Accuracy of linear measurement in the Galileos cone beam computed tomography under simulated clinical conditions.

OBJECTIVES: The aim of this study was to determine the geometric accuracy of cone beam CT (CBCT)-based linear measurements of bone height obtained with the Galileos CBCT (Sirona Dental Systems Inc., Bensheim, Hessen, Germany) in the presence of soft tissues. METHODS: Six embalmed cadaver heads were imaged with the Galileos CBCT unit subsequent to placement of radiopaque fiduciary markers over the buccal and lingual cortical plates. Electronic linear measurements of bone height were obtained using the Sirona software. Physical measurements were obtained with digital calipers at the same location. This distance was compared on all six specimens bilaterally to determine accuracy of the image measurements. RESULTS: The findings showed no statistically significant difference between the imaging and physical measurements (P > 0.05) as determined by a paired sample t-test. The intraclass correlation was used to measure the intrarater reliability of repeated measures and there was no statistically significant difference between measurements performed at the same location (P > 0.05). CONCLUSIONS: The Galileos CBCT image-based linear measurement between anatomical structures within the mandible in the presence of soft tissues is sufficiently accurate for clinical use.

Gingival plasma cell granuloma.

Plasma cell granulomas (pseudotumors) are rare benign, tumor-like proliferations composed chiefly of plasma cells that manifest primarily in the lungs, but may occur in various anatomic locations. We report this case of a 54-year-old male who presented with an unusual maxillary anterior gingival overgrowth treated by excisional biopsy. Histological examination revealed a dense inflammatory cell infiltrate containing mainly plasma cells. Immunohistochemistry for kappa and lambda light chains showed a polyclonal staining pattern confirming a diagnosis of plasma cell granuloma. Intraoral plasma cell granuloma is exceedingly rare, although case reports documenting such lesions have been reported. This case highlights the need to biopsy unusual lesions to rule out potential neoplasms.

The osteoinductive potential of demineralized freeze-dried bone allograft in human non-orthotopic sites: a pilot study.

BACKGROUND: The use of demineralized freeze-dried bone allograft (DFDBA) in periodontal therapy is widely accepted. In addition to histologic studies demonstrating its role in regenerating the attachment apparatus, its recognized ability to exhibit osteoinduction in small laboratory mammals has prompted many clinicians to regard it as osteoinductive when utilized in periodontal therapy. Despite such a theoretical deduction, evaluating and establishing the osteoinductive potential of DFDBA in humans has been problematic. The purpose of this study was to investigate, through the use of a novel implantation/recovery model, the potential of DFDBA to induce new bone formation at sites not normally considered capable of de novo osteogenic activity. METHODS: Seven patients scheduled to undergo periodontal therapy utilizing non-absorbable membranes agreed to have sterile polypropylene mesh capsules placed adjacent to the primary surgical site for the purpose of this investigation. One capsule was left empty while the second capsule contained DFDBA. At the appropriate time interval for removal of the therapeutic membrane, the capsules were removed and submitted for histologic analysis. Five of the subjects had procedures directed at regenerating bone within molar furcations (guided tissue regeneration) and had the membranes and associated capsules removed between 6 and 8 weeks. The 2 remaining patients had procedures directed toward ridge augmentation (guided bone regeneration) and had the membranes removed either at 8 or 9 months, respectively. In addition, one of the 2 long-term membrane patients had liberal cortical penetration performed directly beneath the implanted capsule. RESULTS: Histologic analysis of all recovered capsules by 2 independent oral and maxillofacial pathologists could not confirm the presence of either osteoblastic or osteoclastic activity associated with the DFDBA particles, although the 2 longer-term specimens clearly exhibited trace amounts of vital bone non-contiguous with the implanted material. CONCLUSIONS: The results of this pilot study do not support the osteoinductive potential of DFDBA when utilized in quantities normally associated with periodontal bone grafting, although they do support the use of this implantation/recovery model to study other preparations and mechanisms of bone formation.

Myospherulosis complicating cortical block grafting: a case report.

