Comparison of Virtual Dental Implant Planning Using the Full Cross-Sectional and Transaxial Capabilities of Cone Beam Computed Tomography vs Reformatted Panoramic Imaging and 3D Modeling.

PURPOSE: To compare the choice and placement of virtual dental implants in the posterior edentulous bounded regions using the full cross-sectional and transaxial capabilities of cone beam computed tomography (CBCT) vs reformatted panoramic images and three-dimensional (3D) virtual models. MATERIALS AND METHODS: Fifty-two cases with posterior bounded edentulous regions (61 dental implant sites) were identified from a retrospective audit of 4,014 radiographic volumes. Two image sets were created from selected CBCT data: (1) a combination of reformatted panoramic imaging and a 3D model (PIref/3D), and (2) the full 3D power in CBCT image volume analyses (XS). One virtual implant was placed by consensus of three prosthodontists in each image set: PIref/3D and XS. The choice of implant length and the perceived need for ridge augmentation were recorded for implant placement in both test situations. All the virtual implant placements from both PIref/3D and XS image sets were inspected retrospectively using virtual 3D models, and the number of exposed threads on both the buccal and lingual/palatal aspects of the virtual dental implant was evaluated. The chi-square and paired t tests were used with the level of significance set at α = .05. RESULTS: Shorter implants were chosen more often using XS than PIref/3D (P = .001). Fewer threads were exposed when placed with XS than with PIref/3D (P = .001). The use of XS reduced the perceived need for ridge augmentation compared with PIref/3D (P = .001). CONCLUSION: The use of the full 3D power of CBCT (including cross-sectional images in all three orthagonal planes and transaxially) provides supplemental information that significantly changes the choice of virtual implant length and vertical position of the implant, and reduces the frequency of perceived need for ridge augmentation before implant placement.

Utility and effectiveness of computer-aided diagnosis of dental caries.

Digital radiography has created a growing opportunity for computer-aided diagnostic (CAD) tools. The Logicon Caries Detector (LCD), with upgraded CAD software based on user feedback, was re-evaluated for its effectiveness via a retrospective clinical study. Using the upgraded LCD software, 12 dentists (evaluators) blindly assessed 17 radiographs taken by another (attending) dentist, who restored 28 proximal surfaces. The attending dentist confirmed the presence of early dentinal caries, as well as identifying 48 surfaces as caries-free or with enamel caries only subject to noninvasive treatment. The radiographs, imported into the software using a digital imaging and communications in medicine (DICOM) reader, were visually assessed under typical operatory lighting conditions, then with the aid of the software's density analysis tool. The effectiveness of the evaluators was gauged by calculating two measures of performance, sensitivity and specificity, for the detection and classification of dentinal caries. Sensitivity among all evaluator dentists was 30% with the initial image; 34% with the brightness and contrast adjusted image; 39% when the image was sharpened; and 69% when the density analysis tool was utilized. Specificity was found to be 97% with the initial image; 95% with the brightness and contrast adjusted image; 93% with the sharpened image; and 94% when the density analysis tool was used. Compared to the unaided eye, the LCD can significantly improve dentists' ability to detect and classify caries. Dentists may be able to find twice as much early dentinal caries requiring restoration (or at least aggressive noninvasive treatment) than previously, while not unnecessarily restoring additional healthy teeth. The LCD enables dentists to obtain more information from dental digital radiography than is possible with the unaided eye, leading to improved patient care.

Success rate of immediate implants placed and restored by novice operators.

