Craniofacial Abnormalities: Congenital structural deformities, malformations, or other abnormalities of the cranium and facial bones.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)Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Macroglossia: The presence of an excessively large tongue, which may be congenital or may develop as a result of a tumor or edema due to obstruction of lymphatic vessels, or it may occur in association with hyperpituitarism or acromegaly. It also may be associated with malocclusion because of pressure of the tongue on the teeth. (From Jablonski, Dictionary of Dentistry, 1992)Ectromelia: Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.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).Abnormalities, MultipleBranchial Region: A region, of SOMITE development period, that contains a number of paired arches, each with a mesodermal core lined by ectoderm and endoderm on the two sides. In lower aquatic vertebrates, branchial arches develop into GILLS. In higher vertebrates, the arches forms outpouchings and develop into structures of the head and neck. Separating the arches are the branchial clefts or grooves.Cleft Palate: Congenital fissure of the soft and/or hard palate, due to faulty fusion.Neural Crest: The two longitudinal ridges along the PRIMITIVE STREAK appearing near the end of GASTRULATION during development of nervous system (NEURULATION). The ridges are formed by folding of NEURAL PLATE. Between the ridges is a neural groove which deepens as the fold become elevated. When the folds meet at midline, the groove becomes a closed tube, the NEURAL TUBE.Syndrome: A characteristic symptom complex.Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Maxillofacial Development: The process of growth and differentiation of the jaws and face.Craniofacial Dysostosis: Autosomal dominant CRANIOSYNOSTOSIS with shallow ORBITS; EXOPHTHALMOS; and maxillary hypoplasia.Cephalometry: The measurement of the dimensions of the HEAD.Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Skull Base: The inferior region of the skull consisting of an internal (cerebral), and an external (basilar) surface.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.Mandibulofacial Dysostosis: A hereditary disorder occurring in two forms: the complete form (Franceschetti's syndrome) is characterized by antimongoloid slant of the palpebral fissures, coloboma of the lower lid, micrognathia and hypoplasia of the zygomatic arches, and microtia. It is transmitted as an autosomal trait. The incomplete form (Treacher Collins syndrome) is characterized by the same anomalies in less pronounced degree. It occurs sporadically, but an autosomal dominant mode of transmission is suspected. (Dorland, 27th ed)Frontal Bone: The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the NASAL BONE and the CHEEK BONE on each side of the face.Jaw: Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.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.Tooth Abnormalities: Congenital absence of or defects in structures of the teeth.Cleft Lip: Congenital defect in the upper lip where the maxillary prominence fails to merge with the merged medial nasal prominences. It is thought to be caused by faulty migration of the mesoderm in the head region.