Memories of the first 50 years of the journal .

As celebrates 50 years of publication, some former editors who have helped the journal reach this milestone reminisce on their time at the helm of the journal.

First bone-cracking dog coprolites provide new insight into bone consumption in and their unique ecological niche.

Borophagine canids have long been hypothesized to be North American ecological 'avatars' of living hyenas in Africa and Asia, but direct fossil evidence of hyena-like bone consumption is hitherto unknown. We report rare coprolites (fossilized feces) of from the late Miocene of California and, for the first time, describe unambiguous evidence that these predatory canids ingested large amounts of bone. Surface morphology, micro-CT analyses, and contextual information reveal (1) droppings in concentrations signifying scent-marking behavior, similar to latrines used by living social carnivorans; (2) routine consumption of skeletons; (3) undissolved bones inside coprolites indicating gastrointestinal similarity to modern striped and brown hyenas; (4) body weight of ~24 kg, reaching sizes of obligatory large-prey hunters; and (5) prey size ranging ~35-100 kg.

A basal ursine bear (Protarctos abstrusus) from the Pliocene High Arctic reveals Eurasian affinities and a diet rich in fermentable sugars.

The skeletal remains of a small bear (Protarctos abstrusus) were collected at the Beaver Pond fossil site in the High Arctic (Ellesmere I., Nunavut). This mid-Pliocene deposit has also yielded 12 other mammals and the remains of a boreal-forest community.

Feeding capability in the extinct giant Siamogale melilutra and comparative mandibular biomechanics of living Lutrinae.

At 50 kg in estimated weight, the extinct Siamogale melilutra is larger than all living otters, and ranks among the largest fossil otters. The biomechanical capability of S. melilutra jaws as related to their large size is unknown but crucial to reconstructing the species' potentially unique ecological niche.

Impact of cone-beam computed tomography on orthodontic diagnosis and treatment planning.

Introduction: In this study, we measured the impact of cone-beam computed tomography (CBCT) on orthodontic diagnosis and treatment planning.

Methods: Participant orthodontists shown traditional orthodontic records for 6 patients were asked to provide a diagnostic problem list, a hypothetical treatment plan, and a clinical certainty. They then evaluated a CBCT scan for each patient and noted any changes, confirmations, or enhancements to their diagnosis and treatment plan.

Dentition, dental health habits, and dementia: the Leisure World Cohort Study.

Objectives: To explore the association between dentition and dental health behaviors and incident dementia.

Design: Longitudinal cohort.

Setting: Leisure World, Laguna Hills, CA; a retirement community.

Update on the biological effects of ionizing radiation, relative dose factors and radiation hygiene.

Diagnostic imaging is an indispensable part of contemporary medical and dental practice. Over the last few decades there has been a dramatic increase in the use of ionizing radiation for diagnostic imaging. The carcinogenic effects of high-dose exposure are well known.

Dental health behaviors, dentition, and mortality in the elderly: the leisure world cohort study.

In the last decade the effect of oral health on the general health and mortality of elderly people has attracted attention. We explored the association of dental health behaviors and dentition on all-cause mortality in 5611 older adults followed from 1992 to 2009 (median = 9 years) and calculated risk estimates using Cox regression analysis in men and women separately. Toothbrushing at night before bed, using dental floss everyday, and visiting the dentist were significant risk factors for longevity.

Legal considerations in the use of cone beam computer tomography imaging.

Cone beam computed tomography imaging represents a paradigm shift for enhancing diagnosis and treatment planning. Questions regarding cone beam computed tomography's associated legal responsibility are addressed, including cone beam computed tomography necessity, recognition of pathosis in the scan's entire volume, adequate training, informed consent and/or refusal and current court status of cone beam computed tomography. Judicious selection and prudent use of cone beam computed tomography technology to protect and promote patient safety and efficacious treatment complies with the standard of care.

Cone-beam imaging in dentistry.

Cone-beam imaging has gained broad acceptance in dentistry in the last 5 years. The purpose of this review is to describe the use in dentistry and consider issues requiring further development. Cone-beam machines emit an x-ray beam shaped liked a cone rather than a fan as in conventional computed tomography (CT) machines.

The evolution and application of dental maxillofacial imaging modalities.