AIMS: The primary aim of this study was to evaluate the 1-year crestal bone loss and success rate of an immediately placed single-stage implant placed and restored by novice operators. A secondary aim was to determine the patient's assessment of the appearance of the final restoration. METHODS: Fifty-one patients received a tooth extraction and placement of at least 1 immediate implant by a Graduate Periodontics resident. Clinical and radiographic measurements were taken at the surgical, 4-month, and 1-year follow-up visits. After at least 3 months healing, dental students restored the implants with either a crown or an overdenture. Patient satisfaction was assessed using 5 categories: excellent, very good, good, fair, or poor. RESULTS: Sixty-two immediate implants were placed. The success rate was 100% at the 12-month visit and was subclassified as grade 3 because of the mean first year bone loss of 1.3 +/- 1.0 mm. Using the 2008 classification of Misch et al, 42 implants were classified as success optimum health, 19 as survival satisfactory health, and 1 as survival compromised health. Radiographic bone loss was stratified by implant platform position relative to the alveolar crest and changed from time 0 to time 12 by -1.0 +/- 1.2 mm for the supracrestal group (n = 25, P < 0.05), -1.5 +/- 0.9 mm for the crestal group (n = 31, P < 0.05), and -1.3 +/- 1.2 mm for the subcrestal group (n = 6, P < 0.05). The supracrestal group had significantly less bone loss than either the crestal or the subcrestal group (P < 0.05). The appearance of the final restoration at 1 year was rated excellent by 82% of patients, very good by 16%, and good by 2%. CONCLUSIONS: Immediate implant placement by novice operators using routine dental school procedures was a highly predictable procedure as indicated by the 100% success rate at 12 months. Most patients rated the restoration appearance as excellent.

Prevalence of carotid and pulp calcifications: a correlation using digital panoramic radiographs.

OBJECTIVE: To compare the prevalence of pulp calcification with that of carotid calcification using digital panoramic dental radiographs. STUDY DESIGN: Digital panoramic radiographs of patients at a dental oncology clinic were included if (1) the carotid artery bifurcation region was visible bilaterally and (2) the patient had non-restored or minimally restored molars and/or canines. An endodontist evaluated the images for pulpal calcifications in the selected teeth. An oral and maxillofacial radiologist independently evaluated the same images for calcifications in the carotid bifurcation region. Odds-ratio and Pearson chi(2) were used for data analysis. Presence of pulpal calcification was also evaluated as a screening test for the presence of carotid calcification. RESULTS: A total of 247 panoramic radiographs were evaluated. 32% (n = 80) had pulpal calcifications and 25% (n = 61) had carotid calcifications with 12% (n = 29) having both carotid and pulp calcifications. A significantly higher prevalence of both pulp and carotid calcification was found in subjects older than age 60 years compared to younger age groups. Accuracy of pulpal calcification in screening for carotid calcification was 66.4%. CONCLUSIONS: Both pulp and carotid calcifications were more prevalent in older individuals. The presence of pulp calcification was not a strong predictor for the presence of carotid calcification.

Root coverage using acellular dermal matrix and comparing a coronally positioned tunnel with and without platelet-rich plasma: a pilot study in humans.

BACKGROUND: The primary aim of this randomized, controlled, blinded clinical pilot study was to compare the percentage of recession defect coverage obtained with a coronally positioned tunnel (CPT) plus an acellular dermal matrix allograft (ADM) to that of a CPT plus ADM and platelet-rich plasma (CPT/PRP) 4 months post-surgically. METHODS: Eighteen patients with Miller Class I or II recession >or=3 mm at one site were treated and followed for 4 months. Nine patients received a CPT plus ADM and were considered the positive control group. The test group consisted of nine patients treated with a CPT plus ADM and PRP. Patients were randomly selected by a coin toss to receive the test or positive control treatment. RESULTS: The mean recession at the initial examination for the CPT group was 3.6 +/- 1.0 mm, which was reduced to 1.0 +/- 1.0 mm at the 4-month examination for a gain of 2.6 +/- 1.5 mm or 70% defect coverage (P <0.05). The mean recession at the initial examination for the CPT/PRP group was 3.3 +/- 0.7 mm, which was reduced to 0.4 +/- 0.7 mm at the 4-month examination for a gain of 2.9 +/- 0.5 mm or 90% defect coverage (P <0.05). There were no statistically significant differences between the groups (P >0.05). CONCLUSIONS: The CPT plus ADM and PRP produced defect coverage of 90%, whereas the CPT with ADM produced only 70% defect coverage. This difference was not statistically significant, but it may be clinically significant.

