The fibula osteomyocutaneous flap for mandible reconstruction: a 15-year experience.

PURPOSE: This report documents our experience over the previous 15 years using free vascularized fibular flaps for comprehensive reconstruction of large defects in the mandible, after combined resections of aggressive, malignant odontogenic tumors or for post-traumatic defects. PATIENTS AND METHODS: Charts were reviewed retrospectively for 117 consecutive patients who underwent microsurgical reconstruction of the oromandibular complex with a fibula osteocutaneous or osteomyocutaneous free flap over a 15-year period, with an average follow-up of 4 years. All charts were reviewed retrospectively for tumor type, stage and location, surgical procedure performed (including type of plate used), dental restoration if done, the use of pre- or postoperative radiotherapy, length of follow-up, and evidence of complications. RESULTS: Fibula osteocutaneous free flaps were used for reconstruction in 117 patients, of whom 60% were men (mean age, 57.1 years) and 40% were women (mean age, 56.6 years). Most cases (61.1%) were secondary to oral malignancies (89.1% of these were squamous cell carcinoma). Thirty-one patients (26.5%) developed postoperative complications, including hardware failure or intolerance in 16 patients (13.7%), total or partial flap failure in 10 patients (8.5%), wound infection in 3 patients (2.6%), and peroneal nerve damage in 2 patients (1.7%). Regarding donor site morbidity, calf paresthesias were recorded in 21% of cases. Similar rates of claw-toe deformity were also observed. CONCLUSIONS: In our opinion, the free fibula osteocutaneous flap is the most versatile and reliable option for microsurgical reconstruction of large mandibular defects. It provides a large quantity of bone, which is easily shaped to passively adapt to the remaining mandible. The bone height is suitable for an implant-based prosthetic restoration. Preoperative mapping of the cutaneous perforators of the skin paddle improves the versatility of the flap design and decreases the morbidity at the donor site. In selected cases, other options (iliac crest or scapular free flap) may also be considered.

Thermodynamics of micellization of alkyldimethylbenzylammonium chlorides in aqueous solutions.

Specific conductivities of alkyldimethylbenzylammonium chlorides (alkyl=decyl-, dodecyl-, tetradecyl-, and hexadecyl-) in aqueous solutions were measured as a function of molality and temperature. Critical micelle molalities (cmc) and degrees of ionization of the micelles, beta, were estimated from the dependence of the specific conductivity on molality. It was found that temperature dependence of cmc is U-shaped with a minimum shifting toward higher temperatures with a decrease in the chain length of the alkyl group. The temperature dependence of ln xcmc (where xcmc is the cmc in mole fraction units) was fitted to the equation of Muller, which we modified by taking into account the temperature dependencies both of beta and of change in heat capacity upon micellization. From the fitting parameters, Gibbs free energies, enthalpies, and entropies of micellization as a function of temperature were estimated.