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Aim: To evaluate the impact of cone beam computed tomography (CBCT) on treatment planning for impacted maxillary canines; secondly, to identify CBCT factors influencing a change in the treatment plan; and thirdly, to assess 2D radiographic factors that can aid in selecting appropriate candidates for CBCT., Material and Methods: Patients with impacted maxillary canines and an overlap of a neighboring tooth in 2D radiographs and the suspicion of root resorption were referred for CBCT examination. An initial treatment plan was based on 2D radiographs, and the final treatment plan was established after the CBCT examination. Logistic regression analyses and t-tests were performed to evaluate differences in radiographic findings between the groups with and without a change in treatment plan., Results: The study prospectively included 125 impacted canines, and 43 (34.4%) of them had a change in treatment plan after the CBCT examination. The most common change was a modification in the direction of cantilever traction (n = 28; 22.4%), while the least common was the change in decision to remove/keep the canine (n = 4; 3.2%). The size of the alpha and lateral angles had a significant impact on the decision to change the treatment plan. Other radiographic findings did not influence a change in treatment plan., Conclusions: One-third of the canines had a change in treatment plan after supplemental CBCT examination. Canines with large alpha and lateral angles measured in the panoramic image were found to be significantly more likely to undergo changes in the initial direction of cantilever traction or changes to the canine extraction strategy following CBCT examination., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: External apical root resorption (EARR) is a side effect of orthodontic treatment that results in root shortening. However, this condition has yet to be evaluated in African Americans. The aim of this study was to determine the EARR prevalence within this ethnicity and investigate how patient and treatment-related factors contribute to root resorption., Methods: The records of 336 African Americans treated at the University of Alabama at Birmingham School of Dentistry Department of Orthodontics were retrospectively analyzed with Dolphin Imaging software. Pre-treatment and post-treatment panoramic radiographs were used to measure EARR. Resorption was recorded when final roots were at least 2 mm shorter after orthodontic treatment. Additionally, moderate and severe EARR was reported when 20% and 50% or more of the root structure was lost for any of the four maxillary incisors, respectively. The Pearson chi-square test was used to evaluate the associations of individual patient and treatment-related factors with EARR., Results: The prevalence of root resorption with 2 mm or greater of root structure loss was 51.8%. The prevalence of ≥ 20% EARR was 29.8%. Only one patient displayed severe resorption (0.3%). The associations between the patient-specific and treatment-specific variables and EARR were not statistically significant (P > .05)., Conclusions: More than half of the African American patients exhibit at least 2 mm of root resorption with orthodontic treatment. However, in this ethnicity, patient-related factors such as age, gender, dental malocclusion, and skeletal classifications, as well as treatment-related factors do not indicate a significant correlation with the risk of developing EARR., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background/objective: Orthodontic alignment of impacted upper canines is desirable for functional and aesthetic reasons, but time-consuming and difficult. Estimated treatment time is thus an important factor in treatment planning, its predictability based on hitherto available two-dimensional radiological measurements, however, quite limited (max. 39.1-42%). We thus aimed to improve treatment time prognosis of palatally impacted upper canines based on a three-dimensional quantification of eruption path length in baseline cone-beam computed tomographical (CBCT) diagnostic data., Materials and Methods: Baseline CBCT and orthopantomogram (OPT) data and treatment times of 30 adolescent non-syndromic/cleft orthodontic patients with an unilaterally palatally impacted upper canine, aligned by fixed orthodontic non-extraction traction treatment (closed eruption), were retrospectively analysed. Eruption path length was quantified by conventional two-dimensional and new three-dimensional methods, correlated with time to canine alignment and a prediction equation derived by linear regression., Results: CBCT and OPT eruption path length and time to canine alignment did not show significant gender, age, or impaction side differences, but CBCT methods a distinct correlation (r = 0.856/0.844, P < 0.001) and high concordance [Lin's concordance correlation coefficient (CCC) = 0.9438]. Linear regression yielded a predictability (r2 × 100%) of time to canine alignment from eruption path length of 73.3 per cent (CBCT trigonometry), 71.3 per cent (CBCT-simplified), and 50.0 per cent (OPT), respectively., Limitations: The proposed model for treatment time prediction is only valid for eruption path lengths up to 8 mm. In some cases of canines being defined as impacted, these may have had the potential of spontaneous eruption. Possible inter-individual differences have to be considered., Conclusions: Treatment time prediction for alignment of impacted upper canines can be achieved at an improved certainty of up to 73.3 per cent by the proposed CBCT methods for quantifying eruption path length compared to OPT measurements. Due to absence of gender, age, and impaction side differences, the derived regression formula should be universally usable in non-syndromic/cleft adolescents with palatally impacted upper canines.