Linear accuracy of cone beam CT derived 3D images.

OBJECTIVE: To compare the in vitro reliability and accuracy of linear measurements between cephalometric landmarks on cone beam computed tomography (CBCT) 3D volumetric images with varying basis projection images to direct measurements on human skulls. MATERIALS AND METHODS: Sixteen linear dimensions between 24 anatomic sites marked on 19 human skulls were directly measured. The skulls were imaged with CBCT (i-CAT, Imaging Sciences International, Hatfield, Pa) at three settings: (a) 153 projections, (b) 306 projections, and (c) 612 projections. The mean absolute error and modality mean (+/- SD) of linear measurements between landmarks on volumetric renderings were compared to the anatomic truth using repeated measures general linear model (P < or = .05). RESULTS: No difference in mean absolute error between the scan settings was found for almost all measurements. The average skull absolute error between marked reference points was less than the distances between unmarked reference sites. CBCT resulted in lower measurements for nine dimensions (mean difference range: 3.1 mm +/- 0.12 mm to 0.56 mm +/- 0.07 mm) and a greater measurement for one dimension (mean difference 3.3 mm +/- 0.12 mm). No differences were detected between CBCT scan sequences. CONCLUSIONS: CBCT measurements were consistent between scan sequences and for direct measurements between marked reference points. Reducing the number of projections for 3D reconstruction did not lead to reduced dimensional accuracy and potentially provides reduced patient radiation exposure. Because the fiducial landmarks on the skulls were not radio-opaque, the inaccuracies found in measurement could be due to the methods applied rather than to innate inaccuracies in the CBCT scan reconstructions or 3D software employed.

Simulated microbe removal around finger rings using different hand sanitation methods.

AIM: It is our opinion that the CDC and the WHO have underestimated cross-contamination under examination gloves in dental clinics while wearing jewelry, such as finger rings. These agencies only "recommend" removing jewelry, and only washing hands for 15 seconds with soap and warm water before donning gloves. This study examined several washing procedures and finger rings using simulated microbes. METHODOLOGY: A gloved rubber hand manikin was made and fitted with a fresh disposable vinyl glove. Four fingers were fitted with rings or no ring, dusted with simulated microbes, and washed with a scrub brush for 5, 15, and 25 seconds under 20 degrees C and 40 degrees C water alone, or with liquid hand soap. Light levels (in lux) of fluorescent powder before and after washing were measured and delta scores calculated for changes in light levels, equivalent to effectiveness of hand washing procedures. A full-factorial, 3-factor analysis of variance (ANOVA) was used to test for differences among levels of the three study factors-time, temperature, and soap use. Tukey's post hoc honestly significant difference (HSD) test was applied to significant factors to examine pair-wise differences between factor levels. RESULTS: It was found that the longer the hands with rings were washed with a scrub brush under flowing water, the more simulated microbes were removed. By 25 seconds, all methods were essentially the same. Simulated microbes were more difficult to remove from the palm compared to the back of the hand. The liquid hand soap used in this study was more effective with warm water than cold. When given a choice of washing with cold water up to 15 seconds, it would be preferable not to use soap to remove simulated microbes. Qualitatively, the outer surface of finger rings were more effectively cleaned than the crevice below the ring, and the ring with a stone setting appeared to accumulate and retain simulated microbes more than other rings. CONCLUSION: The most effective treatment was washing with warm water and liquid soap. Longer times were more effective. Rings should not be worn under examination gloves due to difficulty cleaning in the crevice under the ring, and the well-known consequences of cross-contamination between the patient and the health care worker.

Root coverage using acellular dermal matrix and comparing a coronally positioned tunnel to a coronally positioned flap approach.

