A cone beam computed tomography (CBCT) study of buccal plate thickness of the maxillary and mandibular posterior dentition.

BACKGROUND: Buccal plate thickness is of clinical importance in treatment planning for implants. The purpose of this study was to evaluate the buccal plate thickness in posterior dentate areas of both the maxilla and mandible using cone beam computed tomography in order to estimate the approximate distributions of this anatomic variable. METHODS: Two hundred and sixty-five subjects were included for a total of nine hundred and thirty-four roots assessed by cone beam computed tomography. CBCT scans were taken and evaluated at the ideal buccolingual cross-sections of each root at 1 mm, 3 mm, and 5 mm apical to the alveolar crest to measure buccal plate thickness. Data are reported by geometric means and 95% confidence intervals. RESULTS: Both arches demonstrated increasing buccal plate thickness from anterior to posterior. Maxillary teeth had a significant decrease in thickness from coronal to apical along the tooth root (P < 0.001), except at second molars. The first premolar and mesial root of the first molar were significantly thinner than all other roots in the maxilla. Conversely, the mandible demonstrated a significant increase in buccal plate thickness from coronal to apical (P < 0.001). The premolars were significantly thinner than all other roots. Age and sex were found to have limited impact on buccal plate thickness in both arches. CONCLUSIONS: Buccal plate thickness is highly dependent upon the arch position, tooth location, and measurement point, but age and sex have limited impact.

Accuracy of dental calculus detection using digital radiography and image manipulation.

BACKGROUND: The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs. METHODS: Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners. RESULTS: None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05). CONCLUSIONS: Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

The effect of ultrasound on bone dimensional changes following extraction: a pilot study.

BACKGROUND: Because of bone resorption following tooth extraction, preservation of adequate bony dimension is performed often for subsequent treatment with dental implants. This study evaluated a novel, non-invasive treatment using ultrasound to accelerate healing following extraction to minimize alveolar bone loss. The objective of this study was to evaluate the effect of ultrasound on the dimensional healing changes of alveolar bone following tooth extraction using cone-beam volumetric tomography (CBVT). METHODS: This randomized, split-mouth trial involved 12 subjects requiring extraction of two contralateral erupted permanent teeth. Baseline CBVT scans were captured 7 to 10 days following extraction, after which time ultrasound therapy commenced in test sites. Ultrasound therapy was delivered for 20 minutes using a piezoelectric transducer for 10 sessions over the subsequent 4 weeks. Follow-up radiographic scans were obtained at 4 weeks and 3 months postextraction. Analyses of variance and covariance were performed to assess dimensional changes over the 3-month healing period. RESULTS: Analysis of dimensional changes in all measures of vertical height and horizontal width demonstrated no statistically significant differences between the ultrasound and control groups from baseline to 3 months postextraction. Evaluation of correlations between dimensional changes demonstrated a moderately strong correlation (r = 0.67; P = 0.023) in the ultrasound group between the change in buccal vertical height and the baseline crestal ridge width. Analysis of the change in buccal vertical height relative to baseline crestal width demonstrated a statistically significant benefit to ultrasound compared to control (P = 0.016). This benefit was more pronounced in wider sockets compared to narrow sockets. CONCLUSIONS: In this pilot study, there was no significant benefit to ultrasound in absolute bony dimensional changes following tooth extraction. There was a significant interaction between the treatment rendered (ultrasound versus control) and the change in buccal ridge height relative to baseline ridge width at the crest and 3 mm apical to the crest. This benefit was apparent in wide sockets compared to narrow sockets; however, the clinical importance of these relative dimensional changes in the ultrasound group are difficult to determine given the inclusion of all tooth types in a pilot study with a small sample size.

Accuracy of cone beam computed tomography in determining the location of the genial tubercle.

OBJECTIVE: To determine the accuracy of cone beam computed tomography (CT) to predict the location of the genial tubercle. STUDY DESIGN AND SETTING: Cadaver study for anatomic analysis of 17 adult human cadaver heads. Each skull/cadaver head underwent radiographic imaging with cone beam CT and cadaver dissection. Measurements, including mandibular height (MH), genial tubercle width (GTW), genial tubercle height (GTH), distance from inferior border of mandible to genial tubercle (IBM/GT), and mandibular thickness (MT) were recorded. RESULTS: Statistical analysis with paired t test showed no significant difference between cadaver dissections versus cone beam measurements. Ninety-five percent confidence intervals (CI) were as follows: GTW (-0.2 to 1.0), GTH (-0.1 to 0.9), distance IBM/GT (-0.8 to 5.0), MH (-1.3 to -2.6), and MT (-0.1 to 0.3). CONCLUSION: These results show the accuracy of the 3D cone beam CT in the anatomic location of the genial tubercle. SIGNIFICANCE: This radiographic technique may prove useful in pre-operative planning for the mandibular osteotomy in genioglossus advancement procedures.

