Demos Kalyvas

Localized jaw enlargement in renal osteodystrophy: Report of a case and review of the literature

Renal osteodystrophy is a common long-term complication of end-stage renal disease. Involvement of the jaws is common and radiographic alterations are often one of the earliest signs of chronic renal disease. However, marked enlargement of the jaws is a rare complication of renal osteodystrophy. A case of localized asymptomatic enlargement of the mandible in a 38-year-old woman with chronic renal failure is presented. The clinical, radiographic, and histological findings were consistent with renal osteodystrophy. To our knowledge, this is the third case of localized mandibular enlargement of renal osteodystrophy reported in the English-language literature.

Bone Regeneration Using B-Tricalcium Phosphate in a Calcium Sulfate Matrix

The aim of the study was the histomorphometric comparison of the osteogenic potential of beta-tricalcium phosphate (beta-TCP) alone or in a calcium sulfate matrix. Three round defects, 10 mm (diameter) x 5 mm (depth), were created on each iliac crest of 4 dogs. The defects were divided into 3 groups. Ten defects were filled with beta-TCP in a calcium sulfate (CS) matrix (Fortoss Vital; group A), 10 defects were filled with beta-TCP alone (Fortoss Resorb; group B), and 4 defects were left ungrafted to heal spontaneously (group C). All defects were left to heal for 4 months without the use of a barrier membrane. Histologic evaluation and morphometric analysis of undecalcified slides was performed using the areas of regenerated bone and graft remnants. All sites exhibited uneventful healing. In group A sites (beta-TCP/CS), complete bone formation was observed in all specimens, graft granules dominated the area, and a thin bridge of cortical bone was covering the defect. Group B (beta-TCP) defects were partially filled with new bone, the graft particles still dominated the area, while the outer cortex was not restored. In the ungrafted sites (group C), incomplete new bone formation was observed. The outer dense cortical layer was restored in a lower level, near the base of the defect. The statistical analysis revealed that the mean percentage of new bone regeneration in group A was higher than in group B (49.38% and 40.31%, respectively). A statistically significant difference existed between the 2 groups. The beta-TCP/CS group exhibited significantly higher new bone regeneration according to a marginal probability value (P = .004 < .05). The use of beta-TCP in a CS matrix produced significantly more vital new bone fill and preserved bone dimensions compared with the use of beta-TCP alone.

The influence of alendronate on osseointegration of nanotreated dental implants in New Zealand rabbits

OBJECTIVES Growing clinical demands for stronger and faster bone bonding to the implant have motivated the development of methods enhancing osseointegration. Lately, the application of bisphosphonates (bis) in order to optimize bone healing has become a topic of great interest. N-containing bis, such as alendronate (ALN), are the more potent drugs of this class. It was the aim of this study to determine the effect of ALN on the osseointegration of a well-documented nanotreated implant system in a rabbit femoral condyle model. MATERIAL AND METHODS Thirty-two adult female New Zealand White rabbits received one implant (3.25 mm in diameter and 10 mm in length) in their left femoral condyle, a week after they were ovariectomized. Half of them were saline treated (control, group A) and the other half were ALN treated (group B). Rabbits from both groups were euthanized after 6 and 12 weeks, respectively. RESULTS The specimens were evaluated histologically and histomorphometrically. Upon histological evaluation, no obvious differences were found between the control and the treatment group. Implants showed good integration into the bone tissue surrounding them. There were also no statistically significant differences in bone-to-implant contact and the amount of bone tissue in the immediate neighborhood of the implant at both healing periods. CONCLUSIONS The systemic administration of ALN was not found to affect histological osseointegration of implants in animals with a hormonal status resembling that of postmenopausal healthy women. Further research will be needed to investigate this approach.

The use of digital subtraction radiography to evaluate bone healing after surgical removal of radicular cysts