BACKGROUND: The primary aim of this randomized, controlled, masked clinical trial was to compare the percentage of root coverage obtained with a coronally positioned flap plus acellular dermal matrix (ADM) allograft to that of a tunnel technique plus ADM 4 months post-surgically. METHODS: Twenty-four subjects with one site with > or =3 mm Miller Class I or II recession were treated and followed for 4 months. Twelve patients received a coronally positioned flap plus ADM and were considered the positive control group (CPF). The test group consisted of 12 subjects treated with a coronally positioned tunnel technique plus ADM (TUN). Subjects were randomly selected by a coin toss to receive the test or control treatment. RESULTS: The mean facial recession defect at the initial examination for the TUN group was 3.1 +/- 0.3 mm; this was reduced to 0.7 +/- 0.9 mm at the 4-month examination for a gain of 2.4 +/- 1.0 mm or 78% defect coverage (P <0.05). The mean facial recession defect at the initial examination for the CPF group was 3.4 +/- 0.8 mm; it was reduced to 0.2 +/- 0.3 mm at the 4-month examination for a gain of 3.2 +/- 0.9 mm or 95% defect coverage (P <0.05). There was no statistically significant difference between groups (P >0.05). CONCLUSIONS: The coronally positioned flap plus ADM produced a defect coverage of 95%, whereas the tunnel technique plus ADM produced only 78% coverage. This difference was considered clinically significant but was not statistically significant.

Linear accuracy and reliability of cone beam CT derived 3-dimensional images constructed using an orthodontic volumetric rendering program.

OBJECTIVE: To compare accuracy of linear measurements made on cone beam computed tomographic (CBCT) derived 3-dimensional (3D) surface rendered volumetric images to direct measurements made on human skulls. MATERIALS AND METHODS: Twenty orthodontic linear measurements between anatomical landmarks on 23 human skulls were measured by observers using a digital caliper. The skulls were imaged with CBCT and Dolphin 3D (version 2.3) software used to generate 3D volumetric reconstructions (3DCBCT). The linear measurements between landmarks were computed by a single observer three times and compared to anatomic dimensions using Student's t-test (P < or = .05). The intraclass correlation coefficient (ICC) and absolute linear and percentage error were calculated. RESULTS: The ICC for 3DCBCT (0.975 +/- 0.016) was significantly less than for skull (0.996 +/- 0.007) measurements. Mean percentage measurement error for 3DCBCT (2.31% +/- 2.11%) was significantly higher than replicate skull measurements (0.63% +/- 0.51%). Statistical differences between 3DCBCT means and true dimensions were found for all of the midsagittal measurements except Na-A and six of the 12 bilateral measurements. The mean percentage difference between the mean skull and 3D-based linear measurements was -1.13% (SD +/- 1.47%). Ninety percent of mean differences were less than 2 mm, and 95% confidence intervals were all less than 2 mm except for Ba-ANS (3.32 mm) and Pog-Go(left) (2.42 mm). CONCLUSIONS: While many linear measurements between cephalometric landmarks on 3D volumetric surface renderings obtained using Dolphin 3D software generated from CBCT datasets may be statistically significantly different from anatomic dimensions, most can be considered to be sufficiently clinically accurate for craniofacial analyses.

Accuracy of linear measurements from imaging plate and lateral cephalometric images derived from cone-beam computed tomography.

