Changing trabecular patterns in panoramic radiographs of Swedish women during 25 years of follow-up.

Objectives: The radiographic trabecular pattern on dental radiographs may be used to predict fractures. The aim of this study was to analyze longitudinal changes in the mandibles of 145 females between 1980 and 2005.

Methods: Panoramic radiographs were obtained in 1980 and 2005.

Predicting fractures using trabecular patterns on panoramic radiographs.

Objectives: The observer score of the trabecular pattern on panoramic radiographs is known to be a strong predictor of bone fractures. The aim of this study was to enhance the predictive power of panoramic radiographs by means of texture analysis methods.

Material And Methods: The study followed 304 postmenopausal women during 26 years.

Association Between Peri-implant Bone Morphology and Marginal Bone Loss: A Retrospective Study on Implant-Supported Mandibular Overdentures.

Purpose: The present study aimed to explore the association between marginal bone loss and type of peri-implant bony defect determined using a new peri-implant bony defect classification system.

Materials And Methods: A total of 110 patients with implant-supported mandibular overdentures were involved. Clinical information was collected, including gender, age, smoking habit, and the overdenture attachment system used.

Implant-supported mandibular overdentures can minimize mandibular bone resorption in edentulous patients: results of a long-term radiologic evaluation.

Purpose: It has been suggested that functional loading and light irritative stimuli could lead to changes in bone architecture, shape, and volume, and that by placing implants in the edentulous mandible and subsequently loading them, functional conditions could be created to limit bone resorption or even stimulate bone apposition (the latter was reported only for fixed implant-supported prosthetic reconstructions) in the distal area of the mandibular osseous crest. The aim of this study was to radiographically assess the bone height changes in the posterior area of the mandible after implant placement and loading with an overdenture on two or four implants over a mean follow-up period of 10.5 years.

Annual bone loss and success rates of dental implants based on radiographic measurements.

Objectives: Bone loss around dental implants is generally measured by monitoring changes in marginal bone level using radiographs. After the first year of implantation, an implant should have <0.2 mm annual loss of marginal bone level to satisfy the criteria of success.

A new classification of peri-implant bone morphology: a radiographic study of patients with lower implant-supported mandibular overdentures.

Objective: This study aimed to classify peri-implant bone defects (PIBDs) on the basis of their radiographic appearance in a cohort of patients with lower implant-supported overdentures.

Materials And Methods: Eighty-three patients with lower implant-supported overdentures were recruited to participate in the study, which was approved by the ethics committee of Ignatius Teaching Hospital. Details about the patients' smoking habits were recorded.

[Radiographs for the assessment of bone loss around implants. Exploring the potential].

Twelve per cent of oral implants fail due to the loss of bone within 15 years after implantation. If bone loss is detected early, measures can be taken which increase the success rate of implants. To monitor implants, radiographs are made regularly.

Sparseness of the trabecular pattern on dental radiographs: visual assessment compared with semi-automated measurements.

Objective: In diagnostic imaging; human perception is the most prominent, yet least studied, source of error. A better understanding of image perception will help to improve diagnostic performance. This study focuses on the perception of coarseness of trabecular patterns on dental radiographs.

Detecting bone loss along dental implants by subtraction of panoramic radiographs.

Objectives: To test an extended subtraction method for measuring changes in bone along dental implants depicted on non-standardized panoramic radiographs.

Material And Methods: The measuring method consisted of a subtraction module extended with modules correcting gray values, correcting geometry and defining the region of interest mesial and distal of dental implants. It was applied to an archive of panoramic radiographs of implant patients who had been monitored up to 16 years.

Radiographic features of mandibular trabecular bone structure in hypodontia.

Purpose: Radiographic parameters of mandibular trabecular bone structure between 67 subjects having hypodontia and those without were studied on digital panoramic radiographs.

Materials And Methods: Three regions of interest (ROI) were defined: the ascending ramus, apical of the mandibular molar and mesial of the first mandibular molar. The effects of the presence of hypodontia and the ROI on the mandibular trabecular bone structure were tested for statistical significance by means of multivariate analysis.

Prediction of osteoporosis with dental radiographs and age.

Objectives: In this study age and the trabecular pattern present on dental radiographs were used to predict the presence of osteoporosis. The objective was to evaluate the contribution of the trabecular pattern to the prediction.

Methods: In this project, 671 women between 45 and 71 years of age were recruited.

Selecting regions of interest on intraoral radiographs for the prediction of bone mineral density.

Objectives: A previous study showed that the trabecular pattern on dental radiographs correlates with femoral and spinal bone mineral density (BMD). The objective of this study was to determine if the correlation is affected by the size and location of the region of interest (ROI).

Methods: In a European research project on osteoporosis, BMD was measured at the left hip and the lumbar spine of 525 women.

Spatial orientation in bone samples and Young's modulus.

