Sterol composition and biosynthesis in mouse salivary glands.

Sterol components of mouse submandibular, sublingual and parotid glands were studied by thin-layer and gas-liquid chromatography. The major sterol was cholesterol (5-cholesten-3 beta-ol; 26.7, 28.0, 18.8 micrograms/mg protein respectively), with minor amounts of squalene, lathosterol (5 alpha-cholest-7-en-3 beta-ol), desmosterol (cholesta-5,24-dien-3 beta-ol), lanosterol (4,4',14-trimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol), dihydrolanosterol (4,4',14-trimethyl-5 alpha-cholest-8-en-3 beta-ol) and methylstenol. Chromatograms of salivary sterols were similar to those of liver, and different from those of skin in which the amount of lathosterol was much higher. Administration of the anticholesterolaemic agent, 20,25-diazacholesterol, resulted in accumulation of desmosterol in all tissues tested, and additional sterols also accumulated in skin. The gas-liquid chromatographic profiles of salivary sterols from the treated animals were similar to those of liver, but different from those of skin. Thus sterols were synthesized in salivary glands and the biosynthetic pathway was via C24-unsaturated side-chain intermediates, as in liver. This was verified by showing that [2-14C]-mevalonate was incorporated into sterols in vitro when it was incubated with homogenates of these glands.

A study of infraorbital foramen, canal and nerve in adult Egyptians.

The infraorbital foramen, canal and nerve were examined in 30 Egyptian adult skulls and 15 adult human cadavers. The infraorbital foramen was single in 90% of cases and double in 10%. It was oval in 65% of cases and round in the remaining cases. It was directed downward, forward and medially in 60%, downward in 25% and medially in 15% of cases. The distance from the centre of the foramen to the inferior orbital margin was 6.1 +/- 2.4 mm and to the lateral nasal border was 14.7 +/- 2.7 mm. The infraorbital foramen was opposite the 2nd maxillary premolar in 50% of cases, opposite the 1st premolar in 15% and between the 1st and 2nd premolar teeth in 15% of cases. The length of the infraorbital canal was 28.8 +/- 2.9 mm and it showed an infraorbital groove in 60% of cases, a complete roof in 25% and a deficient roof leaving a short bony bridge in 15% of cases. The anterior superior alveolar nerve arose either from the middle third of the infraorbital nerve (in 10 out of 15 cases) or from its anterior third in the remaining 5 cases. The middle superior alveolar nerve was not apparent in 8 cases and it arose from the middle third of the infraorbital nerve in the remaining 7 cases. Radiographic study of the infraorbital foramen and canal on 15 adult dry skulls were also done using 3 different views for each skull. The panoramic view showed to be better than either of the lateral or the postero/anterior view.

Evaluation of the paraskeletal clamp system (Mennen plate) in treatment of mandibular fractures.

In this study, we used the relatively recent Paraskeletal clamp system (Mennen plate) to evaluate its effectiveness in the treatment of mandibular fractures. This study was conducted on eight patients with mandibular fractures selected from the out patient clinic, Oral Surgery Department, Faculty of Oral and Dental Medicine, Cairo University. Patient sample consisted of six males and two females, four patients were children below the age of 11 years, while the other four were edentulous above the age of 58. Each patient was thoroughly examined both clinically and radiographically. Data collected from each patient were recorded in a special examination chart. Under general anesthesia, the fracture was exposed using a submandibular approach. The fractured segments were reduced and fixed using micro-5 Mennen plates. All patients were followed up both clinically and radiographically for six months postoperatively. Results obtained from this study showed uneventful healing of all patients with no cases of non-union, bony infection or osteomyelitis as proven both clinically and radiographically. All the patients presented normal functioning occlusion and facial symmetry. No bony step deformities were detected.

Modified lingual split technique versus conventional buccal technique in odontectomy of impacted mandibular third molars.

