Free oral communications 15 Biostereometric Recording of the Face and Dental Occlusion using Stereophotogrammetry
Ayoub A., Moos K., Wray D., Siebert P.
Department of Oral Surgery, University of Glasgow, Glasgow, UK Based on recent advances in stereophotogrammetry, we developed a new biostereometric technique to capture the 3-D morphology of the face and dental occlusion. This technique is based on automatic construction of a 3-D graphics model of the surface to be surveyed from stereo-pair of images. The images are captured using television cameras with special illumination and are analysed by means of advanced digital image processing techniques to extract the 3-D shape morphology. For orthognathic surgical planning and prediction, the lateral cephalograph is integrated with the captured 3-D facial model using a calibration object that can be imaged by both the cameras and X-ray machine. The technique is also used for archiving dental study models in digital format. Modern computer aided design (CAD) techniques are applied to manipulate the captured dental study model in three dimensions. The resulting model is of a high metric precision. It can be viewed on the computer from any angle or position and allows the direct measurements of real distances, areas, volumes and angles. The specification of the newly developed biostereometric technique is presented and its further applications are discussed.
Extraoral Fixation Bone Fragment Method in Lower Jaw Gunshot Defects
Badalian K.A., Pogosiane Y.M., Karapet Z.Z.
Maxillo-Facial Surgery Department, Yerevan Medical University, Yerevan, Armenia In the case of lower jaw gunshot injuries, bone defects of different lengths are noted in 30% of cases. To restore the lower jaw (bone) defects with the help of demyehnized allogenic bone or by the other method of osteosynthesis, we should first of all carry out the surgical injury treatment with close fixation of bone fragments at the normal occlusial position. For this purpose, an extraoral fixation apparatus was developed for the fragments with two fixing wires on each side of it, which fixes the fragments safely during the whole period of injury healing. The apparatus was tested on 25 patients injured with gunshot wounds to the low jaw. In all cases the results were satisfactory. The method does not need complicated interventions, it is available for any traumatic conditions, fixes fragments safely. The wound is not macerated and promotes free use of liquid food up to the patient's complete recovery. The apparatus has obvious advantages over the existing methods and can be recommended at the clinic practice as a method of choice.
Salivary Gland Cancers in Kuwait: Disease Trends and Etiological Considerations
Bader A., Morris R.
Dental Administration, Ministry of Health, Aldasmah, Kuwait A review of cancers of the head and neck from 1979 to 1988 showed that the nasopharynx and salivary glands are the primary sites for head and neck cancers (ICD code 140-149), 24.7% respectively. Nasopharyngeal cancers as a
primary site have not been previously reported. Salivary gland cancer rates in non-Kuwaiti residents of Kuwait are 7 times greater than in Kuwaitis. The ageadjusted annual incidence rates in males increased 100% from 1974 to 1978 and 1978 to 1988. The per cent of salivary gland tumours as function of all head and neck cancers had increased from 10.9% in males and 13.4% in females in 1974-1981, to 26% in males and 39% in females by 1988. These turnouts make up some 13% of head and neck cancers in Bangladesh and 7% in the USA. Possible risk factors and health policy recommendations for control will be discussed.
Long-Term Results in Stability of Le Fort I and Sagittal Mandibular Osteotomy
Badia D.1, Boghi F.1, De Francesco E.1, Cassaro G.2, Rossi M2, Frascetti A.L2
11st Department of Oral and Maxillo-Facial Surgery and 21st Orthodontic Department, GeorgeEastman Hospital, Rome, Italy The objective of our study is to examine skeletal stability after maxillary and mandibular osteotomy in patients who presented for mandibular excess and maxillary deficiency. The relationship between the stability and the type of the fixation was evaluated too. One hundred and one, patients who underwent orthognathic surgery in the period 1989-1993 were selected. In 62 patients, a combined osteotomy of maxilla and mandible was performed. In 39 patients, only Le Fort I osteotomy or mandibular sagittal bilateral osteotomy was performed. All patients had lateral cephalometric radiographs taken postoperatively and at a 3 years follow-up visit. Eight maxillary and mandibular landmarks (S, N, A, B, ANS, PNS, Go, Gn) were used to examine the postoperative and long-term changes. A New Resorbable Anastomotic Device for Small Vessels An Experimental Study in Rabbits
Biihr W., Rosbander R., Gutwald R., Seholz C.
Department of Oral and Maxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany A new mechanical system for anastomosis of small vessels has been tested in 15 rabbits to join 54 sectioned carotid arteries and jugular veins. The system is resorbable and consists of a cuff and a shrinkable sleeve. The shrinking feature of the sleeve allows a high adaptability to various vessel diameters. To carry out the anastomosis, one vessel end is pulled through the cuff and everted over it. The sleeve is pulled over the end of the other vessel, and this vessel end is then slipped over the everted vessel. The sleeve is positioned over the joint site and made to shrink. This presses the outer vessel onto the everted vessel and cuff. The time needed for this procedure was less than 5 min both in arteries and veins. The anastomoses have been histologically evaluated after in situ periods between 24 h and 3 months. The overall patency rate was 96%. The endothelialization both in arteries and veins was complete in the first postoperative week. With this technique, the trauma associated with the eversion of the vessels was less than the perforation trauma caused by the suture technique. Further advantages include a short insertion time, simple instrumentation, a high patency rate and resorbability. However, the method requires additional vessel