Cranioplasty remains a difficult procedure for all craniofacial surgeons, particularly when concerning the reconstruction of large lacunae in the skull. Considering the significant clinical and economic impact of the procedure, the search for materials and strategies to provide more comfortable and reliable surgical procedures is one of the most important challenges faced by modern craniofacial medicine.The purpose of this study was to compare the available data regarding the safety and clinical efficacy of materials and techniques currently used for the reconstruction of the skull. Accordingly, the scientific databases were searched for the following keywords autologous bone, biomaterials, cranial reconstruction, cranioplasty, hydroxyapatite, polyetheretherketone, polymethylmethacrylate, and titanium. This literature review emphasizes the benefits and weaknesses of each considered material commonly used for cranioplasty, especially in terms of infectious complications, fractures, and morphological outcomes.As regards the latter, this appears to be very similar among the different materials when custom three-dimensional modeling is used for implant development, suggesting that this criterion is strongly influenced by implant design. However, the overall infection rate can vary from 0% to 30%, apparently dependent on the type of material used, likely in virtue of the wide variation in their chemico-physical composition. Among the different materials used for cranioplasty implants, synthetics such as polyetheretherketone, polymethylmethacrylate, and titanium show a higher primary tear resistance, whereas hydroxyapatite and autologous bone display good biomimetic properties, although the latter has been ascribed a variable reabsorption rate of between 3% and 50%.In short, all cranioplasty procedures and materials have their advantages and disadvantages, and none of the currently available materials meet the criteria required for an ideal implant. Hence, the choice of cranioplasty materials is still essentially reliant on the surgeon's preference.

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Object During the past decades, in small-to-medium size vestibular schwannomas, Gamma Knife surgery (GKS) has become a reliable therapeutic option because of either excellent local tumor control or minimal morbidity, with cranial neuropathy becoming increasingly rare. Although still insufficiently analyzed in larger cohorts of patients with long-term follow-ups, adequate chances of hearing preservation and vestibular sparing seem clinically guaranteed. However, deeper investigations are needed in this regard, expanding the number of cases and the follow-up period. Methods A small group of patients with vestibular schwannomas (74 patients, including 41 men and 33 women) treated between 2003 and 2009 using GKS at the authors' institution were analyzed—both before and after GKS—with computerized static stabilometry and electronystagmography for balance disorders, vertigo, and ataxia on 1 side and pure tone average, vocal speech discrimination score, auditory brainstem response, and so forth for hearing impairment and tinnitus on the other side. Eligibility criteria for this prospective study included previously untreated unilateral lesions and a Gardner-Robertson hearing class of I–III. Dosimetry plans had been programmed at the lower effective dosages for these tumors (median surface dose 12.4 Gy, range 10–13 Gy), carefully avoiding even minimal toxic dosages on the most vulnerable targets: the cochlea (never > 6 Gy) and the vestibular canals (< 7.5 Gy). Results To date, tumor growth control rates remain satisfactory; at a mean follow-up of 50 months, the rate was 96%. The overall level of hearing preservation was 72%, with 81% having Gardner-Robertson Class I hearing. Tinnitus decreased, from 52% to 28% of patients (p < 0.01). Significant improvements were also observed in vestibular symptoms, with computerized static stabilometry abnormalities decreasing from 62% to 32% (p < 0.001) and electronystagmography abnormalities reducing from 48% to 14% (p < 0.001). Conclusions Using appropriate radiodosimetry planning, GKS seems to guarantee not only adequate tumor growth control rates, but also better levels of hearing preservation, with a documented, long-lasting improvement in vestibular functions.

When a cranioplasty implant becomes infected, standard operating procedure dictates its removal and the initiation of a long course of antibiotic therapy. However, removing such a prosthesis can have a series of adverse consequences, including delayed cognitive and motor recovery, lack of brain tissue protection, unsightly deformity, and the need for two additional surgical procedures, not to mention the additional costs involved. To maintain the advantages of cranioplasty, we opted for a conservative approach (levofloxacin and rifampicin every 24 hours for 8 weeks) in a 68-year-old woman whose custom-made porous hydroxyapatite implant, fitted following aneurysm clipping, had become infected. The tissues overlying the implant were curettaged, and the patient's clinical condition, blood markers, and infection course were continuously monitored (local monitoring was performed by single-photon emission computed tomography [SPECT]/computed tomography [CT after intravenous administration of Tc-labeled antigranulocyte antibody). Blood tests and SPECT/CT evidenced a progressive reduction in phlogosis indices and infection locus, even 1 month after antibiotic therapy was commenced, and at 2 years from cranioplasty, the same tests and clinical examination were negative. At 6-year follow-up, clinical assessment revealed nothing out of the ordinary.Hence, specific cases (hydroxyapatite prosthesis, intact dura, cranial CT and magnetic resonance imaging negative for empyema, well-vascularized scalp, antibiotic-responsive bacteria) of infected cranial implant can be treated using a conservative approach consisting of appropriate antibiotic therapy, accompanied by local debridement where necessary, and assiduous monitoring of phlogosis indices and local verification via labeled-leukocyte scintigraphy. Our report, which was compiled after a long-term follow-up period, shows that this conservative procedure appears to be a viable option in cases of infected, custom-made hydroxyapatite cranioplasty, provided that some basic rules concerning clinical and instrumental standards are adhered to, as clearly stated in our report.

The postoperative result after 16 months allowed us to observe a normal forehead profile with a normal thickness, good skin texture, and well-hidden scars.