Objectives: The aim of this study was to determine whether cone beam computed tomography is a reliable radiological method to diagnose tooth ankylosis., Materials and Methods: A series of teeth clinically diagnosed as ankylosed were collected after extraction in a private practice from 2009 to 2015 and analyzed retrospectively. Inclusion criteria comprised permanent molars extracted due to failed tooth eruption in the absence of any visible mechanical obstruction, existing panoramic view (PV), and cone beam computed tomography (CBCT) and histological sections of sufficient quality. The CBCT scans and PVs were evaluated twice for signs of ankylosis by two independent observers using the following score: clear signs, possible signs, and no signs. The histological sections were evaluated and graded similarly to the radiographs by a specialist blinded to the radiographs and treatment., Results: Out of an initial group of 22 patients, 9 subjects with 10 affected teeth were included for final evaluation. The age ranged from 8.3 to 17 years. No agreement was seen in comparing the PV scores to the histological sections. Fair to moderate agreement was seen in comparing the CBCT scores to the histological sections. All histologically confirmed ankylosis were detected in CBCT by both observers but some false positive results were found., Limitation: Only a small sample size was available as the disorder is rare. It is difficult to distinguish ankylosis from primary failure of eruption., Conclusion: CBCT images can be a useful adjunctive diagnostic tool to diagnose ankylosed teeth, but cannot be recommended as a single diagnostic modality as false positive results were found.

Objectives: To determine and compare the differences in dental age (DA) and chronological age (CA) of Demirjian and Willems methods in 9- to 11-year-old Caucasian boys and girls born with non-syndromic unilateral cleft lip and palate (NSUCLP) to an age-matched control group. Analysis of the results is undertaken to determine whether there are differences between gender, groups, and methods., Materials and Methods: Dental panoramic tomograph (DPT) of 108 children with NSUCLP aged from 8.79 to 10.99 years (x¯=10.05  ±   0.36) were compared to 107 control children. Age, gender, and group were blinded during examination. The Demirjian and Willems methods were used by both authors to visually examine the radiographs. Differences between DA and CA were determined with a repeated two-way ANOVA., Results: Inter-examiner reliability was good (ICC ≈ 0.75). For each of the methods used, the mean DA/CA difference was greater in the control group than in the NSUCLP group (P = 0.011). The control group's Demirjian mean DA/CA difference was 1.08 years and Willems mean was 0.46 years, compared to the NSUCLP group's Demirjian mean DA/CA difference 0.83 years and Willems mean 0.22 years. Only the Willems method determined a statistically significant gender difference (P = 0.000)., Conclusions: The null hypothesis was rejected. Willem's method as compared to Demirjian's displayed greater accuracy in estimating CA. Both methods overestimated CA but detected DA delay in NSUCLP children compared to the control group. However, the methods were inconsistent in estimating gender CA., (© The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com)

Background: Examination with Cone Beam CT (CBCT) is common for localizing maxillary canines with eruption disturbance. The benefits and costs of these examinations are unclear., Objectives: To measure: 1. the proportion of orthodontists' treatment decisions that were different based on intraoral and panoramic radiography (M1) compared with CBCT and panoramic radiography (M2); and 2. the costs of producing different treatment plans, regarding patients with maxillary canines with eruption disturbance., Subjects and Methods: Orthodontists participated in a web-based survey and were randomly assigned to denote treatment decisions and the level of confidence in this decision for four patient cases presented with M1 or M2 at two occasions for the same patient case., Results: One hundred and twelve orthodontists made 445 assessments based on M1 and M2, respectively. Twenty-four per cent of the treatment decisions were different depending on which method the raters had access to, whereof one case differed significantly from all other cases. The mean total cost per examination was €99.84 using M1 and €134.37 using M2, resulting in an incremental cost per examination of €34.53 for M2., Limitations: Benefits in terms of number of different treatment decisions must be considered as an intermediate outcome for the effectiveness of a diagnostic method and should be interpreted with caution., Conclusions: For the patient cases presented in this study, most treatment decisions were the same irrespective of radiological method. Accordingly, this study does not support routine use of CBCT regarding patients with maxillary canine with eruption disturbance., (© The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com)

