Search

Background: Surgical resection of maxillary tumors can result in defects that can be difficult to reconstruct by conventional means due to the complex functional and anatomic nature of the midface and lack of regional bone flap options in the head and neck. Many reconstructive methods have been used to repair maxillary defects, but the ideal technique for the reconstruction of hemi-maxillectomy defects in growing pediatric patients has yet to be determined., Methods: The authors present a rare pediatric patient with melanotic neuroectodermal tumor of infancy resulting in a hemi-maxillectomy defect after resection that was reconstructed using a pedicled vascularized composite flap consisting of temporalis muscle, pericranium, and parietal bone., Results: The patient achieved successful long-term bony reconstruction of his right maxilla with this flap. Stable skeletal fixation with adequate orbital support was maintained over a >3-year follow-up period., Conclusion: A vascularized composite parietal bone flap is a reliable reconstructive option for reconstruction of large maxillectomy defects providing low donor-site morbidity, adequate globe support, excellent long-term skeletal stability, and malar symmetry in rapidly growing pediatric patients. Successful reconstruction for a rare patient with maxillary melanotic neuroectodermal tumor of infancy requiring hemi-maxillectomy was demonstrated with >3-year follow-up.

It remains unknown whether bone graft vascularity influences calvarial healing. The purposes of this study were (1) to develop a model to study nonvascularized and vascularized calvarial grafts as well as (2) to compare effects of bone graft vascularity on calvarial healing. Bilateral calvarial defects were created in 26 Wistar rats. The defects were left empty within 1 parietal region. On the contralateral side, the defects were partially closed with native parietal bone (control group, n = 6), nonvascularized (N-V, n = 10), or vascularized bone grafts (VAS, n = 10). The vascularized grafts were supplied by perforating dural arterioles. Bone mineralization and healing patterns from serial microcomputed tomographic scans were compared within and across the groups using parametric and nonparametric tests. Differences in bone mineral content across sides were significant between the groups at weeks 6 (P = 0.016) and 12 (P = 0.025). Bone formation was greater within both the control and VAS groups versus the N-V group at weeks 6 and 12 (P < 0.05). Healing patterns differed between the groups (P < 0.05), progressing through islands of new bone formation within the control and VAS groups while limited to defect margins on the N-V graft side. In conclusion, a bilateral calvarial defect model was established to study bone graft vascularity. Bone quantity and healing patterns differed in the presence of the nonvascularized versus vascularized grafts. Although the calvarial defect model is often applied within the plastic surgery literature to study bone substitutes, greater understanding of basic mechanisms influencing calvarial healing is first needed to avoid confounding results.

Background: Although bone repair is often a relatively rapid and efficient process, many bone defects do not heal. Because an adequate blood supply is essential for new bone formation, we hypothesized that augmenting new blood vessel formation by increasing the number of circulating vasculogenic progenitor cells (PCs) with AMD3100 and enhancing their trafficking to the site of injury with recombinant human parathyroid hormone (rhPTH) will improve healing., Methods: Critical-sized 3-mm cranial defects were trephined into the right parietal bone of C57BLKS/J 6 mice (N = 120). The mice were divided into 4 equal groups (n = 30 for each). The first group received daily subcutaneous injections of AMD3100 (5 mg/kg). The second group received daily subcutaneous injections of rhPTH (5 mg/kg). The third group received both AMD3100 and rhPTH. The fourth group received subcutaneous injections of saline. Circulating vasculogenic PC numbers, new blood vessel formation, and bony regeneration were assessed. Progenitor cell adhesion, migration, and tubule formation were assessed in the presence of rhPTH and AMD3100., Results: Flow cytometry demonstrated that combination therapy significantly increased the number of circulating PCs compared with all other groups. In vitro, AMD3100-treated PCs had significantly increased adhesion migration, and tubule formation was assessed in the presence of rhPTH. Combination therapy significantly improved new blood vessel formation in those with cranial defect compared with all other groups. Finally, bony regeneration was significantly increased in the combination therapy group compared with all other groups., Conclusions: The combination of a PC-mobilizing and traffic-enhancing agent improved bony regeneration of calvarial defects in mice.

The superficial temporal artery (STA)-based flaps have been used for different reconstructive purposes. These operations may cause facial nerve injury. The variations of the STA and its relation to temporal branch of the facial nerve (TBFN) were evaluated in this study. Thirteen cadavers with 26 STA and TBFN have been dissected. The bifurcation of STA was found to be 60% above the superior border of the zygomatic arc and 40% below this level. The mean lengths of frontal and temporal branches (FB and TB) of STA were 11.5 and 11.4 cm, respectively. The mean numbers of perforators of FB and TB to deep plane were 1.30 and 1.34, respectively. The mean diameter of STA at the superior border of zygomatic arc was 2.5 mm. The mean diameters of TB and FB at the level of bifurcation were 1.8 mm and 2.0 mm, respectively. The mean number of TBFN at the level of zygomatic arc was 3.70. The mean distance of the first and last branching of TBFN to tragus was found to be 24 mm. The mean number of TBFN at the level of the middle orbita was found to be 2.7. The mean distance of first and last branches of TBFN to the lateral orbital rim was 12 and 24 mm, respectively. The results found in this study may increase the accuracy of flaps based on STA and decrease the risk of facial nerve paralysis during these operations.

The clinical and radiographic results of 9 consecutive vascularized full-thickness cranial bone grafts to the midface are examined for a period of 3 to 8 years. Satisfactory contour was maintained throughout the follow-up in 5 patients with severe congenital facial deformities. Axial computerized tomography revealed complete survival of a trilaminar bone graft in each case. The complications were limited to a small area of alopecia in the midportion of one temporal scar. This relatively tedious harvest of bone is indicated for severe congenital malar and maxillary midface hypoplasia beginning at 4 years of age.