Rapid prototyping technology for cranioplasty: A case series

Cranial vault defects may be acquired or congenital in origin. Rehabilitation of these patients often poses challenge to the operating team and prosthodontist. Polymethylmethacrylate is a commonly used alloplastic graft material which is used for the fabrication of cranial prosthesis. Nowadays, with the advancement in the bioengineering, custom-made template and cranial prosthesis can be made by rapid prototyping technology (RPT) by patient three-dimensional (3D) computed tomography (CT) scan images. This series of two cases explained two different techniques for the rehabilitation of the patient with frontotemporoparietal cranial defect. Case 1 had a history of cerebrovascular accident, followed by decompression craniotomy which led to frontotemporoparietal defect of the left side. This defect area was associated with the cerebrospinal fluid accumulation which made delineation of underlying bony margins difficult and interfered with conventional impression procedures. Case 2 had a road traffic accident which led to intracerebral hemorrhage followed by decompression craniotomy which resulted in frontotemporoparietal defect of the right side. The patient had a poor neuromuscular control which impedes with the upright posture of the head during impression making of the defect area. Therefore, these cases were planned to rehabilitate by RPT. In these techniques, the prosthesis was made using custom-made skull template produced by RPT, using the data of 3D-CT scan images. This technique resulted in the prosthesis with good esthetics and better fit of the prosthesis. The contours of the prosthesis were replicated in the same manner as compared to the contralateral side. RPT is an additive manufacturing technology which is now used in the field of dentistry too. This technique is easy to use; fabricate prosthesis with high precision is less time-consuming and has fewer chances of error.

Reconstruction of Cranial Defects in Armed Forces Personnel - Our Experience

BACKGROUND

The aim of this study was to evaluate the efficacy of heat cured 'poly methyl methacrylate resin prosthesis and to assess the acceptability of the indigenously manufactured titanium mini bone plate and screws in patients treated for repair of cranial defects.

METHODS

17 patients with cranial defect were treated for reconstruction of the skull defect with two types of implants i.e. Acrylic resin plate prosthesis and titanium minibone plates, either in combination or singularly. In these cases, the skull defects resulted from trauma (88.23%) or due to ablative tumour surgery (11.96%). Acrylic implant was used in 12 cases (70.85%), titanium plates and screws in 2 cases (11.76%) and a combination of both of the above in 3 cases (17.64).

RESULTS

The primary reconstruction was carried out in 2 cases (11.96%) and secondary reconstruction was done in 15 cases (88.23%). Majority of the cases underwent secondary reconstruction because of the initial surgical emergency requiring quick debulking and closure. In 2 cases where primary reconstruction was done, the second surgery could be avoided with gratifying results.

CONCLUSION

70.85% underwent reconstruction with polymethyl methacrylate resin prosthesis and in the rest either titanium plates were used singly or in combination. Only in one patient, there was rejection of the implant due to infection. In 94% cases the graft was well taken up with excellent results.