Primary Hyper-IgE-Related Salivary Gland Disease: A New Disease Entity.

OBJECTIVES: To clarify the clinicopathological characteristics of primary hyper-IgE-related salivary gland disease (PHIESD), which is a newly proposed entity. METHODS: Fifteen consecutive patients pathologically diagnosed with chronic sialadenitis were enrolled, and their clinicopathological features were comprehensively analyzed. INCLUSION CRITERIA: (1) multiple salivary gland enlargement; (2) elevated serum IgE and/or IgE-positive cell infiltration in salivary gland tissues; (3) histology-confirmed lymphoplasmacytic infiltration; (4) exclusion of other known diseases. RESULTS: The male-to-female ratio was 5:10. The median age was 21 (range, 3-63) years. The average number of affected glands was 3.7 ± 1.4. Submandibular, parotid, and sublingual glands were involved in 15, 8, and 2 patients, respectively. Comorbid diseases included allergic diseases in seven patients and autoimmune diseases in two. Elevated serum IgE (median 175 kU/L) was seen in all patients. Serum IgG4 was slightly elevated in three patients. Histologically, most patients had mild lesions, including mild lymphocyte infiltration (60%) and focal fibrosis (66.7%). Lymphoid follicular formation (53.3%), moderate to severe lymphocytic inflammation (40%) and severe fibrosis (33.3%) were also observed. Immunohistochemically, IgE-positive cells infiltrated mainly around the ducts, with scattered infiltration of IgG4-positive, mast, and interleukin-4 positive cells. During follow-up (median, 46 months) of ten patients without intervention and two with immunosuppressive therapy, no significant changes in gland size or serum IgE level were noted. CONCLUSIONS: PHIESD manifests as homogeneous enlargement of multiple salivary glands and elevated serum IgE. Histopathology further verifies the diagnosis. It might be associated with anaphylaxis or autoimmune dysfunction. Conservative treatment is suggested. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:2132-2138, 2022.

Circular RNA expression profiling identifies specific circular RNAs in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral cancer associated with high malignancy. Circular RNAs (circRNAs) are a form of non­coding RNA with stable and conserved expression in mammalian cells. The aim of the present study was to investigate circRNAs expression profiles in TSCC, and examine the roles and potential mechanisms of circRNA­081069 (circ_081069). A high­throughput circRNA microarray analysis of tumor samples and adjacent normal tissues from four patients with TSCC was performed. Bioinformatic analysis was conducted to screen the differentially expressed circRNAs. Reverse transcription­quantitative PCR was performed to confirm the microarray results. A migration assay and proliferation assay were performed to detect the migratory and proliferative ability of TSCC cells. A luciferase assay was conducted to investigate the interaction between circ_081069 and microRNA (miRNA/miR)­665. In total, 335 circRNAs were found to be differentially expressed in tumor tissues. Among them, 59 were upregulated and 276 were downregulated (P<0.05; fold change ≥2 or ≤0.5). A total of seven circRNAs, including two upregulated and five downregulated circRNAs, were further confirmed using quantitative PCR analysis in the ten paired TSCC tissues and adjacent normal tissues. The present study showed that circRNA_081069 promoted the migratory and proliferative ability of TSCC cells in vitro. Furthermore, the potential circRNA­miRNA interactions were predicted, and the present results identified miR­665 as a miRNA target of circ_081069. The present results suggested that circRNAs may be involved in TSCC development, and understanding the interaction between circ_081069 and miR­665 may facilitate the development of novel diagnostic and therapeutic targets for TSCC.

Prevalence and Morphology of Mandibular Incisive Canal: Comparison among Healthy, Periodontitis and Edentulous Mandibles in a Population of the Beijing Area Using Cone-beam Computed Tomography.

