Two-dimensional vs 3-dimensional comparison of alveolar bone over maxillary incisors with A-point as a reference.

INTRODUCTION: Our objectives were to compare, relative to A-point, (1) bone thickness over the most forward maxillary incisor (MFMI) in 2 dimensions vs 3 dimensions, and (2) bone thickness and inclination of each maxillary incisor in 3 dimensions. METHODS: Thirty-four cone-beam computed tomography (CBCT) images were coded, and 2-dimensional (2D) cephalograms were derived from each image using Dolphin software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). A-point and the MFMI crown were located. After reliability tests, alveolar bone buccal to 3 points on the MFMI root, bone to reference line Frankfort horizontal (FH)-A-point, and incisor inclination were measured. This procedure was repeated on the 3-dimensional (3D) CBCT images comparing MFMI with all maxillary incisors. The 2D and 3D measurements were compared using paired t tests, and 3D measurements were compared with analysis of variance. A 5% significance level was used for all tests. RESULTS: The MFMI's buccal bone thickness at the root apices and the distance between buccal bone and FH-A-point line at 2 root points were significantly greater in 2 dimensions than in 3 dimensions. In 3 dimensions, bone thickness at MFMI's root apex and the distance from FH-A-point line at all root points were significantly greater than those of the lateral incisors. Bone buccal to MFMI was significantly smaller than at the lateral incisors 3 mm from the cementoenamel junction. CONCLUSIONS: Evaluation of 2D CBCT derivations can result in overestimation of alveolar bone buccal to the maxillary incisor root apices compared with 3D evaluations. The anterior nasal spine obscures bone measurements over the maxillary incisors in 2 dimensions.

Chronic fibrosing osteomyelitis of the jaws: an important cause of recalcitrant facial pain. A clinicopathologic study of 331 cases in 227 patients.

OBJECTIVE: This was a retrospective and follow-up analysis of 331 cases of chronic fibrosing osteomyelitis of the jaws (CFOJ) in 227 patients. STUDY DESIGN: Demographic, clinical, surgical, and microscopic characteristics were tabulated for all patients. A follow-up mail survey was used to determine the degree of symptom relief experienced after surgery. RESULTS: The female to male ratio approached 7:1, and mean age of patients was 53 years. The most common sites were the mandibular posterior region, followed by the maxillary posterior region. Consistent clinical findings included intractable jaw pain mimicking that of odontogenic origin but unresponsive to usual therapies, minimal or undetectable radiographic abnormalities on plain films but dramatic radiolucencies detected on cone beam computed tomography, and large cavities that were either empty or filled with blood mixed with lipid globules encountered at surgery. The most common histomorphologic findings were vital lamellar bone, prominent resting and reversal lines, microshards and splaying of trabeculae, rounded trabeculae, marrow fibrosis, and pools of erythrocytes and lipid globules, often together. Moderate to complete relief of symptoms for periods up to 108 months after surgery were reported by 83% of the 70 patients who returned the survey. CONCLUSIONS: On the basis of the findings of this study, CFOJ can be considered a unique entity with consistent clinicopathologic features. Its features suggest a pathogenesis based on bone marrow ischemia. CFOJ can be treated on a rational basis with a justifiable expectation of success and probable cure.

Comparative evaluation of mandibular canal visibility on cross-sectional cone-beam CT images: a retrospective study.

OBJECTIVES: The purpose of this study was to determine the visibility of the mandibular canal (MC) in CBCT images and if the visibility of the MC is affected by gender, location and/or age. METHODS: CBCT images were evaluated for the visibility of the MC by a board-certified oral and maxillofacial radiologist, a board-certified periodontist and a periodontics resident. Representative slices were examined for the first premolar (PM(1)), second premolar (PM(2)), first molar (M(1)) and second molar (M(2)) sites by all examiners. The visibility of the MC was registered as either present or absent. RESULTS: 360 total CBCT cross-sectional images were examined, with the MC identified in 204 sites (56%). Age had a significant effect on MC visibility, but it differed by location: for PM(1), age 47-56 had lower visibility than age 65+ (p = 0.0377). Gender also had a significant effect on canal visibility, where females had lower visibility than males overall (p = 0.0178) and had the most pronounced difference for PM(1) (p = 0.0054). Location had a significant effect on visibility, but it differed by age and by gender: for age 65+, M(2) had lower visibility than PM(1) (p = 0.0411) and PM(2) (p = 0.0180), while for females, PM(1) had lower visibility than M(1) (p = 0.0123) and M(2) (p = 0.0419). CONCLUSIONS: The MC was visualized only in just over half of the CBCT images. Age, gender and location had significant effects on the visibility.

Cone beam computed tomography for the nasal cavity and paranasal sinuses.

