Cone beam computed tomography-based cephalometric norms for Brazilian adults.

This study established cone beam computed tomography (CBCT)-based cephalometric norms for Brazilian adults, including the assessment of sexual dimorphism. An observer performed McNamara's cephalometric analysis twice on 60 CBCT datasets acquired from patients with a normal dental occlusion, divided equally into two groups by sex. Welch's t-test was applied to assess differences between the sexes in hard tissue cephalometric measurements, and Dahlberg's formula was used to calculate measurement error introduced by the observer. The cephalometric measurements of effective mandibular length, effective midfacial length, maxillomandibular differential, and lower anterior facial height presented sexual dimorphism. Linear measurements had error ≤0.78mm, and angular measurements had error ≤1.24°. The results show that (1) the CBCT-based cephalometric norms established in this study are reliable for use by researchers and clinicians, and (2) Brazilian adult males and females have similar craniofacial morphology, with males possessing larger jaws than females.

Effect of delayed scanning on imaging and on the diagnostic accuracy of vertical root fractures in two photostimulable phosphor plates digital systems.

AIM: To evaluate the influence of delayed scanning on images obtained with two PSPs digital systems and on the diagnostic accuracy of vertical root fracture (VRF) by means of objective and subjective analyses. METHODOLOGY: Forty single-rooted human teeth were divided into two groups, one without VRFs and another with VRFs induced by a universal testing machine. Two digital systems (VistaScan(®) and Express(®) ) were used to radiograph all teeth, and the resulting plates were scanned at four time-points: T0-immediately, T1-30 min, T2-2 h and T3-4 h after exposure. An aluminium (Al) wedge was used to evaluate the change in mean grey values as each scan was delayed. Three observers screened all images for VRFs, and one-fourth of the sample was revaluated after thirty days. Areas under the receiver operating characteristic (ROC) curve, sensitivity, specificity and accuracy values were compared by anova. RESULTS: Intra- and interobserver agreement ranged from moderate to substantial and fair to moderate, respectively. There was no significant difference amongst scan delays with regard to sensitivity, specificity and accuracy; however, there were significant differences in the area under the ROC curve, with the 4-h delayed scan being associated with lower values compared to the others (P = 0.019). As for objective analysis, there was a significant difference amongst all different scanning time-points for the two systems (P = 0.001), except between the 30-min and 2-h delayed scans in the VistaScan(®) system. CONCLUSION: Whilst delayed scanning caused changes to the density of images acquired with the systems studied, it did not seem to interfere with VRF diagnosis except when scanning was delayed for 4 h, which should therefore be avoided.

Efficacy of lead foil for reducing doses in the head and neck: a simulation study using digital intraoral systems.

OBJECTIVES: To assess the efficacy of lead foils in reducing the radiation dose received by different anatomical sites of the head and neck during periapical intraoral examinations performed with digital systems. METHODS: Images were acquired through four different manners: phosphor plate (PSP; VistaScan(®) system; Dürr Dental GmbH, Bissingen, Germany) alone, PSP plus lead foil, complementary metal oxide semiconductor (CMOS; DIGORA(®) Toto, Soredex(®), Tuusula, Finland) alone and CMOS plus lead foil. Radiation dose was measured after a full-mouth periapical series (14 radiographs) using the long-cone paralleling technique. Lithium fluoride (LiF 100) thermoluminescent dosemeters were placed in an anthropomorphic phantom at points corresponding to the tongue, thyroid, crystalline lenses, parotid glands and maxillary sinuses. RESULTS: Dosemeter readings demonstrated the efficacy of the addition of lead foil in the intraoral digital X-ray systems provided in reducing organ doses in the selected structures, approximately 32% in the PSP system and 59% in the CMOS system. CONCLUSIONS: The use of lead foils associated with digital X-ray sensors is an effective alternative for the protection of different anatomical sites of the head and neck during full-mouth periapical series acquisition.

4% articaine buccal infiltration versus 2% lidocaine inferior alveolar nerve block for emergency root canal treatment in mandibular molars with irreversible pulpits: a randomized clinical study.