INTRODUCTION: As orthodontic practice moves toward 3-dimensional cephalometric analyses, a solution is required to ensure sustained availability of well-established projected treatment outcomes based on 2-dimensional analyses. This ex-vivo study was conducted to compare the accuracy of linear measurements made on photostimulable phosphor cephalograms with 3 methods for simulating lateral cephalograms with cone-beam computed tomography (CBCT). METHODS: The linear distances between anatomical landmarks on dentate dry human skulls were measured by observers using digital calipers for S-N, Ba-N, M-N, ANS-N, ANS-PNS, Pog-Go, Go-M, Po-Or, and Go-Co. The skulls were imaged with CBCT with a single 360 degrees rotation, producing 306 basis images and achieving 0.4 mm isotrophic voxel resolution on volumetric reconstruction for making ray-sum reconstructed cephalograms. Two other cephalogram approaches were used with the CBCT system--a single transmission image generated as a scout image designed to check patient positioning before CBCT, and a single-frame lateral basis image. Conventional digital lateral cephalograms (LCs) were acquired with the photostimulable phosphor system. Images were imported into a cephalometric analysis program (Dolphin Imaging Cephalometric and Tracing Software, Chatsworth, Calif) to compute the included linear measurements. Analyses were repeated 3 times and statistically compared with measured anatomic truth with ANOVA (P < or =.05). The intraclass correlation coefficient was determined as an index of intra- and interobserver reliability. RESULTS: The intraclass correlation coefficient for the LCs was significantly less than for the measured anatomic truth and for all CBCT-derived images. CBCT images either produced with individual frames or reconstructed from the volumetric data set were accurate for all measurements except Pog-Go and Go-M. CBCT scout images had the second highest accuracy for all measurements except Pog-Go, Go-M, and Go-Co. Conventional LCs had the least accuracy; they were accurate only for Po-Or and ANS-N. CONCLUSIONS: CBCT-derived 2-dimensional LCs proved to be more accurate than LCs for most linear measurements calculated in the sagittal plane. No advantage was found over single-frame basis images in using ray-sum generated cephalograms from the CBCT volumetric data set.

Childhood obesity and skeletal maturation assessed with Fishman's hand-wrist analysis.

INTRODUCTION: The purpose of this study was to determine whether increased body mass index is associated with accelerated skeletal maturation. METHODS: The skeletal ages of 107 children, aged 9 to 16 years, were determined by using Fishman's hand-wrist analysis. The difference between chronologic age and dental age was analyzed against body mass index, sex, and age. RESULTS: The mean differences between chronologic and skeletal ages for normal weight, overweight, and obese subjects were 0.51 years, 0.44 years, and 1.00 years, respectively. Although there was a trend for obese subjects to have accelerated skeletal maturation compared with overweight and normal-weight subjects, the difference was not statistically significant. Skeletal age differences significantly decreased with increasing age. The mean skeletal age differences were 0.90 year for 9- to 13-year-olds and 0.26 year for 13- to 16-year-olds. Mean skeletal age did not differ significantly by sex. CONCLUSIONS: Overweight or obese children did not have significantly accelerated skeletal maturation after adjusting for age and sex.

Digitized hand-wrist radiographs: comparison of subjective and software-derived image quality at various compression ratios.

INTRODUCTION: The objectives of this study were to compare the effect of JPEG 2000 compression of hand-wrist radiographs on observer image quality qualitative assessment and to compare with a software-derived quantitative image quality index. METHODS: Fifteen hand-wrist radiographs were digitized and saved as TIFF and JPEG 2000 images at 4 levels of compression (20:1, 40:1, 60:1, and 80:1). The images, including rereads, were viewed by 13 orthodontic residents who determined the image quality rating on a scale of 1 to 5. A quantitative analysis was also performed by using a readily available software based on the human visual system (Image Quality Measure Computer Program, version 6.2, Mitre, Bedford, Mass). ANOVA was used to determine the optimal compression level (P < or =.05). RESULTS: When we compared subjective indexes, JPEG compression greater than 60:1 significantly reduced image quality. When we used quantitative indexes, the JPEG 2000 images had lower quality at all compression ratios compared with the original TIFF images. There was excellent correlation (R2 >0.92) between qualitative and quantitative indexes. CONCLUSIONS: Image Quality Measure indexes are more sensitive than subjective image quality assessments in quantifying image degradation with compression. There is potential for this software-based quantitative method in determining the optimal compression ratio for any image without the use of subjective raters.

Correlation between carotid area calcifications and periodontitis: a retrospective study of digital panoramic radiographic findings in pretreatment cancer patients.

