Modified Cranioplasty Technique Using 3-Dimensional Printed Implants in Preventing Temporalis Muscle Hollowing

Temporalis muscle (TM) hollowing is a complication of cranioplasty which diminishes the aesthetical outcome of the surgery and results in suboptimal functional outcome. We present and compare a modified split-temporalis muscle elevated margin cranioplasty using 3-dimensional printed titanium implant with conventional 3-dimensional printed titanium implant cranioplasty to determine an effective treatment method.

A modified 3-dimensional printed cranial implant was designed where the anteroinferior border of the implant was extended and elevated between the frontozygomatic suture and root of zygomatic process. Furthermore, the implant was placed in between superficial and deep layers of the temporalis muscle. Aesthetical evaluation was carried out at the outpatient clinic, and a quantitative analysis showing the percentage difference in length of the operated and nonoperated sides was performed.

For both conventional and augmented groups, there were 0% major or minor complications. Out of 10 conventional cranioplasty patients, there were 3 cases of mild and 1 case of severe TM hollowing, whereas for 10 augmented cranioplasty patients, there was only 1 patient with mild TM hollowing. When a quantitative analysis was carried out, the overall percentage difference in length at the coronal view for conventional and augmented cranioplasty was -2.17% and 0.07%, respectively.

The augmented cranioplasty leads to superior aesthetical outcome, and the quantitative analysis also supports the efficacy of augmented cranioplasty. The surgery is technically simpler than the conventional method, therefore lowering the risk of surgical complications. Therefore, we hope that the modified cranioplasty method will be considered as an effected cranioplasty method for preventing TM hollowing.