ObjectiveThe purpose of this study was to evaluate the bone healing process after surgical removal of radicular cysts by using preoperative and postoperative panoramic radiographs, which were digitized and subtracted using a projective standardization software program (Emago).MethodsSeventeen patients with large radicular cysts treated by surgical enucleation were included in the study. All surgical procedures were performed by one of the authors (D.K.). Each patient had a panoramic preoperative radiograph (plain film) and a panoramic postoperative radiograph (plain film), which was taken 6 to 12 months after surgery. All radiographs were taken with the same panoramic unit. The part of the radiograph that included the lesion in the preoperative radiograph was digitized using a CCD digital camera at a standard distance. The postoperative radiograph was also digitized using the same standardized parameters. The preoperative and postoperative images were then manipulated by means of the projective standardization software program Emago to reveal the regenerated area. This area was calculated in pixels, and the percentage of bone healing was determined for each patient. The data were analyzed using Students t test and the Wilcoxon test for pair differences.ResultsThe percentage of bone healing ranged from 55.14% to 95.68% with a mean of 72.27%. In all cases, the differences were significantly different at P = 0.01.ConclusionsDigitizing the part of the panoramic radiograph that included the lesion area and subsequently performing projective standardization is a suitable method for analyzing the healing process by means of subtraction radiography. The projective standardization software program performs the geometric reconstruction and subtraction process. An evaluation of the healing process can be obtained by calculating the regenerated bone area in the subtracted images.

Mucocele of the dorsal surface of the tongue: a case report

Mucoceles represent one of the most common lesions of the oral cavity, developing as a result of saliva accumulation. The most frequent affected area is the lower lip, followed by floor of mouth, ventral tongue and buccal mucosa. Despite numerous reports of mucoceles originating on the ventral surface of the tongue, only scarce cases of such a lesion identified on the dorsal tongue surface have been described. In this report a mucocele developed on the dorsal tongue of a 74-year-old woman is described. Additionally a review of previously published mucoceles of the dorsal surface of the tongue is provided and discussed. A 74-year-old female patient was referred for a painless swelling on the dorsal surface of the tongue of 1 month duration. Possible clinical diagnosis included granular cell tumor and lingual thyroid gland. Proper blood testing for TSH, T3 and T4 as well as ultrasonography were requested, found to be within normal limits. An excisional biopsy was performed and tumor was removed with no intra-operative complications. Histopathological examination was consistent with a mucocele, exhibiting an amorphous material surrounded by granular connective tissue without epithelial lining on the periphery. Patient was examined on regular follow-up basis, with no signs of recurrence for the last 1 year. Mucoceles of the dorsal tongue surface represent rare clinical entities, necessitating the need for further case reports to be published in order to widen our understanding of their clinical features. Key words:Mucocele, oral cavity, tongue, minor salivary glands, oral and maxilloafcial pathology.

Evaluation of an In Situ Hardening β-Tricalcium Phosphate Graft Material for Alveolar Ridge Preservation. A Histomorphometric Animal Study in Pigs

The purpose of this study was to investigate the effectiveness of a resorbable alloplastic in situ hardening bone grafting material for alveolar ridge preservation in a swine model. Seven Landrace pigs were used. In each animal, the maxillary left and right deciduous second molars were extracted, and extraction sites were either grafted with a resorbable alloplastic in situ hardening bone substitute, composed of beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic) acid (PLGA), or left unfilled to heal spontaneously. Animals were euthanized after 12 weeks, and the bone tissue was analyzed histologically and histomorphometrically. Linear changes of ridge width were also clinically measured and analyzed. Pronounced bone regeneration was found in both experimental and control sites, with no statistically significant differences. At the experimental sites, most of the alloplastic grafting material was resorbed and remnants of the graft particles were severely decreased in size. Moreover, experimental sites showed, in a statistically nonsignificant way, less mean horizontal dimensional reduction of the alveolar ridge (7.69%) compared to the control sites (8.86%). In conclusion, the β-TCP/PLGA biomaterial performed well as a biocompatible resorbable in situ hardening bone substitute when placed in intact extraction sockets in this animal model.

Recurrence in a patient with a 10-year history of sinonasal mucosal melanoma manifesting as facial swelling

Sinonasal mucosal melanoma is a rare tumor that develops slowly and may manifest with non specific signs and symptoms, causing significant delay in diagnosis. Local recurrence is common and usually occurs within the first two years after the initial treatment. Prognosis of recurrent lesions is poor and 5-year survival ranges between 10-47%. We report the clinical, radiographic, histopathological and immunohistochemical findings of a recurrent sinonasal mucosal melanoma which was diagnosed 10 years after the initial treatment, in a patient who presented with unilateral facial swelling and one-sided difficulty in breathing of two years duration. We discuss the causes of late diagnosis and review the negative predictive factors for recurrence and survival. As early diagnosis is of paramount importance for prognosis, we emphasize the signs and symptoms of patients with a history of sinonasal mucosal melanoma which should raise the suspicion for recurrence, in spite of a long time interval since diagnosis. Key words: Mucosal melanoma, nasal cavity, sinus, recurrence.