Abstract
In clinical pediatric dentistry, there are numerous cases encountered of abnormality in the number of teeth. The effect of abnormality in the number of teeth on the deciduous dentition and permanent dentition, and also on the state of the occlusion is great. We encountered a rare case where _??__??__??_were congenitally missing and a supernumerary maxillary median tooth was found in the same oral cavity of a 9-year-old boy. These congenitally missing teeth and the supernumerary tooth caused malalignment and occlusal disharmony. Treatment by occlusal guidance was completed during the three years and six months since the first examination.
(1) The patient is a boy,9 years and 10 months old, and came to our hospital with the chief complaint of esthetic impairment of the region of the anterior teeth. (2) The case was stage IIIB of Hellman's dental age. (3) _??__??__w?e?r_e congenitally missing and an inversed supernumerary tooth was found in the maxillary median region. (4)_??__??__??_ showed a slight crowding, and median diastema was found at _??__??. _(5_)? ?_T he anterior showed crossbite. (6) The treatment was completed with an occlusal guidance device using quad helix, chin cap, class III elastic, and the serial extraction method during the 3 years and 6 months since the first examination.
