Comparative analysis of traditional radiographs and cone-beam computed tomography volumetric images in the diagnosis and treatment planning of maxillary impacted canines

Comparison of 3D Easy Box cone-beam computed tomography analysis with 2D Modified Easy Box on OPG as a prognostic tool for impacted maxillary canines: A pilot study

OBJECTIVE

To assess and compare the validity of 2D modified Easy Box and measurement of the Beta angle on standard conventional orthopantomogram (OPG) versus 3D cone-beam computed tomography (CBCT) OPG-constructed view.

DESIGN

A retrospective agreement study.

METHODS

The aim of this study was to construct an Easy Box on a standard conventional OPG and to validate this novel method by comparing it with the Easy Box method on 3D CBCT. After approval from the Ethics Committee, OPG and CBCT radiographs were obtained for the study from departmental records and five private practices in the same location (Indore, India). The radiographs were selected based on record availability and with written consent from the participants before the commencement of the study. The records were analysed to enable a comparison and to assess the accuracy of Easy Box construction on both 3D CBCT and standard conventional OPG radiographs. The location of the impacted canine within the Easy Box boundaries and the measurement of the Beta angle were determined on both views.

RESULTS

A perfect agreement was obtained for the comparison of 3D Easy Box CBCT analysis with 2D modified Easy Box on OPG for impacted maxillary canines (Kappa = 1.0). A Bland-Altman (LoA) analysis showed no proportional bias in the comparison of the Beta angle on 3D and 2D OPG radiographs.

CONCLUSION

Beta angle and 2D modified Easy Box on a conventional OPG yield similar results when compared to Easy Box on 3D CBCT OPG-constructed view. The standard OPG was valuable and cost-effective, particularly in the early stages of diagnosis and treatment planning, either as a substitute or when CBCT was unavailable.

Diagnostic accuracy of conventional orthodontic radiographic modalities and cone-beam computed tomography for localization of impacted maxillary canine teeth

BACKGROUND

Orthodontic treatment planning for an impacted canine tooth requires accurate information about its position. The aim of this study was to compare the diagnostic accuracy of two conventional orthodontic radiographic modalities with cone-beam computed tomography (CBCT) for localization of impacted maxillary canine teeth.

MATERIALS AND METHODS

Panoramic radiographs, lateral cephalograms, and CBCT scans of 30 patients with unilaterally impacted maxillary canine teeth were retrieved from the archives. Eight expert orthodontists evaluated the parameters related to the location of impacted canine teeth by using panoramic radiographs and lateral cephalograms of patients. After 4 weeks, the same parameters were evaluated on CBCT scans of patients. The diagnostic accuracy of conventional modalities and CBCT was compared with each other and also with the gold standard.

RESULTS

The conventional radiographic modalities and CBCT had similar accuracy for assessment of the overall inclination (p = 0.11), apex morphology (p = 0.18), and mesiodistal position of the apex (p = 0.12). CBCT had significantly higher accuracy for determination of incisal tip location (p = 0.001), labiopalatal (p = 0.001) and vertical (p = 0.01) position of the crown tip, minimum bone thickness covering the crown (p = 0.001), and root resorption of the adjacent tooth (p = 0.001).

CONCLUSION

The combination of panoramic radiographs and lateral cephalograms was sufficiently accurate to assess some diagnostic parameters such as overall inclination, apex morphology, and mesiodistal apex location of impacted canine teeth.

The diagnostic accuracy of cone-beam computed tomography and two-dimensional imaging methods in the 3D localization and assessment of maxillary impacted canines compared to the gold standard in-vivo readings: A cross-sectional study

BACKGROUND

Although the widespread cone-beam computed tomography (CBCT) is a diagnosing tool for impacted canines, the surgical exposure-based diagnostic accuracy of this 3D imaging modality has not been established yet. Therefore this study aimed to (1) compare the accuracy of CBCT- and 2D-based interpretations of impacted canine and its relationships with the neighbouring structures with the gold standard (GS) readings, (2) and calculate the diagnostic accuracy, sensitivity, and specificity values of the variables assessed using CBCT and 2D methods.

MATERIAL AND METHODS

Patients with unilateral impacted maxillary canines (IMCs) planned for surgical extraction between 2016-2018 were checked in-depth to include in this cross-sectional study. For each patient, 2D and 3D radiographic records were obtained and assessed by eight postgraduate orthodontic students. These assessments were compared with the GS readings based on surgical exposure and direct vision of the IMCs. To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.

RESULTS

A total of 17 patients (6 males, 11 females; mean age: 20.52±3.98 years) were randomly selected and included in this study. Significant differences were found between the CBCT-based assessments and the GS only concerning shape and bony coverage of the IMC (P=0.001 and P<0.001, respectively). On the contrary, there were significant differences between the 2D-based assessments and the GS regarding all the assessed variables except for the ankylosis and the proximity to the adjacent teeth (P=0.424, and P=0.080, respectively). CBCT-based assessments had remarkably higher values of diagnostic accuracy, sensitivity, and specificity compared to 2D-based ones.

CONCLUSIONS

The diagnostic accuracy of CBCT outperformed 2D radiography in localizing the IMC (labiopalatal, mesiodistal, and vertical location), detecting root apex development of the IMCs, and the resorption of the adjacent incisors. Although both 2D and 3D techniques showed the same ability in the diagnosis of IMCs ankylosis, the diagnostic accuracy of CBCT was superior. However, both techniques inaccurately determined the shape of the impacted canine and the bony coverage.

Cone-beam computed tomographic reconstructions in the evaluation of maxillary impacted canines

Purpose

Prior to cone-beam computed tomography (CBCT), orthodontic competence included radiological interpretation. Nevertheless, maxillary impacted canines (MICs), because of their position and adjacent complex anatomy, have been challenging to interpret, particularly with regard to root resorption. Although CBCT cross-sectional reconstructions of MICs yielded clearer insights into its diagnosis and treatment planning, the value of simultaneously using 2 different cross-sectional or multiplanar reconstructions of the CBCT datasets - orthogonal and curved/panoramic multiplanar reconstructions - has hitherto not been considered.

Materials and Methods

Both orthogonal and curved/panoramic multiplanar reconstruction series of 5 screenshots were each reconstructed from the 5 cm × 5 cm CBCT datasets of 15 separate MICs. Fifteen credentialled and experienced orthodontist volunteers reviewed 2 separate PowerPoints of 15 randomized series each, 1 week apart. Their review considered 6 factors that could affect treatment: the position and level of the MIC, the presence or absence of root resorption, ankylosis, cysts, and dilaceration.

