Grams per square centimeter (or g/cm2) was a unit of density used for measuring areal bone mineral density (aBMD) in a humanoid body.
In 3189, an atomic scan performed on Philippa Georgiou's musculoskeletal system revealed that the aMBD in the spine was 1.01 g/cm2 and of the whole body was .99 g/cm2. (DIS: "The Sanctuary")