Fluoride effects on teeth, bones, and antlers of mule deer (Odocoileus hemionus):: A progress report

Mule deer, Odocoileus hemionus, from the USA Air Force Academy (USAFA) at Colorado Springs, CO have brittle antlers and tooth lesions. Brittle bones and tooth lesions have been associated with the ingestion of high concentrations of fluoride. Possible relationships between fluoride concentrations and the strength of mandibular bone were determined in mule deer (> 1.5 yo.) collected 1993 through 1995 at the USAFA (n = 193), Pinon Canyon Maneuver Site (PCMS), Model CO (n = 22) and Game Management Units (GMU's) from northwestern CO (n = 16). Fluoride concentrations were measured using a fluoride selective ion electrode. Mandibular bone strength was measured in an Instron apparatus as Shear Force and Shear Stress was determined correcting for bone cross-sectional area. Fluoride concentrations (mg/g d.w.) were higher at the USAFA (P < 0.001) than on the two other sites (USAFA Median = 848.7; PCMS Median = 494.7; GMU's Median = 446.0). Overall, the Shear Force (Newtons) of mule deer bone from the USAFA was lower (P < 0.001) than that found in the two other sites (USAFA Median = 2359; PCMS Median = 4007 GMU's Median = 2613). Differences were not found in the Shear Stress (MPa) among collection sites (p = 0.234), but the Shear Stress required to break a bone at the USAFA was lower than that required in the two other sites (USAFA Median = 22.61; PCMS Median = 24.56; GMU's Median = 22.69). Among USAFA deer, a low correlation was found between fluoride bone concentrations and the mandibular bone strength characteristics measured (Shear Force, P < 0.008, R-2 = 0.0367; Shear Stress, p = 0.711, R-2 = 0.001). Although weaker bones were found at the USAFA the data do not support a clear relationship between fluoride concentrations and strength characteristics of bone of mule deer.