The paranasal sinuses are 4 paired airspaces that border the nasal cavity. Dental professionals are most familiar with the maxillary sinuses as viewed in 2-D imaging (eg, periapical, panoramic projections). With increasing implementation of 3-D imaging, specifically cone beam CT, there is a high probability that much or all of the paranasal sinuses and nasal cavity will be captured in a scan. It is incumbent on practitioners to be familiar with all the structures contained within a scanned area. The purpose of this article is to provide an overview of the anatomy of the nasal cavity as well as common anatomic variants and pathologic entities.

A framework for estimating probability of a match in forensic bite mark identification.

In forensic dentistry, a human expert typically does the comparison and identification based on bite marks. Unlike DNA analysis, however, there is no quantitative basis with which to assign a probability for this given match. This paper proposes a framework for empirically estimating the probability of such a bite mark match and reports on initial experimental results. The methodology involved collection of dental population data (3D dental casts and bite mark images), image analysis for quantitatively measuring the degree of match (based on chamfer distance), and performing a logistic regression analysis using the collected population data to estimate the probability of match from the calculated degree of match. The model correctly predicted 35 of the 42 matches and 585 of the 588 mismatches. The method also has potential for use in other forensic applications in which the assignment of quantitative probabilities is important.

Digital radiographic imaging: is the dental practice ready?

BACKGROUND: Digital radiographic imaging is slowly, but surely, replacing film-based imaging. It has many advantages over traditional imaging, but the technology also has some drawbacks. The author presents an overview of the types of digital image receptors available, image enhancement software and the range of costs for the new technology. PRACTICE IMPLICATIONS. The expenses associated with converting to digital radiographic imaging are considerable. The purpose of this article is to provide the clinician with an overview of digital radiographic imaging technology so that he or she can be an informed consumer when evaluating the numerous digital systems in the marketplace.

An evaluation of DNA yield, DNA quality and bite registration from a dental impression wafer.

BACKGROUND: The authors determined the amount and quality of the DNA captured by a bite impression wafer and analyzed any inaccuracies in the impression wafer. METHODS: The authors made bite registrations for subjects aged 7 to 12 years by using a dental impression wafer (Toothprints, Kerr, Orange, Calif.), obtained an oral rinse sample, took cheek cells by using buccal swabs and made an alginate impression to pour a stone model. They extracted and quantified the DNA from the dental impression wafer, mouthwash and buccal swabs by using the Quant-iT PicoGreen (Invitrogen, Carlsbad, Calif.) assay and a real-time polymerase chain reaction (RT-PCR) assay. They compared the stone models and imprints from the wafer. RESULTS: The average amounts of DNA determined by using Quant-iT PicoGreen from the buccal swab, mouthwash and dental impression wafer samples were 113.61, 509.57 and 1.03 micrograms, respectively. The average amounts of DNA determined by using RT-PCR from the buccal swab, mouthwash and dental impression wafer samples were 11.5240, 22.2540 and 0.0279 mug, respectively. The bite registrations and stone models had an average of 14 percent of mismatches. CONCLUSION: The dental impression wafers captured DNA but not in high quantities. They did not produce an accurate representation of the dentition. CLINICAL IMPLICATIONS: The dental impression wafers captured enough DNA to permit amplification. The accuracy of the bite registration was not sufficient for identification purposes. Therefore, dental impression wafers may be useful only as a reservoir for DNA.

Oral manifestations of systemic disease.

Most systemic diseases can affect the oral cavity. Some oral changes are nonspecific, whereas others directly lead to the diagnosis of a particular disorder. A systems approach is used here to catalog these oral changes. In some instances it is difficult to separate the oral manifestations of pharmacotherapy for a particular disease from that entity. The oral manifestations of pharmacotherapy are presented for selected disease processes. This article introduces the most common oral manifestations of systemic disease.

Digital radiography: an overview.

Since the discovery of X-rays in 1895, film has been the primary medium for capturing, displaying, and storing radiographic images. It is a technology that dental practitioners are the most familiar and comfortable with in terms of technique and interpretation. Digital radiography is the latest advancement in dental imaging and is slowly being adopted by the dental profession. Digital imaging incorporates computer technology in the capture, display, enhancement, and storage of direct radiographic images. Digital imaging offers some distinct advantages over film, but like any emerging technology, it presents new and different challenges for the practitioner to overcome. This article presents an overview of digital imaging including basic terminology and comparisons with film-based imaging. The principles of direct and indirect digital imaging modalities, intraoral and extraoral applications, image processing, and diagnostic efficacy will be discussed. In addition, the article will provide a list of questions dentists should consider prior to purchasing digital imaging systems for their practice.