Factors affecting the diagnostic quality of bitewing radiographs: a review

The bitewing radiograph (BWR) has been used in dental practice for over 90 years and is a widely used technique. This paper outlines the ideal technique for producing reproducible BWR of good diagnostic quality. In particular, it reviews the technical errors that may occur while exposing and processing BWR and the psychological errors that may result when radiographs are viewed. The consequences of these errors, (unnecessary patient exposure to radiation, poor diagnosis and potentially inappropriate treatment) are outlined in detail. Steps to improve the quality of BWR and decrease patient exposure to radiation are given in line with recent recommendations.     

An economic evaluation of the use of rare earth screens to reduce the radiation dose from diagnostic X-ray procedures in Israel

In Israel the diffusion of rare earth screen technology has been limited. These screens could halve the radiation dose to the patient from diagnostic X-ray radiography, with little managerial effort and without being detrimental to the quality of the diagnostic image. We estimated the total effective dose from diagnostic film radiography capable of reduction by the use of rare earth screens, based on the number of hospital and ambulatory diagnostic X-ray procedures. This number was multiplied by the computed radiation dose per body site for a series of diagnostic procedures. The annual dose was approximately 0.53 mSv per head, approximately half of which could be averted by the introduction of rare earth screen technology. Based on a fatality risk of 3% Sv-1, it is estimated that the adoption of rare earth screen technology might reduce the annual incidence of cancer by some 93 cases, half of which would be fatal after an average latency period of 18.4 years. The cost of purchasing rare earth screens on a nationwide basis is approximately $3.0 million. This cost is outweighed by a saving of $9.6 million in X-ray tube replacement costs over the period 1997-2006. Government legislation enforcing the use of rare earth screens is essential, because of the lack of prestige associated with acquiring rare earth technology, as well as institutional reluctance to accept the external benefits of reduced morbidity and mortality and/or to extend budgetary time horizons.     

An approach to the diagnostic imaging of jaw lesions, dental implants, and the temporomandibular joint

This article is an overview of three complex and often confusing areas of diagnostic imaging. It provides the reader with a starting point and a frame of reference from which to proceed when confronted with either an unknown jaw lesion, evaluating a potential dental implant patient, or a patient with TMJ internal derangement.     

The transition from the dose-area product to the effective dose in x-ray studies

The effective dose obtained by a patient on X-ray diagnostic studies may be determined by the Russian and foreign devices that measure the product of the absorbed dose by the radiation area while using the transition factors presented. They are calculated by the published data on the surface and effective doses per exposure unit, which are obtained on the phantoms by thermoluminescence dosimetry by taking into account the area of radiation, anode voltage, and projection, which characterize the standard conditions for performing basic X-ray diagnostic studies of adults and children (5 age groups). In the anode voltage range 40-120 kV, the factors are 10(-4) to 2.10.cm2) with errors of about +/- 32%.     

A convenient method for guarding against localized mucositis during radiation therapy

Metal restorations, such as full gold crowns and dental implants, can cause forward and back scatter radiation during radiation therapy with a dose enhancement to adjacent tissues. Mucositis, one of the most common complications of the radiation treatment of oral, as well as other head and neck malignancies can result. A method for constructing a buccolingual guard in the clinical setting using hydroplastic material is described. The guard can be easily oriented and adapted to an existing radiation stent, adding positional stability and patient comfort. When adequate thickness of material is used, the guard can attenuate forward and back scatter radiation, separate the adjacent tissues from metal restorations, and protect the oral mucosa from localized incidents of mucositis.     

Bilateral temporal lobe necrosis after radiotherapy: confounding SPECT results

A patient with seizures and a contrast-enhancing temporal lesion after radiation therapy for a chondrosarcoma of the nasal septum is described. To differentiate between radiation necrosis and recurrent tumor, thallium-201 (201Tl) SPECT was used. 201Tl SPECT revealed high local accumulation suggesting tumor growth; however, pathologic examination demonstrated focal necrosis with reactive changes but without tumor. The 201Tl SPECT findings in this patient demonstrate a possible diagnostic pitfall in differentiating recurrent tumor from radiation necrosis.     