AIM: To compare the anaesthetic efficacy of inferior alveolar nerve blocks (IANB) with 1.8 mL of 2% lidocaine (LI) to a buccal infiltration (BI) with 1.8 mL of 4% articaine (AR), both with 1 : 100 000 epinephrine, in patients with symptomatic irreversible pulpits in a randomized controlled trial. METHODOLOGY: Volunteers presenting at the Emergency Centre (FOP-UNICAMP) were randomly divided into two groups (30 for AR and 20 for LI). Operator and patient were not blinded. Success was recorded when complete pain-free treatment was achieved after a single injection (IANB or BI) or when one supplemental injection was needed for emergency endodontic procedures. Success rate of supplemental injection was evaluated between and within groups using Fisher's exact test and chi-square test. RESULTS: A higher success rate (P = 0.03/Fisher's exact test) was observed with AR (40%) than with LI (10%). No significant difference was found when a single injection plus one supplemental injection was compared between groups (P = 1.0; AR = 70%; LI = 80%). However, supplemental injection increased the anaesthetic success rates (AR, P = 0.04; LI, P = 0.0001) within groups. CONCLUSIONS: Single anaesthesia techniques (IANB or BI) were not able to achieve pain-free emergency endodontic treatment. Supplemental anaesthetic techniques should be considered prior to treatment procedures in order to increase success rate (consort: registration number - NCT01912755/Fapesp: #2009/10834-4).

Influence of exposure factors on the variability of CBCT voxel values: a phantom study.

OBJECTIVES: To assess the influence of milliamperage and kilovolt peak (kVp) on the variability of cone beam CT (CBCT) voxel values. METHODS: CBCT scans were obtained from radiographic phantoms in varying concentrations of dipotassium hydrogen phosphate solutions (200-1200 mg ml(-1)) under different protocols of milliamperage and kVp. In addition, scans were performed with and without a dental implant and exo-mass. The variability of CBCT voxel values was measured on each scan, and factorial analysis of variance and the post hoc Tukey test were performed (α = 0.05). Linear regression was performed to assess the relationship between voxel value variability and dipotassium hydrogen phosphate concentration. RESULTS: milliamperage and the presence of a dental implant did not produce significant interference (p = 0.28 and 0.87, respectively) in voxel value variability. Scans at the highest kVp value presented a significant reduction (p ≤ 0.0001) in voxel value variability when only exo-mass was not present. Voxel value variability was not influenced by exo-mass in scans at the highest levels of milliamperage and kVp. The presence of exo-mass produced a significant reduction (p ≤ 0.0001) in voxel value variability in most of the scans. Higher concentrations yielded greater variations in voxel values in all scans, except for those operating at the highest levels of mAs and kVp. CONCLUSIONS: mAs did not influence the variability of CBCT voxel values; higher kVp reduced such variability when only the object was smaller than the field of view.

Relationship between orofacial function, dentofacial morphology, and bite force in young subjects.

OBJECTIVE: The aim was to evaluate the relationship between orofacial function, dentofacial morphology, and bite force in young subjects. SUBJECTS AND METHODS: Three hundred and sixteen subjects were divided according to dentition stage (early, intermediate, and late mixed and permanent dentition). Orofacial function was screened using the Nordic Orofacial Test-Screening (NOT-S). Orthodontic treatment need, bite force, lateral and frontal craniofacial dimensions and presence of sleep bruxism were also assessed. The results were submitted to descriptive statistics, normality and correlation tests, analysis of variance, and multiple linear regression to test the relationship between NOT-S scores and the studied independent variables. RESULTS: The variance of NOT-S scores between groups was not significant. The evaluation of the variables that significantly contributed to NOT-S scores variation showed that age and presence of bruxism related to higher NOT-S total scores, while the increase in overbite measurement and presence of closed lip posture related to lower scores. Bite force did not show a significant relationship with scores of orofacial dysfunction. No significant correlations between craniofacial dimensions and NOT-S scores were observed. CONCLUSION: Age and sleep bruxism were related to higher NOT-S scores, while the increase in overbite measurement and closed lip posture contributed to lower scores of orofacial dysfunction.

Comparative diagnostic yield of cone beam CT reconstruction using various software programs on the detection of vertical root fractures.

OBJECTIVES: To evaluate the effect on diagnostic yield in the detection of experimentally induced vertical root fractures on cone beam CT images using four dental software program. METHODS: 190 single-rooted extracted human teeth were divided into three groups according to the pulp canal status: unrestored (UR), filled with gutta-percha (GP) and restored with a metallic custom post (Post). One-half of the sample of each group was artificially fractured and the segments repositioned. All teeth were scanned on a cone beam CT device at 0.2 mm nominal voxel resolution (i-CAT Platinum; Imaging Sciences International, Hatfield, PA). The data were exported as digital imaging and communications in medicine files and imported into Dolphin Imaging & Management Solutions, v. 11.5 (Patterson Dental Supply Inc., St Paul, MN), InVivoDental, v. 5.0 (Anatomage Inc., San Jose, CA) and Kodak Dental Imaging Software 3D module, v. 2.1.11 (Carestream Health Inc., Rochester, NY) software. Cross-sectional images in the acquisition (using Xoran CAT™, v. 3.0.34 software; Xoran Technologies, Ann Arbor, MI) and additional software were presented to three calibrated oral radiologists who rated the presence or absence of root fracture on a five-point scale. Receiver operating characteristic analysis was performed, and treatment comparisons compared by analysis of variance and pairwise comparisons were performed using Tukey's test at an a priori value of α < 0.05%. RESULTS: All dental software performed equally at detecting fractures. Fractures were significantly more difficult to detect when posts were present. CONCLUSIONS: The diagnosis of root fracture is software-independent. The presence of an intracanal metallic post significantly decreases the detection of artificially created root fractures.