OBJECTIVE: To evaluate and quantify the prevalence and morphology of the mandibular incisive canal (MIC) comparatively among healthy, periodontitis and edentulous mandibles using cone-beam computed tomography (CBCT). METHODS: CBCT images of 1,070 hemimandibles from 535 consecutive patients, including 448 with healthy dentition, 42 with severe periodontitis mandibles and 45 with edentulous mandibles, were retrospectively analysed. MICs were identified, and linear measurements were performed. Statistical analyses were conducted to investigate differences in the prevalence and morphology of MICs relative to gender, laterality, age group and dental status. RESULTS: The MIC was observed in 92.8% of 1,070 hemimandibles. No significant differences of MIC prevalence were found between left and right sides, or between healthy and periodontitis mandibles. However, males had a higher prevalence of MIC than females, and patients with dentate mandibles had a higher prevalence of MIC than those with edentulous mandibles. For dentate mandibles, MICs started most commonly below the first premolar (51.9%) and ended around the canine (58.5%). The mean diameter of MIC was 2.5 ± 0.5 mm at origin, and 20.6% of MICs began with a diameter of ≥ 3 mm. The mean length of MIC was 13.4 ± 3.3 mm. The mean distances from the MIC to the labial cortex, lingual cortex, alveolar ridge and inferior border of mandible were 3.7 ± 0.9, 5.1 ± 1.6, 19.5 ± 3.8 and 8.9 ± 1.7 mm, respectively. Moreover, significant differences of measurements were found relative to gender, age group, and dental status. CONCLUSION: Due to the large variations in size and course of MICs, special caution should be exercised in any individual surgery affecting the anterior mandible.

Ultrasonographic Features of Immunoglobulin G4-Related Sialadenitis.

The aim of this study was to determine the role of ultrasonography in the diagnosis and follow-up evaluation of immunoglobulin G4-related sialadenitis. In this study, 42 patients with immunoglobulin G4-related sialadenitis underwent ultrasonography of the parotid and submandibular glands, and the sonographic appearance was compared with the pathologic findings. Post-treatment ultrasonographic appearance was compared with the pre-treatment findings in 30 patients who received immunomodulatory therapy. The ultrasonographic appearance of the affected glands was divided into five patterns: superficial hypo-echoic, multiple hypo-echoic foci, whole-gland heterogeneity, space occupying and normal echo. Histopathologic examination revealed marked lymphoplasmacytic inflammation and inter-lobular fibrosis, which were more severe in the superficial than deep portion of the affected glands. After treatment, the volume of the affected gland decreased significantly, the internal echo became more homogeneous and the superficial hypo-echoic area disappeared or was reduced. In conclusion, ultrasonography may play an important role in the diagnosis and follow-up evaluation of immunoglobulin G4-related sialadenitis.

Cheek fistula from the ectopic salivary gland: a variant of the oculo-auriculo-vertebral spectrum.

OBJECTIVES/HYPOTHESIS: This study aimed to investigate the diagnosis and management of a distinct developmental deformity syndrome characterized by congenital cheek fistula, ectopic accessory parotid gland, and preauricular appendage. STUDY DESIGN: Retrospective study. METHODS: We analyzed the medical records, radiologic and histopathologic findings, and follow-up data for seven patients (four males) with a congenital cheek salivary fistula. Computed tomography, fistulography, and sialography had been performed for diagnosis. Surgical treatment effect was evaluated. RESULTS: The mean age of the patients was 8.1 years (range, 2-16 years). The distinctive clinical feature was a congenital skin orifice lateral to the commissure with saliva discharge during eating. The cheek fistulae were accompanied by ipsilateral preauricular appendages in all seven patients. The skin orifice connected to an ectopic gland anterior to the masseter and inferior to Stensen's duct. Parotid sialography demonstrated an intact Stensen's duct in all cases. Hypoplasia of the ipsilateral mandible could be observed in five cases. Excision of the ectopic gland, skin orifice, and fistula was performed in five cases resulting in optimal treatment outcomes with no recurrent or adverse events. CONCLUSIONS: A congenital saliva-discharging fistula with an ectopic accessory parotid gland, ipsilateral preauricular appendage, and mandibular hypoplasia constitutes a rare developmental syndrome. Surgical excision can effectively treat congenital cheek salivary fistula. LEVEL OF EVIDENCE: 4.

[Sialoendoscopy-assisted sialolithectomy for large parotid stones].

