Orthometry

Orthometry is a term that appears in several disciplines but does not have a single, universally accepted definition. Etymologically, it combines orthos meaning straight or correct with metron meaning measure, suggesting a focus on measuring straight-line or orthogonal relationships. In practice, the meaning of orthometry varies by field and historical context.

In dentistry and orthodontics, orthometry has been used to describe the quantitative assessment of dental alignment and occlusion. Clinicians may measure distances and angles between teeth, across dental arches, and relative to reference planes. Methods include physical measurements on dental casts, intraoral scans, and 3D models, yielding data such as arch width, tooth spacing, overjet, and overbite. These measurements support diagnosis, treatment planning, and monitoring of orthodontic progress.

In surveying, civil engineering, and geodesy, orthometry has appeared in discussions of measurements tied to orthogonal coordinate systems or to height measurements related to the geoid, though this usage is not standardized. In such contexts, the term can reflect an emphasis on right-angled relationships or on linear distances rather than a specific procedures manual.

Common measurement approaches across contexts involve calipers, digital scanning, and software analysis to compute lengths and angles from models or images. Because orthometry spans disciplines with different aims, its meaning is often determined by the particular field and source.

See also: geometry, orthogonality, orthodontics, geodesy, cephalometric analysis.