Supraorbital Notch/Foramen, Infraorbital Foramen and Mental Foramen in Thais: anthropometric measurements and surgical relevance.

OBJECTIVE: To determine the morphology and the locations of the SupraOrbital Notch/Foramen (SON/F), InfraOrbital Foramen (IOF), and Mental Foramen (MF) relative to frequently encountered surgical landmarks. MATERIAL AND METHOD: One hundred and six Thai adult skulls were investigated. RESULTS: Mean horizontal widths of SON, SOF, IOF and MF were 4.31 +/- 1.61 mm, 2.81 +/- 0.62 mm, 3.35 +/- 0.62 mm and 2.80 +/- 0.70 mm, respectively. The SON/F was situated 25.14 +/- 4.29 mm lateral to the nasal midline, 26.57 +/- 3.92 mm medial to the temporal crest of the frontal bone and 3.15 +/- 1.29 mm superior to the supraorbital rim. The IOF was 28.43 +/- 2.29 mm lateral to the maxillary midline, 9.23 +/- 2.03 mm below the infraorbital rim and 2.15 +/- 1.67 mm medial to the zygomaticomaxillary suture. Mean vertical distances from the IOF to the SOF and to occlusal plane of the upper teeth were 44.95 +/- 2.96 mm and 42.52 +/- 3.89 mm, respectively. The IOF was frequently found in the same vertical line with the second upper premolar and its usual direction of opening pointed downward medially. The MF was a mean of 28.52 +/- 2.15 mm lateral to the symphysis menti and most commonly observed in line with the second lower premolar. Its usual direction of opening was in a posterosuperior direction. CONCLUSION: The results of the present study may assist surgeons to localize important maxillofacial neurovascular bundles passing through these foramina in facilitating surgical, local anesthetic and other invasive procedures.

Opisthorchis viverrini: the effects of colchicine and cytochalasin B on the adult tegument.

The roles of the tegumental cytoskeleton were tested by treating adult flukes with colchicine and cytochalasin B. Following a short incubation period (10-20 minutes), colchicine disrupted microtubules in the tegumental cells' processes which, in turn, affected the transport of dense granules from the cells' soma to the tegument; as a result some of these granules were fused together to form membrane-bound vacuoles. In addition, at many spots microtrabeculae were also depolymerized, which resulted in the formation of non-membrane-bound vacuoles and the distension of microvilli to form blebs, some of which were disrupted. After prolonged incubation (120 minutes), general breakdown of the tegumental cytoskeleton occurred, and parts of it were sloughed off. In cytochalasin B treatment, the responses were similar to those of colchicine but with less severity. After a short incubation period (10-20 minutes), the microtrabeculae were depolymerized which led to the formation of non-membrane-bound vacuoles in the apical and middle zones of the tegument. Later, the tegumental microvilli were distended to form blebs but no evidence of tegumental sloughing occurred even in prolonged incubation. From these observations, it was concluded that microtubules played a role in the translocation of granules from the tegumental cells to the tegument which modulated the synthesis of membrane and glycocalyx, while microtrabeculae were involved in the maintenance of the structure and integrity of the tegument.

Opisthorchis viverrini: effect of praziquantel on the adult tegument.

Ultrastructural changes of the tegument of adult liver flukes, Opisthorchis viverrini, after in vitro incubation in Minimal Essential Medium containing 0, 0.1, 1.0 and 10.0 micrograms/ml of anthelminthic praziquantel for 5, 15, 30, 45 and 60 minutes were investigated by scanning (SEM) and transmission (TEM) electron microscopy. SEM observations showed that the surface damage was composed of blebbing due to the swelling of microvilli, followed later by the disruption of these structures to form lesions that caused the erosion and desquamation of the surface. Sensory papillae, by contrast, appeared relatively unaffected. The surface changes could be observed at all doses but the extent of damage increased with increasing duration of incubation and concentration of the drug. The ventral as well as the dorsal surfaces exhibited similar change, whereas the anterior part tended to be damaged less than the posterior part. Under TEM observations, the earliest sign of changes was the depolymerization of the microtrabecular network in scattered foci, which resulted in the formation of non-membrane-bound vacuoles under microvilli. The basal infoldings also became dilated, and some turned into membrane-bound vacuoles in the basal zone. Subsequently, microvilli became enlarged, and eventually formed blebs that later rupture to form lesion spots as observed in the SEM. Finally, the microtrabecular network in all regions broke down, creating vacuoles of various sizes throughout the tegument, leading to its total disintegration and detachment. The sequence of morphological changes was generally similar at all doses; however, the changes occurred faster at the higher doses and the longer incubation times. In addition, at the longer durations myofilaments in most muscle cells also became depolymerized, while microtubules were unchanged by the drug. Therefore, it is possible that praziquantel, through its induction of Ca2+ influx, causes depolymerization of the microtrabecular network that leads to the vacuolization, swelling, blebbing, and eventually the disruption and detachment of the tegument, and the breakdown of myofilaments in the muscle cells.