Developments in imaging methods used in hip arthroplasty: A diagnostic algorithm.

BACKGROUND: Several imaging modalities can be used to diagnose complications of hip prosthesis placement. Despite progress in these imaging techniques, there are, as yet, no guidelines as to their respective indications. METHODS: We formed a panel of experts in fields related to prosthesis imaging (radiology, nuclear medicine, orthopedic surgery) and conducted a review of the literature to determine the value of each modality for diagnosing complications following hip replacement. RESULTS: Few recent studies have investigated the benefits related to the use of the latest technical developments, and studies comparing different methods are extremely rare. CONCLUSIONS: We have developed a diagnostic tree based on the characteristics of each imaging technique and recommend its use. Computed topography was found to be the most versatile and cost-effective imaging solution and therefore a key tool for diagnosing the complications of hip replacement surgery.

CT of hip prosthesis: New techniques and new paradigms.

Patients with hip pain after joint replacement are first assessed by analyzing the clinical presentation and conventional radiography findings. When this first step is inconclusive, various different imaging techniques can be used to identify the anomalies. Based on our experience, computed tomography (CT) is the cornerstone for diagnosing the main prosthesis-related complications. In this article, we describe the different CT techniques used for this kind of investigation and provide indications for each technique.

A Survey for 'Candidatus Liberibacter' Species in South Africa Confirms the Presence of Only 'Ca. L. africanus' in Commercial Citrus.

Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by 'Candidatus Liberibacter africanus', a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, 'Ca. L. asiaticus'. A 'Ca. L. africanus' subspecies, 'Ca. L. africanus subsp. capensis', has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, 'Ca. L. americanus', and the spread of 'Ca. L. asiaticus' to a number of additional countries over the last few years prompted us to assess whether only 'Ca. L. africanus' is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of 'Ca. L. americanus' infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate 'Ca. L. africanus' Nelspruit sequence in GenBank. No instance of 'Ca. L. asiaticus' or 'Ca. L. africanus subsp. capensis' sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only 'Ca. L. africanus' is associated with citrus greening in commercial citrus in South Africa.

Transmission of Activated-Episomal Banana streak OL (badna)virus (BSOLV) to cv. Williams Banana (Musa sp.) by Three Mealybug Species.

Four different mealybug species (Dysmicoccus brevipes, Planococcus citri, P. ficus, and Pseudococcus longispinus) were evaluated for their ability to transmit putative activated-episomal Banana streak OL (badna)virus (BSOLV) to banana cv. Williams (Cavendish subgroup, AAA). Expressible endogenous sequences of banana streak viruses (BSVs) have been reported to be present in the DNA of various Musa hybrids, including FHIA-21 (AAAB). To obtain activated episomal BSOLV for this experimental transmission study, intentional stress by tissue culture propagation was applied to indexed FHIA-21 which, while free of other viruses, can contain activated episomal BSOLV. Immunocapture polymerase chain reaction and triple-antibody sandwich enzyme-linked immunosorbent assay results revealed that 13.4% of the derived progeny of the mother plants were infected with episomal BSOLV. Four of these BSOLV-infected progeny were used as sources of episomal virus for transmission studies. D. brevipes, Planococcus citri, and P. ficus mealybugs were able to transmit the putative activated episomal BSOLV. Control plants for the transmission experiments included FHIA-21 corms with no background history of tissue culture, as well as virus-free Williams plants. Episomal Banana streak GF (badna)virus (BSGFV) was transmitted from asymptomatic corm-derived FHIA-21 plants by P. citri and P. ficus. This is the first report of P. ficus as a vector of BSVs.

Structure of a monoclinic crystal from of cyctochrome b1 (Bacterioferritin) from E. coli.

Crystals of E. coli cytochrome b1, alias bacterioferritin, were grown fr om a low ionic strength solution. The resulting monoclniic P21 structure was solved by molecular replacement and refined using noncrystallographi c symmetries applied to the fundamental unit, consisting of two protein subunits and a single haem. From the Patterson self-rotation results it was shown that the asymmetric unit of the monoclinic crystal consists of 12 such dimers and corresponds to a complete, nearly spherical, molecule of bacterioferritin (M4 = 450 kDa) of 432 point-group symmetry. It is thus the most symmetrical cytochrome. As previously determined for the tetragonal form, the haem is located in a special position on a local twofold axis of the dimer. A bimetal centre is also observed within the four-helix bundle of each monomer; a metal-binding site is located on the fourfold axis.

Dental management of neonates requiring prolonged oral intubation.

An orotracheal route is frequently the preferred method of intubation for premature infants. Nasal intubation may contribute to airway obstruction and possible hypoxia, further contributing to labored breathing. Additional complications include occlusion of the nasal aperture during a crucial period of development, nasal infections, and hypertrophy of the nasal lining. Oral mucosa is less susceptible to damage than nasal mucosa; however, orotracheal tubes must be stabilized against displacement from tongue and jaw movements to prevent discomfort and subsequent tissue trauma. Problems associated with rehabilitation of very-low-birth-weight neonates and other infants requiring long-term oral intubation include palatal grooving, acquired cleft palate, and damage to the primary dentition. Various intraoral aids have been used to reduce pressure application from intubation and feeding tubes on the palatal tissues. References to these procedures have yet to be reported in the prosthodontic literature. This article presents a rational for design and construction of an intraoral device which protects the palatal tissues and stabilizes the orotracheal tube.