Results

All 15 orthodontists were statistically similar regarding overall years of experience and of CBCT use. Although either reconstruction alone allowed the orthodontists to determine whether ankylosis and, to a lesser extent, most of the other features were present or absent in the MIC, reviewing both reconstructions together was necessary to determine whether root resorption was present or absent in the adjacent tooth.

Conclusion

Reviewing both orthogonal and curved/panoramic multiplanar reconstructions was necessary to evaluate the presence or absence of root resorption in the teeth adjacent to MICs and that of many other features.

Three-Dimensional Measurements of the Palate and Dental Arch Perimeter as Predictors for Maxillary Palatal Canine Impaction-A Cone-Beam Computed Tomography Image Analysis

(1) Background: Accurate diagnosis and treatment plans in orthodontics were facilitated by novel technologies. The prediction of occlusal problems is of utmost importance for clinicians. This present study aimed to find any possible correlation between unilateral and bilateral palatally impacted maxillary canine, palatal dimensions, and maxillary arch perimeter using digital measurements and determine the factors that could be used as predictors for maxillary palatal canine impaction. (2) Method: A cross-sectional study was conducted on cone-beam computed tomography images of orthodontic patients aged 15 to 25. Palatal dimensions and maxillary arch perimeter were digitally measured using Materialize Interactive Medical Image Control System. (3) Results: A significant difference was found between the case and the study groups regarding palatal depth, length, and arch perimeter, except for the palatal width. A weak correlation was reported in palatal depth and length with canine impaction, whereas the correlation was moderate concerning the arch perimeter. They can be used as predictors for palatal canine impaction. (4) Conclusion: Palatal dimensions and dental arch perimeter affect maxillary palatal canine impaction. Deficient arch perimeter, palatal depth, and length could be helpful in the prediction of maxillary palatal canine impaction.

Development and validation of a new prognostic tool for impacted maxillary canines, 'Easy box': A cone-beam computed tomographic study

OBJECTIVE

To develop a tool to facilitate simple, easy and rapid assessment of the level of difficulty in disimpaction of an impacted canine using cone-beam computed tomography (CBCT).

DESIGN

A cross-sectional study.

METHODS

A panel of four experienced orthodontists formulated a questionnaire capable of portraying the limits of a three-dimensional (3D) area around impacted maxillary canines on CBCT images, which would determine the disimpaction difficulty level. In total, 14 experienced orthodontists graded each item in the questionnaire and assigned scores in the range of 0-5. Average scores obtained outlined the limits of a 3D area, within which an impaction was deemed favourable. This area was termed 'Easy box'. The disimpaction difficulty level of 170 impacted maxillary canines was then assessed using 'Easy box' and the existing tool KPG index for convergent validation.

RESULTS

Perfect inter-examiner agreement was obtained as evidenced by Fleiss kappa value of 0.984 for the tool 'Easy box' and 0.948 for the KPG index. There was also perfect agreement between the two methods of assessment (Cohen weighted kappa, k>0.86). The average time taken for assessment using 'Easy box' was 3.3 min compared to 8.8 min for the KPG index.

CONCLUSION

'Easy box' proves to be a simple, accurate and rapid assessment tool for the prognostic evaluation of impacted canines, using CBCT images. Impacted maxillary canines with cusp tips that lie beyond the limits of the 3D 'Easy box' area with a beta angle greater than 45°, were rated to be more difficult to align.

Cone beam computed tomography indications for interdisciplinary therapy planning of impacted canines

OBJECTIVE

To investigate how cone beam computed tomography (CBCT) affects the therapeutic planning of impacted maxillary canines.

STUDY DESIGN

A total of 132 impacted canines from 89 pediatric patients were collected from 3 specialist clinics in Stockholm, Sweden. An interdisciplinary therapy planning team consisting of 5 dental specialists evaluated each case and chose their preferred treatment alternative, initially without and later with CBCT images, to decide whether CBCT was justified for therapy planning. Predefined variables measurable using only 2-dimensional (2D) assessments were analyzed using stepwise logistic regression analyses.

RESULTS

The CBCT was considered indicated in 47% of the cases. Additional information from CBCT led to a treatment decision change in 9.8%. Significant 2D predictors for CBCT justification were horizontal canine angulation compared with vertical angulation (odds ratio [OR] = 10.9), extraction strategy involvement (OR = 6.7), and buccally positioned canines compared with palatal (OR = 5.3), central (OR = 25.0), and distal or uncertain positions (OR = 7.7).

CONCLUSIONS

The benefit-risk assessment of CBCT for impacted canines may be reinforced by performing and applying justification decisions for CBCT acquisition at the therapeutic thinking level. If preliminary treatment planning motivates further in-depth investigation of either root status or tooth location, a CBCT is indicated.

Evaluation of maxillary sinus dimensions and volume using cone beam computed tomography in patients with unilaterally displaced palatal and buccal maxillary canines

OBJECTIVES

To evaluate and compare the maxillary sinus (MS) dimensions and volume in unilaterally displaced palatal and buccal maxillary canines.

METHODS

CBCT images for 133 patients were included in the study. Maxillary canines were unilaterally displaced palatally in 83 patients (PDCs) and buccally in 50 patients(BDCs). The following variables were measured: canine position in relation to MS walls, MS pneumatization and MS dimensions and volume.

RESULTS

MS was extended to the incisor region in 10% and 13% and to the canine region in 48% and 23% in BDCs and PDCs subjects, respectively. In BDC subjects, maxillary canine crown tip was more laterally (24.23 mm compared to 22.93 mm (p < 0.05)) and closer vertically (5.82 mm compared to 9.58 mm (p < 0.001)) to the MS, maxillary canine root tip was closer to the MS anterior (0 mm compared to 1.64 mm (p < 0.05)) and lateral (19.70 mm compared to 22.02 mm (p < 0.001)) walls and the MS volume (11.57mm³ compared to 9.09 mm³ (p < 0.001)) was increased in the displaced side compared to the non-displaced side. In PDC subjects, a significant difference between the displaced and non-displaced sides was detected in the vertical (3.28 mm compared to 5.89 mm (p < 0.001)) and lateral (21.63 mm compared to 24.25 mm (p < 0.001)) position of maxillary canine to the MS wall, the anterior (- 0.84 mm compared to 1.13 mm (p < 0.05)) and lateral (20.48 mm compared to 22.44 mm (p < 0.001)) position of canine root tip to the MS and the MS volume (7.71mm³ compared to 9.14mm³ (p < 0.001)). PDC sides differed from BDC sides in the lateral and vertical position of canine crown tip to MS and in MS volume. PDC showed negative association with MS volume and anteroposterior skeletal relationship and a positive association with MS height.