Document imaging and the patient chart: envisioning the future for your practice

This plan for computerizing the dental patient record is designed to be implemented in a stepwise fashion. It assumes a fully developed and well accepted practice management system is already present in the business office to ensure organizational readiness and a culture embracing technology and its accompanying changes. Electronic claims submission is implemented next to not only realize the competitive advantages of EDI in the dental office; but also, to introduce the process of multi-user communication. Electronic charting in the dental operatory is first implemented as a stand alone system. This allows users to understand the new workflow requirements and oral exam redesign when a computer is introduced in the treatment room. The dental team must understand that the ultimate goal of this plan is to network the entire system and enhance communication both within and external to the dental office. No specific time requirements were given for this plan because of the variability from office to office. People need time to develop awareness, prepare for, and become skilled in using new technology. Financial constraints may also limit the speed at which the plan can be implemented. Finally, individuals in the practice must work together as a team to assess the practice's level of acceptance and ability at each step in the process. Modification will be necessary along the way as technology is constantly changing. This is a significant paradigm shift, considering that many pieces of equipment purchased for the dental office can last the dentist's entire career. This plan allows for alteration, encourages team involvement and requires a long-term strategic vision for information technology's role in the dental office.     

Cutaneous odontogenic sinus tract to the chin: a case report

We report a case of cutaneous odontogenic sinus tract to the chin. The patient first noticed the cutaneous condition in 1977. Inappropriate medical and dental treatment was ineffective. Correct diagnosis and treatment was completed in 1993. We offer diagnostic and treatment guidelines for the management of similar cases.     

Prevalence and predictors of work related respiratory symptoms in workers exposed to organic dusts

Treatment of initial caries, albeit an everyday occurrence for the dental practitioner, presents considerable demands of patient assessment and diagnosis. Whatever decisions are made--to restore caries or to attempt to arrest its progress--the adoption of a maintenance program is of paramount importance. Patient motivation, in respect to dietary control and satisfactory oral hygiene, is central to a successful outcome, and in the future, practice management programs may include RAC as a diagnostic aid. New methods of caries management are more dynamic than traditional methods and place restoration of the lesion toward the bottom of the list of possible treatments, with the biologic rather than the mechanistic approach being a priority. However, the teaching of RAC in dental schools and the third-party funding of diagnostic tests and diagnosis are also required to reflect the increasing complexity of management of initial caries. If restorative intervention is indicated following diagnosis and RAC, treatment of initial caries should involve a minimal-intervention adhesive technique.     

Endosseous implant and autogenous bone graft reconstruction of mandibular discontinuity: a 12-year longitudinal study of 31 patients

Surgical, medical, and prosthodontic records of 61 consecutively treated patients with mandibular discontinuity were reviewed retrospectively. All 61 patients had undergone discontinuity reconstruction with autogenous bone grafts; 31 of 61 had also received endosseous dental implants and a dental osseoprosthesis. Of these 31 implant-reconstructed patients, 23 had free autogenous nonvascularized and 8 had vascularized bone grafts. The surgical-prosthetic protocol consisted primarily of secondary, free autogenous nonvascularized bone graft reconstruction and secondary root-form endosseous implant and fixed prosthesis dental reconstruction. Vascularized bone (8 patients) or soft tissue (4 patients) grafts were utilized selectively for severely compromised patients after extensive oncologic resection, avulsive trauma, or after previous radiation treatment. Endosseous implant survival (95.5% in 31 patients), autogenous bone graft success (98.4% in 61 patients), and dental osseoprosthesis success (100% in 31 patients) were favorable. A high incidence (9.1%) of nonfunctioning (sleeping) implants was recorded for this patient population. The need to remove the titanium mesh tray for various reasons (17.6%) and the need to reconstruct soft tissue in the irradiated patient (12%) were noteworthy.     