Managing obstructive sleep apnea.

Obstructive sleep apnea, cessation of breathing during sleep, is potentially life threatening and requires prompt intervention. A prosthesis can reposition the mandible during sleep and minimize or prevent the tongue from collapsing against the pharynx. Two case reports discuss the effectiveness of prosthetic devices.

Fabrication of an obstructive sleep apnea prosthesis.

Obstructive sleep apnea, a sleep disorder, is becoming more prevalent and requires prompt and effective treatment by the dental and medical specialties. Conservative treatment modalities (ie, intraoral devices that prevent or minimize airway obstruction by the tongue) are recommended for treating mild to moderate forms of OSA. This article describes a simplified technique for fabricating an intraoral OSA prosthesis.

Sleep apnea prosthesis for dentate patients.

This article describes clinical and laboratory techniques for the fabrication of a sleep apnea prosthesis for a dentate patient. The treatment objective is to posture the mandible at an increased vertical and protrusive position to diminish or eliminate the collapse of the base of tongue into the oropharynx. During fabrication of the prosthesis, cephalograms are used to evaluate spatial change between the base of the tongue and the posterior pharyngeal wall.

Intranasal stent for stabilization and fixation of interstitial radioactive isotopes.

This article introduces the use of an intranasal stent for the stabilization and fixation of afterloading catheters during interstitial radiation therapy. After catheters have been positioned to desired locations within the stent, they are immobilized with light polymerizing resin. The fixation of the catheters to the stent allows the radiotherapist to afterload predetermined radiation sources to desired locations. This technique maximizes tumor response and minimizes untoward effects to normal surrounding tissues.

Fabrication of a prosthesis to prevent sleep apnea in edentulous patients.

This article describes clinical and laboratory technique to use in the fabrication of a prosthesis to prevent sleep apnea in the edentulous patient. The objective of the treatment is to establish a comfortable protrusive and vertical posture of the mandible that prevents or minimizes obstruction of the airway during sleep. During fabrication of the prosthesis, cephalograms are used to assess spatial changes between the base of the tongue and the posterior pharyngeal wall.

The sleep apnea syndrome. Part II: Treatment.

An increase in the number of obstructive sleep apnea patients has brought a paralleled demand for timely and effective treatment. Conservative measures to maintain airway patency during sleep include weight loss, lateral decubitus sleep posture, drug therapy, nasal continuous positive airway pressure, and the use of intraoral prostheses. Surgical measures are used to correct gross anatomic defects that cause or contribute to obstruction, remove redundant tissues (uvulopalatopharyngoplasty), or provide an airway below the suspected area of obstruction (tracheostomy). Part II of this article examines the rationale, benefits, disadvantages, and potential complications of each modality of treatment.

Fabrication of a custom recessed tracheostoma valve retainer for the total laryngectomy patient.

Total laryngectomy patients who depend on a prosthesis for the production of alaryngeal speech often have irregular peristomal anatomy. The standard tracheostoma (speech) valve retainer cannot be intimately adapted to uneven and highly mobile tissue. Fabrication of a custom speech valve retainer is indicated under such circumstances but may be complicated by restricted access to the surgically created stoma. This article describes the clinical and laboratory techniques for the fabrication of a custom tracheostoma valve retainer that displaces the peristomal soft tissues and musculature. This technique permits access for placement of the speech valve and valve retainer in close proximity to the speech button prosthesis. Enclosure of the custom retainer in the recess underlying the peristomal musculature also provides a plug that enhances retention and increases patient confidence during alaryngeal speech. The coordinated efforts of the speech specialist and the prosthodontist in the fabrication of this prosthesis enhances the quality of life for the total laryngectomy patient.

Light-cured interim palatal augmentation prosthesis. A clinical report.

The interim palatal augmentation prosthesis produced a significant improvement in function within a short period of time. With the visible light-curing system, modifications of the prosthesis were made quickly and easily. The methods described enable the treatment team to immediately assess the results of prosthesis modifications.

The sleep apnea syndrome. Part I: Diagnosis.

Part I of this two-part article presents a review of the symptoms, pathophysiology, and diagnosis of the sleep apnea syndrome. The more common obstructive type is characterized by disturbed sleep and daytime hypersomnolence. Subjective signs and symptoms should be correlated with objective findings by way of polysomnography (sleep study) to confirm the diagnosis and determine the severity of obstructive sleep apnea. Electrocardiographic monitoring during polysomnography has revealed potentially life-threatening arrhythmias during sleep. Differential diagnosis should include central sleep apnea and narcolepsy to avoid inappropriate therapy and worsening of symptoms.

The acid-etch retained rest for removable partial dentures.

This article will describe the techniques for composite and metal rests. It will also discuss a clinical follow-up of 18 patients who have had metal or composite rests in place from three to 18 months.

Clinical evaluation of ramus frame and staple bone implants.

Atwood pointed out that "variability of human response (resistance to infection, susceptibility to bone resorption, and psychologic capacity) demands more basic research and clinical trials to improve success." This study can serve as a baseline for further longitudinal studies and controlled clinical research. Barring tissue or systemic complications, the prosthodontist must take the responsibility through sound treatment principles and awareness to ensure continued satisfaction and success of these implant systems.