A four-parameter index of marrow dysplasia has predictive value for survival in myelodysplastic syndromes.

Marrow dysplasia is a major characteristic of patients with myelodysplastic syndrome (MDS), along with marrow blastosis, cytopenia and cytogenetic anomalies. However, the impact of the degree of marrow dysplasia on survival has not been fully assessed. In this retrospective analysis of 111 patients selected according to the IPSS criteria of MDS diagnosis, the presence or absence of 21 dysplasia characteristics recognizable in bone marrow smears stained by the May-Grünwald-Giemsa method was correlated with patient survival. Using Cox proportional hazards regression analysis, megaloblastosis (MEGALO), neutrophil agranularity (AGRAN) and hypogranularity (HYPOGRAN) were highly significant predictors (p < 0.005), and Pelger-Huët anomaly (PELGHUET) a significant predictor (p = 0.05), of patient survival. The regression analysis yielded a dysplasia-based risk index (DI) where DI = 1.26 MEGALO + 0.82 AGRAN - 1.08 HYPOGRAN + 0.45 PELGHUET. The two subgroups of 60 and 47 patients with DI < or = 0 and > 0 showed highly significant differences in median survivals (2.6 vs 1.1 yrs; p <0.0001). Multivariate analysis further showed that DI offered additional predictive power that was independent of that provided by the IPSS (p=0.002 and 0.001 respectively). Analysis of survival curves stratified for IPSS and DI showed that the additional predictive power offered by inclusion of the DI essentially concerned the IPSS low/INT-1 risk categories. Further stratification for age did not improve survival prediction. The data indicate that a set of 4 dysplasia parameters can offer some prediction for survival of MDS patients in addition to that provided by the IPSS. Further multicenter studies should aim at including some form of evaluation of the degree of dysplasia in prognostic systems.

Dynamic ultraviolet sterilization of different implant types.

This paper investigates the use of the dynamic ultraviolet sterilization process with various dental implants, stainless steel orthopedic cortical bone screws, and polysulfone polymer healing caps. These biomaterials were inoculated with the spores of Bacillus subtilis and Bacillus stearothermophilus. They were then exposed to dynamic ultraviolet radiation in the chamber of a BUD Ultraviolet Device. Samples were incubated in trypticase soy broth at 37 degrees C and 56 degrees C, and they were subcultured onto an enriched agar medium. Results indicate that 16 seconds of dynamic ultraviolet radiation is effective in sterilizing these materials. This is significantly less time than other sterilization techniques presently used.

Dynamic sterilization of titanium implants with ultraviolet light.

All implantable devices must be sterile. However, autoclaves produce poor surface properties that jeopardize the integration process. The application of a modified ultraviolet light source has proven to enhance bioreactivity by controlling surface properties, but it lacks validation of its sterilization capabilities. Forty-eight titanium implants were contaminated with spores of the biological indicator Bacillus stearothermophilus and subjected to "dynamic sterilization" by ultraviolet light. Forty-seven of the implants were successfully sterilized, as indicated by not producing turbidity in a suitable growth medium. This sterilization technique only requires a 20-second exposure to achieve sterility.

Utilization of a plastic "washer" to prevent auricular prosthesis abutment overgrowth: report of a case and description of a technique.

Skin overgrowth of auricular implant abutments can be a difficult and frustrating problem, leading to multiple procedures and delaying the placement of a definitive prosthesis. In the present patient, plastic rings or "washers" were employed to successfully deal with this problem. A discussion of the management of peri-implant soft tissues is presented.

Evaluation of the peri-implant epithelial tissue of percutaneous implant abutments supporting maxillofacial prostheses.

The use of commercially pure titanium endosseous implants has become state-of-the-art treatment for patients with craniofacial defects. This study defined criteria that can be used in assessing the peri-implant abutment epithelium. The criteria were then used to examine overall tissue reaction. In this investigation, seven patients with percutaneous craniofacial implants were evaluated. Two of these patients exhibited adverse skin reactions that were associated with heavy sebaceous crusting, skin cultures positive for Staphylococcus aureus, higher Periotest values, and thicker peri-abutment tissue with greater mobility. It was determined that these factors can predispose the patient to local infection, which, if ignored, can result in failure of the implant. This study indicates that adequate patient hygiene is crucial to maintaining healthy tissues in the peri-implant abutment site.

Visualization and initial characterization of the titanium boundary of the bone-implant interface of osseointegrated implants.

A simple procedure has allowed consistent visualization of the titanium boundary of the bone-implant interface of osseointegrated titanium implants at the electron microscope level. This was accomplished by embedding the intact bone-implant specimen block with low-viscosity resin prior to removal of the device in preparation for sectioning. The titanium boundary consisted of either a thin, compact amorphous electron dense layer, a broad layer of dense amorphous granules, or both. This material was removed by decalcification in formic acid (prior to embedding) and did not diffract electrons (ie, was noncrystalline). Scanning-transmission electron microscopy-EDX analysis indicated the presence of titanium, calcium, and phosphorus in the electron dense material. Field emission scanning electron microscopy-EDX dot-mapping analysis confirmed the presence of these elements and mapped them to the same locations at the implant-interface boundary.

Microscopic observations of the bone/implant interface of surface-treated titanium implants.