Common errors in panoramic radiography of edentulous patients

PURPOSE: Instructions for patient positioning during panoramic radiography usually describe positioning dentate patients, and errors in patient positioning are commonly identified by distortion of the dentition. The purposes of this study were to identify common errors in panoramic radiography of edentulous patients, describe the image distortions that can be expected with positioning errors in edentulous patients, and review quality assurance methods that improve the diagnostic value of panoramic films. MATERIALS AND METHODS: Panoramic films were randomly selected from the inactive files of 75 edentulous patients seen at the dental school for complete denture construction. The radiographs were numbered and reviewed by a board-certified oral and maxillofacial radiologist trained to identify errors in panoramic radiography. RESULTS: Of the 75 panoramic radiographs examined, only 6 films (8.0%) were free of errors, and 67 films (89.3%) had one or more errors in patient positioning and 33 films (44.0%) had one or more technical errors. The most common positioning errors were positioning the chin too high (32 films, 41.3%) and positioning the patient too far forward (26 films, 34.7%). CONCLUSIONS: Without modification, manufacturer's instructions for positioning dentate patients during panoramic radiography may result in positioning errors on the panoramic radiographs of edentulous patients. Proper training and appropriate attention to detail while exposing and developing panoramic films are required to ensure maximum diagnostic benefits for edentulous patients.     

The use of bitewing radiographs in the management of dental caries: scientific and practical considerations

The objective of this paper is to synthesize published research on the use of radiographs in caries diagnosis in order to produce recommendations for guidelines that are clinically oriented but scientifically based. The options available include the use of various types of radiographic examination alone or in conjunction with other diagnostic aids. The outcomes should facilitate the optimal management of lesions as either preventive care advised (PCA) or operative care advised (OCA). Small initial lesions (PCA) require prompt detection, the application of appropriate preventive care and subsequent monitoring to maintain the most favourable tooth state achievable in the long term. Larger dentinal lesions (OCA) also require prompt detection so that appropriate high-quality operative care can be provided before further loss of tooth substance. Evidence was collected from the literature by updating several recent reviews by the author. The values employed were broadly analogous to those of the Canadian Task Force on the Periodic Health Examination. The use of ionizing radiation is always associated with a degree of risk: therefore all exposures must be kept as low as is reasonably achievable. Present evidence on the balance of risk and benefit indicates that the diagnostic yield for caries diagnosis is high enough to justify individualized examinations, particularly as changes in the morphology of caries have rendered clinical diagnosis of dentinal lesions less sensitive. This issue must be kept under review as alternative diagnostic technologies develop. There is good evidence that initial posterior bitewing radiographs are required for all new dentate patients over five years of age with posterior teeth. This procedure is required as an adjunct to clinical examination for the detection of caries on both the approximal and occlusal surfaces of the teeth. Although a 'blanket' regimen of routine radiographic examination at fixed intervals cannot be advocated, individualized bitewing examinations at varying frequencies determined on the basis of caries risk are supported. At the initial visit, an assessment of caries risk of the individual patient should be made. Varying intervals of first radiographic recall can then be suggested on the basis of differing degrees of risk. At present, risk assessment is imprecise, and risk status may change over time. Therefore, intervals between subsequent radiographic examinations must be re-assessed for each period. The purpose of detecting individual lesions should be to facilitate the planning of appropriate preventive treatment decisions based on lesion severity, caries risk and the patient. Different treatment should be employed for lesions in the PCA and OCA categories. Further rigorous studies are required to evaluate diagnostic methods appropriate for use in individual patient care, epidemiology and clinical research, and to increase the understanding of how findings from these applications inter-relate. Development and validation of reliable methods of caries risk assessment which are usable in general practice is a priority. Investigations of the processes involved in, and the outcomes of, dental decision-making are required to ensure that existing and new methods are used appropriately. Further work should develop and evaluate effective mechanisms of disseminating and implementing research findings by information transfer to dental educators and clinicians.     