CONCLUSIONS

PDCs subjects have a reduced MS volume and BDCs subjects have an increased MS volume. PDCs are associated with reduced MS volume, increased MS height and Class III skeletal relationship.

The Interdisciplinary Orthodontic–Surgical Diagnostic and Treatment Protocol for Odontogenic Cyst-like Lesions in Growing Patients—A Literature Review and Case Report

Tooth eruption disturbances associated with developmental odontogenic cysts represent a particular challenge in orthodontic treatment. Early diagnosis, crucial for prompt and effective therapy, is possible with a thorough radiological analysis. Three-dimensional digital images provided by CBCT are indispensable to establish an interdisciplinary orthodontic–surgical treatment plan. The aim of this paper is to present a case of an odontogenic cyst in a nine-year-old male patient. Particular attention is paid to radiological findings, possible therapeutic approaches and potential complications connected with an attempt to improve the alignment of teeth. Orthodontic implications associated with cysts in growing patients are widely described according to clinical observations and literature review.

Predictive factors associated with adjacent teeth root resorption of palatally impacted canines in Arabian population: a cone-beam computed tomography analysis

Background

This study aimed to evaluate three-dimensionally the factors associated with adjacent teeth root resorption of palatally impacted canines.

Methods

In this retrospective cross-sectional study, one-hundred and fourteen cone beam computed tomography scans with palatally impacted maxillary canines were evaluated for the presence of adjacent root resorption. Seven parameters were analyzed: alignment of maxillary incisors, presence of deciduous canines, first premolars’ roots configuration, impacted canines rotation, angulation of impacted canine to the midline, contact relationship, and area of contact with adjacent teeth. The association between dependent and independent qualitative and quantitative variables was analyzed using chi-square and independent student’s t-test, respectively. The multivariate analysis was performed using regression analysis. The significant value was set at P ≤ 0.05.

Results

The overall incidence of vertical, horizontal impaction and adjacent root resorption were 92, 8 and 77.2%, respectively. The apical third was the most involved area (57%); resorption of a single tooth was found in 21.9% of the total sample. The most common resorbed teeth were lateral first premolars (24.6%), followed by central lateral incisors (20.2%), and lateral incisors (15.8%) of the total sample. The severity of resorption was highest in grade I (31.5%) and lowest in grade III (7.6%). Three variables showed significant differences between resorption and non-resorption groups namely; canine rotation (P < 0.013), contact relationship (P < 0.001), and area of contact with adjacent teeth (P < 0.001). Regression analysis revealed an association between adjacent root resorption and permanent canine rotation, adjacent premolars’ roots configuration, contact relationship, and area of contact (P < 0.05).

Conclusion

Two-thirds of impacted maxillary canines showed a form of root resorption. The most commonly resorbed tooth was the lateral incisors while the least affected one was the central incisors with apical one-third being of the highest risk. The predisposing factors including the canine rotation, premolar with separated roots, contact relationship, and area of contact with adjacent teeth are to be considered for any interceptive treatment.

Radiographic features in 2D imaging as predictors for justified CBCT examinations of canine-induced root resorption

OBJECTIVES

This retrospective observational study aimed to evaluate the diagnostic accuracy of two-dimensional radiographs on canine-induced root resorption (CIRR) in lateral incisors and identify predictors of CIRR in patients with impacted maxillary canines (IMC).

METHODS

Ninety-nine patients aged 9-17 years, with 156 IMCs, were included in the study. All had CBCT-volumes and two-dimensional radiographs consisting of at least one panoramic radiograph. Two radiologists jointly viewed all cases twice. First, radiographic features related to the IMC and possible CIRR were recorded from two-dimensional radiographs. Then, CIRR was determined from CBCT and according to position and extension classified as mild, moderate and severe.

RESULTS

CIRRs was detected in 80% of lateral incisors (mild: 45%; moderate: 44%; severe: 11%). The sensitivity was generally low at mild and moderate cut-offs (29 and 29%), and somewhat higher for severe (50%). Corresponding specificities were 48%, 63% and 68%. Canine cusp-tip superimposing the lateral incisor's middle third and root/crown ratio >1 was positively associated with mild CIRR, with an odds ratio (OR) of 3.8 and 6.7, respectively. In addition, the root development stage was positively associated with moderate/severe CIRR when the canine root was nearly or fully developed (OR = 3.1).

CONCLUSIONS

The diagnostic accuracy of two-dimensional radiographs was inadequate for detecting CIRR amongst patients referred for CBCT examinations. Based on our results, none of the suggested two-dimensional radiographic features could predict moderate/severe CIRR except for root development stage. IMC in a later stage of root development seems to be associated with a higher risk of moderate/severe CIRR.

Evaluation of impacted maxillary canine position using panoramic radiography and cone beam computed tomography

Introduction

Localization of impacted maxillary canine (IMC) position is essential in orthodontic treatment for accurate orthodontic treatment as well as prognosis.

Objectives

This study aimed to: 1- investigate the relationship between the locations of IMC in panoramic radiograph (PR) using sectors in relation to their labio-palatal position in cone beam computed tomography (CBCT): 2- report the incisor root resorption in CBCT in relation to its sector location of IMC in PR.

Material and Methods

The study is a retrospective imaging assessment of 60 IMCs in multiple centers in Riyadh, Saudi Arabia. Sector location of IMC was determined on the PR and correlated with each of their labio-palatal positions and resorption of the root of permanent incisors using CBCT.

Results

There is a significant correlation between sector location and impaction location of IMC. No statistical correlation was found between IMC sector location and lateral incisor root resorption, whereas a significant correlation was found between sector location and central incisor root resorption.

Conclusions

For Sectors I and II, IMC tended to be in either the mid-alveolus or labial location, whereas Sectors III and IV tended to show palatal impaction. Therefore, sector could be a good tool for localization of IMC and to predict the possibility of incisor root resorption.

Image quality assessment of low-dose protocols in cone beam computed tomography of the anterior maxilla

OBJECTIVES

To evaluate overall image quality and visibility of anatomic structures on low-dose cone beam computed tomography (CBCT) scans and the effect of a noise reduction filter for assessment of the anterior maxilla.

METHODS

We obtained 48 CBCT volumes on 8 skull-phantoms using 6 protocols: 2 clinical default protocols [standard definition (SD) and high definition (HD)] and 4 low-dose protocols, 2 with a noise reduction filter [ultra-low-dose with high definition (ULDHD) and ultra-low-dose (ULD)] and 2 without [low-dose with high definition (LDHD) and low-dose (LD)]. Overall image quality and visibility of 8 anatomic structures were assessed by 5 observers and statistically analyzed using the Wilcoxon signed rank test. Intra- and interobserver agreement was measured using Cohen's weighted kappa.

