.Education, Dental: Use for articles concerning dental education in general.Schools, Dental: Educational institutions for individuals specializing in the field of dentistry.Students, Dental: Individuals enrolled a school of dentistry or a formal educational program in leading to a degree in dentistry.Speech: Communication through a system of conventional vocal symbols.Mandibular Condyle: The posterior process on the ramus of the mandible composed of two parts: a superior part, the articular portion, and an inferior part, the condylar neck.Dental Caries: Localized destruction of the tooth surface initiated by decalcification of the enamel followed by enzymatic lysis of organic structures and leading to cavity formation. If left unchecked, the cavity may penetrate the enamel and dentin and reach the pulp.Siloxanes: Silicon polymers that contain alternate silicon and oxygen atoms in linear or cyclic molecular structures.Dental Impression Materials: Substances used to create an impression, or negative reproduction, of the teeth and dental arches. These materials include dental plasters and cements, metallic oxide pastes, silicone base materials, or elastomeric materials.Dental Care for Chronically Ill: Dental care for patients with chronic diseases. These diseases include chronic cardiovascular, endocrinologic, hematologic, immunologic, neoplastic, and renal diseases. The concept does not include dental care for the mentally or physically disabled which is DENTAL CARE FOR DISABLED.Temporomandibular Joint: An articulation between the condyle of the mandible and the articular tubercle of the temporal bone.