[A statistical study on the orthodontic patients in Meikai University Hospital]

We analyzed statistically two thousand orthodontic patients in Meikai University Hospital (formerly Josai Dental University Hospital) who have undergone treatment since the establishment of the hospital (1970-1985). By classifying the data in various ways, we obtained the following statistics; 1) The number of new patients increased quickly after the first class graduated from our university; 2) The number of patients from six to fifteen years old was the largest, with the peak being nine years old; 3) For the time of the first visit, many new patients came during spring and summer vacations, and a few junior high school and high school students came just season before taking their entrance examination; 4) The female sex predominated in most age groups; however, among patients in their twenties, the male sex was predominant, and in recent years the male ratio tended to increase; 5) Most patients came from a radius of less than 20 km from the hospital (mostly from along Tohbu railway line), with few from beyond 30 km; 6) Anterior crossbite and anterior crowding cases were many, particularly, young patients comprised many of the anterior crossbite cases; and in adult patients large overjet cases increased with the advance of age.