OBJECTIVE: To explore the clinical application of endoscope-assisted operative retrieval of large parotid stones as a minimally invasive alternative. METHODS: From January 2010 to April 2013, 6 patients (male: 5, female: 1, age from 30-62 years, and median age: 49.5 years)suffering from recurred swelling of parotid gland due to sialoliths were treated by endoscope-assisted parotid surgery in Peking University School and Hospital of Stomatology. All of the patients underwent clinical, ultrasonographic and cone-beam CT (CBCT) examinations to get the detailed information of the number, location and size of stones, which was recorded in the medical records. endoscope-assisted parotid surgery was performed under general anesthesia in all the 6 cases after the failure of basket or forcep retrieval firstly. During the operation, sialoendoscope was used to locate the stone exactly and then the calculus was exposed through a pre-auricular approach and released by incising the duct. The postoperative complications were recorded and observed during the follow-up periods. RESULTS: Preoperative radiological examinations showed that all of the sialoliths were near the hilum of parotid gland ducts in the 6 cases, which were 5-9 mm in diameter. All of the stones were removed successfully by endoscope-assisted operative retrieval. The incisions healed smoothly in all the 6 cases. There were no cases of facial nerve weakness, infection or salivary fistula. After a mean follow-up of 19 months (ranging from 6-36 months), 5 patients remained asymptomatic and 1 patient had mild obstructed or infective symptoms. The final results were satisfied. CONCLUSION: It is suggested that endoscope-assisted operative retrieval is a viable minimally invasive alternative to remove the large or recalcitrant parotid stones with a high successful rate and low complications.

Sialoendoscopy-assisted sialolithectomy for submandibular hilar calculi.

PURPOSE: To assess the clinical effects of endoscopy-assisted sialolithectomy for submandibular hilar calculi. MATERIALS AND METHODS: The present study was undertaken in 70 patients with symptomatic stones in the hilum of submandibular glands who underwent endoscopy-assisted sialolithectomy from December 2005 through March 2011 in the Peking University School and Hospital of Stomatology. The operative data were analyzed retrospectively. All patients were followed periodically postoperatively. Submandibular gland function was investigated by postoperative symptoms, clinical examinations, sialography, and scintigraphy. RESULTS: Submandibular stones were successfully removed in 65 patients, with a success rate of 92.9%. Temporary lingual nerve injury occurred in 1 patient. Two patients developed ranulae and underwent an uneventful sublingual gland excision. During a mean follow-up of 23 months (range, 6 to 55 mo), 52 of 65 patients were symptom free, whereas 11 patients complained of occasional swelling of the affected gland at mealtimes and 2 patients developed a recurrent stone. Thirty patients underwent postoperative sialography. The sialographic appearances included 4 types: 1) approximately normal; 2) the main duct was significantly dilated at the hilum, but no persistent contrast was seen on the functional film; 3) the main duct was significantly dilated in the hilar region, and persistent contrast was seen at the dilated hilum of the functional film; 4) the main duct was dilated or strictured, and persistent contrast was seen on the functional film. Three of the 4 patients who underwent scintigraphy exhibited good function. CONCLUSIONS: Sialoendoscopy-assisted sialolithectomy is a safe and effective gland-preservation technique for patients with hilar stones of the Wharton's duct.

[Core needle biopsy in the diagnosis of oral and maxillofacial tumors].

OBJECTIVE: To summarize and evaluate the utility of core needle biopsy in diagnosis of head neck tumors. METHODS: Lesions were performed with core needle biopsy in 47 patients who were considered with tumors or other diseases in the head neck. According to the pathological diagnoses, their treating plans were made. If the pathological results could not give definite diagnoses and the lesions were considered tumors or other diseases, then operation or another biopsy was needed and, the other patients could be followed-up. The accurate rate was calculated. RESULTS: The biopsy tissue was enough for pathological diagnosis and immunohistochemical staining. Compared with the pathological results and follow-up, positive diagnosis was in 36 cases, negative diagnosis in 9 cases, false-negative in 2 cases, and the accurate rate was 95.7%. The pathological results had guided the treatment in 43 patients, accounting for 91.5%. No serious side effects were found. CONCLUSION: The core needle biopsy is significant for diagnosis and treatment of head neck tumors.

[Diagnostic accuracy of cone beam computed tomography and eight-slice computed tomography for evaluation of external root reabsorption].