Bone mass is the most important determinant of the mechanical strength of bones, and spatial structure is the second. In general, the spatial structure and mechanical properties of bones such as the breaking strength are direction dependent. The mean intercept length (MIL) and line frequency deviation (LFD) are two methods for quantifying directional aspects of the spatial structure of bone.

Osteoporosis and the general dental practitioner: reliability of some digital dental radiological measures.

Objectives: Dental radiographs are relatively inexpensive and are regularly made of a large fraction of the adult population; therefore, they represent an enormous potential as a screening tool for osteoporosis. Monitoring the population by means of dual X-ray absorptiometry (DXA), which is currently the most accepted method for diagnosing osteoporosis, involves enormous costs and facilities. In previous studies, it was shown that the radiographic trabecular pattern shows correlations with the bone mineral density (BMD) as measured by DXA.

Prediction of bone mineral density with dental radiographs.

There is consensus to use the bone mineral density (BMD) for the operational definition of the degree of osteoporosis and the risk of osteoporotic fractures. Dual X-ray absorptiometry (DXA) is the common technique to determine BMD. Because of high costs and limited availability of DXA equipment it is worthwhile to look for alternative diagnostic techniques.

A sensitive method for measuring spatial orientation in bone structures.

Objectives: This article introduces the newly developed line frequency deviation (LFD) method for measuring the orientation of the trabecular structure and shows that it is more sensitive than the mean intercept length (MIL) method that is commonly used.

Methods: The LFD method, which has been developed to measure the orientation of bone on two-dimensional X-ray images, was expanded to handle three-dimensional shapes. For the purpose of comparison, both the LFD and the MIL methods were applied to micro CT scans of 24 trabecular bone samples as well as to 24 simple synthetic samples.

An efficient filling algorithm for counting regions.

Region filling has many applications in computer graphics and image analysis. Some region filling tasks can be performed by fast scan line filling algorithms. Other region filling tasks require seed filling algorithms which are more general but slower.

Fractal properties of bone.

Objective: To introduce the applications of fractal analysis of bone in medical imaging in general and dental radiographs in particular.

Results: Various methods for measuring fractal dimension have been used to compare normal with osteoporotic bone with contradictory results. This disparity may be attributed to differences in the anatomical sites studied and differences in methods used to obtain the 2D images.

Effect of noise on the compressibility and diagnostic accuracy for caries detection of digital bitewing radiographs.

Objectives: To determine the effect of noise on the compressibility and the diagnostic accuracy for caries detection of digital bitewing radiographs.

Methods: Bitewing radiographs of patients were obtained with a storage phosphor (Digora, Soredex, Helsinki, Finland) and compressed at different JPEG compression levels (2, 27, 53 and 128). A just noticeable difference study was performed to select a compression level to study the added noise effect.

A radiographic method for measuring radiation dose based on beam quality.

Objectives: To develop a radiographic method for measuring radiation dose based on beam quality for inexpensive postal surveys of general dental practitioners.

Methods: Different beam qualities were simulated to expose a commercially available film (X-Omat MA 18 x 22.4 cm, Ready Pack, Kodak Pathe, Paris, France).

Agreement between radiographic and photographic trabecular patterns.

Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics.

Material And Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years.

Radiographic assessment of changes in marginal bone around endosseous implants supporting mandibular overdentures.

Objectives: To evaluate the reliability of a new method for quantification of radiographic changes in the marginal bone around implants.

Methods: Three groups of seven patients treated with an overdenture supported by two endosseous implants (Brnemark, n = 7 patients; IMZ, n = 7 patients; ITI Bonefit, n = 7 patients) were selected. Six weeks after loading the implants, radiographs were obtained using the long cone technique and an aiming device, scanned and digitized.

Comparison of two methods for measuring orientation.

At the Department of Dental Radiology of ACTA, the line fraction deviation (LFD) method was developed to measure orientation on radiographic trabecular patterns. This article explains the measurement of the LFD index of orientation in a downscaled model. When investigations began to produce noteworthy results, the need for deeper understanding of the method and the resulting diagrams increased.

Impact of scale standardization on images of digital radiography systems.

Objectives: To test the effect of altering image size on diagnostic quality.

Methods: Endodontic files, size 10 and 15 were prepared to full root length and 1.5 mm short, in upper and lower molars and premolars.

The radiographic trabecular pattern of hips in patients with hip fractures and in elderly control subjects.

Due to the increasing number of osteoporotic fractures of hip, spine, and wrist there is a growing need for methods to track down the subjects with inferior bone structure and to monitor the effects of therapeutic measures. This study aims at a noninvasive diagnostic tool, deriving architectural properties of trabecular bone from in vivo measurements on plane radiographic films. Pelvic radiographs of the nonfractured hips of 81 patients with hip fractures and of the right hips of 74 controls were studied.