Biomedical subjects
Publications and source records attributed to Mehmet Emin Mavili.
Goldenhar syndrome is a well-known developmental anomaly of maxillofacial skeleton and hemi-facial soft tissue, was later included to a broader classification called oculo-ariculo-vertebral spectrum. Here we report a patient presenting goldenhar syndrome with accessory auricula, defined as polyotia, coloboma and bifid tongue.
Distraction osteogenesis has become popular for the treatment of hypoplastic congenital craniomaxillofacial anomalies. Rigid external distraction (RED II) after Le Fort III osteotomy was shown to be a highly effective treatment for the management of midface hypoplasia. This device is used with a halo vest, which is placed at the cranial equator. Intracranial penetration of the fixation pins of the halo is one of the complications of an external distraction device. To prevent pin penetration in rigid external distraction, the authors designed polylactic acid/polyglycolic acid (PLA/PGA) plates that were circular; the plates were 0.8 cm in diameter and had 1.5-mm holes in the center, through which the tip of the pins would pass. To quantify the applied torque by manual tightening of the screws of the distraction device and to measure intraosseous cone depth created by the penetration of the conical part of the screws with and without the PLA/PGA composite stopper, first an in vitro experiment was undertaken on cadaver. Then these PLA/PGA plaques, or stoppers, were placed over the bone surfaces of the cranium of the patients where the tip of the pins press. PLA/PGA stoppers are malleable and adapt their shape to the interactive forces between bone and the pins. They act as a second barrier, and spread the pressure of the screws to larger surfaces, thus securing better stabilization. The penetration of wider portions of the screw into scalp is reduced, minimizing the scalp damage caused by the screws. Biodegradable and biocompatible PLA/PGA stoppers avoid intracranial migration of the fixation pins, especially in children.
Topographic and temporal changes in circulation were studied with laser Doppler flowmetry in rabbit dorsal skin flaps comprised of three vascular territories. The reduced caliber vessels along the dorsal median line, rather than the vessels interconnecting the thoracodorsal and deep circumflex iliac vascular trees, behaved as true choke vessels. The authors found an increased proximal circulation lasting for 48 to 72 hr. This coincided with the reported rapid phase of choke vessel dilatation. The increase in distal circulation began after postoperative day 3, coinciding with the resolution of proximal hyperemia but not with the earlier prominent vasodilatation. Secondary elevation of the flaps at 3 weeks did not disturb the homogeneous distribution of circulation and did not cause a hyperemic response at postoperative 24 hr. Based on these findings, the authors postulate that the same mechanisms may underlie the rapid choke vessel dilatation and microvascular dilatation observed at 48 to 72 hr postoperatively. Surgical delay may work not only by diminishing the resistance to blood flow along the flap, but also by diminishing the steal effect of increased proximal microcirculation, which characterizes this period, over the distal circulation.