OBJECTIVES: The objective of this study was to examine the prevalence of carotid area calcifications retrospectively detected on digital panoramic radiographs of pretreatment cancer subjects, and to correlate the finding of such calcifications with radiographic evidence of periodontal bone loss in the same subjects. STUDY DESIGN: Digital panoramic radiographs of 201 subjects were evaluated for calcifications projected in the carotid artery bifurcation area as well as for alveolar bone loss as a result of periodontal disease. Inclusion criteria were unobscured carotid artery bifurcation regions bilaterally and sufficient index teeth present with a definable cemento-enamel junction and alveolar crest. Radiographs were independently observed for carotid area calcifications and for periodontal status. Image enhancements permitted for detection of calcifications projected in the carotid area included window/level, inverse, and emboss. Periodontal measurements were made on index teeth using proprietary imaging software and a mouse-driven measurement algorithm. A 3-factor analysis of variance was performed with 3 between-subjects comparisons. Percentage of bone loss was the dependent variable. Independent variables were age, subject sex, and the presence or absence of carotid area calcifications. RESULTS: Differences measured in percentage of bone loss between sexes were not statistically significant. While bone loss did increase with age, comparison of the mean bone loss of each age category revealed no statistical significance. There was a highly significant correlation between carotid artery area calcifications visible on panoramic radiographs and percent alveolar bone loss. Radiographs showing unilateral and bilateral calcifications had a mean percent bone loss of 24.2% +/- 12.6% and 25.7% +/- 13.0% respectively, compared to those with no calcification at 10.4% +/- 9.9%. CONCLUSIONS: Nearly 1 in 4 subjects in this study evidenced calcifications projected in the carotid bifurcation region. The finding of such calcifications was significantly related to the calculated percentage of alveolar bone loss.

Effects of imaging system and exposure on accurate detection of the second mesio-buccal canal in maxillary molar teeth.

OBJECTIVES: The objectives of this study were to determine observer ability to detect the second mesio-buccal canal (MB2) in maxillary molars using analog film, CMOS, and photostimulable phosphor x-ray detectors across a wide range of radiation exposures and to determine the optimal exposures for these modalities accurately detecting presence of the MB2. RESEARCH DESIGN: Using 6 experimental models with 2 maxillary molars in each, images were generated with the 3 detector modalities at nominal x-ray beam angulations of 0 degrees and 10 degrees across a range of radiation exposures. Observers independently assessed presence of the MB2 in images presented in random order. Horizontal root sections were then evaluated to determine true MB2 presence. RESULTS: For single images at optimal exposures, the correct number of mesiobuccal canals could be identified 55% of the time for CMOS (RVG 6000), 44% of the time for analog x-ray film (InSight), and 39% of the time for photostimulable phosphor (DenOptix). Statistically significant differences were observed between the imaging modalities (chi2 = 23.4, crucial value = 5.99, P < or = .05). RVG 6000 CMOS outperformed both DenOptix photostimulable phosphor (z score = -5.5) and InSight analog direct exposure x-ray film (z score = 4). Exposure affected the rate of accuracy for MB2 detection across the exposure range tested for RVG 6000 and for film, but not to any appreciable degree for DenOptix. CONCLUSIONS: The CMOS detector (RVG-6000) performed best for evaluating presence of the MB2. This was the only modality to exceed 50% reliability with optimal exposure when single images were considered.

Orthodontic treatment provided by general dentists who have achieved master's level in the Academy of General Dentistry.