Objectives: To investigate the effects of orthodontic non-extraction treatment with or without headgear on the position of and the space available for upper third molars in growing children with class II malocclusions., Materials and Methods: The sample consisted of pre- and post-treatment panoramic radiographs and lateral cephalograms of 294 class II orthodontic patients; 160 were treated with headgear and 134 were treated without headgear. The space available for the upper third molar was measured on the lateral cephalogram as the distance from pterygoid vertical (PTV) to the distal surface of the upper first molar crown (PTV-M1). Angulation, vertical position and tooth development stage of the upper third molars were evaluated on panoramic radiographs. All measurements were evaluated statistically., Results: In both groups PTV-M1 increased, but the increase in PTV-M1 was significantly higher for patients treated without headgear. A linear model for repeated measures revealed that this difference was still significant after correction for age, gender and molar occlusion. Further, there is no evidence that the change in angulation, vertical position and development stage of the upper third molars during orthodontic treatment is influenced by headgear therapy., Conclusion: This study indicates that the use of headgear in growing patients significantly affects the space available for upper third molars. However, orthodontic treatment with headgear does not influence the angulation, vertical position and development stage of upper third molars. It is therefore important to always take into account third molars during treatment planning., (© The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Background: Ectopic eruption and/or impaction of maxillary permanent canines is a frequent problem in clinical dentistry. Previous studies aimed to identify potential associated factors and predictors for impacted maxillary canines have only used conventional univariate statistics, which does not allow the analysis of the interaction between and within variables. Multivariate data analysis (MVDA) is a better and more powerful tool for the integration and interpretation of complex datasets., Aim: The aim of this study was to validate previously explored predictors of permanent maxillary canine impaction using MVDA., Subjects and Methods: This cohort study included all the patients referred during 2011 to Mölndal Hospital, Sweden for surgical exposure of impacted canines (N = 45). Age- and gender-matched orthodontic patients (N = 45) with normally erupting canines comprised the control group. The age range for both groups was 11-17 years. The positions of the canine teeth (orthopantograms), the skeletal variables (profile radiographs), and dentoalveolar traits (casts) were evaluated as potential predictive factors for impaction., Results: None of the parameters evaluated with either profile radiography or casts were positively correlated with impacted maxillary canines, with the exception of the location of the already impacted canines, as identified by orthopantogram., Conclusion: No correlation between clinical variables and impaction was found using MVDA. Therefore, these variables could not be used as predictors of canine impaction. Other types of parameters, such as inheritance and molecular factors that regulate the biological mechanisms of the eruption process, need to be further investigated., (© The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com)

Objective: The objective of this study was to evaluate whether the calcification stages of maxillary canine, mandibular second molar, and mandibular third molar can be used for assessment of growth phase., Materials and Methods: The study group consisted of 274 subjects. Pre-treatment digital panoramic and lateral cephalometric radiographs of the patients were analysed. The patients' age was ranging from 7 to 19 years. Right maxillary canine, mandibular second molar and third molar were used as a sample. The teeth mineralization was assessed using modification of Gleiser and Hunt method. The skeletal maturation was assessed by the cervical vertebrae maturation (CVM) method., Results: A significant association was found between CVM stage 2 and maxillary canine (UC) stage 4, mandibular second molar (LM2) stage 4, and mandibular third molar (LM3) stage 1. CVM stage 3 corresponded with UC stage 5, LM2 stage 5, LM3 stage 2. CVM stage 4 matched with UC stage 5, LM2 stage 6 and LM3 stage 3. The highest correlations between CVM and calcification stages were in the group of the maxillary canine (r = 0.812, P < 0.01) and mandibular second molar (r = 0.824, P < 0.01)., Limitations: Limitation of our study was that the study sample was not very big and