OBJECTIVE: To evaluate the diagnostic accuracy of cone beam computed tomography (CBCT) and high resolution multi-slice computed tomography (MSCT) with eight-detector-rows in detecting the simulated external root resorption defects. METHODS: External root resorption defects of different sizes and in different locations were simulated in 40 human single rooted teeth. Cavities simulating root resorption defects of 1 mm in diameter and 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm in depth were drilled in the cervical, middle and apical thirds of lingual surfaces of the teeth. The specimens were scanned with both CBCT (Accuitomo 3DX, Morita Co., Japan) and high resolution 8-slice CT (BrightSpeed Edge, GE Co., USA). The CBCT and MSCT images were read by two experienced observers. The data were analyzed with receiver operating characteristics (ROC) analysis. ROC curves were generated and the area under ROC curve (Az) was employed to express the diagnostic accuracy. RESULTS: The diagnostic accuracy (Az value) in detecting the simulated defects of all the locations and sizes were 0.921 for CBCT and 0.770 for MSCT. The Az values for CBCT in detecting defects located in the cervical, middle and apical thirds were 0.885, 0.991 and 0.873, while those for MSCT were 0.752, 0.844 and 0.709, respectively. The Az values for CBCT in detecting the defects of 0.1 mm, 0.2 mm, 0.3 mm and 0.4 mm in depth were 0.794, 0.934, 0.992 and 0.992, and those for MSCT were 0.592, 0.719, 0.920 and 0.990, respectively. CONCLUSION: The diagnostic ability for external root resorption of CBCT is better than that of MSCT. Smaller defects are better delineated with CBCT than with MSCT. The defects in the middle thirds of the roots are easier to be detected than those in the cervical and apical ones using both CBCT and MSCT.

[Sialoendoscopically-assisted sialolithectomy for the hilar stones of the Wharton's duct].

OBJECTIVE: To investigate the clinical effects of sialoendoscopically-assisted sialolithectomy for the sialolithiasis in the hilum of the submandibular glands. METHODS: Between December 2005 and March 2011, treated 80 cases of radiography-verified sialiolithiasis in the hilum of the submandibular glands, The patients included 42 males and 38 females aged from 13 to 68 years. All these patients underwent sialoendoscopic observation and sialoendoscopically-assisted sialolithectomy and were followed up periodically for 3 - 6 months after operation. The success rate of stone removal, postoperative complications and clinical effects were analysed. RESULTS: The stones were completely removed in 71 cases, and almost completely removed in 5 cases, with a successful rate of 95% (76/80). Among 76 successful cases, 8 were treated by basket entrapment, 59 by intraoral open surgery and 9 by both of these two techniques. Within 3 - 6 months' follow-up, 1 case suffered temporary lingual nerve parenthesis and two suffered ranula formation. CONCLUSIONS: Sialoendoscopically-assisted sialolithectomy is a safe and effective gland-preservation technique for the patients with the hilum of the submandibular glands.

Measurement accuracy of temporomandibular joint space in Promax 3-dimensional cone-beam computerized tomography images.

OBJECTIVE: The aim of this study was to evaluate and compare the measurement accuracy of the temporomandibular joint (TMJ) space in the Promax 3D cone-beam computerized tomography (CBCT) images scanned with 2 different dental protocols. STUDY DESIGN: TMJ space impression models were made according to the occlusion. Forty joints were scanned with the standard and the large view protocol of the Promax 3D CBCT scanner. Two observers measured the joint spaces 3 times on both radiographs and the photocopies of the impression models. RESULTS: A total of 120 CBCT images were measured. There were no significant differences among the actual joint spaces and the CBCT measurements performed with the 2 scanning protocols (P = .305). The inter- and intraobserver variabilities were not significant. CONCLUSIONS: The 2 scanning protocols provided by the Promax 3D CBCT scanner were reliable and similar for recording the TMJ space.

[Detection accuracy of occlusal caries by cone-beam computed tomography images scanned with different parameters].