Performance of a photostimulable storage phosphor digital system with or without the sharpen filter and cone beam CT for detecting approximal enamel subsurface demineralization.

OBJECTIVES: The aim of this study was to assess the performance of photostimulable storage phosphor (PSP) radiographs with or without using the sharpen filter and cone beam CT (CBCT) for detecting enamel subsurface demineralization. METHODS: Enamel subsurface demineralization was induced on one of the approximal surfaces of 120 sound human teeth. Standardized images of all teeth were acquired after the demineralization phase using the Digora(®) Optime (Orion Corp./Soredex, Helsinki, Finland) (PSP) and the i-CAT™ (Imaging Sciences International, Hatfield, PA) (CBCT) systems. Three calibrated observers interpreted the images using a five-point scale (1, demineralization definitely absent; 2, demineralization probably absent; 3, unsure; 4, demineralization probably present; and 5, demineralization definitely present). Diagnoses were validated by cross-sectional microhardness profiling in the test areas of the approximal surfaces. Interobserver agreement was analysed using kappa statistics. Accuracy was estimated by the areas under the receiver operating characteristic curves (Az), which were compared using the Kruskal-Wallis test (α = 5%). RESULTS: Interobserver agreement was higher for CBCT (κ = 0.7-0.8), followed by sharpen-filtered (κ = 0.6-0.7) and original (κ = 0.5-0.6) images. CBCT presented the highest accuracy value (Az = 0.897) compared with the original (Az = 0.792) and sharpen-filtered (Az = 0.712) images. However, no statistical differences were observed between the imaging modalities (p = 0.0794). CONCLUSIONS: It can be concluded that PSP radiographs with or without using the sharpen filter and the CBCT images may be useful adjuncts for detecting subtle approximal enamel demineralization.

Magnetic resonance imaging findings of true bifid mandibular condyle with duplicated mandibular fossa.

Bifid mandibular condyle (BMC) is a rare asymptomatic morphological alteration with no predilection for age group or gender. Its morphology varies from a shallow groove to two condylar heads with separate necks, oriented mediolaterally or anteroposteriorly. This report describes an unusual case of anteroposterior bifid condyle in a 39-year-old female patient with the main complaint of mouth-opening limitation and a deviation of the mandible to the left side. Magnetic resonance imaging (MRI) findings revealed a bifid condyle on the left side and duplicated mandibular fossa, with the articular disc over the anterior head. The MRI images in the open-mouth position revealed minimal movement of the condyle. Despite the increased number of mediolateral bifid mandibular condyle cases described in the literature, none of previously reported cases of BMC included an anteroposterior bifid condyle case with two distinct mandibular fossa.

Correlation of panoramic radiography and cone beam CT findings in the assessment of the relationship between impacted mandibular third molars and the mandibular canal.

OBJECTIVES: The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images. METHODS: The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated. RESULTS: Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05). CONCLUSION: Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case.

Evaluation of reconstructed images with different voxel sizes of acquisition in the diagnosis of simulated external root resorption using cone beam computed tomography.

AIM: To evaluate the diagnosis of simulated external root resorption in cone beam computed tomography (CBCT) images acquired with different voxel sizes, then reconstructed with the same voxel size. METHODOLOGY: Buccal, mesial and distal root surfaces of twenty single-rooted premolar teeth were evaluated for the presence or absence of simulated resorption defects. Images were obtained using a Classic i-CAT CBCT unit with two different voxel sizes (0.25 and 0.30 mm). Then all images were reconstructed to 0.25 mm voxel size. The McNemar's test was applied to evaluate the agreement between the two protocols (different voxel sizes/reconstruction parameters) with the gold standard (defects created in the root). Accuracy, sensitivity, specificity, positive and negative predictive values were calculated for each voxel and defect sizes. RESULTS: Better sensitivity and accuracy were obtained with 0.25 (0.25 mm) voxel size. Specificity, positive and negative predictive values were highest with the 0.25 (0.30 mm) voxel size. McNemar's test results revealed significant differences between the protocols with the gold standard (P < 0.0001). The results revealed that as the cavity size increased, sensitivity, accuracy, positive and negative predictive values also increased. When correlating the voxel size and root third, better sensitivity, accuracy, positive and negative predictive values were obtained in the middle third. CONCLUSIONS: In the diagnosis of simulated external root resorption with the Classic i-CAT CBCT unit, images acquired with 0.30 mm voxel size and reconstructed with 0.25 mm voxel size provided the best protocol with a lower radiation dose than the 0.25 mm voxel size.

