Clinical Application of the Pedicled Buccal Fat Pad Flap in Immediate Reconstruction of Oral Tissue Defects in Oral Surgery.

OBJECTIVE: The aim of this study was to present a new immediate reconstructive option for oral tissue defects with a pedicled buccal fat pad flap in oral surgery. MATERIALS AND METHODS: Fifteen cases (10 males, 5 females; mean age: 50 years) suffering from oral tumor and attending the Affiliated Stomatology Hospital of Kunming Medical University were included in this study. All patients underwent immediate repair surgery involving a pedicled buccal fat pad graft in oral surgery, from July 2013 to August 2016. RESULTS: All cases underwent uneventful healing with a surviving graft flap. The buccal fat pad healed in about 9 to 10 weeks and its uncovered surface became epithelialized with similar feature to the normal mucosa. At a follow-up of 3 months to 3 years, a good outcome was obtained with minimal malfunction and face deformity. CONCLUSIONS: The pedicled buccal fat pad is ideal material for repair, and it is a viable option for immediate reconstruction of oral tissue defects in oral surgery.

Polyvinyl alcohol/polyacrylamide double-network hydrogel-based semi-dry electrodes for robust electroencephalography recording at hairy scalp for noninvasive brain-computer interfaces.

Objective.Reliable and user-friendly electrodes can continuously and real-time capture the electroencephalography (EEG) signals, which is essential for real-life brain-computer interfaces (BCIs). This study develops a flexible, durable, and low-contact-impedance polyvinyl alcohol/polyacrylamide double-network hydrogel (PVA/PAM DNH)-based semi-dry electrode for robust EEG recording at hairy scalp.Approach.The PVA/PAM DNHs are developed using a cyclic freeze-thaw strategy and used as a saline reservoir for semi-dry electrodes. The PVA/PAM DNHs steadily deliver trace amounts of saline onto the scalp, enabling low and stable electrode-scalp impedance. The hydrogel also conforms well to the wet scalp, stabilizing the electrode-scalp interface. The feasibility of the real-life BCIs is validated by conducting four classic BCI paradigms on 16 participants.Main results.The results show that the PVA/PAM DNHs with 7.5 wt% PVA achieve a satisfactory trade-off between the saline load-unloading capacity and the compressive strength. The proposed semi-dry electrode exhibits a low contact impedance (18 ± 8.9 kΩ at 10 Hz), a small offset potential (0.46 mV), and negligible potential drift (1.5 ± 0.4µV min-1). The temporal cross-correlation between the semi-dry and wet electrodes is 0.91, and the spectral coherence is higher than 0.90 at frequencies below 45 Hz. Furthermore, no significant differences are present in BCI classification accuracy between these two typical electrodes.Significance.Based on the durability, rapid setup, wear-comfort, and robust signals of the developed hydrogel, PVA/PAM DNH-based semi-dry electrodes are a promising alternative to wet electrodes in real-life BCIs.