Background: Treating temporal volume loss for aesthetic and reconstructive purposes can be achieved by superficial or deep injections of soft tissue fillers into the temples. The latter is performed with bone contact that can lead to intracranial penetration when the bone is accidentally penetrated.
Objective: Based on a clinical case, the potential risk of accidental intracranial penetration was investigated.
Materials and methods: Twenty fresh-frozen hemi-faces (all Caucasian ethnicity, 10 women, 10 men, mean age 72.8 ± 11.2 years) were investigated. Shape of pterion and bone-stability parameters of the temporal fossa were investigated. Bone stability was tested using uniaxial mechanical indentation (18-G, 1.25-mm diameter, 15-mm length blunt-tip device) until intracranial perforation occurred.
Results: Variations in the shape of the pterion, bone thickness, and density correlates were detected, however, without statistical significant differences in side symmetry. Minimum force necessary to penetrate intracranially was 40.4 N. Maximum force generated by an 18-g, 70-mm length blunt-tip cannula was 32.1 ± 4.2 N in 70 mm length and 75.3 ± 10.2 N in 15 mm length.
Conclusion: Based on the results of this investigation, it can be concluded that there is a risk for intracranial penetration performing the deep temple injection technique with direct pressure on the bone.