MRI assessment of temporomandibular disc position among various mandibular positions: a pilot study.

PURPOSE: The aim of this pilot study was to assess temporomandibular joint disc movement relative to the condyle among centric relation (CR), physiologic rest position (PRP), and maximal intercuspation position (MIP) in healthy patients without signs or symptoms of any temporomandibular disorder. The hypothesis was that as the condyle rotated clockwise or translated anteriorly, the disc would also move in an anterior direction. MATERIAL AND METHODS: Magnetic resonance images were obtained on 20 volunteers in CR, physiologic rest, and MIP. Three investigators measured the location of the disc among the different mandibular positions. RESULTS: Disc location differences between CR and PRP exhibited the widest range of measurement. The largest amount of disc protrusion relative to the condyle was found between CR and PRP on the right side. The largest amount of disc retrusion relative to the condyle was found between CR and MIP on the right side. The hypothesis was not supported by the results. CONCLUSIONS: According to the results of this pilot study, the direction of movement of the temporomandibular disc does not correlate with the rotational movement of the condyle in hinge positions. CLINICAL IMPLICATIONS: Increased knowledge of temporomandibular disc movement among various mandibular positions in asymptomatic patients may help clinicians recognize deviations in symptomatic patients.

Thickness of the Buccal Plate in Posterior Teeth: A Prospective Cone Beam Computed Tomography Study.

Buccal plate thickness is an important clinical parameter for postextraction implant treatment planning. The purpose of this study was to assess buccal plate thickness of the posterior maxilla and mandible using cone beam computed tomography (CBCT). A total of 265 patients and 934 teeth met the inclusion criteria for this study. CBCT volumes were taken and aligned for measurement at the ideal midsagittal cross-section. Buccal plate thickness was measured at 1, 3, and 5 mm apical to the alveolar crest. The frequency of thick (≥ 1 mm), thin (< 1 mm), and radiographic absence of the buccal plate were determined. The frequency of thin buccal plate decreases from anterior to posterior, with first premolars and first molar mesial roots most affected. Radiographic absence of the buccal plate was more common in the mandible, at first premolars, and among women. Thin and absent buccal plate are not uncommon in the posterior jaws; consequently, ridge preservation may be indicated even at posterior teeth.

Development of tools for the oral health and panoramic radiograph evaluation of head and neck cancer patients: a methodological study.

PURPOSE: Describe the methodology used to construct tools for standardized data collection of head and neck cancer patients (HNCP). METHODS: We constructed the Oral Health Evaluation Tool (OHET) and Panoramic Radiograph Evaluation Tool (PRET) for systematic collection of long-term oral clinical/radiographical complications, prevalence, and severity. Tools were pilot-tested in 50 chemoradiation-treated HNCP >6 months post-therapy. RESULTS: Tools allowed for collection of extensive clinical and radiographical data. A medium of 1.9 years had elapsed since chemoradiation completion. Patients had a median of 6 missing teeth, 32.7% had no decay and a medium of 30% had filled surfaces; 42.9% had moderate-to-severe decay. Reduced/thickened saliva was noted in 85.4% and dry mucosa in 93.9%. Gingival bleeding was present in 75.5% HNCP and attachment loss in 86%. Four patients had trismus. CONCLUSIONS: Tools were user friendly and provided comprehensive, reproducible, and inexpensive means to evaluate post-therapy oral health of HNCP. Validation testing is ongoing.

Relationship between clinical periodontal biotype and labial plate thickness: an in vivo study.

The primary aim of this study was to evaluate the differences in labial plate thickness in patients identified as having thin versus thick/average periodontal biotypes. The association between biotype and labial plate thickness was evaluated by correlating information obtained from cone beam computed tomographs, diagnostic impressions, and clinical examinations of the maxillary anterior teeth (canine to canine) in 60 patients. Compared to a thick/average biotype, a thin biotype was associated with thinner labial plate thickness (P < .001), narrower keratinized tissue width (P < .001), greater distance from the cementoenamel junction to the initial alveolar crest (P = .02), and probe visibility through the sulcus. There was no relationship between biotype and tooth height-to-width ratio or facial recession. Periodontal biotype is significantly related to labial plate thickness, alveolar crest position, keratinized tissue width, gingival architecture, and probe visibility but unrelated to facial recession.