Efficacy of several digital radiographic imaging systems for laboratory determination of endodontic file length.

AIM: To compare the efficacy of different digital radiographic imaging systems for determining the length of endodontic files. METHODOLOGY: K-type endodontic files were introduced into the canals of 40 extracted human permanent single-rooted teeth and fixed in place at random lengths. The teeth were radiographed using Digora Optime, CygnusRay MPS and CDR Wireless digital imaging systems. Six observers measured every file length in all the images and repeated this procedure in 50% of the image samples, and assigned a score to the level of difficulty found. Analysis of variance for differences between digital systems and Tukey's test were performed. The level of intraobserver agreement was measured by intraclass correlation. The assigned scores were evaluated by Kruskal-Wallis and Dunn's tests. RESULTS: The CDR Wireless values did not differ significantly from the actual lengths and the CygnusRay MPS values. The Digora Optime system was significantly different from the others and overestimated the values (P ≤ 0.05). The Digora Optime was significantly easier to use for taking measurements and the CygnusRay MPS the most difficult (P ≤ 0.05). All digital radiographic imaging systems showed excellent agreement with the Intraclass Correlation Coefficient >0.95. CONCLUSIONS: The three digital radiographic imaging systems were precise. The CDR Wireless system was significantly more accurate in determining endodontic file lengths, and similarly to Digora Optime, was considered the least difficult to use when assessing endodontic file lengths.

Comparison of digital systems and conventional dental film for the detection of approximal enamel caries.

OBJECTIVES: The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries. METHODS: 160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman's rank correlation coefficient. RESULTS: Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06). CONCLUSIONS: The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.

Radiodensity and hardness of enamel and dentin of human and bovine teeth, varying bovine teeth age.

Studies have evaluated dental hard tissues characteristics from animal species in order to be used as a substitute for human teeth. The aim of this study was to evaluate the radiodensity and hardness of human and bovine enamel and dentin, varying bovine teeth age. Five specimens (1mm thick) were obtained from animals aged 20 (B20), 30 (B30), 38 (B38) and 48 (B48)months and from 20 to 30-years-old human third molars (H). The radiographic images were taken with a phosphor plaque digital system (Digora Optime). The radiodensity was obtained and Knoop hardness (KHN) was recorded (100g for 15s--5 indentations per specimen). Data were analyzed by one-way ANOVA following Tukey's HSD test and Dunnet's two-sided t-test. Radiodensity was similar within enamel groups, but bovine dentin presented higher radiodensity than human one regardless of age groups. Enamel-KHN showed differences between B20-B30 and B38-B48-H, and dentin-KHN was similar within all groups. Enamel was always more radiodense than dentin and also presented higher KHN (p=0.001). The use of bovine enamel or dentin should take into consideration the teeth age, but as a general rule it should be recommended to select older bovine teeth due to better chances to find greater similarity with human teeth.

Comparison of transcranial radiograph and magnetic resonance imaging in the evaluation of mandibular condyle position.

OBJECTIVES: Several image modalities have been used to assess the condylar position in the glenoid fossa. However, despite the development of more advanced techniques for imaging the temporomandibular joint (TMJ), the transcranial projection remains widely used in dentistry. The purpose of this study was to compare the condylar position in transcranial radiography (TRANS) with MRI. METHODS: 70 matched pairs of TMJs (35 patients) who had undergone TRANS and MRI were evaluated. The TRANS scans were compared with the lateral, central and medial MRI scans, and the condylar position was assessed in the closed and open mouth position according to subjective and objective methods. The sensitivity, specificity and accuracy values were calculated for each group and Bowker's test was used to analyse the data. RESULTS: There was no statistical significance between TRANS and MRI (P > 0.05). However, even though there were similar mean values between them, the comparison with the lateral image showed higher values, which might be due to TRANS representing the lateral one-third of the condyle. CONCLUSIONS: It can be concluded that TRANS seems to be an acceptable method and its applicability as an adjunctive method in the condylar position should not be rejected.