OBJECTIVE: To compare the detection accuracy of occlusal caries in cone-beam computed tomography (CBCT) images scanned with different scanning parameters. METHODS: Thirty-seven extracted human premolars and molars without restorations or obvious cavities were selected for this study. The teeth 3 or 4 as a group were mounted in 12 plaster blocks and scanned with DCT Pro (VATECH, Co., Ltd., Yongin-Si, S.Korea) at normal and high resolution settings and with ProMax 3D (Planmeca Oy, Helsinki, Finland) at low, normal and high resolution settings. In addition, the tooth blocks were imaged with the ProMax 3D at three different tube currents. Ten doctoral candidates of Peking University School and Hospital of Stomatology evaluated all the images of the tooth blocks using a five-level confident scale. Actual presence and the extent of caries were established by histological examinations. The areas under the ROC curves (Az value) were analyzed. RESULTS: Eleven (29.7%, 11/37) teeth were sound, 13 (35.1%, 13/37) had enamel caries and 13 (35.1%, 13/37) had dentine caries. There were no significant differences between normal resolution and high resolution for DCT Pro on the detection accuracy of occlusal (enamel+dentine) caries (0.698 ± 0.064 vs. 0.735 ± 0.044, P>0.05).No significant differences were found for ProMax 3D among low, normal and high resolution (0.700 ± 0.031 vs. 0.700±0.054 vs. 0.701 ± 0.041, P>0.05). For dentinal caries, there were no significant differences between CBCT images scanned with different resolutions for DCT Pro(0.776 ± 0.078 vs. 0.811 ± 0.047, P>0.05) or ProMax 3D (0.713 ± 0.039 vs. 0.685 ± 0.063 vs. 0.713 ± 0.040, P>0.05). No significant differences were found for enamel caries detection for DCT Pro (0.620 ± 0.068 vs. 0.659 ± 0.048, P>0.05)or ProMax 3D (0.686 ± 0.050 vs. 0.685 ± 0.063 vs. 0.689 ± 0.063, P>0.05). For ProMax 3D, there were no significant differences among different tube currents on the detection accuracy of occlusal caries (0.653 ± 0.065 vs. 0.700 ± 0.054 vs. 0.67 ± 0.062, P>0.05). CONCLUSION: Different resolutions did not have an impact on the detection accuracy of occlusal caries. The tube currents for ProMax 3D did not show any effect on occlusal caries detection.

Detection accuracy of proximal caries by phosphor plate and cone-beam computerized tomography images scanned with different resolutions.

This study was carried out to assess whether the spatial resolution has an impact on the detection accuracy of proximal caries in flat panel CBCT (cone beam computerized tomography) images and if the detection accuracy can be improved by flat panel CBCT images scanned with high spatial resolution when compared to digital intraoral images. The CBCT test images of 45 non-restored human permanent teeth were respectively scanned with the ProMax 3D and the DCT Pro scanners at different resolutions. Digital images were obtained with a phosphor plate imaging system Digora Optime. Eight observers evaluated all the test images for carious lesion within the 90 proximal surfaces. With the histological examination serving as the reference standard, observer performances were evaluated by receiver operating characteristic (ROC) curves. The areas under the ROC curves were analyzed with two-way analysis of variance. No significant differences were found among the CBCT images and between CBCT and digital images when only proximal enamel caries was detected (p = 0.989). With respect to the detection of proximal dentinal caries, significant difference was found between CBCT and digital images (p < 0.001) but not among CBCT images. The spatial resolution did not have an impact on the detection accuracy of proximal caries in flat panel CBCT images. The flat panel CBCT images scanned with high spatial resolution did not improve the detection accuracy of proximal enamel caries compared to digital intraoral images. CBCT images scanned with high spatial resolutions could not be used for proximal caries detection.

[Combined external radiotherapy and 125I-particle implantation for treatment of head and neck cancers].