During the last decades, an exciting new array of imaging modalities, such as digital imaging, CT, MRI, positron emission tomography, and cone-beam CT (CBCT), has provided astounding new images that continually contribute to the accuracy of diagnostic tasks of the maxillofacial region. The most recent, cone-beam imaging, is gaining rapid acceptance in dentistry because it provides cross-sectional imaging that is often a valuable supplement to intraoral and panoramic radiographs. The information content in such examinations is high and the dose and costs are low.

Patient risk related to common dental radiographic examinations: the impact of 2007 International Commission on Radiological Protection recommendations regarding dose calculation.

Background: In 2007, the International Commission on Radiological Protection (ICRP) revised estimates of the radiosensitivity of tissues including those in the maxillofacial region. The authors conducted a study to reassess patients' risk related to common dental radiographic exposures using the 2007 ICRP recommendations.

Methods: The authors used a tissue-equivalent head phantom to measure dose.

A diagnostic challenge: anterior variant of mandibular lingual bone depression.

Mandibular lingual bone depressions are considered to be developmental anomalies and most clinicians are familiar with the posterior variant (known as Stafne's bone cavity) that occurs in lingual mandibular molar regions, adjacent to the submandibular gland and below the mandibular canal. The anterior variant of the mandibular lingual bone depression is an asymptomatic bone cavity that occurs adjacent to the sublingual gland in the anterior mandible. Radiographically, it appears as a well-corticated radiolucency that retains a normal trabecular pattern internally.

Risk factors for fractures in older men and women: The Leisure World Cohort Study.

Background: Osteoporosis results in >1.5 million fractures in the United States each year, leading to substantial health care costs and loss of quality of life. One major gap in our knowledge is how to effectively identify individuals at risk of developing a fracture.

Menstrual and reproductive factors and fracture risk: the Leisure World Cohort Study.

Background: Because menopausal estrogen is related to the development of osteoporosis, we investigated the potential associations of the estrogen-related events of menarche, pregnancy, and menopause with fracture risk in a population-based, prospective study of older women.

Methods: The Leisure World Cohort was established in the early 1980s when residents of a California retirement community, including 8877 women, completed a health survey. Incident fractures of the hip (n = 1220), wrist (n = 463), and spine (n = 613) incurred over two decades were identified from four follow-up questionnaires, hospital discharge records, and (for hip fracture) death certificates.

Visual assessment of the mandibular cortex on panoramic radiographs to identify postmenopausal women with low bone mineral densities.

Objective: The purpose of this study was to determine whether simple visual estimation of the mandibular inferior cortex width on panoramic radiographs is useful for identifying postmenopausal women with low skeletal bone mineral density (BMD).

Study Design: Panoramic radiographs were made on 100 women aged 50-84 years who also had BMD assessment of the lumbar spine and femoral neck by dual-energy x-ray absorptiometry. The panoramic images were examined twice by 4 observers to evaluate the thickness of the mandibular inferior cortex.

Age and trabecular features of alveolar bone associated with osteoporosis.

Objective: To determine the utility of clinical features, combined with optical density measurements and morphologic analysis of periapical images, for identifying individuals with low lumbar or femoral bone mineral density.

Study Design: Study subjects consisted of 37 females and 29 males. Bone mineral densities (BMD) of lumbar spine and proximal femur were measured by dual-energy x-ray absorptiometry.

Clinical and panoramic predictors of femur bone mineral density.

Dentists are a potentially valuable resource for initial patient screening for signs of osteoporosis, as individuals with osteoporosis have altered architecture of the inferior border of the mandible as seen on panoramic radiographs. Our aim was to evaluate the efficacy of combining clinical and dental panoramic radiographic risk factors for identifying individuals with low femoral bone mass. Bone mineral density was measured at the femoral neck and classified as normal, osteopenic or osteoporotic using WHO criteria in 227 Japanese postmenopausal women (33-84 years).

Fourier and wavelet analyses of dental radiographs detect trabecular changes in osteoporosis.

Objectives: Osteoporosis results in loss of bone mass and microarchitectural deterioration. Dental radiographs potentially offer a means of screening for osteoporosis as they are commonly made on adults. Spatial frequency analyses are well suited to detect subtle changes in image patterns.