Management of trauma to primary and developing teeth

Traumatic dental injuries to the young child can present both diagnostic and therapeutic challenges. Luxation injuries to the primary dentition are the most common injuries. Yet, they are the most controversial with regard to definitive treatment, prognosis, and sequelae. Damage to the developing teeth subsequent to primary tooth injury is often unavoidable and has permanent effects on the dentition. Diagnostic criteria, treatment options, and outcomes are presented in this article; however, treatment decisions are often based on patient behavior.     

Magnetic resonance imaging: a useful tool for evaluation of bone prior to implant surgery

OBJECTIVE: To illustrate the potential for use of magnetic resonance imaging (MRI) to gain full sectional information before placement of osseo-integrated dental implants, with no patient exposure to ionising radiation. MATERIALS AND METHODS: Four typical cases are illustrated, the patients being imaged in a one tesla MRI scanner. The setting up of the sequences is explained, along with the use of an imaging/surgical template with gadolinium markers. RESULTS: MRI clearly shows full sectional detail of available bone for safe implant placement, and allows the delineation of cortical and cancellous bone to attain maximum implant length and stability. Vital structures and the floor of the maxillary sinus are clearly shown. CONCLUSIONS: MRI allows the surgeon to assess cases for suitability to place dental implants with confidence. The ability to scan directly at any desired plane, with no reformatting, and to relate this information to a surgical template gives predictable surgery. MRI is a sectional imaging modality giving information about the 3-dimensional relationship of the vital structures, without using ionising radiation. It therefore deserves consideration as an alternative to computed tomography. However, further work is indicated to investigate the relative technical merits of the two imaging modalities.     

Effects of ionizing radiation on proliferation and differentiation of osteoblast-like cells

Diagnostic radiation for immediate post-surgical assessment of osseointegrated dental implants has been discouraged, due to the possibility of detrimental effects of ionizing radiation on healing and remodeling of bone. To assess this possibility, we investigated the effects of ionizing radiation on proliferation and differentiation of osteoblasts using osteoblast-like cells isolated from the calvariae of newborn rats (ROB) and a clonal osteoblastic cell line (MC3T3-E1). The cells were exposed on day 3 to a single dose of x-rays at either 40, 100, 400, or 4000 mGy, respectively, from a linear accelerator radiotherapeutic machine (Linac) or a 40-mGy dose from a diagnostic chest x-ray machine. The effects of radiation on cell growth and alkaline-phosphatase-specific (ALP) activity were evaluated at three-day intervals after irradiation up to day 12 in ROB cells, and evaluated at day 12 in MC3T3-E1 cells. At the culture end-point, the effects on formation of bone-like nodules were also evaluated in both ROB and MC3T3-E1 cells. Exposure of 4000 mGy differentially affected the two cell types. It inhibited cell growth and alkaline phosphatase activity, and inhibited DNA content in MC3T3-E1 cells. This irradiation also strongly inhibited the formation of bone-like nodules in ROB cells. On the other hand, exposure of 40-, 100-, and 400-mGy (Linac) and 40-mGy (diagnostic quality) irradiation induced no significant changes in cell growth, alkaline phosphatase activity, and formation of bone-like nodules in ROB cells. These doses also induced no significant changes in DNA content and ALP activity in MC3T3-E1 cells. These results indicate that ionizing radiation at a single dose of up to 400 mGy induces no significant changes in cell growth and differentiation of osteoblast-like cells, at least in vitro. Higher radiation doses (4000 mGy) may exert different effects on cell proliferation and cell differentiation of osteoblasts, depending on the cell types affected. Thus, diagnostic radiation seems to have less effect on proliferation and differentiation of osteoblasts.     

Dental management of patients irradiated for oral cancer

Management of patients irradiated for oral cancer should include consideration of their oral health prior to, and after, radiation therapy. Data from 130 patients, followed for a period of 1 to 10 years, are presented and evaluated. The philosophy of retention and maintenance of as many teeth as possible is supported by this data. Extraction of teeth with severe periodontal disease after irradiation also proves to be a relatively safe operation. Osteoradionecrosis tends to be limited in extent and is generally well tolerated by the patient when treated conservatively. A treatment regimen is presented that significantly reduces the morbidity from therapeutic irradiation of the jaws. A comprehensive dental evaluation and follow-up plan coupled with patient cooperation are instrumental to the success of this program.     

