The Bone Forming Effect of Sodium Fluoride During The Distraction Osteogenesis on Membranous Bone: An Experimental Study in the Mandibles of Rabbits

The purpose of this study was to improve bone formation and shorten the period involved in distraction osteogenesis using sodium fluoride (NaF). This has been used in managing osteoporosis for several decades. This study was carried out on 40 New Zealand white rabbits. Twenty animals were used for a control group (no medication) and 20 for the experimental group. NaF 1 mg/kg/day was administered to each experimental animal via drinking water beginning 4 weeks prior to surgery and continued until sacrifice for examination. A distraction device was applied to the left mandible along a plane perpendicular to the direction of osteotomy. After a 5-day latent period, the mandibles were lengthened at 1 mm per 24 hours for 10 days. Five rabbits from each group were sacrificed on the 1st day, 2nd week, 4th week and 8th week of the consolidation period. After lengthening, all the rabbits developed a severe cross-bite. By the 4th week, cortical continuity was seen. Bone densities at the site of bony lengthening were measured by quantitative computer tomography (QCT) and dual X-ray absorptiometry (DXA). The results were as follows: the measurements of the experimental group were significantly higher than of the control group by the 1st day of the consolidation period (p>0.05) and insignificantly higher after the 2nd week. Histologically, in the experimental group, there were more osteoblasts, increased and thickened trabeculae and more mature lamellar bones than in the control group. This study showed that osteogenesis of the experimental group was significantly higher during and immediately after distraction. Our study suggested that the use of NaF could improve bone formation and decrease the period of distraction osteogenesis if a safe dose and method of fluoride administration can be determined for growing humans.

Pathologic Analysis and Treatment of Chronic Burn Wounds Suspected to be Marjolin's Jlcers

'Marjolin' ulcer' is used to describe the malignant transformation of a chronic ulcer which has developed in a burn scar. Clinically, although the lesions is slowly progressive, it comes to be more aggressive when the scar barrier is disrupted. We reviewed 24 cases in patients who complained of chronic burn wounds suspected to be Marjolin's ulcer. The mean latent period for developing pathologic lesions was 31 years. Histologically, chronic ulcer and pseudoepitheliomatous hyperplasia were 21% respectively, while malignancy including squamous cell carcinoma and leiomyosarcoma was 56%. The mean elapsed time to diagnose squamous cell carcinogma was 33.2 years. In pseudoepitheliomatous hyperplasia which is considered as a transitional state to malignant tumor, wide excision and reconstruction with free muscle flap was a better procedure than skin graft for the prevention of recurrence and malignant transformation. As well, the same modality of treatment was also applied in malignant tumors.

Vascular Compromised Lower Leg Reconstruction with Modified Microsurgical Salvage Procedures

In the past 5 years, the authors have performed microsurgical reconstruction of the lower leg in 37 patients. Among them, modified microsurgical salvage procedures were performed in 11(29.7) cases with vascular compromise, suggested by the preoperative angiogram of the affected lower leg demonstrating no visible, or only one visible major arter. Modified salvage procedures included free flap operations using distally-based arterial inflow(n=2), temporary diversion of the single main artery with secondary vein grafting(n=2), Jungcross-leg fashioned free flaps(n=4), and end-to-side anastomosis of the main artery((n=1). In absence of arterial flow after lower leg trauma, as interpositional vein graft(n=2) was performed to restore blood flow. No vascular problems occurred after the free flap transfer. However, 9 patients experienced different degrees of limping gait, ranging from as mild(n=2), moderate(n=6) to severe(n=1) at the mean follow-up period of 18 months. In reconstruction of a vascular compromised lower leg, modified salvage procedures should be reviewed and selected after exploration of all vessels, both proximal and distal to the zone of the injury. When evaluating what method is the most appropriate, socioeconomic efficiency and patients' individual requirments should be considered.

