AAOF Iowa Growth Study Overview

The Iowa Growth Study

Curator: Thomas E. Southard DDS, MS

Institution: Department of Orthodontics - College of Dentistry, University of Iowa

In March of 1946 a program designated as the Facial Growth Study was initiated at the University of Iowa under the direction of Howard V. Meredith and L. B. Higley and sponsored jointly by the Iowa Child Welfare Research Station and the College of Dentistry. Although the study is called “Facial Growth,” numerous trunk and limb measurements were procured in addition to those taken of the head and face. Height, weight, dietary information, and medical history data are included among materials gathered at each appointment. Dental models, anterior and profile photographs, and full intraoral radiographs, were secured semiannually, while posteroanterior and lateral cephalometric radiographs were taken at three-month intervals until age 5 and twice yearly after the children reached the fifth birthday. After age twelve, records were made annually until 1960 when many of the subjects were eighteen years of age. The Iowa Facial Growth Study is a true longitudinal study. A number of facial growth studies in the United States are mixed longitudinal. These are studies where the investigators decide to add individuals while the study is ongoing or one in which a series of short-term pure longitudinal studies overlap; that is, the grouping may be from birth to 6, from 5 to 11, from 10 to 16, and from 15 to 20 years of age. The Iowa Facial Growth Study is unique because the same individuals were followed throughout its duration.

The study is composed of 183 Caucasians (92 males and 91 females), some of the subjects were started as early as 3 years of age, and all were started by age five. Examination appointments were scheduled on, or within five days of, the child’s birthday and the same plan was followed for other visits. Ninety-seven percent of the subjects were of northwest European ancestry and all of the subjects possessed clinically acceptable occlusions, with the dentures appearing to be well oriented with respect to the face.

All of the study material is in excellent condition and is stored in a dedicated room (Iowa Facial Growth Study Laboratory) within the Department of Orthodontics, University of Iowa College of Dentistry. A substantial contribution from the Orthodontic Department and the College of Dentistry has resulted in this space being recently remodeled. The study materials are placed on custom shelving and in custom filing cabinets. Approximately 3600 lateral cephalometric radiographs, 3600 anteroposterior cephalometric radiographs, frontal and profile facial photographs, dental radiographs, models, demographic data, and anthropometric measurements are included in the study.