Practicing implant dentistry profitably

The success of dental implants has opened up countless treatment possibilities for restorative dentists to offer to their patients. Just as our clinical paradigms have had to change because of this new technology, so too must our paradigms concerning the way we communicate with our patients change if we are to get them to say "yes" to treatment that we know that they need. Success in clinical treatment using implants requires a systematic approach. A systematic approach to communicating with your patients will allow you to have the same high degree of success with treatment acceptance that is possible with dental implants. The key to the systems we have discussed is Relationship Centered Care. A relationship is fostered and enhanced through a Comprehensive Examination Process, a structured Consultation Process utilizing the influencing process and Financial Arrangements that allow the patient to receive what they want while the office maintains the profitability that it needs. A system for calculating rational fees can be utilized that allows the practice to have control over an area that traditionally was controlled by anecdotal factors. The Pride Institute has developed this material and is presenting it to the profession so that restorative dentists can truly practice implant dentistry profitably.     

The dentist and preventive dental health information

Patients receive differing amounts of preventive dental health information from their dentist. What factors affect the amount of preventive information a patient receives? Many possible reasons which have been advanced for this difference are discussed in this paper. Using the clues presented in the literature, and results of a presurvey, some factors thought to influence the amount of preventive dental health information the patient receives were investigated. Specifically, the research problem was, "What is the relationship between the amount of preventive dental health information a patient receives from the dentist in his private office and the following factors: patient's appearance, interest-responsiveness, nervousness, need for dental care, request for service, orientation to dentistry, and dentist's liking for the patient?" The hypothesized relationships of amount of preventive dental information delivered to dentist's perception of patient's characteristics were not upheld. The paper tentatively concludes that the characteristics of the dentist and his dental practice affect the preventive information delivered more significantly than patient characteristics.     

Service quality in dentistry: the role of the dental nurse

Patients judge the dental service they receive by the interaction with the service providers-the dentist and his or her staff-as they are unable to judge the technical quality of the service. To perform well as a service provider, employees such as dental nurses have to be well motivated and satisfied with their position. A study of the role of the dental nurse in contributing to service quality in dentistry was carried out through interviews with dentists and nurses at 20 dental practices in the South Thames region in 1995. The results revealed that while dental staff believed that the role of the dental nurse was important in terms of the patient's view of the practice, perceptions of the nurse's role differed. The majority of dentists felt that the nurse's role should be to anticipate their needs, while the nurses' opinions were evenly divided between putting the needs of the patient first or those of the dentist. Nurses also felt that their role was stressful and reported a lack of praise and recognition of their efforts by dentists. Few practices had written contracts or performance appraisals. The results indicated a lack of effective communication in many dental practices, producing role strain for the nurse and reducing job satisfaction. Increasing job satisfaction reduces staff turnover, resulting in more consistent service quality and reducing associated costs. In order to achieve this, several recommendations are made with the aim of improving communication between staff in dental practices.     

Image quality, the ideal observer, and human performance of radiologic decision tasks

The quality of medical images must be quantified with reference to specific diagnostic tasks. Image quality is limited by fundamental physics, engineering limitations, radiation safety concerns, and imaging time constraints (among other things). There is now a gold standard for assessing human visual decision performance: the ideal Bayesian observer. Unfortunately, there are no mathematical tools to use this gold standard for realistically complex tasks. As an alternative, one can use the optimum linear discriminator (Fisher-Hotelling) model as a silver standard while en route to clinical realism. The goal of scientists working in the area is to develop mathematical models of human observers that will help equipment designers to optimize design trade-offs for specific diagnostic tasks. The current strategy is to modify the Fisher-Hotelling model to include certain limitations of the human observer visual system. The model must be both robust enough and mathematically tractable enough to be used to predict performance for clinical classification and estimation tasks. Statistical models also must be developed that describe realistic signals (lesions and abnormalities) and the normal patient structure that is the background in which these signals must be detected or identified.