BACKGROUND: Myospherulosis of the oral cavity is an inflammatory, granulomatous lesion historically associated with the use of petrolatum-based antibiotic ointment placed in third molar extraction sites to prevent postoperative infection. METHODS: A case of bilateral myospherulosis is presented, in which large lesions complicated the procurement of a cortical block graft used to prepare a mandibular molar edentulous space for implant placement. By obtaining the block graft from a more lateral location on the mandible, an adequate graft was procured and was successfully grafted into an atrophic edentulous ridge. RESULTS: The cortical block graft was successfully incorporated by the recipient site, which received a wide-body, threaded dental implant 6 months later. Healing was uncomplicated, and a functional implant-supported restoration was successfully achieved. CONCLUSIONS: Myospherulosis, though rare today, may present a significant obstacle to the procurement of cortical block grafts. In this case, thorough debridement of the material resulted in subsequent healing of the myospherulosis defect, but prevented procurement of the cortical graft from the planned site. The dimension and volume of the neighboring cortical bone were adequate, and the augmented edentulous space was subsequently restored with a functional endosseous implant. The success seen in these 2 sites would seem to confirm the assumption that size and location of myospherulosis defects are critical factors in obtaining a successful clinical result in implant patients.

Elevated phenotypic switching and drug resistance of Candida albicans from human immunodeficiency virus-positive individuals prior to first thrush episode.

Strains of Candida albicans obtained from human immunodeficiency virus (HIV)-positive individuals prior to their first episode of oral thrush were already in a high-frequency mode of switching and were far more resistant to a number of antifungal drugs than commensal isolates from healthy individuals. Switching in these isolates also had profound effects both on susceptibility to antifungal drugs and on the levels of secreted proteinase activity. These results suggest that commensal strains colonizing HIV-positive individuals either undergo phenotypic alterations or are replaced prior to the first episode of oral thrush. They also support the suggestion that high-frequency phenotypic switching functions as a higher-order virulence trait, spontaneously generating in colonizing populations variants with alterations in a variety of specific virulence traits.

The prevalence of radiographically evident mandibular tori in the University of Iowa dental patients.

OBJECTIVES: To evaluate the radiographic prevalence of mandibular tori and to determine the attributes which make tori radiographically evident. METHODS: The prevalence of mandibular tori was determined from 1600 radiographic surveys of patients attending the College of Dentistry, University of Iowa, 200 for each decade of life from the first to the eighth. Dry skulls were evaluated at the National Museum of Natural History. Mandibular tori were measured, classified and radiographed to correlate the radiographic findings with the physical characteristics. RESULTS: Overall, 16.9% of the patient population had radiographically detectable mandibular tori with some cohorts within the population as high as 33%. Lobulated tori extending 4 mm or more mediolaterally were radiographically detectable. CONCLUSIONS: This study revealed one of the higher prevalence rates of mandibular tori in the literature for a population within the United States. Radiographic threshold analysis suggests that this group of Iowans has a high percentage of medium to large discretely lobulated tori.

Endodontic considerations of the nasopalatine duct region.

Although rare, anomalies of the nasopalatine region have been reported in the literature mimicking pathoses of endodontic origin. The purpose of this article is to present a case of a patent nasopalatine duct that was originally diagnosed as a sinus tract and referred for endodontic therapy. A review of the anatomy of the nasopalatine region is also discussed.

Experimental evaluation of expanded polytetrafluoroethylene for reconstruction of orbital floor defects.

OBJECTIVE: This study evaluates the efficacy of a medical grade expanded polytetrafluoroethylene (e-PTFE) sheet for reconstruction of the orbital floor. MATERIALS AND METHODS: Orbital floor defects were created in 10 domestic sheep and reconstructed with the 1-mm thick e-PTFE sheet. The surgical sites were evaluated for the development of enophthalmos and biocompatibility at 2 weeks, and at 1-, 2-, 4-, and 6-months intervals. RESULTS: The results of this indicate that the e-PTFE material has excellent handling characteristics, provides stability to correct surgically created enophthalmos, and causes essentially no foreign body reaction. CONCLUSION: Expanded polytetrafluoroethylene proved to be an excellent alloplastic material for the repair of orbital floor defects in this experimental study.