RESULTS

HD provided higher overall image quality than diagnostically required; LD scored lower than diagnostically acceptable. ULDHD, ULD, and LDHD were acceptable. For anatomic structures, ULDHD and ULD were acceptable. LDHD and LD showed significantly inferior visibility for 1 and 4 structures, respectively. Mean values of intra- and interobserver agreement were 0.395 to 0.547 and 0.350 to 0.370, respectively.

CONCLUSIONS

ULDHD, ULD, and LDHD may be recommended for assessment of impacted maxillary canines. The noise reduction filter affects image quality positively only at low exposure.

Patterns of Cone-Beam Computed Tomography (CBCT) Utilization by Various Dental Specialties: A 4-Year Retrospective Analysis from a Dental and Maxillofacial Specialty Center

The study aimed to analyze the uses of cone-beam computed tomography (CBCT) in the diagnosis and treatment in various dental specialties. This 4-year cross-sectional study analyzed the records of 1409 individuals who underwent a CBCT at the Oral and Maxillofacial Center at Sheba Medical Center, Israel. The average age of the patients was 27.9 ± 11.5 (range: 9-86 years). Patients were referred for CBCT by the following departments: Oral and Maxillofacial Surgery (1063; 75.5%), Endodontics (182; 12.9%), Periodontology (122; 8.6%) and Orthodontics (42; 3.0%). Most CBCT radiographs evaluated the maxilla (774; 55.0%), followed by the mandible (481; 34.1%) and both (154; 10.9%). The target anatomical structures included: bone (694; 49.3%), teeth (307; 21.7%), and both jaws (408; 29.0%). The main indications for CBCT use were: assessment of anatomical structures and implant sites (787; 55.9%), determine root canals morphology (182; 12.9%), visualization of impacted teeth, tooth alignment, and localization (177; 12.6%), suspected cysts or tumors (148; 10.5%), evaluation of Temporomandibular joint disorders (106; 7.5%) and other reasons (9; 0.6%). In 279 (19.8%) of cases, the diagnosis changed following CBCT, mainly in Orthodontics tooth analysis (28 (66.7%); p < 0.001). Practitioners and health authorities should be aware of this baseline information regarding CBCT use in the diagnosis and assessment of various oral and maxillofacial pathologies, anomalies and tooth position relative to anatomic structures. Continuing research and publications of CBCT utilization and guidelines are recommended.

Prognosis for the impacted lower third molars: Panoramic reconstruction versus tomographic images

OBJECTIVE

The aim of this cross-sectional accuracy study was to compare panoramic reconstruction (PR) and multiplanar reconstruction (MPR) images, which are used to establish the prognosis for impacted mandibular third molars in relation to professional decision making.

STUDY DESIGN

Images of 10 patients who had undergone cone beam computed tomography (CBCT) examination were selected, resulting in 2 distinct groups of images, with 10 in each group: PR and MPR. To check prognostic accuracy, 2 images from each group were randomly selected and reinserted into the sample, totaling 24 images. A questionnaire was completed by 54 professionals: 27 orthodontists and 27 oral and maxillofacial surgeons (OMFSs). Data were evaluated by using the χ² and McNemar's tests and Kappa statistics at P < .05.

RESULTS

There were no statistically significant differences when isolated PR images were compared with MPR images by orthodontists (P = .72) or OMFSs (P = .45). However, there were significant differences in the professional decision regarding the prognosis for impacted teeth, where OMFSs indicated the need for more extractions compared with orthodontists (P < .0001).

CONCLUSIONS

There are no differences between PR and multiplanar CBCT images with regard to the determination of the prognosis for impacted mandibular third molars. However, there was a difference in the decision making between the different specialties.

CBCT in orthodontics: a systematic review on justification of CBCT in a paediatric population prior to orthodontic treatment

BACKGROUND

Taking into account radiation doses, safety, and protection, we highlighted the features in which cone-beam computed tomography (CBCT) can offer an advantage compared to the conventional two-dimensional imaging in paediatric dentistry before orthodontic treatment.

OBJECTIVE

The aim of this article was to conduct a systematic review to assess the diagnostic efficacy of CBCT in the paediatric population at a pre-orthodontic phase.

SEARCH METHODS

MEDLINE via PubMed was searched to identify all peer-reviewed articles potentially relevant to the review until 1 July 2018. Relevant publications were selected by two reviewers independently.

SELECTION CRITERIA

The literature selection for this systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was based on predetermined inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data were collected on overall study characteristics and examination characteristics of the selected studies. Methodological quality of the selected studies was evaluated. Original studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Thereafter, levels of evidence were obtained according to Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

As a result of the QUADAS assessment, a total of 37 articles were included in the protocol. Following a proper protocol, CBCT was regarded as a reliable tool for assessment and management of impacted canine and root fracture. It provided a better evaluation of normal and pathological condylar shape and volume. CBCT was a superior choice for pre-surgical diagnostic applications in cleft lip and/or palate over a medical computed tomography based on its lower radiation exposure, shorter investigation time, and low purchase costs.

CONCLUSIONS

CBCT is justified only in those cases where conventional radiography fails to provide a correct diagnosis of pathology. Therefore, it cannot be regarded as a standard method of diagnosis. CBCT imaging may also be justified when it positively affects treatment options or provides treatment optimization.

REGISTRATION

None.

CONFLICT OF INTEREST

None to declare.

Evaluation of impacted canines' localization and adjacent lateral incisors' root resorption with orthopantomography and cone-beam computed tomography

OBJECTIVES

In this retrospective study, the frequency and severity of ectopic eruption in the children's permanent canines, changes between the impacted canine parameters on orthopantomography (OPG) taken for routine follow-up were demonstrated. Also, it was aimed to reveal the differences between OPG and cone beam computed tomography (CBCT).

METHODS

Ten thousand (5020 girls, 4980 boys) pediatric patient, were retrospectively investigated for the presence of impacted canine radiographically. OPG and CBCT images of 343 pediatric patients (207 girls, 136 boys) detected impacted canines (n = 432) were evaluated in four steps that the angular and linear measurement, position and status relationships with adjacent anatomical structures were investigated.

RESULTS

The incidence of impacted canine in children was 3.43% (4.02% girls, 2.73% boys). The percentage of adjacent lateral incisor' resorption was 33%. Although the presence of resorption in lateral incisors in contact with a canine was found to be statistically significant (p = 0.02), there was no statistically significant relationship the follicle size and localization of canine in the transverse plane. When images were compared, it was found that there was a statistically significant difference between CBCT and OPG about the parameter of canine angulation to the midline and parameter of canine angulation to the lateral incisor.

