ANEURYSMAL BONE CYST IN THE MANDIBLE (A Case Report)

Aneurysmal bone cyst is commonly seen in the long bones and vertebrae and is rare in the jaws. Its association with other lesions of the bone has been stressed by many workers. Because of its variable radiological appearance, diagnosis of the lesion is established by histopathological examination. A case of aneurysmal bone cyst occurring in the mandible is reported.KEY WORDS: Aneurysmal bone cyst, Mandible     

COMPARATIVE STUDY OF BONE HEALING FOLLOWING BONE CUTS USING SURGICAL BURS AND MICROSAWS

Bone cuts on the tibia of 6 healthy dogs were studied using surgical burs and microsaws arranged in two groups by random selection to assess the speed of cutting, precision and bone healing. Bone cuts in Group A were made with surgical burs of 1.6 mm diameter using micromotor at 40,000 revolutions per minute (RPM) whereas in Group B they were created using Stryker microsaws of 0.75 mm width at the speed of 40,000 RPM. In each group, the dogs were sacrificed at the end of 8, 12 and 16 weeks and a section of the tibia containing the fracture site was removed to assess healing histopathologically. Based on clinical, radiological and histopathological examination, the results of this study indicate that microsaws have their best use in osteotomy procedures in terms of precision and thermal injury to bone whereas ostectomy procedures are more convenient with surgical burs.KEYWORDS: Bone cuts, Bone healing, Microsaws, Surgical burs     

EFFICACY OF INDIGENOUSLY MANUFACTURED TITANIUM BONE PLATES AND SCREWS IN MAXILLOFACIAL SURGERY

Titanium plates and screws (implants) developed indigenously by DRDO were used to manage 20 patients with maxillofacial fractures. Efficacy of these implants was evaluated clinically and radiographically so that these can be put into use on routine basis. In 18 patients recovery was uneventful. Extended maxillomandibullar fixation was employed for 3 to 7 days only depending on the degree and displacement of fractures and; mobilisation of jaw was allowed fully from 7th post operative day onwards. 2 patients developed discharging sinus at the fractured mandibular angle region which was due to impacted mandibular third molar in the line of fracture. This healed completely after extraction of offending tooth and appropriate medication. There was no occlusal or nerve disturbances, wound dehiscence or rejection of the bone implant. Radiographical evaluation at various intervals showed good alignment, approximation and sound healing of fractured fragments, with complete osteointegration.KEY WORDS: Biocompatibility, Maxillofacial fractures, Osteointegration, Titanium bone plates and screws, Titanium implants     

CLINICO-RADIOGRAPHIC EVALUATION OF XENOGRAFTS IN MAXILLOFACIAL SURGERY

An endeavour to find a suitable substitute for autogenous bone graft in corrections of maxillofacial deformities has been going on. Evaluation of commercially processed xenograft (SURGIBONE) has been carried out as a substitute for autogenous grafts in various maxillofacial surgical procedures in the Department of Dental Surgery at Armed Forces Medical College. Clinical and radiographic evaluation in 15 patients revealed highly satisfactory result with complete integration of the graft without any adverse host tissue reaction within the follow-up period lasting from 12-18 months.KEY WORDS: Bone substitute, Surgibone, Xenograft     

Quantitative and qualitative differences in bronchoalveolar inflammatory cells in Pseudomonas aeruginosa-resistant and -susceptible mice

The difference in severity of Pseudomonas aeruginosa-induced chronic lung infection may be determined by differences in host inflammatory responses. In the present study we investigate this possibility using BALB/c and C57Bl/6 mice, resistant and susceptible, respectively, to chronic lung infection with P. aeruginosa. Following intratracheal inoculation of P. aeruginosa-impregnated agar beads, C57Bl/6 mice mounted a stronger inflammatory response with significantly higher total cell numbers in the bronchoalveolar lavage fluid compared with BALB/c mice. While polymorphonuclear leucocytes were the predominant cell in C57Bl/6 mice, macrophages constituted the majority in BALB/c mice at day 7 post-infection. Alveolar macrophages from C57Bl/6 mice showed significantly higher spontaneous production of nitric oxide (NO) at day 7 post-infection compared with BALB/c mice. Following in vitro stimulation with heat-killed Pseudomonas antigen, these cells produced significantly higher NO compared with cells from BALB/c mice at day 21 post-infection. Production of tumour necrosis factor-alpha (TNF-α) by alveolar macrophages was significantly higher at day 7 in BALB/c mice compared with C57Bl/6 mice, which showed significantly higher levels at day 28 post-infection. Taken together, these results suggest that defects in the host inflammatory process contribute to the variable outcome of chronic lung infection with P. aeruginosa. An exaggerated inflammatory response dominated by polymorphonuclear cells correlates with susceptibility to infection, whilst a modest inflammatory response dominated by macrophages correlates with resistance. Moreover, the quantity and timing of production of NO and TNF-α by alveolar macrophages may modulate the course and outcome of infection.