the distribution value in the groups was very high, so it was impossible to check more statistical parameters., Conclusions: The calcification stages of UC, LM2, and LM3 as indicators of skeletal maturity could be clinically used with caution, until this method is verified with a larger sample group., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: The aim was to identify a prediction model for root resorption (RR) caused by impacted canines based on radiographic variables assessed on 2D panoramic radiographs with the intention to reduce the need for additional cone beam computed tomography (CBCT) imaging., Materials and Methods: Three hundred and six patients (188 female, 118 male; mean age, 14.7 years; standard deviation, 5.6; range, 8.4-47.2 years) were included in the study. In total, 406 impacted maxillary canines were studied, from 206 patients with unilateral impaction and from 100 patients with bilateral impaction. Initial 2D panoramic radiography was available, and 3D CBCT imaging was obtained upon clinical indication. The generated radiographic variables and specific features investigated were collected on 2D panoramic imaging and were correlated to the presence/absence of RR detected on CBCT. A validation sample consisting of 55 canines from 45 patients with maxillary canine impactions was collected to validate the outcome of the present study., Results: The incidence of RR of the adjacent teeth was 33.8%. A prediction model using panoramic images for the possible presence of RR was established [area under the curve (AUC) = 0.74, 95% confidence interval (CI): 0.69-0.79] and validated by applying leave-one-out cross-validation (AUC = 0.71, 95% CI: 0.66-0.77). For the subgroup of presence of severe RR the discriminative ability increased to 0.80. In this prediction model, patient gender, canine apex, vertical canine crown position, and canine magnification were the strongest predictors for RR., Conclusions: The final prediction model for RR based on available panoramic radiographs could be a helpful tool in justifying the need of additional CBCT examination., (Published by Oxford University Press on behalf of the European Orthodontic Society 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Objectives: Children are especially vulnerable to harmful effects of ionizing radiation. Cutting down the dimensions of the X-ray beam is the most effective way to reduce the patient dose. We evaluated the appropriateness of field-size in the most frequent radiographs, dental panoramic tomographs (DPTs) and lateral cephalometric radiographs (LCRs) among 7- to 12-year-olds., Materials and Methods: The image field-size of 241 DPTs and 118 LCRs was analysed. The image field was considered appropriate when it did not include anatomic structures beyond the area of clinical interest. The image field was compared with factors such as the age of the patient, the radiographic equipment used and the programme selected. Moreover, we assessed the use of thyroid shield in LCR., Results: The field-size was too large in 70% of the DPTs horizontally and in 96% vertically. None of the DPTs were segmented. Every LCR showed appropriate limitation anteriorly, but the image field was too large in 54% posteriorly, in 86% superiorly, and in 76% inferiorly. A thyroid shield had been used in only 71% of cases., Conclusion: Most DPTs and LCRs had been performed sub-optimally. An abundancy of DPTs had been taken using an adult programme, and the field-size had not been sufficiently adjusted in LCRs, possibly for technical reasons. To facilitate adherence to radiological best practice the equipment used for DPTs and LCRs should facilitate the adjustment of field-size in both the vertical and horizontal planes. In addition, those involved in taking radiographs should maintain their skills through regular update courses., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Numbers of dental panoramic tomographs (DPTs) and lateral cephalometric radiographs (LCRs) outweigh other radiographic examinations in 7- to 12-year-old Finns. Orthodontists and general practitioners (GPs) involved in orthodontics hold therefore the highest responsibility of the exposure of children to ionising radiation with its risks. Against this background, lack of reports on the quality of orthodontic radiography is surprising. The purpose of our study was to shed some light and draw the awareness of the orthodontic community on the subject by analyzing the quality of orthodontic radiography in Oral Healthcare Department of City of Helsinki, in the capital of Finland., Materials and Methods: We analyzed randomly selected 241 patient files with DPTs and 118 patient files with LCRs of 7- to 12-year-olds for the indications of radiography, quality of referrals, status of interpretation, and number of failed radiographs., Results: The majority of DPTs (95%) and all LCRs had been ordered for