Leiomyosarcoma Arising in Marjolin's Ulcer: A Case Report

Leiomyosarcoma is a malignant tumor showing smooth muscle differentiation, and it accounts for 2% to 8% of soft tissue sarcoma. Clinically, substantial mortality and morbidity are related to the propensity for distant metastasis and local recurrence, respectively. Microscopic findings characteristically reveal intersecting bundles of spindle-shaped cells having fibrillar cytoplasm and blunt-ended nuclei. Immunohistochemistry for intermediate filaments is helpful in establishing a definitive diagnosis. We experienced a case of large protruding leiomyosarcoma that developed on an old burn scar of the medial calf of a 45-year-old man. On preoperative evaluation, we recommended amputation due to a distant metastasis to the lung(stage IV). As the patient refused amputation of his lower leg, the tumor was radically excised and immediate reconstruction was done using free latissimus dorsi muscle flap and skin graft. Four months after excision despite adjuvant chemotherapy, amputation was performed due to local recurrence.

The Effects of the Short Latent Period During Destraction osteogenesis : An Experimental Study in the Mandibles Rabbits

To evaluate the effect of shortening the latent period for distraction osteogenesis, the authors experimented with distraction osteogenesis for a 24-hour latent period in the mandibles of rabbits. This study was carried out on 32 New Zealand white rabbits, each weighting 2000 to 2500 gm. Twenty animals were used for the control group and 12 for the experimental group. A unilateral external fixation device was applied to the left mandible. The mandibles were lengthened at 1 mm per 24 hours for 10 days. Five rabbits from the control group and three from the experimental group by random selection were sacrificed on the first day, and at the second, fourth and eighth week of the consolidation period. After lengthening bone densities at the site of the left mandibular bony lengthening were measured by quantitative computer tomography (QCT) and dual energy x-ray absorptiometry (DXA). As a result, the DXA value showed no difference compared to the control group after two week's consolidation. The trabeculae were thicker and had begun to be surrounded by lamellar bone both in the control and experimental groups histologically. In conclusion, the results of this study indicate that the osteogenetic effect in the experimental group was nearly the same as in the control group. If stable fixation and minimal periosteal dissection were performed during the procedure, the latent period would not be an important factor in distraction osteogenesis of membranous bone.

Correction of malunited zygoma through limited exposure

This study includes 40 patients of post-traumatic facial bone deformities to whom underwent realignment of zygomatic bone. In 13 cases, we modified the approach technique using limited exposure such as subciliary, intraoral and preauricular incisions instead of conventional wide exposure. Preoperative evaluation of deformity was done by using x-rays, photographs and detail communication with the patients. Through this limited exposure, osteotomy and repositioning of the zygoma were accomplished. There were no postoperative differences between wide and limited exposure, but limited exposure was more advantageous in terms of reduced operative time, transfusion, hospitalization and scaring. This approach was an effective method for the relatively simple tetrapod type-malunited fracture of zygoma without comminution.

An analysis of 1,210 facial bone fractures in 835 patients: 5 year survey

This retrospective study was undertaken to provide information when considering aspects of future prevention and quantifying demand fir medical services. And it comprised 835 patients with facial bone fractures in various accidents and treated in the department of Plastic and Reconstructive Surgery, the Yeungnam University Hospital during the past five years from January 1991 to December 1996. The medical records of this 835 patients(1,210 fractures) were reviewed and analyzed in order to obtain the clinical pattern and understand the therapeutic tendency. The following results were obtained; 1. The greatest number of patients were sustained facial bone injuries between midnight and 3:00. The monthly incidence showed in September at the most and at the least in December. The increase of facial bone injuries of 11.3% per year was shown. 2. The mean age of patients was 30 years. The most prevalent age group was at third decade(31.9%). Males were predominated more than female(3.6 : 1). 3. The most common cause was traffic accidents(41.6%) followed by violence, fall, industrial accidents and others. 4. The most common fracture was found in the nose(35.1%) followed by mandible(22.6%), zygoma(21.1%), and maxilla(11.2%). 5. Associated injuries were as following order of frequency; ophthalmologic injury(21.0%), other facial bone fractures(18.2%), head injury(10.2%). 6. Open reduction was used for 53.9% of total cases while 40.6% of total cases required closed reduction, and 5.5% of total cases treated conservatively. The complication rate was 18.5% and complications were as following order of frequency; facial asymmetry(37.2%), diplopia and enophthalmos(19.4%), and local infection(12.8%).