Identification and classification of pulp calcifications in posterior teeth according to dental condition using digital panoramic radiography and cone beam computed tomography

OBJECTIVE

To compare digital panoramic radiography (DPR) and cone beam computed tomography (CBCT) in the detection and classification of pulp calcifications in posterior teeth in relation to tooth condition and its location.

METHODS

250 patients with simultaneous DPR and CBCT scans were selected from a dental image bank. For each posterior tooth, its condition was registered (healthy, restored, or decayed). The presence of calcifications was assessed and classified according to location (coronal or radicular) and type (total obliteration, partial obliteration, narrowing, and no calcification). Chi-square and McNemar tests were used to compare DPR and CBCT results, with a significance level of 5%. DPR diagnostic values were calculated using CBCT as reference.

RESULTS

Decayed and restored teeth showed a significantly (p < 0.001) higher prevalence of pulp calcifications than healthy teeth in both imaging exams. There was a significant discrepancy between the imaging modalities in the identification of calcifications (p < 0.001), especially for radicular calcifications of maxillary teeth (DPR = 55.2%; CBCT = 30.9%). In the case of coronal calcifications, there was a greater discrepancy between CBCT and DPR in the mandibular teeth (10.7%) than in the maxillary teeth (7.7%). Overall, DPR presents higher sensitivity (0.855) than specificity (0.483) for pulp calcifications detection.

CONCLUSION

DPR considerably overestimates pulp calcifications in posterior teeth, as compared to CBCT. A higher prevalence of pulp calcifications is related to decayed and restored teeth.

Radiographic evaluation of the mandible to predict age and sex in subadults

OBJECTIVE

Forensic examinations involve the identification of age and sex from living or mortal remains. The mandible comprises several growth parameters and is often recovered intact, making it an important tool for radiological identification. Therefore, the present study was conducted to determine the accuracy of various mandibular measurements on digital panoramic images in indicating sex and age in a subadult population. Methods: Panoramic images from 1,100 individuals (550 males, 550 females) ranging in age between 3 and 13 years were divided into 11 groups according to age. Ten mandibular linear dimensions (ramus height, condylar ramus height, coronoid ramus height, maximum ramus breadth, minimum ramus breadth, bigonial breadth, bicondylar breadth, bimental breadth, lateral length of mental foramen, vertical length of mental foramen) and gonial angle were measured bilaterally. Univariate discriminant and regression analyses were performed to determine the most significant predictors of sex and age.

RESULTS

All linear dimensions were higher for males than females for all age groups. Gonial angle did not vary significantly by gender. Discriminant analysis showed linear measurements and gonial angle exhibited poor accuracy in sex determination. Despite a positive correlation between linear measurements and a negative correlation between gonial angle and age, the discriminant analysis found that age estimations made using all the recorded variables had an accuracy of only 66.72%.

CONCLUSION

In line with previous research on different populations, findings for the selected subadult population sample showed that the growing mandible does not present sufficient sexual dimorphism to be useful for sex and age estimations.

Assessment of the Relationship between Skeletal Maturity and the Calcifications Stages of Permanent Canines and Second Premolars

Objective

This study aimed to evaluate the relationship between the calcification stages of permanent maxillary and mandibular canines and second premolars and skeletal maturity in both sexes.

Methods

This study included 138 patients (82 females, 56 males) who were treated in the Department of Orthodontics, Altınbaş University. The mean age of the patients was 12.31±1.76 years, ranging from 7.8 years to 15.8 years. Dental maturity stages of canines and second premolars were evaluated according to the Demirjian index on digital panoramic radiograph. The skeletal maturation stage was determined using the cervical vertebral maturation (CVM) index. The Pearson correlation analysis was performed to assess the association among CVM stages and calcification stages of canines, second premolars, sex, and chronological ages.

Results

A statistically significant correlation was found between CVM and the calcification stages of the canines and second premolars (p<0.05). The calcification stages of the canines and second premolars had the highest distribution of Stage F and Stage G at CVM2 (p<0.01). For the canines and second premolars, Stage H corresponded to CVM3 in female patients and a high percentage of Stage G corresponded to CVM3 in the male group.

Conclusion

A significant correlation was found between the calcification stages of maxillary and mandibular canines, second premolars, and skeletal maturity in both sexes. It was observed that calcification stages and cervical maturations were advanced in female subjects compared with male subjects.

Dynamic focal plane estimation for dental panoramic radiography

PURPOSE

The digital panoramic radiography is widely used in dental clinics and provides the anatomical information of the intraoral structure along the predefined arc-shaped path. Since the intraoral structure varies depending on the patient, however, it is nearly impossible to design a common and static focal path or plane fitted to the dentition of all patients. In response, we introduce an imaging algorithm for digital panoramic radiography that can provide a focused panoramic radiographic image for all patients, by automatically estimating the best focal plane for each patient.