CONCLUSIONS

Pediatric dentists should prefer OPG as the first choice for radiographic imaging for the diagnosis of impacted canine at an early age. Follow-up OPGs should be carefully studied with advancing age. The CBCT should be preferred to prevent complications, to view its relationship with adjacent anatomical structures and canine localization in detail.

Surgical Exposure of Impacted Teeth

Impacted incisors, canines, premolars, and second molar are problems encountered frequently by general dentists, orthodontists, and oral and maxillofacial surgeons. The etiology of impacted teeth is multifactorial. Traditional radiographs can be used for location of the impacted tooth but 3-D CBCT is superior in evaluating the tooth's position. Successful management requires an interdisciplinary approach with an orthodontist responsible for the overall success of the treatment plan. Surgical exposure of these impacted teeth is accomplished using an open or closed surgical procedure. Choosing the appropriate surgical procedure and orthodontic treatment plan will result in a stable, predictable, and aesthetic result.

Comparison of Three-Dimensional and Conventional Orthodontic Imaging Modalities for Localization of Impacted Maxillary Canines in Patients With Alveolar Cleft

OBJECTIVE

The purpose of this study was to identify which diagnostic parameters related to impacted maxillary canines can be reliably detected by the conventional orthodontic radiographic modalities and which factors need to be assessed by cone-beam computed tomography (CBCT).

DESIGN

In this cross-sectional study, 8 orthodontists evaluated 7 parameters related to the position and anatomy of the impacted canines by means of 2-dimensional (2D) records. After 1 month, the same process was repeated by means of CBCT by the same clinicians.

SETTING

Qazvin University of Medical Sciences.

PATIENTS AND PARTICIPANTS

Thirty-two patients with alveolar cleft and impacted maxillary canines who had CBCT scans, lateral cephalograms, and orthopantomographs as pretreatment records.

MAIN OUTCOME MEASURE

The diagnostic accuracy of 2D and 3-dimensional (3D) radiographic modalities was compared with each other and also with the gold standard by 3 radiologists.

RESULTS

The diagnostic accuracy of 2D and 3D imaging modalities was not significantly different regarding the mesiodistal inclination of the impacted tooth (P = .09), apex anatomy (P = .10), and mesiodistal position of the apex (P = .19). Cone-beam computed tomography had significantly higher diagnostic accuracy than conventional radiographic modalities regarding overlapping the adjacent tooth (P = .001), labio-palatal and apico-coronal position of the crown tip, and root resorption of the adjacent tooth (P = .01).

CONCLUSION

The conventional orthodontic radiographic modalities were as accurate as CBCT for determination of impacted canine inclination, apex anatomy, and mesiodistal position of the apex. Cone-beam computed tomography showed higher diagnostic accuracy for other parameters.

Diagnostic efficacy of and indications for intraoral radiographs in pediatric dentistry: a systematic review

PURPOSE

To systematically evaluate the diagnostic efficacy of intraoral radiographs and evidence supporting the indications for taking of intraoral radiographs in children in the following five clinical categories: caries, pathological conditions (including acute odontogenic infections and periodontal disease), dental/developmental anomalies, dental trauma, and enhancement of comfort/technique for taking radiographs in children. This was carried out to facilitate the updating of existing European Academy of Paediatric Dentistry (EAPD) guidelines on dental radiography in pediatric dentistry.

METHODS

A systematic electronic literature search was conducted on Cochrane Library (1992-24 July 2018), MEDLINE (PubMed, 1946-24 July 2018), EMBASE (Embase.com, 1974-24 July 2018) and Scopus (pre-1970-24 July 2018). Hand search of handbooks and grey literature search was also performed. Study screening and study inclusions were agreed upon by three authors. Data extraction, and methodological quality and risk of bias assessment were carried out in duplicate for each of the included studies.

RESULTS

A total of 9581 papers were identified. Following the primary and secondary assessment process, 36 papers were included in the final analysis. The included studies were further categorized into five main clinical categories for analysis: caries, pathological conditions, dental/developmental anomalies, dental trauma and comfort/technique-related studies. Only one paper was found to be of good quality and at low risk of bias; while, 9 papers were found of be at moderate risk of bias and 26 papers were at high risk of bias. Meta-analysis was not possible for any of the aforementioned clinical situations, and only a narrative synthesis was done.

CONCLUSION

There is insufficient high-quality evidence for the use of intraoral radiographs in pediatric dentistry and current guidelines are based largely on expert opinion. There is a clear need for well-conducted and standardized studies regarding the use of intraoral radiography in pediatric dentistry.

The effect of digital diagnostic setups on orthodontic treatment planning

INTRODUCTION

This study aimed to evaluate whether viewing digital treatment simulations influenced orthodontic treatment planning decisions or practitioners' confidence in their selected plans.

METHODS

Records of 6 patients representing different case types (eg, missing teeth, crowding, sagittal discrepancies) were collected. A total of 22 orthodontists and 7 orthodontic residents viewed these records and formulated treatment plans for each case, indicating their most recommended plan and up to 2 alternative plans. After treatment planning each case, digital setups of each treatment plan indicated by the practitioner were shown. The practitioners were then asked if they still recommended their original plan, or if they would now recommend a different plan. Their confidence levels in the success of their plans were recorded before and after viewing the setups.

RESULTS

After viewing the digital setups, there was a significant change in the treatment plan for 9.2% of the cases. These included modifications like changing the extraction pattern or proposing space closure rather than opening space for an implant. In an additional 14.4% of the cases, treatment plans underwent partial changes, like adding interproximal reduction or temporary anchorage devices. Practitioner confidence levels increased after viewing the setups. In cases where the treatment plan changed, the practitioner's confidence level in the plan increased the most, and the final confidence level was uniformly high among all practitioners. Practitioners reported the most helpful features of digital setups were the ability to superimpose the setup with the original model, determine the amount of tooth movement needed, check the final incisal relationship (overjet and overbite), and establish the amount of interproximal reduction required.

CONCLUSIONS

Viewing digital setups resulted in changes to the treatment plans in about 24% of the cases. The use of digital setups was associated with higher levels of confidence in the selected plans.

