A Simplified Approach to Jaw-in-a-Day Using a Preassembled Prosthesis: Lowering the Barrier to Entry.

Fibula flap reconstruction with primary dental implant placement has been established as a successful procedure for composite mandibular defects. When using virtual surgical planning, these techniques typically require additional personnel and materials preoperatively and intraoperatively to fabricate occlusal-based guidance and prosthesis. The authors present a technique utilizing a custom-made implant-supported prosthesis completed before surgery that greatly reduces lead time and needed resources. The authors follow the established workflow of segmental mandibulectomy and fibula flap reconstruction using premanufactured cutting guides and placement of dental implants. Cylindrical holes along the implant axes are included in the printed surgical model provided by the guide manufacturer. Acrylic resin and abutments are added to the model to a positioning stent for use during surgery that does not require intraoperative modification before fibula inset. This ensures optimal position for facial esthetics and fixed dental rehabilitation. The presented technique uses printed models already provided by the guide manufacturer, reducing preparation time and requiring fewer personnel and materials intraoperatively. This is an approach to the jaw-in-a-day procedure with a lower barrier to entry that may be used by new craniofacial teams.

Infusion pressure and pain during microneedle injection into skin of human subjects.

Infusion into skin using hollow microneedles offers an attractive alternative to hypodermic needle injections. However, the fluid mechanics and pain associated with injection into skin using a microneedle have not been studied in detail before. Here, we report on the effect of microneedle insertion depth into skin, partial needle retraction, fluid infusion flow rate and the co-administration of hyaluronidase on infusion pressure during microneedle-based saline infusion, as well as on associated pain in human subjects. Infusion of up to a few hundred microliters of fluid required pressures of a few hundred mmHg, caused little to no pain, and showed weak dependence on infusion parameters. Infusion of larger volumes up to 1 mL required pressures up to a few thousand mmHg, but still usually caused little pain. In general, injection of larger volumes of fluid required larger pressures and application of larger pressures caused more pain, although other experimental parameters also played a significant role. Among the intradermal microneedle groups, microneedle length had little effect; microneedle retraction lowered infusion pressure but increased pain; lower flow rate reduced infusion pressure and kept pain low; and use of hyaluronidase also lowered infusion pressure and kept pain low. We conclude that microneedles offer a simple method to infuse fluid into the skin that can be carried out with little to no pain.