orthodontic reasons. Of the DPTs, 60% were ordered by GPs, and of the LCRs, 64% by orthodontists. The referrals were adequate for most DPTs (78%) and LCRs (73%), orthodontists being responsible for the majority of inadequate referrals. Of the DPTs, 80% had been interpreted. Of the LCRs, 65% lacked interpretation, but 67% had been analysed cephalometrically. Failed radiographs, leading to repeated exposure, were found in 2-3%., Conclusion: The quality assessment revealed that orthodontic radiography may not completely fulfill the criteria of good practice. Our results stress further need of continuing education in radiation protection among both orthodontists and GPs involved in orthodontics., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: The purpose of this study was to evaluate the alveolar bone dimensions and arch perimeter discrepancy in unilateral palatally impacted canines., Methods: This retrospective split-mouth study reviewed 207 cone-beam computed tomography (CBCT) scans of patients with unilateral or bilateral impacted canines referred for orthodontic treatment. Out of 207 CBCT scans, only 39 scans in which canines were unilaterally palatally impacted were approved for the study based on our inclusion and exclusion criteria. Two fiducial lines were used to orient the examiners and standardize the measurements. Arch perimeter, buccopalatal (BP) width, and alveolar height were measured both on the impacted and non-impacted side. Two different examiners measured all the parameters. A one-sample Kolmogorov-Smirnov test was used to examine normality of distribution of outcomes. Wilcoxon Signed Rank tests were used for comparing arch width and alveolar bone height between the impacted and non-impacted sides. For arch perimeter, the paired-sample t-test was used., Results: The arch perimeter, BP width, and alveolar bone height was significantly decreased on the impacted side (P < 0.05). The mean arch perimeter on the impacted side was 41.7 ± 2.5mm compared to 43.5 ± 2.37 on the non-impacted side. Similarly, BP width and alveolar bone height on the impacted side was 6.87 ± 1.08 mm and 18.12 ± 2.28 mm, respectively, whereas on the non-impacted side was 8.70 ± 1.13 mm and 19.49 ± 2.09 mm, respectively., Conclusion: There was a significant decrease in the arch perimeter and alveolar bone dimensions (BP width and alveolar bone height) on the impacted side., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background/objectives: To compare different imaging procedures [cone beam computed tomography (CBCT), computed tomography (CT), magnetic resonance imaging (MRI), orthopantomography (OPG), and lateral cephalometry (LC)] for assessing the mandibular height [ramus height (RH)] and condylar process (CondProc) length as they reflect mandibular growth., Materials/methods: The RH and CondProc of eight cadaver heads (each side separately) were measured using CBCT, CT, MRI, OPG, and LC. They were measured twice by two independent observers parallel to the posterior border of the mandibular ramus. An intraclass correlation coefficient (ICC) was used to assess the inter- and intraobserver reliability. The coefficient of variation was used to elucidate precision. Bland-Altman (BA) plots were used to assess the agreement between the procedures and the intra- and interobserver measurements., Results: All procedures, with the exception of LC, showed good intra- and interobserver agreement (maximum range of agreement: 5.3mm) and excellent reliability (ICC > 0.9). The BA plot analysis for the CondProc and RH showed similar ranges of agreement between MRI, CT, and CBCT (maximum 6.4mm) but higher ranges for OPG and LC. The MRI and OPG values were generally smaller., Conclusions/implications: All 3D imaging procedures yielded nearly equal results when used to measure the CondProc and RH. MRI is recommended because it avoids ionizing radiation and has higher sensitivity in the detection of inflammation. A 2-year threshold for detecting growth in the follow-up period should be taken into account for all 3D imaging methods. Measuring the RH is recommended for the follow-up of condylar growth because reference values for annual increments are published., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: The aim of this study was to compare the orthodontic treatment planning for impacted maxillary canines based on conventional orthodontic treatment records versus three-dimensional (3D) information taken from single cone beam computed tomography (CBCT) scans., Materials and Methods: This study consisted of 40 individuals with impacted maxillary canines. Patients were identified from among those referred for orthodontic treatment (26 females, 14 males) with a mean age of 12.5 years (± SD 3). In total, 64 impacted canines were identified, justifying the need for CBCT scans by the treating orthodontist. Two sets of information were obtained. The first