This study was conducted to compare two different techniques used in odontectomy of impacted mandibular third molar; the modified lingual split technique and the conventional buccal technique as regarding the duration of surgery as well as the incidence of postoperative sequelae such as pain, edema, and trismus. This study was carried out on thirty adult male patients having class II, position B mesioangular impacted mandibular third molar scheduled for removal, the cases were divided into two equal groups. Group one using the conventional buccal technique and group two using the modified lingual split technique. Pain was categorized into a three grade scale according to the dose of the analgesic taken by the patients postoperatively. The degree of trismus was calculated by measuring the interincisal distance when the mouth was opened at a maximum using a graduated caliper both preoperatively and postoperatively. Edema was measured linearly using a tape between different predetermined facial anatomical landmarks in different planes. All measurements were carried out immediately before surgery and after one, two and seven days postoperatively. The collected data were tabulated and were statistically analyzed. There was a significant difference between the two techniques as regarding the duration of surgery in favour of the modified lingual split technique, with a mean of 36.3 minutes, in group two against a mean of 54.3 minutes in group I. As regarding pain there was no significant difference in the first and the second postoperative days, while there was a significant difference in favour of the modified lingual split bone technique in the seventh postoperative day. Trismus and edema were comparable in both groups.

Carcinogenesis of mouse submandibular salivary gland using DMBA implant.

Carcinogenesis of 35 ddy male mice submandibular salivary glands were attempted; using implants of a 1 mg (2 mm) prepared pellets of the potent chemical carcinogen 9, 10-dimethyl-1, 2-benzanthracene (DMBA) dry powder without a vehicle or carrier. This method appeared to be easy, fast and effective. Within a period ranging from 7-14 weeks; twenty animals developed epidermoid carcinoma (two of them developed squamous cell carcinoma of covering skin as well), and two animals developed mixed tumors (pleomorphic adenoma like tumor) but neither adenocystic carcinoma nor sarcoma were found, the results were adequately discussed.

Hepatitis B and C viruses among Egyptian dentists.

The present study was conducted on 105 subjects, 70 dentists working or studying at the Faculty of Oral and Dental Medicine, Cairo University, and 35 non medical non dental subjects. There were 47 males and 48 females, their ages ranged from 20-50 years. Detailed history and the required information were collected from each subject and were recorded in a specially a prepared questionnaire study cards. 10 C.C. of venous blood were obtained from each candidate using Venoject, sera were separated from clotted blood by centrifuge; their sera were tested for Hepatitis B surface antigen (HBsAg), Antibody to hepatitis B surface antigen (anti HBs), Antibody to hepatitis B core antigen (anti HBc) and Antibody to hepatitis C virus antigen (anti HCV) using ELISA (enzyme linked immuno sorbent assay) techniques according to Abbott Laboratories (West Germany). The ALT level (Alanine aminotransferase) was determined only for HBsAg and anti HCV positive cases using commercial Biomérieux kits (France). After statistical analysis of the results, the exposure rate of HBV among dentists was found to be 27.1% with a carrier rate of 7.1% compared to 31.4% with a carrier rate of 17.1% in the control group. The exposure rate of HCV infection among dentists was 1.4% compared to 17.1% in the control group. The exposure rate of HBV and HCV infections were 2.9% compared to 5.7% in the control group; these results and other important conclusions were adequately discussed.

Comparative study of meniscus replacement using autogenous auricular cartilage versus Zenoderm.

Twelve adult mongrel dogs were divided into two groups and were used in this study; to compare and to evaluate histologically in 3 months period; unilateral replacement of the dogs meniscus of temporomandibular joint with either autogenous cartilage of their external ears or with Zenoderm heterogeneous graft. Autogenous cartilage of the dogs ear was progressively replaced by fibrous tissue and its attachment to the lateral pterygoid muscle was started at the third month postoperatively. On the other hand, Zenoderm was replaced by vascular fibrous tissue and begun to attach to the lateral pterygoid muscle from the first month postoperatively and showed also good functional adaptation to the bony surfaces. In both grafts there were no changes of the bone architecture.

Competent closure of chronic oroantral fistula with Zenoderm.

Ten patients suffered from chronic oroantral fistula had been closed with Zenoderm (lyophilized porcine dermis) covering the bony defects by 1-2 mm. The Zenoderm was covered by buccal sliding and rotating pedicle palatal flaps after complete resolution of sinusitis and/or infection of the fistula. In nine patients, competent closure of the fistula had been achieved also Zenoderm supported the flaps against negative or positive pressure from the sinus and supported the bony contour. In only one case the Zenoderm was expelled from the tissues due to infection which prevented healing of the flaps; this patient was controlled diabetic. The current study showed that Zenoderm had promising results in closing the chronic oroantral fistula.