Alveolar bone regeneration in response to local application of calcitriol in vitamin D deficient rats.

AIM: Vitamin D deficiency is considered to diminish bone regeneration. Yet, raising the serum levels takes months. A topic application of the active vitamin D metabolite, calcitriol, may be an effective approach. Thus, it becomes important to know the effect of vitamin D deficiency and local application on alveolar bone regeneration. MATERIAL AND METHODS: Sixty rats were divided into three groups; two vitamin depletion groups and a control group. Identical single defects (2 mm diameter) were created in the maxilla and mandible treated with calcitriol soaked collagen in one deficiency group while in the other two groups not. Histomorphometric analysis and micro CTs were performed after 1 and 3 weeks. Serum levels of 25(OH)D3 and PTH were determined. RESULTS: Bone formation rate significantly increased within the observation period in all groups. Bone regeneration was higher in the maxilla than in the mandible. However, bone regeneration was lower in the control group compared to vitamin depletion groups, with no significant effects by local administration of calcitriol (micro CT mandible p = 0.003, maxilla p < 0.001; histomorphometry maxilla p = 0.035, mandible p = 0.18). CONCLUSION: Vitamin D deficiency not necessarily impairs bone regeneration in the rat jaw and a single local calcitriol application does not enhance healing.

Rhinocerebral zygomycosis: an increasingly frequent challenge: update and favorable outcomes in two cases.

Zygomycosis or mucormycosis is an increasingly frequent life-threatening infection caused by opportunistic fungal organisms of the class Zygomycetes. The pathognomonic feature is the presence of invasive aseptate mycelia that are larger than other filamentous fungi with the hyphae exhibiting right angle and haphazard branching. Usually classified as rhinocerebral, disseminated, and cutaneous types, this classification serves as important predictor of pathogenesis and outcome. These occur mostly in immunosuppressed patients including individuals with diabetes (43% exhibit the rhino-cerebral form) and patients with organ transplants and hematologic malignancies. Without early aggressive treatment, the disease follows a dismal and fatal course. The prognosis has not shown any appreciable change in the past 40 years with a stagnant mortality rate of 44%. We present 2 cases of rhinocerebral zygomycosis (RCZ), in a 58-year-old male and a 63-year-old female; both were poorly controlled diabetic patients with maxillary lesions suggestive of osteomyelitis. The patients were leading a near normal life with minimal discomfort or signs and symptoms of underlying mycosis. Most of the health care professionals treating these patients often overlooked the disease or recommended inadequate therapy. Despite long delays and inadequate initial therapy these patients survived with little outward morbidity. The prognosis for this condition may therefore be considered less dire than previously thought.

Treatment of maxillary ridge resorption by sinus augmentation with iliac cancellous bone, anorganic bovine bone, and endosseous implants: a clinical and histologic report.

In this clinical study, a 1:1 mix of particulate cancellous bone and marrow (PCBM) and bovine deproteinized bone (Bio-Oss) was used to fill cavities after elevating the sinus mucosa for major sinus dehiscences. Ten patients with edentulous posterior maxillae were treated with 12 sinus augmentation procedures according to a 2-stage technique, and 30 Frialit-2 endosseous implants were used to complete the implant-prosthetic rehabilitation. Bone cylinders were removed at second-stage surgery immediately prior to implant placement (5 to 7 months after grafting), and histologic evaluation was performed. The results showed that Bio-Oss is a reliable osteoconductive material and its association with PCBM leads to the formation of new bone with an increased overall density.

A modified protocol for early treatment of osteomyelitis and osteoradionecrosis of the mandible.

BACKGROUND: The treatment of osteoradionecrosis (ORN) and early chronic osteomyelitis (COM) of the mandible and maxilla is controversial. Hyperbaric oxygen (HBO) at two to three times the atmospheric pressure at sea level can result in tissue oxygen tension of almost 400 mmHg. Herewith HBO increases oxygen supply in hypoxic tissue, thus inducing fibroblastic proliferation and capillary formation. METHODS: From 1981 to 1991, we used a monoplace chamber and since 1992, we have also had a multiplace chamber for HBO treatment. Hyperbaric oxygen was given at 2.5-2.8 atmosphere absolute pressure (ATA) for 90-120 minutes, once per day. The patients had five to 10 preoperative and five to seven postoperative sessions. Surgical therapy consisted of decortication of the affected bone, subsequently covered with a free periosteal transplant from the tibia. RESULTS: Thirty-six patients with ORN and 33 with COM of the mandible and maxilla was treated with this protocol. The median follow-up time in this material is 34 months, with a minimum of 10 months. Thirty-six ORN patients (92%) and 26 COM patients (79%) have remained symptom-free after the first treatment period. Three failed ORN patients were successfully treated with a free microvascular flap. The seven failed COM patients have been retreated, and five of them have occasional clinical symptoms. CONCLUSIONS: Hyperbaric oxygen is a promising adjunct to surgery in the treatment of mandibular and maxillary ORN and COM. Using this protocol, the necessary HBO treatment sessions have been reduced from earlier protocols, without adverse effect on the outcome.

Alveolar bone loss on neolithic man remains on 38 skulls of Khirokitia's (Cyprus) inhabitants.

38 skulls, belonging to inhabitants of various age groups of the Neolithic settlement of Khirokitia in Cyprus (5800-3000 BC) were studied and the alveolar bone loss was evaluated in areas where teeth still existed. It was found that the alveolar bone loss increased with age. The differences deriving from the comparison of skulls belonging to older people (the mean life-span of the inhabitants was 35.2 years), with skulls belonging to younger people suggest that our findings are not due to postmortem weathering of bones through the centuries but represent a real fact. The results of this study indicate that periodontal disease has accompanied human beings since prehistoric time without being affected by civilization.

Legume-associated residual cyst.

This report describes three unique cases of residual cyst (RC) which were characterized by large legume implants. To determine whether these represented a distinctive RC subset or if implanted materials have general importance in RC pathogenesis, a retrospective comparison of these cases and 37 further RCs with 40 control periapical cysts was performed. The frequency of foreign material implantation and the associated histopathologic features were assessed. No significant differences were noted suggesting that foreign implantations do not have an etiologically significant association with RCs and that the legume-associated RCs represent a unique subgroup. The relationship of the legume-associated RCs to the category of lesions variously termed giant cell hyaline angiopathy, oral pulse granuloma or hyaline ring granuloma is discussed.