The frequency of bucal and palatal impaction maxillary canines

Introduction: Maxillary canines are usually impacted teeth the second after third molar. Frequency of impacted maxillary canines is about 1 to 3% of population (in 85% of the cases palataly, and in 15% of the cases bucaly). The aim of this research was to find the frequency of bucal and palatal impacted maxillary canines in relation to sex and position of impacted tooth. Matherial and method: We analyzed three-dimensional computed tomography images (CBCT) of 64 examinees (aged 12 to 33 years) with 80 unerupted maxillary canines to plan the orthodontic therapy. Results: Among 64 examines with impactions, 80 impacted maxillary canines are diagnosed. The average age of all respondents in the survey is 16,3±4,3. Of 64 examinees in research 41(64.1%) were female which is significantly more important than the representation of male examinees whose number was 23(35.9%). Frequency of unilateral impactions of maxillary canines is three times higher 48 (75%) in comparison to bilateral impactions 16 (25%). Of total 80 impacted maxillary canines 19 (23.75%) were bucal impacted, 3 (2.75%) in the middle of alveolus and 58 (72.5%) palatally. With the bucal and palatal impaction usually was represented partially vertical impaction (70%); completely horizontal impaction (10%) was represented only in the palatal impaction. Conclusion: The analysis of CBCT images of maxilla shows a statistically significant frequency of partially vertical, unilateral and paltally localized impacted maxillary canines.

Diagnostic efficacy of cone beam computed tomography in paediatric dentistry: a systematic review

Purpose

To determine in which clinical situations it is indicated or contra-indicated to prescribe cone beam computed tomography (CBCT) for paediatric patients.

Methods

Systematic review of in vivo paediatric research studies of diagnostic efficacy using CBCT, with supplementary searches for guideline documents on CBCT and for systematic reviews permitting inclusion of ex vivo and adult studies.

Results

After screening, 190 publications were included, mostly case studies. No systematic reviews were found of in vivo paediatric research. Fourteen studies of diagnostic efficacy were identified. The supplementary searches found 18 guideline documents relevant to the review and 26 systematic reviews. The diagnostic efficacy evidence on CBCT was diverse and often of limited quality. There was ex vivo evidence for diagnostic accuracy being greater using CBCT than radiographs for root fractures. The multiplanar capabilities of CBCT are advantageous when localising dental structures for surgical planning. Patient movement during scanning is more common in children which could reduce diagnostic efficacy.

Conclusions

No strong recommendations on CBCT are possible, except that it should not be used as a primary diagnostic tool for caries. Guidelines on use of CBCT in the paediatric age group should be developed cautiously, taking into account the greater radiation risk and the higher economic costs compared with radiography. CBCT should only be used when adequate conventional radiographic examination has not answered the question for which imaging was required. Clinical research in paediatric patients is required at the higher levels of diagnostic efficacy of CBCT.

Electronic supplementary material

The online version of this article (10.1007/s40368-019-00504-x) contains supplementary material, which is available to authorized users.

Risk factors for external root resorption of maxillary second molars due to impacted third molars as evaluated using cone beam computed tomography

The purpose of this retrospective study was to evaluate risk factors for external root resorption (ERR) on maxillary second molars (MxM2) in association with impacted third molars (MxM3) using cone beam computed tomography (CBCT) scans. The angles between the axes of MxM2/MxM3 (inclination) were measured. Further, ERR on MxM2 was classified as absent, slight, moderate, or severe. Contact location between MxM3 and MxM2, the size of the dental follicle, type of impaction, root formation, and patient demographic characteristics were also assessed. Half of the 84 MxM2 showed ERR (slight 36.9%, moderate 6.0%, severe 7.1%). Patient age was a significant factor for the presence of ERR (P = 0.03). The inclination was also a relevant factor, with transverse MxM3 exhibiting the highest risk of ERR (P = 0.02). The cervical third (28.6%) showed a significantly lower risk percentage of ERR compared to the apical (73.7%) and middle thirds (60.6%) of the root (P = 0.004). Based on these findings, clinicians assessing the need for surgical removal should be able to selectively identify impacted MxM3 at risk of causing ERR on MxM2 early on, especially when the MxM3 is located in close contact with the apical and middle thirds of the MxM2 roots and has a transverse inclination.

Accuracy of High- and Low-Resolution Cone-Beam Computed Tomographic Scans in the Detection of Impacted Tooth-Induced External Root Resorption: An Ex-Vivo Study

Objectives:

Cone-beam computed tomography (CBCT) is used in diagnostic situations, as well as tooth impaction and its complications. A possible sequela of tooth impaction is resorption of adjacent teeth, complicating the treatment plans. This study aimed to determine the diagnostic accuracy of high- and low-resolution CBCT scans in the detection of external root resorptions (ERRs), caused by an adjacent impacted tooth in the cementoenamel junction (CEJ), mid-root, and apical areas.

Materials and Methods:

Forty-five intact single-rooted teeth were divided into three groups of 15. Each group was dedicated to each zone of the root. Slight, moderate, and severe ERRs were formed, and CBCT scans were taken before and after the formation of ERRs. The diagnostic accuracy was assessed, and the Proportion test was used to compare the results.

Results:

The statistical analyses of high- and low-resolution images showed a significant difference (P<0.05), which implies the higher accuracy of high-resolution images. The highest diagnostic accuracy among different zones was related to the mid-root, and the lowest was related to the apical zone. In terms of the size of ERRs, the diagnostic accuracy was the lowest for slight ERRs.

Conclusion:

The most reliable and accurate diagnostic mode was found in high-resolution images, in the mid-root zone, and with severe ERRs. The lowest diagnostic accuracy was found in low-resolution images, in the apical zone, and with slight ERRs.

Cone-Beam Computed Tomography in Orthodontics

Unlike patients receiving implants or endodontic treatment, most orthodontic patients are children who are particularly sensitive to ionizing radiation. Cone-beam computed tomography (CBCT) carries risks and benefits in orthodontics. The principal risks and limitations include ionizing radiation, the presence of artifacts, higher cost, limited accessibility, and the need for additional training. However, this imaging modality has several recognized indications in orthodontics, such as the assessment of impacted and ectopic teeth, assessment of pharyngeal airway, assessment of mini-implant sites, evaluation of craniofacial abnormalities, evaluation of sinus anatomy or pathology, evaluation of root resorption, evaluation of the cortical bone plate, and orthognathic surgery planning and evaluation. CBCT is particularly justified when it brings a benefit to the patient or changes the outcome of the treatment when compared with conventional imaging techniques. Therefore, CBCT should be considered for clinical orthodontics for selected patients. Prescription of CBCT requires judicious and sound clinical judgment. The central question of this narrative review article is: when does CBCT add value to the practice of orthodontics? To answer this question, this article presents discussion on radiation dosage of CBCT and other imaging techniques used in orthodontics, limitations of CBCT in orthodontics, justifying the use of CBCT in orthodontics, and the benefits and evidence-based indications of CBCT in orthodontics. This review summarizes the central themes and topics in the literature regarding CBCT in orthodontics and presents ten orthodontic cases in which CBCT proved to be valuable.