INTRODUCTION: The purposes of this study were to document orthodontic treatment currently provided by general dentists for comparison with past and future studies and to ascertain variables that influence practitioners' orthodontic treatment patterns. METHODS: A 21-item survey was mailed to 750 master's level members of the Academy of General Dentistry. Surveys returned within 8 weeks were included for statistical analysis. RESULTS: The response rate was 62%. Most practitioners spent less than 10% of their practice time providing orthodontic treatment and reported that this would not change in the future. Many provided orthodontic treatment in the permanent dentition, and the most common conditions or malocclusions treated were space maintenance, anterior crossbite, rotation, habits, molar uprighting, and posterior crossbite. The most common orthodontic appliances used were removable Hawley appliances with finger springs, straight wire orthodontic therapy, rapid palatal expanders, and functional appliances. CONCLUSIONS: The number of general dentists providing comprehensive orthodontic treatment has not changed since previous surveys; practitioners also do not expect a change in the next 5 years. Factors that influenced the orthodontic treatment provided included the primary source of orthodontic training, the number of orthodontic continuing education hours earned per year, the practitioner's location, and the proximity to the nearest orthodontist.

Association between childhood obesity and smooth-surface caries in posterior teeth: a preliminary study.

PURPOSE: The purpose of this study was to determine if increased body mass index (BMI) is associated with an increased risk for dental caries. METHODS: Caries severity averages were calculated for a convenience sample of 178 children, ages 8 to 11 years, who participated in the University of Louisville Dental School-based dental treatment program "Smile Kentucky." Caries severity averages were then analyzed against the children's BMI, with gender and age used as covariates. RESULTS: The mean caries average for permanent molars significantly increased with increased BMI, even after adjusting for age and gender. The mean overall caries average did not vary significantly with patient age, BMI, or gender and may be due to confounding mixed dentition events such as eruption, extraction, variable teeth exfoliation, etc. CONCLUSIONS: Elevated body mass index is associated with an increased incidence of permanent molar interproximal caries.

Childhood obesity and dental development.

PURPOSE: The purpose of this study was to determine if increased body mass index (BMI) is associated with accelerated dental development in children ages 8 to 15. METHODS: The dental development ages of 104 children were determined using the Demirjian method and panoramic radiographs. Using the system developed by the International Obesity Task Force, BMI status was determined for each subject (63 normal weight, 23 overweight, and 18 obese subjects). The difference between chronologic age and dental age was analyzed against BMI, age, and gender using 3-way analysis of variance. RESULTS: Dental development was significantly accelerated with increased BMI, even after adjusting for age and gender (P < .01). The mean difference between chronologic and dental age among all subjects was 0.68 +/- 1.31 years. The mean dental age acceleration for overweight and obese subjects was 1.51 +/- 1.22 years and 1.53 +/- 1.28 years, respectively. CONCLUSIONS: Children who were overweight or obese had accelerated dental development, even after adjusting for age and gender. Accelerated dental development in obese children is an important variable to consider in pediatric dental and orthodontic treatment planning where timing is crucial.

Accuracy of linear temporomandibular joint measurements with cone beam computed tomography and digital cephalometric radiography.

INTRODUCTION: Cone beam computed tomography (CBCT) is making headway into imaging for orthodontics. The purpose of this study was to define CBCT multi-planar reformatted projections for temporomandibular joint (TMJ) examination and compare the accuracy of linear measurements of the TMJ and related structures from these projections with similar measurements made with conventional cephalograms and with the anatomic truth. METHODS: Linear dimensions between 11 anatomical sites were measured with a digital caliper to assess the anatomic truth for 25 dry human skulls. The skulls were imaged with iCAT (Xoran Technologies, Ann Arbor, Mich/Imaging Sciences International, Hatfield, Pa) CBCT, and cephalograms were made in all 3 orthogonal planes (lateral cephalometric [LC], posteroanterior [PA], and submentovertex [SMV]) acquired with photostimulable phosphor plates. Linear measurements were made on 7 custom CBCT reconstructions and the digital cephalograms. Modality means and the natural log of the standard deviations were compared post hoc against the actual dimensions by using analysis of variance with the Dunnett t test. Significance was set at P < .05. RESULTS: All CBCT measurements were accurate; however, 3 of 5 LC measurements, 4 of 5 PA measurements, and 4 of 6 SMV measurements varied significantly from the truth. Intraobserver CBCT measurements were highly reliable compared with anatomic truth and significantly more reliable than measurements made from LC, PA, and SMV images. CONCLUSIONS: Custom oblique multi-planar reformatted reconstructions with iCAT CBCT provide accurate and reliable linear measurements of mandibular and TMJ dimensions.

