The detection and management of root resorption lesions using intraoral radiography and cone beam computed tomography - an in vivo investigation

Comparison of 6 cone-beam computed tomography systems for image quality and detection of simulated canine impaction-induced external root resorption in maxillary lateral incisors

INTRODUCTION

The most frequent adverse effect of canine impaction is resorption of the adjacent incisors. The subjective image quality and the radiographic diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors were compared among 6 cone-beam computed tomography (CBCT) systems in vitro.

METHODS

A child cadaver skull in the early mixed dentition was obtained. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16-mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm) resorption. The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus with approximal contacts to the impacted maxillary left canine. Six sets of radiographic images were obtained with 3D Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), Scanora 3D CBCT (Soredex, Tuusula, Finland), Galileos 3D Comfort (Sirona Dental Systems, Bensheim, Germany), Picasso Trio (E-WOO Technology, Giheung-gu, Republic of Korea), ProMax 3D (Planmeca OY, Helsinki, Finland), and Kodak 9000 3D (Trophy, Croissy-Beaubourg, France) for each tooth setup. The CBCT images were acquired and subsequently analyzed by 12 observers. Linear models for repeated measures were used to compare the CBCT systems for the image quality and the degree of agreement between the diagnosed severity of root resorption and the true severity.

RESULTS

The differences in the image quality between CBCT systems were statistically significant (P <0.001). The root resorption scores between CBCT systems showed a significantly higher score for the ProMax when compared with the Galileos and the Kodak. However, the differences in agreement between the diagnosed severity of root resorption and the true severity for all resorption sizes were not significantly different (P >0.05) among the different CBCT systems.

CONCLUSIONS

High image quality is important when detecting root resorption. The CBCT systems used in this study had high accuracy with no significant differences between them in the detection of the severity of root resorption.

Comparison between cone-beam computed tomography and intraoral digital radiography for assessment of tooth root lesions

INTRODUCTION

Cone-beam computed tomography (CBCT) might be more accurate in identifying radicular surface lesions compared with digital periapical radiography. In this study, we compared these techniques in detecting simulated root resorption lesions.

METHODS

A porcine mandible was used to support 10 human maxillary central incisors. CBCT and digital periapical radiographic images were generated before and after the introduction of standardized and sequentially larger root defects on either the mesial or the lingual root surfaces. The images were randomly labeled and evaluated by 3 examiners. Each image was classified according to defect size (0, none; 1, mild; 2, moderate; 3, severe).

RESULTS

Interrater reliability was acceptable (0.856 ≤ P ≤ 0.981). The location of the root defect (mesial vs lingual) had no significant effect on the evaluation of defect size. Both periapical radiographs and CBCT were slightly better at detecting lingual defects than mesial defects (75% vs 65% and 65% vs 60%, respectively), but these effects were not statistically significant (P = 0.49 and P = 0.74, respectively). The mean percentages of correctly diagnosed defect sizes were 65% for CBCT and 75% for periapical radiographs. Examiners using CBCT images tended to overestimate defect sizes (κ = 0.481) and correctly categorized teeth with no, mild-moderate, and severe defects 80%, 45%, and 90% of the time, respectively. Examiners using periapical radiographs tended to underestimate defect sizes (κ = 0.636) and categorized teeth with no, mild-moderate, and severe defects 100%, 50%, and 100% of the time, respectively.

CONCLUSIONS

There was no difference in accuracy of identifying defects between periapical radiographs and CBCT images.

Observer ability to detect ex vivo simulated internal or external cervical root resorption

INTRODUCTION

The objective of this study was to assess observer ability to detect ex vivo simulated internal and external cervical root resorption.

METHODS

A total of 90 single-rooted mandibular anterior teeth were split along the coronal plane. By using a 0.5-mm diameter round bur, 50 of the teeth were drilled to simulate resorptive cavities (25 internal and 25 external cervical resorption), and the remaining 40 teeth were left without surface defects. The sectioned teeth were rejoined and placed in the alveolar sockets of a dry human mandible in groups of 6 and imaged with intraoral film by using 3 different angulations and with a cone-beam computed tomography (CBCT) unit. Film and CBCT image sets were evaluated twice by 3 separate observers. Teeth were scored for the presence and location of resorption by using a 5-point scale. Intraobserver and interobserver kappa coefficients and Az values were calculated for each observer and image set. Differences between modalities were compared by using z statistics, with the significance level set at α = 0.05.

RESULTS

Both intraobserver and interobserver agreements were statistically higher (p < .05) for the Iluma CBCT images than for the intraoral images. Az values for CBCT images were also statistically higher (p < .05) than for film images for all observers and readings. In addition, kappa and Az values of external cervical resorption cavities were statistically higher (p < .05) than those of internal cervical resorption cavities for all observers, image types, and readings.

