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.