Reconstruction of post-traumatic frontal-bone depression using hydroxyapatite cement

Prior research has shown that post-traumatic frontal-bone depression often requires augmentation to restore facial structure and aesthetics. Established methods include autogenous bone grafts and methyl methacrylate, but these approaches come with limitations such as donor site morbidity or material rigidity. This gap motivated the exploration of alternative materials like hydroxyapatite cement, which offers potential advantages in biocompatibility and ease of application. No prior work had resolved whether hydroxyapatite cement could provide stable augmentation for frontal-bone depressions in patients of oriental descent. The absence of long-term data on cement resorption and aesthetic outcomes in this population remained a key uncertainty. Researchers proposed that hydroxyapatite cement could serve as a viable alternative to traditional grafting techniques. This paper's contribution lies in evaluating the material's safety and efficacy in a specific demographic group. The study aimed to address whether cement placement could maintain volume and contour without complications over extended follow-up periods.

The aim of this clinical investigation was to evaluate the safety and effectiveness of hydroxyapatite cement in augmenting post-traumatic frontal-bone depressions among oriental patients. The specific problem addressed was the lack of long-term data on cement resorption and aesthetic outcomes in this demographic group. The motivation stemmed from the need to find an alternative to autogenous bone grafts and methyl methacrylate, which carry risks of donor site morbidity and material rigidity. Researchers sought to determine whether hydroxyapatite cement could provide stable volume maintenance and acceptable aesthetics over time. The study focused on a cohort of 20 oriental patients with frontal-bone depressions ranging from 5 x 5 cm to 8 x 5 cm in size. The goal was to assess whether cement placement could avoid complications such as infection or extrusion. The researchers also aimed to document any changes in contour or volume during the follow-up period. The ultimate objective was to establish hydroxyapatite cement as a viable option for frontal-bone augmentation in this patient population.

The study involved 20 consecutive oriental patients with post-traumatic frontal-bone depressions. The cement used was hydroxyapatite (Bone Source, Howmedica, Leibinger, Inc., Dallas, TX). The size of the depressions ranged from 5 x 5 cm to 8 x 5 cm. The cement was placed in contact with the frontal sinus in 12 patients, none of whom had a history of paranasal sinus mucoperiosteal disease. Postimplantation evaluations included serial photographs, repeated physical examinations, and 3-dimensional computed tomography for all patients. Follow-up averaged 28 months. Meticulous hemostasis was emphasized to ensure a dry surgical field. The study design focused on assessing the cement's contouring ability, stability, and any complications such as infection or extrusion.

The cement paste allowed for precise and easy contouring of the bony depression's restoration. No infection of the surgical site or extrusion of the cement was noted for any of the 20 patients. The contour of the reconstructed frontal bone was acceptable esthetically without any secondary depression during the follow-up period. Three-dimensional computed tomographic scans taken 2 years after implantation revealed good preservation of the cement restoration material. Small areas of cement loss due to absorption into ambient fluid were noted for 2 patients, but such resorption did not affect the final aesthetic results. The follow-up period averaged 28 months, indicating long-term stability of the cement. The results suggest that hydroxyapatite cement is a biocompatible material suitable for frontal-bone augmentation. The study found that the material maintained volume and contour without significant complications.

The results from this clinical study indicated that hydroxyapatite cement is a biocompatible, alloplastic material useful for augmentation of post-traumatic frontal-bone depression. The material demonstrated stable volume maintenance over time, with no instances of infection or extrusion observed in the 20 patients. The contour of the reconstructed frontal bone remained acceptable esthetically during the follow-up period. Three-dimensional computed tomographic scans taken 2 years after implantation confirmed good preservation of the cement restoration. Small areas of cement loss due to absorption were noted in 2 patients but did not influence the final aesthetic outcome. The study supports the use of hydroxyapatite cement as an alternative to autogenous bone grafts or methyl methacrylate for augmentation of the craniofacial skeleton. The material's ease of contouring and biocompatibility make it a viable option for frontal-bone reconstruction. The findings suggest that hydroxyapatite cement offers a safe and effective solution for post-traumatic frontal-bone depression in oriental patients.