CONCLUSIONS

High-resolution Iluma CBCT images performed better than film in the ex vivo detection and localization of simulated internal and external cervical root resorption.

Use of CBCT to identify the morphology of maxillary permanent molar teeth in a Chinese subpopulation

AIM

To investigate variations in root canal configuration in the maxillary permanent molar teeth of a Chinese subpopulation using cone-beam computed tomography (CBCT).

METHODOLOGY

A total of 269 patients with healthy, untreated, well-developed maxillary molars were enrolled, including those suffering facial trauma, and those who required a pre-operative assessment for implants. Radiographic examination by CBCT was conducted as part of their routine examination, diagnosis and treatment planning. Overall, 299 maxillary first and 210 maxillary second molar teeth were examined in vivo by CBCT. The number of roots, the number of canals per root, the canal configuration and the presence of additional mesiobuccal canals were recorded. Vertucci's classification for root-canal configurations was utilized.

RESULTS

All maxillary first molars had three separate roots; however, 52% of mesiobuccal (MB) roots had two canals with the remainder having one. All distobuccal and palatal roots had Vertucci Type I canal configurations. When the MB2 canal was present, 14, 69 and 16% of MB roots had Type II, IV and V canal configurations, respectively. The root canal system of the maxillary first molar teeth could be categorized into two variants: one with three separate roots with one canal in each of the distobuccal and palatal roots and two canals in the MB root, and the other with three separate roots with one canal in each root. Of 210 maxillary second molars, 10% had one root, 8% two roots and 81% three roots. Of the MB roots, 22% had two canals with the remainder having one. When the MB2 canal was present, 18%, 58%, 10% and 3% of MB roots had type II, IV, V and VI canal configurations, respectively. The root canal system of the maxillary second molar could be categorized into eight variants.

CONCLUSIONS

Mesiobucccal roots of maxillary molar teeth had more variation in their canal system than the distobuccal or palatal roots. The root canal configuration of the maxillary second molars was more variable than that of the first molars. CBCT can enhance detection and mapping of the mesiobuccal root-canal system with the potential to improve the quality of root canal treatment.

A comparison of the diagnostic accuracy of CBCT images of different voxel resolutions used to detect simulated small internal resorption cavities

AIM

To assess ex vivo the use of two different cone-beam computerized tomography (CBCT) units at different voxel resolutions for the detection of simulated small internal resorption cavities.

METHODOLOGY

A total of 60 single-rooted mandibular incisors and canines were split mesiodistally along the coronal plane into labial and lingual sections. Artificial internal root resorption was simulated by drilling with a 0.5-mm-diameter round bur to its full depth at either the cervical or apical portion of the labial wall. In total, 60 cavities were created (30 cervical and 30 apical), and 60 locations (30 cervical and 30 apical) were left without cavities. The sections were rejoined and placed in dry human mandibles in groups of 6 and imaged using two different CBCT units at different resolutions to obtain five image sets as follows: Iluma, ultra-resolution (0.1 mm(3)); Iluma, high-resolution (0.2 mm(3)); Iluma, low-resolution (0.3 mm(3)); 3D Accuitomo 170, 6 x 6 cm FOV (0.125 mm(3)); 3D Accuitomo 170, 8 x 8 cm FOV (0.160 mm(3)). Each image set was viewed by two observers and evaluated using a 5-point scale for detection of internal resorption cavities. Kappa coefficients were calculated to assess intra- and inter-observer agreement. Az values were calculated and compared, with a significance level of alpha = 0.05.

RESULTS

Kappa values were fair-to-moderate for the low-resolution Iluma images and good to excellent for all other image sets. Both intra- and inter-observer agreement values were higher for the Accuitomo images than for the Iluma images. The highest Az values were obtained with the Accuitomo 0.125 mm(3) images and the lowest with the Iluma 0.3 mm(3) images. The Az values for the Accuitomo and Iluma ultra- and high-resolution images were higher than those of the low-resolution Iluma images. No differences (P > 0.05) for internal resorption detection were found between the Az values of the Accuitomo 0.125 mm(3), Accuitomo 0.160 mm(3), ultra-resolution Iluma and high-resolution Iluma images.

CONCLUSION

Ultra-and high-resolution Iluma and Accuitomo 0.125 and 0.160 mm(3) CBCT images performed similarly and better than low-resolution Iluma images in the detection of simulated internal resorption ex vivo.

Modern dental imaging: a review of the current technology and clinical applications in dental practice

A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental "in-office" radiographic techniques are discussed.