OBJECTIVE: To evaluate the relative incidence of local control and toxicity in patients with head and neck cancers who underwent external beam radiotherapy (EBRT) plus (125)I seeds implantation. METHODS: Ten patients diagnosed as head and neck cancers at the department of oral and maxillofacial surgery of Peking University School of Stomatology during the period of February 2008 to July 2010 were collected. The histologic types included squamous cell carcinoma in 8 patients, poorly differentiated adenocarcinoma of salivary gland in 2 patients. All patients could not receive surgical treatment due to poor medical status or unresectable advanced-stage tumors and underwent EBRT plus (125)I seeds implantation. Eight patients with squamous cell carcinoma had conventional fractionated EBRT with a total dose of 50 Gy; two patients with poorly differentiated adenocarcinoma had conventional fractionated EBRT with a total dose of 70 Gy. They all then had (125)I seeds implantation with matched peripheral dose of 60 Gy (TNM stage I-II) or 80 Gy (TNM stage III-IV ). The apparent activity per seed ranged from 25.9 to 29.6 MBq. follow-up of the patients was done to analyze acute and late toxicity, local control, and survival. RESULTS: After a median follow-up of 12 months (range 2-28 months), soft tissue necrosis was seen in one patient, dysphagia and hemorrhage in another. No other serious side effects were observed. All the tumor mass of 10 cases disappeared within 6 months, regional metastases was observed in one patient, and distant metastases was observed in another. Seven of 10 patients survived till the date of investigation. CONCLUSION: External beam radiotherapy plus (125)I seeds implantation is a safe and effective therapy regimen for patients with unrectable head and neck cancers.

Investigation of the clinical and radiographic features of osteoarthrosis of the temporomandibular joints in adolescents and young adults.

OBJECTIVE: The objective of this study was to investigate the clinical and radiographic features of osteoarthrosis (OA) of the temporomandibular joints (TMJOA) in human adolescents and young adults. STUDY DESIGN: Patients (n = 4883) with temporomandibular disorders (age, 11 to 30 years) underwent clinical and radiographic examinations. The radiographic findings were classified as erosive bony changes, proliferative changes mainly, including flattening with uneven sclerosis, and osteophytes of the condyle, and bilaterally short condylar processes. In addition, we interpreted the reassessment radiographs of 156 of the patients. RESULTS: Seven hundred eleven patients had radiographic signs of OA. The frequency of OA was higher in women (563/3360, 16.8%) than in men (148/1523, 9.7%). Most patients (541/711, 76.1%) with signs of OA showed proliferative changes of OA. Moreover, 56.4% of patients with TMJOA (88/156) remained stable. CONCLUSIONS: These results suggest that although OA is an age-related disease, aging is not the crucial factor in the pathogenesis of OA.

The detection accuracies for proximal caries by cone-beam computerized tomography, film, and phosphor plates.

OBJECTIVES: To evaluate the accuracy of cone-beam computerized tomography (CBCT) for the detection of noncavitated proximal caries and to compare the detection accuracies of 2 CBCT imaging systems with those based on plain-film radiographs and phosphor-plate images. STUDY DESIGN: Test radiographs of 39 noncavitated unrestored human permanent teeth were obtained with film, phosphor-plate, ProMax 3D, and Kodak 9000 3D imaging systems. Seven observers used a 5-level scale to evaluate test images for the presence of proximal caries. With histologic examination serving as the reference standard, observer performances were assessed with receiver operating characteristic (ROC) curves, and the areas under the ROC curves (A(z) values) for the observers, and modalities were analyzed with a repeated-measures analysis of variance. RESULTS: The mean A(z) values for film, phosphor plates, ProMax 3D, and Kodak 9000 3D imaging systems were 0.541, 0.523, 0.528, and 0.525, respectively (P = .763). CONCLUSION: For detecting subtle noncavitated proximal caries, the detection accuracy with the CBCT images was little better than chance performance and was similar to that with phosphor plate- and film-based intraoral images.

[Comparative dosimetry of dental cone-beam computed tomography and multi-slice computed tomography for oral and maxillofacial radiology].

OBJECTIVE: To compare the effective radiation dose levels of cone beam computed tomography (CBCT) with those of multi-slice computed tomography (MSCT) when scanning the same maxillofacial regions. METHODS: The effective doses of 2 CBCT (NewTom 9000 and DCT Pro) and 1 MSCT (bright speed edge select 8 slice) scanners were calculated using thermoluminescent dosimeters (TLD) that were placed in a head and neck phantom, and expressed according to the International Commission on Radiation Protection (ICRP) 2007 guidelines. RESULTS: Effective dose values ranged from 41.8 to 249.1 µSv for CBCT. The doses of MSCT scanning for maxilla, mandible and maxilla + mandible were 506.7, 829.9 and 1066.1 µSv, respectively. Dose levels of scanning only for maxilla or mandible were significantly lower than those for maxilla + mandible. CONCLUSIONS: When scanning the same maxillofacial regions, the dose levels for NewTom 9000 and DCT Pro CBCT images were lower than those for Bright speed edge select 8 slice MSCT images. Dose levels reduction could be obtained when smaller regions were scanned.

Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols.

OBJECTIVES: The aim of this study was to compare effective doses resulting from different scan protocols for cone-beam computerized tomography (CBCT) using International Commission on Radiological Protection (ICRP) 1990 and 2007 calculations of dose. STUDY DESIGN: Average tissue-absorbed dose, equivalent dose, and effective dose for a ProMax 3D CBCT with different dental protocols were calculated using thermoluminescent dosimeter chips in a human equivalent phantom. Effective doses were derived using ICRP 1990 and the superseding 2007 recommendations. RESULTS: Effective doses (ICRP 2007) for default patient sizes from small to large ranged from 102 to 298 µSv. The coefficient of determination (R(2)) between tube current and effective dose (ICRP 2007) was 0.90. When scanning with lower resolution settings, the effective doses were reduced significantly (P < .05). CONCLUSIONS: ProMax 3D can provide a wide range of radiation dose levels. Reduction in radiation dose can be achieved when using lower settings of exposure parameters.

Evaluation of dental root fracture using cone-beam computed tomography.

OBJECTIVE: To evaluate the application of cone-beam computed tomography (CBCT) in the detection of dental root fractures and to analyse the demographic profile of these fractures. METHODS: The study group comprised 398 teeth that were examined by CBCT for determining whether they had a root fracture. Patient characteristics were recorded, and the location, fractured roots, fracture types and three-dimensional images of the related skeletal structures were analysed. Two experienced oral radiologists independently analysed each case and reached a consensus, and the diagnosis was graded in one of the following three categories: fracture definitely present (FDP), fracture probably present (FPP) and no visible fracture (NVF). RESULTS: Among these teeth, 155 (39.0%) were diagnosed as FDP, 14 (3.5%) as FPP and 229 (57.5%) as NVF in the consensus reading. During follow-up, all teeth diagnosed as FDP and 4 of the 14 teeth diagnosed as FPP were intra-operatively demonstrated to be fractured. In FDP cases, 60.0% of the patients were aged from 50 to 69 years. In total, 107 FDP teeth were non-endodontically treated, and the remaining were endodontically treated with (n = 16) or without (n = 32) crown placement. The maxillary and mandibular molars were most frequently affected (81.9%). The fractured roots were mostly palatal (65.7%) in maxillary molars and mesial (84.2%) in mandibular molars. The fractures were characterised as vertical (n = 84), horizontal (n = 34), oblique (n = 5) and complicated (n = 32) fractures. CONCLUSION: The application of CBCT is valuable for the diagnosis of root fracture.

Diagnostic accuracy of proximal caries by digital radiographs: an in vivo and in vitro comparative study.

OBJECTIVES: The aim of this study was to evaluate if the diagnostic accuracy of proximal dental caries in digital radiographs was similar when obtained in in vivo and in vitro conditions. STUDY DESIGN: Thirty-nine noncavitated teeth were collected from 11 subjects who had part of upper or lower jaws excised owing to cyst or neoplasm. Before operation, radiographs of the teeth involved were taken with the digital imaging system Digora Optime (Soredex, Helsinki, Finland), and after operation, the same extracted teeth were mounted in plaster blocks and exposed with the same digital imaging system. The teeth were subsequently sectioned for histologic validation of the lesions. Six observers evaluated all of the radiographs according to a 5-category scale. Receiver operating characteristic analysis was performed. Repeated-measure analysis of variance was used for the statistical analysis. RESULTS: There were no significant differences between digital radiographs taken in in vivo and in vitro conditions for diagnosis of proximal dental caries (P = .286). CONCLUSION: Detection accuracy of proximal dental caries obtained from an in vitro study can be considered to be representative of diagnostic accuracy of proximal dental caries obtained in the real clinical situation.