Light microscopy, and transmission and scanning electron microscopy were used to evaluate osseointegration of extraoral titanium implant surfaces treated by either autoclaving, exposure to ultraviolet light (UV), or radiofrequency glow discharge (RFGD). Ultraviolet and RFGD-treated implants showed faster healing in the initial 5-week to 3-month period. By 6 months of healing, no structural differences were found at the bone/implant interface among the different treatments. It was concluded that UV or RFGD surface treatment of titanium implants may shorten the time interval between placement and loading.

Effects of pretreatment sterilization and cleaning methods on materials properties and osseoinductivity of a threaded implant.

A new endosseous titanium implant has been designed to replace skin adhesives as a method of retention of maxillofacial prostheses. The effects of various methods of preimplantation preparation on surface characteristics of the implant were analyzed with electron spectroscopy for chemical analysis. Having undergone one of several pretreatment protocols, fixtures were implanted in the crania of Yucatan miniature hairless swine. Both argon radiofrequency glow discharge and ultraviolet chamber treated implants were associated with the rapid ingrowth and maturation of new bone around the fixture. Conventional steam sterilization was associated with a paucity of neo-osteogenesis accompanied by the production of thick collagen slings at the interface. Apparently, the bulk material, fixture design, and method of surface preparation all contribute to the ultimate clinical fate of an implant.

Custom surgical stent for naris stenosis.

A technique has been described that allows accurate fabrication of a surgical nasal stent, made preoperatively, based on a mirror image of the shape of the normal naris. The advantage to the surgeon is a surgical stent that has the greatest accuracy possible preoperatively, plus the ability to remake the stent postoperatively with even more accuracy should it be needed. This stent can then be worn long term with minimal visibility and maximum patient acceptance during the critical months postoperatively when relapse is most likely.

Obturators on complete dentures.

A philosophy and technique for the preparation of removable silicone rubber obturators on complete dentures have been presented. Either of two methods for construction is used depending on whether the defect is large or small. Advantages of the silicone rubber obturator-denture combination were elaborated.

The spinal curvature irregularity index independently identifies vertebral fractures.

INTRODUCTION AND HYPOTHESIS: The spinal curvature irregularity index (SCII) is a quantitative measure of the irregularity of the spinal curvature. We evaluated the predictive ability of SCII to identify subjects with vertebral fractures (VF). METHODS: Vertebral heights were measured by quantitative vertebral morphometry in 461 Lebanese women 20-89 years of age and VFs were ascertained by the grade 1 Eastell method. SCII scores were log-transformed and expressed as Z-SCII, the number of standard deviations above or below the mean ln(SCII) of young patients without VF. Univariate and multivariate binary logistic regression models were used to identify clinical predictors of VF. RESULTS: Women with a higher SCII were more likely to have prevalent VF. A higher SCII was associated with a greater prevalence of VF within each category of femoral neck BMD (normal, osteopenia, osteoporosis). In univariate analysis, predictors of VF included Z-SCII (odds ratio, OR: 2.21, 95% CI: 1.80-2.71) and femoral neck T-score (OR: 1.35, 95% CI: 1.12-1.63). In multivariate analysis, predictors of VF were: Z-SCII (OR: 1.54, 95% CI: 1.02-2.32), femoral neck T-score (OR: 1.41, 95% CI: 1.11-1.78) and age(3) (OR: 1.40, 95% CI 1.10-1.82). At a cutoff SCII of 9.5%, the sensitivity and specificity of SCII for VF were 71 and 64% respectively, and higher SCII cutoffs identified VFs with greater specificity. CONCLUSION: The SCII is a robust, simple and independent indicator of the presence of VFs.

Maxillofacial prosthetics and the head and neck cancer patient.

The rehabilitation of cancer patients has been an important aspect of patient care in recent decades. Disabilities resulting from acquired surgical defects in the head and neck area frequently are corrected by using nonliving substitutes or prostheses. A number of specialists in the prosthetic reconstruction of head and neck patients, namely maxillofacial prosthodontists, have been trained over the past 20 years. Now more large metropolitan areas have these services available for cancer patients. In addition, pertinent research in materials and design has resulted in a whole array of possible prostheses that can be constructed to meet specific patient needs. Both the current state of the art in maxillofacial prosthetics and recent advances are highlighted in this paper. The areas covered are: extraoral (facial) prostheses, intraoral prostheses, implant prostheses, and treatment prostheses. The multidisciplinary nature of head and neck cancer patient rehabilitation is also reviewed.

Oral reconstruction for edentulous patients after partial mandibulectomies.

The prosthodontic reconstruction of the patient who has had a partial mandibulectomy is a formidable challenge. A realistic view of the positive and negative factors must be maintained so that unrealistic promises are not made by the prosthodontist and no unfulfilled hopes are left for the patient. Because of the instability of the mandibular denture, the patient's relaxed central position is used as the jaw relationship for setting posterior teeth with flat occlusal surfaces to allow for lateral freedom of mandibular movements.

Technical aspects of reed fistula speech rehabilitation following pharyngolaryngectomy.

The reed fistula method is under development as a method of voice restoration in patients who have undergone larynogopharyngectomy. Introducing extrinsic sound into the pharynx involves a series of biomedical engineering problems. The approaches to solution of these problems are covered in the present article.