Craniofacial Research Instrumentation Laboratory



Definition of Terms

Acquisition Group – An Acquisition Group is a set of records, including headfilms and treatment records, acquired from a single location. Locations include private practices and teaching and research institutions. Once the records that make up an acquisition group have been cataloged by CRIL, they are sampled and analyzed in groupings called Studies. Acqusition Groups are designated by names, usually indicating the practice or institution from which the records were selected. Currently, the CRIL Web Site displays the raw images for each acquisition. If you want to see the landmarks and other data that were acquired from these images, look in the Study section of the database.

Case – A case is the total collection of records for a single patient. Each case may have multiple records collected over a period of time, before, during, or after treatment, or during growth without treatment

Overlay – Overlays are graphical data overlaid on top of an image, usually a lateral headfilm. The simplest overlay is a set of anatomical landmarks, displayed on a headfilm. The coordinates of the landmarks are extracted from the CRIL database, and the landmarks and their names are displayed on the film image. In addition, angular or linear measurements (such as Mandibular Plane Angle or Lower Lip to E line) can also be displayed.

Record – A record contains information about a case at a particular moment in time. Records consist of headfilms, photographs, study casts, written treatment records, and other information formats. At this time, most records in the CRIL database are lateral, frontal, and oblique headfilms.

Study – A Study is an investigation or experiment based on cases from one or more Acquisition Groups. Studies are designated by number. Studies contain the patient images, as well as landmark locations and, in some cases, computed angular and linear measures. A good example of a Study with landmark and computed data is the 9603 study, created from the Pearson Acqusition Group.