Evaluation of Drill-Induced Heat Transmission in an Orbital Model

Abstract

ABSTRACTPurpose: To evaluate the influence of saline irrigation on temperature rise in orbit bones and the optic canal during high-speed drilling.Methods: An experimental study measuring temperature rise in an orbit during high-speed drilling was conducted. The orbital rims, sphenoid bone, and optic canals of 6 unpreserved caprine orbits were drilled with a 3.1-mm diamond drill bit at 35,000 rpm. Each orbit was divided into groups receiving no irrigation, continuous or intermittent external irrigation at 5-second intervals during the procedures. The temperature rise of each site was compared among the groups, along with the duration of drilling.Results: The mean (±SD) temperature elevation in the optic canal without irrigation was 2.38 °C (±0.30 °C). This was significantly higher than in the canals receiving intermittent irrigation (0.90 °C ± 0.40 °C; p < 0.001) and continuous irrigation (0.66 °C ± 0.40 °C; p < 0.001). Mean temperature rise in the orbital rim without irrigation was significantly higher (3.51 °C ± 1.30 °C) than with intermittent (1.05 °C ± 0.31 °C; p < 0.001) and continuous (0.98 °C ± 0.61 °C; p < 0.001) irrigation. Mean temperature rise in the sphenoid was significantly higher (3.68 °C ± 1.66 °C) without irrigation than with intermittent (1.36 °C ± 1.17 °C; p = 0.005) and continuous (0.90 °C ± 0.33 °C; p < 0.001) irrigation. There were no statistically significant differences between any of the intermittent and continuous irrigation groups.Conclusions: The presence of either continuous or intermittent irrigation during orbital drilling procedures significantly decreases the temperature rise in the region adjacent to the surgical site. This has important implications for surgical technique when operating near the optic canal. Further studies regarding potential effects on the optic nerve are warranted.