[en] In this prospective study, mandibular reconstruction using titanium plates was evaluated in 31 patients treated between July 1988 and January 1990. Sixteen patients had prior surgery; 13 had prior radiotherapy. In 11 patients, prior radiation and surgery had failed. Sixteen patients received postoperative radiotherapy either in standard or accelerated fractions. Twelve patients had complications of either intraoral (8), extraoral (5), or combined (1) plate exposure or fistula formation (2). Factors significantly related to complications were poor nutrition, accelerated radiation, and recurrence. Sixty-one percent of all patients healed uneventfully. When patients with complications secondary to recurrence who subsequently died were excluded, the success rate was 73%. Only one patient had an unacceptable result that produced a cosmetic and functional deformity despite secondary repair

[en] Static high-pressure measurements are extremely useful for obtaining thermodynamic and phase stability information from a wide variety of materials. However, studying energetic materials can be challenging when extracting information from static high-pressure measurements. Energetic materials are traditionally C, H, N, O compounds with low crystalline symmetry, producing weak signal in commonly performed x-ray diffraction measurements. The small sample volume available in a static high-pressure cell exacerbates this issue. Additionally, typical hydrostatic compression media, such as methanol/ethanol, may react with many energetic materials. However, characterization of their thermodynamic parameters and phase stability is critical to understanding explosive performance and sensitivity. Crystalline properties, such as bulk modulus and thermal expansion, are necessary to accurately predict the behaviour of shocked solids using hydrodynamic codes. In order to obtain these values, equations of state of various energetic materials were investigated using synchrotron angle-dispersive x-ray diffraction experiments at static high-pressure and temperature. Intense synchrotron radiation overcomes the weak x-ray scattering of energetic materials in a pressure cell. The samples were hydrostatically compressed using a non-reactive hydrostatic medium and heated using a heated diamond anvil cell. Pressure - volume data for the materials were fit to the Birch-Murnaghan and Vinet formalisms to obtain bulk modulus and its first pressure derivative. Temperature - volume data at ambient pressure were fit to obtain the volume thermal expansion coefficient. Data from several energetic materials will be presented and compared.