METHODS

The aim of this study is to improve the image quality of dental panoramic radiography based on a three-dimensional (3D) dynamic focal plane. The plane is newly introduced to represent the arbitrary 3D intraoral structure of each patient. The proposed algorithm consists of three steps: preprocessing, focal plane estimation, and image reconstruction. We first perform preprocessing to improve the accuracy of focal plane estimation. The 3D dynamic focal plane is then estimated by adjusting the position of the image plane so that object boundaries in the neighboring projection data are aligned or focused on the plane. Finally, a panoramic radiographic image is reconstructed using the estimated dynamic focal plane.

RESULTS

The proposed algorithm is evaluated using a numerical phantom dataset and four clinical human datasets. In order to examine the image quality improvement owing to the proposed algorithm, we generate panoramic radiographic images based on a conventional static focal plane and estimated 3D dynamic focal planes, respectively. Experimental results show that the image quality is dramatically improved for all datasets using the 3D dynamic focal planes that are estimated from the proposed algorithm.

CONCLUSIONS

We propose an imaging algorithm for digital panoramic radiography that provides improved image quality by estimating dynamic focal planes fitted to each individual patient's intraoral structure.

Root Resorption Diagnostic: Role of Digital Panoramic Radiography

INTRODUCTION

Root resorption is a pathological process characterized by loss of dental root substance, caused by bacterial infections, traumatic injuries or chemical irritation. Root resorption might be accidentally observed on digital panoramic radiography.

OBJECTIVE

The objective of the study was to identify characteristic radiological aspects for the different types of root resorption that could be observed on digital panoramic radiography, to make an easier diagnostic of root resorption.

MATERIAL AND METHOD

The retrospective study used the X-ray base from the Oral Rehabilitation and Dental Prosthetics Clinic of UMF Craiova to identify the most representative images for different types of root resorption. Digital panoramic radiographies were analysed by two investigators, of which the most suggestive images were selected and described.

RESULTS

Digital panoramic radiographies and dental charts of 240 patients were analyzed. 113 cases of root resorption were identified. External inflammatory root resorption (EIRR) was present in 27.07% of studied cases, external cervical root resorption (ECRR) was identified in 10.83% of all studied cases, external replacement root resorption (ERRR) was diagnosed in 7.08% of studied cases and internal root resorption (IRR) was the most rare type of root resorption, with only 2.08% from all studied cases. 16 cases were selected to describe the radiologic features of different types of root resorption, featuring the most interesting images of root resorption evident on digital panoramic radiographies.

DISCUSSION

Comparative analyses have been made between our results and the results of other specific studies, with both similar and different values. The radiological features which lead to the diagnostic of each type of RR were highlighted, assessing the causes that caused the lesions, as well as the treatment recommendations.

CONCLUSIONS

Digital panoramic radiography is a useful tool to identify root resorption, since it has become the most common radiological investigation for diagnostic in dentistry. Description of radiological aspects of different types of root resorption on panoramic digital radiography allows faster diagnosis. Still, the CBCT may be recommended in some cases to confirm the diagnosis.

Digital panoramic radiography versus cone beam computed tomography in the delineation of maxillomandibular tumors

This research aimed to compare the efficacy of digital panoramic radiography (DPR) with that of cone beam computed tomography (CBCT) for delineation of odontogenic and nonodontogenic tumors. From November 2009 through March 2011, 23 tumors in the maxillomandibular complex were diagnosed by histopathological examination. All DPRs and CBCTs were obtained and analyzed by a single previously calibrated radiologist, who considered the following radiographic aspects: clarity of the lesion edges, relation with dental elements, involvement of adjacent anatomical structures, cortical bone expansion and disruption, and, if present, type of involved anatomical structures and site of bone expansion and disruption. Of 23 patients, 15 (65.2%) were male and 8 (34.8%) were female. The tumor was classified as odontogenic in 73.9% of patients and nonodontogenic in 26.1% of patients. Analysis revealed that 56.5% of the tumors were located in the mandible, 34.8% in the maxilla, and 8.7% in both arches. For all analyzed variables, CBCTs offered more accurate details than did DPRs. Panoramic radiography should not be the examination of choice to visualize lesions in the maxillomandibular complex.

Shielding effect of thyroid collar for digital panoramic radiography

OBJECTIVES

To evaluate the shielding effect of thyroid collar for digital panoramic radiography.