set consisted of conventional planning records [two-dimensional (2D) panoramic, 2D lateral cephalograms, and dental casts] and the second set of 3D volumetric images obtained from a single CBCT scan (3D panoramic, 3D lateral cephalograms, 3D virtual study model). For both sets, intra- and extraoral images were included. The radiographic diagnostic features, treatment planning, orthodontists' opinions, and case classifications of both sets were produced and subsequently analysed by four orthodontists., Results: There was no statistically significant difference in treatment planning between the use of both sets, in terms of either orthopaedic growth modification or orthodontic compensation. Also, anticipated complications during treatment and expected treatment duration did not differ significantly. Orthodontists found the conventional set to be insufficient for treatment planning in 22.5 per cent and requested additional radiographs needed in 63 per cent of cases, compared with 1.3 and 0.5 per cent, respectively (P < 0.001). The observers' confidence level was higher for therapy based on the 3D set compared with the conventional set (96.3 per cent versus 61.9 per cent, P < 0.001)., Conclusions: There was no statistically significant difference in treatment planning between the use of conventional and CBCT sets. CBCT images have been shown to offer useful orthodontic treatment planning information similar to that of conventional planning with a high confidence level., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The aim of this study was to evaluate whether there is any difference in the diagnostic information provided by conventional two-dimensional (2D) images or by three-dimensional (3D) cone beam computed tomography (CBCT) in subjects with unerupted maxillary canines. Twenty-seven patients (17 females and 10 males, mean age 11.8 years) undergoing orthodontic treatment with 39 impacted or retained maxillary canines were included. For each canine, two different digital image sets were obtained: (1) A 2D image set including a panoramic radiograph, a lateral cephalogram, and the available periapical radiographs with different projections and (2) A 3D image set obtained with CBCT. Both sets of images were submitted, in a single-blind randomized order, to eight dentists. A questionnaire was used to assess the position of the canine, the presence of root resorption, the difficulty of the case, treatment choice options, and the quality of the images. Data analysis was performed using the McNemar-Bowker test for paired data, Kappa statistics, and paired t-tests. The findings demonstrated a difference in the localization of the impacted canines between the two techniques, which can be explained by factors affecting the conventional 2D radiographs such as distortion, magnification, and superimposition of anatomical structures situated in different planes of space. The increased precision in the localization of the canines and the improved estimation of the space conditions in the arch obtained with CBCT resulted in a difference in diagnosis and treatment planning towards a more clinically orientated approach.

The aim of the present study was to determine any association between tooth transposition and bridging of the sella turcica, given the evidence of common embryonic origins associated with these structures and a genetic basis underlying these two conditions. Clinical records of subjects demonstrating dental transposition and normal controls were collected from several hospital orthodontic departments and specialist orthodontic practices. All cases and controls were documented with good quality lateral cephalometric radiographs and dental panoramic tomograms (DPTs). The study sample consisted of 21 Caucasian subjects (7 males and 14 females; mean age 14.5 years; SD 2.2 years), demonstrating either maxillary or mandibular dental transposition. The control group, matched for age and gender to the study sample, comprised 70 Caucasians (31 males and 39 females; mean age 13.8 years; SD 1.8 years) without dental anomalies randomly selected from subjects referred for orthodontic treatment within the same departments. The extent of sella turcica bridging was quantified from each profile radiograph using comparative measurement of length and diameter. Sella turcica bridging was found more frequently in subjects diagnosed with dental transposition than in the controls, with the difference being statistically significant [chi-square=7.4; degrees of freedom (df)=2; P=0.025; Fisher's exact test; P=0.042]. The increased frequency of complete and partial bridging of the sella turcica in subjects with dental transposition provides further evidence of a genetic basis to this condition. As calcification and bridging of this region can present during early childhood, it may act as a useful diagnostic predictor of susceptibility to local dental problems.

