[Arteriovenous malformation in the mandibula]. / Calamiteit bij extractie van een kies. Een arterioveneuze malformatie in de mandibula.

A 15-year-old autistic boy of subnormal intelligence appeared at the office of his dental practitioner complaining about pain in the third quadrant. Investigation revealed that the second molar could be intruded easily. No other irregularities, such as caries or periodontal disease were apparent. Due to the severe pain it was decided that the tooth should be extracted. Extraction of the tooth induced massive bleeding. Hemostasis was achieved by repositioning the molar in its alveolus, according to the principle of putting a cork in a bottle. Radiographic investigation showed the presence of an intraosseous arteriovenous malformation. These malformations are potentially life-threatening lesions. Treatment of choice is a combination of transarterial embolization and surgical removal of the malformation.

Functional results after conservative treatment of fractures of the mandibular condyle.

Since the introduction of osteosynthesis materials for rigid internal fixation after anatomical reduction there is an ongoing discussion about the treatment of condylar fractures of the mandible. Sixty patient files were analyzed and 28 patients were seen for re-examination and a x-orthopantomogram was taken. Functionality was graded with the Helkimo index at an average of 3.0 years follow-up. The clinical dysfunction index showed: severe symptoms in 11%, moderate symptoms in 39%, mild symptoms in 39% and 11% had no symptoms. Index for occlusal state showed: 21% severe occusal disturbances, 61% moderate occlusal disturbances and 18% no occlusal disturbances. According to the anamnestic dysfunction index 89% of the patients were symptom-free. The clinical outcome group showed a significant left/right ramus length difference compared with a 20-person control group. The re-examined group did not significantly differ from the control group. Conservative treatment for condylar fractures was successful in only 46% according to the 1999 consensus criteria described by Bos et al.

Utilization of trihalogenated propanes by Agrobacterium radiobacter AD1 through heterologous expression of the haloalkane dehalogenase from Rhodococcus sp. strain M15-3.

Trihalogenated propanes are toxic and recalcitrant organic compounds. Attempts to obtain pure bacterial cultures able to use these compounds as sole carbon and energy sources were unsuccessful. Both the haloalkane dehalogenase from Xanthobacter autotrophicus GJ10 (DhlA) and that from Rhodococcus sp. strain m15-3 (DhaA) were found to dehalogenate trihalopropanes to 2,3-dihalogenated propanols, but the kinetic properties of the latter enzyme are much better. Broad-host-range dehalogenase expression plasmids, based on RSF1010 derivatives, were constructed with the haloalkane dehalogenase from Rhodococcus sp. strain m15-3 under the control of the heterologous promoters P(lac), P(dhlA), and P(trc). The resulting plasmids yielded functional expression in several gram-negative bacteria. A catabolic pathway for trihalopropanes was designed by introducing these broad-host-range dehalogenase expression plasmids into Agrobacterium radiobacter AD1, which has the ability to utilize dihalogenated propanols for growth. The recombinant strain AD1(pTB3), expressing the haloalkane dehalogenase gene under the control of the dhlA promoter, was able to utilize both 1,2,3-tribromopropane and 1,2-dibromo-3-chloropropane as sole carbon sources. Moreover, increased expression of the haloalkane dehalogenase resulted in elevated resistance to trihalopropanes.