Cone Beam Computed Tomography in Oral and Maxillofacial Surgery: An Evidence-Based Review

Cone Beam Computed Tomography (CBCT) is a valuable imaging technique in oral and maxillofacial surgery (OMS) that can help direct a surgeon’s approach to a variety of conditions. A 3-dimensional analysis of head and neck anatomy allows practitioners to plan appropriately, operate with confidence, and assess results post-operatively. CBCT imaging has clear indications and limitations. CBCT offers the clinician 3-dimensional and multi-planar views for a more accurate diagnosis and treatment without the financial burden and radiation exposure of conventional computed tomography (CT) scans. Furthermore, CBCT overcomes certain limitations of 2-dimensional imaging, such as distortion, magnification, and superimposition. However, CBCT lacks the detailed depiction of soft tissue conditions for evaluation of pathologic conditions, head and neck infections, and temporomandibular joint (TMJ) disc evaluation. This review evaluates the evidence-based research supporting the application of CBCT in the various fields of oral and maxillofacial surgery, including dentoalveolar surgery, dental implants, TMJ, orthognathic surgery, trauma, and pathology, and will assess the value of CBCT in pre-operative assessment, surgical planning, and post-operative analysis when applicable. Additionally, the significant limitations of CBCT and potential areas for future research will be discussed.

Use of 3D Imaging for Treatment Planning in Cases of Impacted Canines

Background:

The use of 3D imaging offers the possibility to improve diagnosis and treatment planning in several fields of dental science.

Objective:

The aim of this study is to evaluate the usefulness of 3D evaluation for surgical exposure treatment planning in cases of impacted canine.

Methods:

This retrospective study has been conducted on the clinical reports of twenty patients (11 F - 9 M) with a mean age of 15.4 years, affected by the impacted canine. Each patient underwent a CBCT exam (Hitachi MercuRay, Hitachi Medical Technology, Tokyo, Japan), in order to obtain sagittal, axial and coronal images and a 3D surface rendering. The images have been evaluated by 14 experts orthodontists who were divided into two groups. The first group first evaluates the bidimensional images and then the 3D images and the second group instead has done exactly the opposite. Each orthodontist has elaborated a treatment plan for the impacted canine correction with a specific indication about surgical exposure approach (Palatal-Vestibular) and orthodontic biomechanics.

Results:

The level of concordance in treatment planning of the 3D images evaluation and the bidimensional images was found to be greater in the second group of orthodontists. Moreover, in this group, the time spent for the treatment plan has been lower than in the first group (12 ± 3.32 min vs. 23 ± 2.53 min, p < 0.05).

Conclusion:

According to the results of the present study, it is possible to state that CBTC is fundamental for the diagnosis and treatment planning of impacted canine. However, further studies are necessary to confirm the greater reliability of 3D surface rendering compared to the bidimensional images.

Are panoramic radiographs good enough to render correct angle and sector position in palatally displaced canines?

OBJECTIVES

The early interceptive treatment of palatally displaced canines (PDCs) has for decades been based on their position in panoramic radiographs. In the 1990s, cone-beam computed tomography (CBCT) started to become popular in cases with PDCs. The aims of this prospective study were to evaluate the agreement of PDC sector position and angle to midline between panoramic radiographs and CBCT scans.

METHODS

PDC sector and angle to midline were measured in panoramic radiographs and CBCT scans in 58 consecutive patients with 64 PDCs. Kappa with linear weighting was used to assess the agreement between the measurements of PDC sector position and Bland-Altman limits of agreement to assess the agreement between the PDC angular measurements in the 2 methods.

RESULTS

PDC sector position and angle to midline had systematically higher values in panoramic radiographs compared with those in the CBCT scans. The agreement of sector position between the methods was fair: weighted kappa 0.36 (95% CI 0.24-0.49). The mean difference in angle was almost 7° (95% CI 5.9°-7.9°) higher in panoramic radiographs compared with CBCT.

CONCLUSIONS

Panoramic radiographs overestimate PDC sector and angle to midline position, compared with the use of CBCT scans, but clinically the differences are quite modest. Panoramic radiographs could be considered good enough for rendering PDC position when the need for 3D information is not crucial for treatment planning.

Correlation between radiographic parameters for the prediction of palatally impacted maxillary canines

Objective:

This study aimed to identify radiographic parameters on routine orthopantomograms to aid in early diagnosis of palatally impacted canines.

Design:

Split-mouth case-control study.

Setting:

Single-centre university dental hospital.

Methods:

Thirty-three individuals with palatally impacted canines and non-impacted contra-lateral teeth were recruited. Radiographic variables angle A, angle B, angle C, distance D, sector class and depth of vertical impaction were measured for both groups. Mann–Whitney U test and Spearman’s correlation coefficient were used to analyse significant differences and association between variables with sector class and depth of vertical impaction, respectively. Logistic regression analysis determined radiographic parameters as predictors of palatal impaction.

Results:

Significant differences were seen between sector class, depth of vertical impaction and the radiographic parameters between cases and controls ( P ⩽ 0.001). For cases, strong correlation was found for angle C between the impacted canine and occlusal plane (r = −0.28, P = 0.022) and perpendicular distance D of impacted canine to the occlusal plane (r = 0.81, P ⩽ 0.001) with the depth of vertical impaction. Logistic regression analysis showed the odds of canine impaction increase with an increase in angle B and angle C.

Conclusions:

Our study showed that greater depth of vertical impaction, sector class, increased perpendicular distance and reduced angulation from occlusal plane resulted in palatal impaction of permanent maxillary canines. The odds of palatal canine impaction increase nearly twofold with every 10 increase in angle B and angle C.

Do we need CBCTs for sufficient diagnostics?-dentist-related factors

Background

The aim of this study was to assess the diagnostic accuracy of various dentoalveolar pathologies based on panoramic radiography (OPG), cone beam computed tomography (CBCT) and printed 3D models in consecutive order; and to evaluate the impact of specialisation of residents in oral surgery (OS) versus residents in orthodontics (ORTH).

Methods

Fourteen residents were recruited to evaluate nine selected cases with different dentoalveolar pathologies. The residents were given for each case an OPG, a CBCT and a printed 3D model. For each case and imaging modality, the residents were asked several questions relating to (i) diagnosis, and (ii) the request for consecutive imaging in order to enable treatment. Further, aspects like impact of specialisation (OS versus ORTH), gender and years of experience were analysed.

