Palatal Expansion Technique: An orthodontic method used for correcting narrow or collapsed maxillary arches and functional cross-bite. (From Jablonski's Dictionary of Dentistry),Dental Arch: The curve formed by the row of TEETH in their normal position in the JAW. The inferior dental arch is formed by the mandibular teeth, and the superior dental arch by the maxillary teeth.Palate: The structure that forms the roof of the mouth. It consists of the anterior hard palate (PALATE, HARD) and the posterior soft palate (PALATE, SOFT).Osteotomy, Le Fort: Transverse sectioning and repositioning of the maxilla. There are three types: Le Fort I osteotomy for maxillary advancement or the treatment of maxillary fractures; Le Fort II osteotomy for the treatment of maxillary fractures; Le Fort III osteotomy for the treatment of maxillary fractures with fracture of one or more facial bones. Le Fort III is often used also to correct craniofacial dysostosis and related facial abnormalities. (From Dorland, 28th ed, p1203 & p662)Maxillary Osteotomy: Surgery of the upper jaw bone usually performed to correct upper and lower jaw misalignment.Dentofacial Deformities: An abnormality of the jaws or teeth affecting the contour of the face. Such abnormality could be acquired or congenital.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.Jaw Abnormalities: Congenital absence of or defects in structures of the jaw.Orthodontic Appliances: Devices used for influencing tooth position. Orthodontic appliances may be classified as fixed or removable, active or retaining, and intraoral or extraoral. (Boucher's Clinical Dental Terminology, 4th ed, p19)Dental Models: Presentation devices used for patient education and technique training in dentistry.Orthodontic Appliance Design: The planning, calculation, and creation of an apparatus for the purpose of correcting the placement or straightening of teeth.Extraoral Traction Appliances: Extraoral devices for applying force to the dentition in order to avoid some of the problems in anchorage control met with in intermaxillary traction and to apply force in directions not otherwise possible.Malocclusion, Angle Class III: Malocclusion in which the mandible is anterior to the maxilla as reflected by the first relationship of the first permanent molar (mesioclusion).Cephalometry: The measurement of the dimensions of the HEAD.Molar: The most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)Bicuspid: One of the eight permanent teeth, two on either side in each jaw, between the canines (CUSPID) and the molars (MOLAR), serving for grinding and crushing food. The upper have two cusps (bicuspid) but the lower have one to three. (Jablonski, Dictionary of Dentistry, 1992, p822)Malocclusion: Such malposition and contact of the maxillary and mandibular teeth as to interfere with the highest efficiency during the excursive movements of the jaw that are essential for mastication. (Jablonski, Illustrated Dictionary of Dentistry, 1982)Palate, Hard: The anteriorly located rigid section of the PALATE.Palatal Muscles: The muscles of the palate are the glossopalatine, palatoglossus, levator palati(ni), musculus uvulae, palatopharyngeus, and tensor palati(ni).Palatal Obturators: Appliances that close a cleft or fissure of the palate.Palatal Neoplasms: Tumors or cancer of the PALATE, including those of the hard palate, soft palate and UVULA.Cleft Palate: Congenital fissure of the soft and/or hard palate, due to faulty fusion.Palate, Soft: A movable fold suspended from the posterior border of the hard palate. The uvula hangs from the middle of the lower border.