軟骨無形成症の頭蓋顎顔面骨格とこう合の形態的特徴

Abstract

Achondroplasia is a disorder of growth-plate chondrocytes, with short, thick limbs and craniofacial malformation due to lack of development of the nasomaxillary complex. Two cases of achondroplasia with apertognathia, maxillary protrusion, and different malocculusions were reported, and the morphological characteristics of the craniofacial skeleton in each case were discussed. One patient was a 12-year 10-month-old male with anterior open-bite and crowding. The other patient was a 10-year 0-month-old female who complained of remarkable lahial tipping of her maxillary incisors. She had habits of lip biting and tongue thrusting. Both patients had the following common characteristics of craniofacial skeleton and teeth: 1. The anterior cranial base was very large, and the occipital base was small.2. Both showed skeletal Class III abnormalities due to maxillary retrusion.3. No unusual abnormality was recognized in the form, number or eruption time of permanent teeth.4. The maxillary incisors showed marked labial tipping.However, their malocculusions were different due to the differences in stage of skeletal maturity, degree of maxillary retrusion, oral habits, and function of the muscles surrounding the oral cavity.