Effects of Modified Osteoplastic Pterional Craniotomy on Temporal Muscle Volume and Frontal Muscle Nerve Function.

Pterional craniotomy is a surgical approach frequently used in aneurysm and skull base surgery. Pterional craniotomy may lead to cosmetic and functional problems, such as eyebrow drop due to facial nerve frontal branch damage, temporal muscle atrophy, and temporomandibular joint pain. The aim was to compare the postoperative effects of our modified osteoplastic craniotomy with classical pterional craniotomy in terms of any change in volume of temporal muscle and in the degree of frontal muscle nerve damage.  Aneurysm cases were operated with either modified osteoplastic pterional craniotomy or free bone flap pterional craniotomy according to the surgeon's preference. Outcomes were compared in terms of temporal muscle volume and frontal muscle nerve function 6 months postoperatively.  Preoperative temporal muscle volume in the modified osteoplastic pterional and free bone flap pterional craniotomy groups were not different (  > 0.05). However, significantly less atrophy was observed in the postoperative temporal muscle volume of the osteoplastic group compared with the classical craniotomy group (  < 0.001). In addition, when comparing frontal muscle nerve function there was less nerve damage in the modified osteoplastic pterional craniotomy group compared with the classical craniotomy group, although this did not reach significance (  > 0.05).  Modified osteoplastic pterional craniotomy significantly reduced atrophy of temporal muscle and caused proportionally less frontal muscle nerve damage compared with pterional craniotomy, although this latter outcome was not significant. These findings suggest that osteoplastic craniotomy may be a more advantageous intervention in cosmetic and functional terms compared with classical pterional craniotomy.