Comparison of an allograft in an experimental putty carrier and a bovine-derived xenograft used in ridge preservation: a clinical and histologic study in humans.

PURPOSE: The aim of this randomized, controlled, blinded clinical study was to compare ridge dimensions and histologic characteristics of ridges preserved with 2 different graft materials. MATERIALS AND METHODS: Twenty-four subjects, each requiring a nonmolar extraction and delayed implant placement, were randomly selected to receive ridge preservation treatment with either an allograft in an experimental putty carrier plus a calcium sulfate barrier (PUT) or a bovine-derived xenograft (BDX) plus a collagen membrane. Horizontal and vertical ridge dimensions were determined using a digital caliper and a template. At 4 months postextraction, a trephine core was obtained for histologic analysis. RESULTS: The average ridge width decreased by 0.50 mm for both groups (P < .05). The midbuccal vertical change for the PUT group was a loss of 0.3+/-0.7 mm versus a gain of 0.7+/-1.2 mm for the BDX group, a difference of 1.0 mm (P > .05). Histologic analysis revealed vital bone in the PUT group of about 61%+/-9% versus 26%+/-20% for the BDX group (P < .05). DISCUSSION: Greater vital bone fill in the PUT group may be attributable to earlier and greater vascular invasion of the carrier material. The putty material was characterized by ease of handling, simple placement, and enhanced graft particle containment. CONCLUSIONS: Allograft mixed with an experimental putty carrier produced significantly more vital bone fill than did the use of a xenograft with no carrier material. Ridge width and height dimensions were similarly preserved with both graft materials.

Endodontic measurement accuracy and perceived radiograph quality: effects of film speed and density.

OBJECTIVES: This study sought to determine the effects of direct exposure x-ray film speed and background density on observer assessment of endodontic working lengths and on perceived radiographic image quality. STUDY DESIGN: A human cadaver maxilla section with surrounding soft tissues was used for the study. The canal length to the radiographic apex was determined on 4 canals in maxillary posterior teeth by using Trophy RVG images and adjusting the position of a No. 15 file in each canal until the file tip coincided with the radiographic apex in images made at 3 different vertical angulations. The files were measured with a micrometer from the file stop to the file tip to obtain the length to the radiographic apex. Then No. 10 files were placed in the 4 canals at varying lengths short of this previously determined length, and 5 observers assessed the distance from the file tip to the radiographic apex on radiographs made with Kodak D-, E-, and F-speed and Flow D- and E-speed direct exposure x-ray films that were exposed to produce background densities of 1.5, 2.0, and 3.0. Subjective appraisal of radiographic quality was also assessed. RESULTS: Analysis of variance and Tukey honestly significantly different post-hoc analysis results concerning measurement errors made with each film type revealed significantly less error for Kodak Ektaspeed Plus (E-speed) intraoral x-ray film than for Kodak InSight (F-speed) and Flow E; however, no difference was detected among Kodak Ektaspeed Plus (E-speed), Kodak Ultra-Speed (D-speed), and Flow D. Films with a background optical density of 3.0 received 98% favorable ratings; radiographs with a background optical density of 2.0 received 77% favorable ratings; and those with background optical density of 1.5 received only 18% favorable ratings at the 95% confidence level. Flow D film received the most favorable ratings, but there was no statistically significant difference among other film types at the 95% confidence level. CONCLUSIONS: Underexposed radiographs are perceived as inferior to slightly overexposed radiographs for endodontic file length assessment regardless of the film speed used. Current Flow and Kodak E-speed and F-speed radiographs appear to be as accurate as other accepted radiographs used in determining endodontic working lengths. Image background density should be kept constant when making comparisons among x-ray films.