The prevalence of bifid mandibular condyle detected in a Brazilian population.

OBJECTIVES: To determine the prevalence of bifid mandibular condyle (BMC) detected on panoramic radiographs in a Brazilian population. METHODS: The panoramic radiographs of 50 080 radiographs taken from 1999 to 2006 were retrospectively reviewed in order to identify BMC cases. RESULTS: 9 (0.018%) of the 50 080 patients, 2 men and 7 women, with age ranging from 20 years to 74 years, had BMC. These conditions were unilateral in 7 (78%) subjects and bilateral in 2 (22%) subjects. All patients denied a history of any previous trauma or fracture of the mandible, pain, or trismus. CONCLUSIONS: BMC is an uncommon finding in a group of Brazilian subjects and, although it is rare, dentists should be aware of this condition on routine panoramic radiographs and its implications for function and appropriate treatment modalities.

Diagnostic accuracy of cone beam computed tomography scans compared with intraoral image modalities for detection of caries lesions.

OBJECTIVES: The aim was to compare the caries diagnostic accuracy of two cone beam CT systems (CBCT) with two intraoral receptors, one digital and one film. METHODS: 100 non-cavitated extracted human teeth were placed with approximal contacts: each row of teeth comprised 1 canine, 1 first and second premolar, and 1 first and second molar. Radiographs of each tooth were recorded using two intraoral modalities: Digora-fmx (Soredex) and film (Kodak Insight), and two CBCT systems: NewTom 3G (Quantitative Radiology) in three fields of view (FOVs): pixel size of 0.36 mm (FOV 12 inches), pixel size of 0.25 mm (FOV 9 inches), pixel size of 0.16 mm (FOV 6 inches); and 3DX Accuitomo (Morita), pixel size of 0.125 (FOV 4 cm). The volumetric data from the CBCT systems were reconstructed and sectioned (0.5 mm) in the mesiodistal tooth plane. Six observers scored approximal and occlusal surfaces for the detection of caries lesions. The teeth were clinically sectioned and microscopy served as the validation tool. Two-way ANOVA tested differences in sensitivity, specificity and overall true score (true positives plus true negatives) between the modalities. RESULTS: Microscopy of approximal surfaces found 63% sound, 31% enamel and 6% dentin lesions; of occlusal surfaces, 6% sound, 59% enamel, 19% dentin lesions and 16% had fillings. For approximal surfaces, NewTom 12 inch and 9 inch images had significantly lower sensitivities than Accuitomo (P < 0.02); and NewTom 9 inch and 6 inch had significantly lower specificities than film and Digora-fmx (P < 0.04). Accuitomo images were not significantly different from film or Digora-fmx images for any of the tested variables (P > 0.2). For occlusal surfaces, the Accuitomo presented a higher sensitivity than the other systems. Specificity and overall true score did not differ (P > 0.06) among the modalities. CONCLUSIONS: In conclusion, the NewTom 3G CBCT had a lower diagnostic accuracy for detection of caries lesions than intraoral modalities and the 3DX Accuitomo CBCT. The Accuitomo CBCT had a higher sensitivity than the intraoral systems for detection of lesions in dentin, but the overall true score was not higher.

Tonsillolith--report of an unusual case.

Tonsilloliths are rare concretions found in the tonsillar crypt. They are usually single and unilateral, but occasionally may be multiple or bilateral. This report describes a case of a 47-year-old woman whose radiography revealed one radiopaque image located in the right ramus of the mandible. The patient revealed a history of slight dysphagia, halitosis and swallowing pain with a foreign body sensation. Her medical history revealed a tonsillectomy when she was eight years old and the removal of the uvula because of sleep apnoea six years ago. Computer tomography showed a delimited and calcified oval image measuring 0.6 x 0.6 cm. The tonsillar concretion might have been formed because of a calcification of the lymphoid tissue. On the patient's request, surgical excision was not performed and she will be monitored due to the tendency of such lesions to grow.

Kartagener syndrome.

Kartagener syndrome (KS), an autosomal recessively inherited disease, is characterized by the triad of situs inversus, bronchiectasis and sinusitis. This disorder affects the activity of proteins important to the movement of cilia, especially in the respiratory tract and the spermatozoa, developing a series of systemic alterations, which can be diagnosed through radiographic examination. The aim of this paper is to describe a clinical case of this unusual pathology, including a brief literature review, emphasising the radiographic aspects of this pathology and stressing the importance of early diagnosis, which could be determined by an oral radiologist.