The diagnostic accuracy for the localization of impacted canines and the detection of canine-induced root resorption of maxillary incisors were compared between conventional radiographic procedures using one two-dimensional (2D) panoramic radiograph with that of two three-dimensional (3D) cone beam computed tomography (CBCT) scans. The clinical records of 60 consecutive patients who had impacted or ectopically erupting maxillary canines were identified from those seeking orthodontic treatment. For each case, two sets of radiographic information were obtained. The study sample was divided into two groups: group A (n = 30) included those for whom a dental pantomograph (DPT) and CBCT obtained with a 3D Accuitomo-XYZ Slice View Tomograph were available and group B (n = 30) who had a DPT and CBCT obtained with a Scanora. The DPT and CBCT images were subsequently analysed by 11 examiners. Statistical analysis included an evaluation of the agreement between observers based on the standard error of the measurement, kappa statistics and coefficient of concordance, as well as an assessment of the differences between 2D and 3D imaging employing Wilcoxon signed rank and McNemar tests. There was a highly significant difference between the 2D and 3D images in the width of the canine crown (P < 0.001) and in canine angulation to the occlusal plane. Moreover, there was a highly significant difference between the DPT and Scanora CBCT images in canine angulation to the midline (P < 0.001). There was also a significant difference between 2D and 3D images with respect to canine location (P = 0.0074 for group A and P = 0.0008 for group B). The presence or absence of root resorption of the lateral incisor was also significantly different in both groups (P = 0.0201 and P < 0.001 for groups A and B, respectively). Detection of central incisor root resorption was significantly different between the Accuitomo and DPT images (P = 0.045). There was also a significant difference in the severity of lateral incisor root resorption between the DPT and CBCT in both groups (P = 0.02). The results of this study suggest that CBCT is more sensitive than conventional radiography for both canine localization and identification of root resorption of adjacent teeth.

The purpose of the study was to analyse longitudinal vertical facial and dentoalveolar changes using panoramic radiographs (PRs) and to compare the results with measurements on lateral cephalometric radiographs (LCRs) in order to determine whether, under certain circumstances, the radiation dose for a patient may be reduced by taking only a PR instead of a PR and a LCR. Pre- and post-treatment PRs and LCRs of 30 (15 females and 15 males) orthodontically treated adolescents (mean age pre-treatment 10.9 years, post-treatment 13.4 years) were analysed using Pearson's correlation coefficients and gender differences using Fisher's z-transformation. The results revealed that most variables exhibited larger absolute values on PRs than on LCRs. Comparison of dentoskeletal morphology between the LCRs and the PRs revealed moderate to high, mostly statistically significant, interrelations both before and after orthodontic treatment. The lowest correlations were found for the maxillary jaw base angle (NL/H; r= 0.35***) and the highest for the gonial angle (ML/RL; r = 0.90***). However, when assessing the combined growth and treatment changes from before to after treatment, only weak to moderate, not statistically significant, interrelations were found between LCRs and PRs. Anterior face height (AFH; r = 0.43***), the mandibular plane angle (ML/H; r = 0.06*), and the distance of the incisal tip of the most extruded mandibular incisor to the ML-line (ii-ML; r = -0.21*) were the only statistically significant parameters. The average group differences for growth and treatment changes, however, were small for most parameters. Analysis of vertical facial and dentoalveolar parameters on PRs delivers a moderate approximation to the situation depicted on LCRs. However, PRs cannot be recommended for the analysis of individual longitudinal changes in vertical facial and dentoalveolar parameters.

This study compared two different radiographic techniques for localization of impacted maxillary canines: vertical parallax (from a panoramic and a maxillary anterior occlusal radiograph) and magnification (from a single panoramic radiograph). The radiographs and the information regarding the impacted canines were obtained retrospectively from records of patients treated in the Day Stay Unit of the Eastman Dental Hospital. The two different radiographic techniques were tested blind and compared for localization of the impacted canine by six examiners. The 'gold standard' used for the radiographic comparisons was the true position of the canine as recorded at operation. The results showed a wide variation between the six examiners in the prediction of the canine position with the two different techniques. Localization with vertical parallax was more successful overall than with magnification, although the difference failed to reach significance. Seventy-six per cent of the impacted canines could be successfully located with vertical parallax and 66 per cent with magnification. Further analysis showed that, while almost 90 per cent of the palatally impacted canines could be correctly detected with both techniques, less than half of the buccal canines could be detected with parallax and only one in 10 buccal canines could be detected with magnification. If a canine is suspected to be buccally placed from its appearance on a panoramic film and cannot be palpated, further views are justified.