Results

In this study, diagnostic accuracy (i) improved for OS from OPG to CBCT (OPG 66.3%, CBCT 83.4%) and likewise for ORTH (OPG 63.7%, CBCT 78.0%). 3D models generally did not seem more useful than CBCTs. For treatment planning (ii), residents in orthodontics considered OPGs significantly more often as sufficient compared to residents in oral surgery (OR 6.3, p < 0.001). Further, the odds to request a CBCT after OPG for treatment planning is influenced by dentist-related factors: female dentists (OR 3.8) or residents with limited professional experience as dentists (OR 3.0) asked more frequently for a CBCT.

Conclusions

Overall diagnostic accuracy is decent with OPG and can be improved with CBCT. Specialisation seems to have a moderate impact on diagnostic accuracy, but influences whether a CBCT was requested for treatment planning. Based on these findings, future studies shall analyse the diagnostic accuracy of specific pathologies in higher number in order to substantiate the present findings with regard to specific pathologies.

Estimated radiation risk of cancer from dental cone-beam computed tomography imaging in orthodontics patients

Background

Radiation dose evaluation is important to cone-beam computed tomography (CBCT) for routine orthodontic treatment planning, especially for a significant proportion of children in orthodontic patients. This study evaluated the patient radiation dose and estimated the radiation cancer risk on dental CBCT according to the calculations by the Monte Carlo simulation method.

Methods

The dental CBCT scanner evaluated in this project was the i- CAT® (Imaging Sciences International Inc., PA, U.S.A.) device. Organ doses and effective doses were calculated by using personal computer-based Monte Carlo simulation (PCXMC 2.0 Rotation) software. The cancer risk resulting from the exposure to ionizing radiation was estimated by using the BEIR VII (Biologic Effects of Ionizing Radiation VII) report model, and the risk of exposure-induced death (REID) was assessed by PCXMC 2.0 Rotation software.

Results

The largest contribution to the organ dose and effective dose at Zref 83 cm positioned in the dental CBCT x-ray beam centerline was from the salivary glands (738.29μGy, 7.38 μSv). The different organ doses showed the maximum values at the different Zref locations, and the largest contribution to the organ dose and effective dose of all simulated positions was from the thyroid (928.77μGy, 37.5 μSv). The REID values in the 10-year olds (22.6 × 10^− 7, female; 19 × 10^− 7, male) were approximately double than those in 30-year olds (10.4 × 10^− 7, female; 8.88 × 10^− 7, male) for all cancers. The highest change during age range from 10 to 30 was shown in breast cancer of females.

Conclusions

Although individual cancer risk estimates as a function of gender and age are small, the concern about the risks from dental CBCT is related to the rapid increase in its use for orthodontic practice, especially in children patients.

Unexpected artefacts and occult pathologies under CBCT

Purpose

To present the most frequent occult pathologies unexpectedly encountered via cone-beam computed tomography (CBCT), with particular reference to the diagnostic role of the dentist and that of the radiographer, with a view to clarifying where the diagnostic responsibility lies.

Material and methods

A narrative literature review on the most diffused occult pathologies under CBCT was conducted, with iconographical guide as an example for each category.

Results

The most frequent forms of unexpected pathologies encountered are: the presence of foreign bodies, airway anomaly, and the presence of radio-opacity or -transparency in the maxillofacial district.

Conclusions

The orthodontists must know that they are responsible to recognize these frequent, and potentially serious, pathologies of the head and neck. If the dentist feels unable to take on this responsibility, he or she should, however, be sure to have the scans read by a specialist radiologist.

Cone Beam Computed Tomography in Orthodontics

Orthodontists treat malocclusions by applying three-dimensional forces. For years, the diagnosis of this three-dimensional condition and the related treatment plan has been based on two-dimensional imaging. Lateral and anteroposterior cephalometric, panoramic, and periapical radiographs are some of the two-dimensional radiographs routinely used in orthodontics. Despite being highly beneficial in evaluating skeletal and dental relations, these radiographs fail to provide sufficient two-dimensional information in certain cases. The purpose of this compilation is to review the use of cone-beam computed tomography in orthodontics.

Reliability of different radiographic methods for the localization of displaced maxillary canines

INTRODUCTION

The purpose of this study was to evaluate the reliability of the radiographic images of the main conventional x-ray techniques compared with the information from cone-beam computed tomography (CBCT).

METHODS

Twenty patients with unilateral or bilateral impaction of the maxillary canines had radiographic examinations by means of periapical x-rays, occlusal x-rays, panoramic x-rays, and CBCT scans. Three experienced orthodontists examined all x-rays from each patient and evaluated the radiographic images of the impacted canines. The examiners were asked to detect resorption in adjacent teeth and the buccal-palatal position of the impacted canines. Agreement between examiners was statistically tested.

RESULTS

Different diagnoses were produced by the 3 examiners regarding localization of the impacted canines and the presence or absence of root resorption of the adjacent teeth in conventional radiographic images. It appears that whereas panoramic x-ray is more sensitive in detecting resorption and tooth position, occlusal and periapical imaging have higher specificity and positive predictive value. The examiners were in good or excellent agreement when occlusal and periapicals were used for the definite diagnosis of resorption and tooth position. There was no disagreement of the examiners in CBCT images, which were used as the gold standard.

CONCLUSIONS

Conventional radiographic methods demonstrated a more subjective diagnostic procedure compared with CBCT images. CBCT is a more accurate and precise examination method compared with conventional radiography for the localization of impacted teeth and root resorption of the adjacent teeth.

Radiation dose from X-ray examinations of impacted canines: cone beam CT vs two-dimensional imaging

OBJECTIVES

To compare the radiation dose to children examined for impacted canines, using two-dimensional (2D) examinations (panoramic and periapical radiographs) and cone beam CT (CBCT).

METHODS

Organ doses were determined using an anthropomorphic 10-year-old child phantom. Two CBCT devices, a ProMax3D and a NewTom5G, were examined using thermoluminescent dosimeters. For the panoramic radiograph, a Promax device was used and for periapical radiographs, a Prostyle device with a ProSensor digital sensor was used. Both the panoramic and the intraoral devices were examined using Gafchromic-QR2 dosimetric film placed between the phantom slices.

RESULTS

ProMax3D and NewTom5G resulted in an effective dose of 88 µSv and 170 µSv respectively. A panoramic radiograph resulted in an effective dose of 4.1 µSv, while a periapical radiograph resulted in an effective dose of 0.6 µSv and 0.7 µSv using a maxillary lateral projection and central maxillary incisor projection respectively.

CONCLUSIONS

The effective dose from CBCT ranged from 140 times higher dose (NewTom5G compared to two periapical radiographs) to 15 times higher dose (ProMax3D compared to three periapical and one panoramic radiograph) than a 2D examination.