METHODS

4 machines [Orthopantomograph(®) OP200 (Instrumentarium Dental, Tuusula, Finland), Orthophos CD (Sirona Dental Systems GmbH, Bensheim, Germany), Orthophos XG Plus (Sirona Dental Systems GmbH) and ProMax(®) (Planmeca Oy, Helsinki, Finland)] were used in this study. Average tissue-absorbed doses were measured using thermoluminescent dosemeter chips in an anthropomorphic phantom. Effective organ and total effective doses were derived according to the International Commission of Radiological Protection 2007 recommendations. The shielding effect of one collar in front and two collars both in front and at the back of the neck was measured.

RESULTS

The effective organ doses of the thyroid gland obtained from the 4 panoramic machines were 1.12 μSv for OP200, 2.71 μSv for Orthophos CD, 2.18 μSv for Orthophos XG plus and 2.20 μSv for ProMax, when no thyroid collar was used. When 1 collar was used in front of the neck, the effective organ doses of the thyroid gland were 1.01 μSv (9.8% reduction), 2.45 μSv (9.6% reduction), 1.76 μSv (19.3% reduction) and 1.70 μSv (22.7% reduction), respectively. Significant differences in dose reduction were found for Orthophos XG Plus and ProMax. When two collars were used, the effective organ doses of the thyroid gland were also significantly reduced for the two machines Orthophos XG Plus and ProMax. The same trend was observed in the total effective doses for the four machines.

CONCLUSIONS

Wearing a thyroid collar was helpful when the direct digital panoramic imaging systems were in use, whereas for the indirect digital panoramic imaging systems, the thyroid collar did not have an extra protective effect on the thyroid gland and whole body.

Planning of dental implant size with digital panoramic radiographs, CBCT-generated panoramic images, and CBCT cross-sectional images

OBJECTIVES

To compare the implant size (width and length) planned with digital panoramic radiographs, cone beam computed tomography (CBCT)-generated panoramic views, or CBCT cross-sectional images, in four implant systems.

MATERIAL AND METHODS

Seventy-one patients with a total of 103 implant sites in the upper premolar and/or lower molar regions were examined with digital panoramic radiography (D-PAN) and (CBCT). A metal ball 5 mm in diameter was placed in the edentulous area for the D-PAN. CBCT data sets were reformatted to a 10-mm thick CBCT panoramic view (CBCT-pan) and 1-mm cross-sections (CBCT-cross). Measurements were performed in the images using dedicated software. All images were displayed on a monitor and assessed by three observers who outlined a dental implant by placing four reference points in the site of the implant-to-be. Differences in width and length of the implant-to-be from the three modalities were analyzed. The implant size selected in the CBCT-cross images was then compared to that selected in the other two modalities (D-PAN and CBCT-pan) for each of the implant systems separately.

RESULTS

The implant-to-be (average measurements among observers) was narrower when measured in CBCT-cross compared with both D-PAN and CBCT-Pan. For premolar sites, the width also differed significantly between D-PAN and CBCT-pan modalities. The implant-to-be was also significantly shorter when recorded in CBCT-cross than in D-PAN. In premolar sites, there were no significant differences in implant length among the three image modalities. It mattered very little for the change in implant step sizes whether CBCT-cross was compared to D-PAN or CBCT-pan images.

CONCLUSION

Our results show that the selected implant size differs when planned on panoramic or cross-section CBCT images. In most cases, implant size measured in cross-section images was narrower and shorter than implant size measured in a panoramic image or CBCT-based panoramic view.

A retrospective radiographic study of coronal-periapical status and root canal filling quality in a selected adult Turkish population

OBJECTIVE

To investigate the oral health (with regard to the periapical status, quality of root fillings and coronal restorations) in an urban adult Turkish subpopulation using digital panoramic radiographs.

MATERIALS AND METHODS

One thousand digital panoramic radiographs involving 28,000 teeth were selected from the archive of the Public Oral and Dental Health Center of Isparta. Coronal status (the type of restoration, signs of marginal leakage or decay), root filling quality (length and lateral seal) and periapical status (according to Periapical Index, PAI) were evaluated. Correlations between apical periodontitis (AP) and the quality of root fillings or coronal restorations were statistically analyzed using the χ(2) test.

RESULTS

Of the 28,000 teeth evaluated, 22,380 (80.0%) were sound, 4,732 (16.9%) were missing, 753 (2.6%) were filled and 135 (0.5%) were decayed. Of the 753 coronal restorations, 400 (53.1%) were radiographically acceptable. Of the 23,268 teeth, 601 (2.6%) were root filled and 247 root fillings were adequate. Ninety-five (15.8%) root-filled teeth had AP (PAI 3-5). Out of the total, the AP prevalence was 0.4% in root-filled teeth and 0.8% in teeth without root fillings. The presence of AP was significantly correlated with inadequate coronal restorations and root canal fillings (p = 0.000).

CONCLUSION

Tooth type, quality and type of coronal restorations, and length and homogeneity of root fillings significantly affected periapical status.