Genetic similarity and phenotypic diversity of commensal and pathogenic strains of Candida albicans isolated from the oral cavity.

Colony phenotype and genetic similarity were assessed within and between groups of commensal and pathogenic strains of Candida albicans collected from the oral cavities of individuals in a single geographical locale. Thirty-eight percent of pathogenic isolates contained predominant or minor variant colony morphologies (other than smooth) when samples from the sites of infection were cultured on plates, while 16% of commensal isolates contained minor variant colony morphologies when samples from the sites of carriage were cultured. The genetic similarities of isolates within and between groups were assessed by DNA fingerprinting by using Southern blot hybridization with the fingerprinting probe Ca3 and analysis with the computer-assisted, automated Dendron system. Both the commensal and the pathogenic groups contained a major cluster of genetically similar C. albicans isolates representing 31 and 33% of the strains in the respective groups. When a combined dendrogram of both commensal and pathogenic isolates was generated, the major clusters of genetically similar isolates in each group mixed into one large cluster. Minor clusters in the individual dendrograms also mixed. These results suggest common clonal origins for commensal and pathogenic strains in the same geographical locale.

Autologous calvarial and iliac onlay bone grafts in miniature swine.

Calvarial bone has been reported to be superior to iliac bone for onlay bone grafting due to decreased resorption. This study evaluated the physical, histologic, and radiographic characteristics of calvarial and corticocancellous iliac onlay bone grafts in nine Pitman-Moore miniature swine at 2 weeks, and at 1-, 2-, 4-, 6-, 7-, 8-, 10-, and 12-month intervals. Compared with iliac grafts, the calvarial onlay grafts had more than a twofold greater radiographic density. Statistical analysis of the mature grafts using the standard of estimated means of the bone graft volumes revealed 85% retention of the calvarial grafts compared with 34% retention of the grafted iliac bone. There was no subjective difference in the rate or degree of revascularization between the two grafted materials.

Differentiation of sugar assimilation characteristics and colony phenotypes in pathogenic and commensal oral candidal isolates.

A comparison of sugar assimilation patterns has been made using 72 oral candidal isolates recovered from diseased and non-diseased patients. Significant differences were demonstrated between isolates recovered from diseased versus healthy mouths. In addition, significant changes in colony phenotype (switch frequency and morphologic predominance) were found to relate to predictive data generated from carbon source utilization data. These results suggest that biochemical properties and colony phenotypic characteristics may hold promise in predicting the behavior of oral candidal isolates in disease.

Candida and candidosis. Epidemiology, diagnosis and therapeutic management.

Infections caused by Candida species comprise one of the most common oral disease conditions encountered in the practice of dentistry. Gradual changes in population demographics have been accompanied by an increased incidence in candidal and related opportunistic infection rates. Candida albicans and other candidal species traditionally have been recognized as opportunistic pathogens. Recent advances in both the scientific basis for and the clinical significance of candidal organisms, however, have demonstrated these fungi to be distributed widely and to be important contributors to a broad range of mucosal and systemic disease conditions. These factors have allowed for a better understanding of fungal pathogenesis as it affects human oral disease through improvements in clinical and laboratory diagnosis and the therapeutic management of candidosis.

Oral candidosis. Clinical, historical, and therapeutic features of 100 cases.

Oral candidosis is an increasingly important disease that affects a significant percentage of the population. Traditionally known as an opportunistic pathogen, the broader clinical scope of oropharyngeal candidal infections is now being recognized. The clinical and historical features of 100 patients referred for diagnosis and management of candidosis have been reviewed. The age, gender, chief complaint, medical history, medications, and clinical findings have been noted. A wide range of clinical signs and symptoms, and the rationale behind the topical and systemic antifungal therapies provided to this patient population, are discussed.

Radiographic support in highly mobile operations.

A lightweight radiographic package is described for use in highly mobile operations, especially light units. Weight, volume, and power requirements of the current medical field x-ray machine create a situation in which radiographic support is impractical if not possible in the early phase of high mobility medical operations. A method for immediate utilization of the dental field x-ray unit to overcome the limitations of the standard field x-ray machine (GX-111) is described.