Effect of impacted maxillary canines on adjacent lateral incisor root resorption: Association with alveolar bone thickness, incisor angulation, and traction difficulty: A retrospective CBCT study.

Objective: To assess the relationship of ɑ and ß angles of maxillary impacted canines with maxillary lateral incisor root resorption. Material and Methods: For this, 40 patients (between 11 and 45 years) with impacted maxillary canines presenting to a private orthodontic clinic were evaluated.20% of the cases were male and 80% were female. The ɑ and ß angles were measured on panoramic radiographs to determine the angulation of impacted canine. CBCT scans had been taken by ProMax 3D CBCT system were used to examine lateral root reorption. The relationship between the size of ɑ and ß angles of impacted maxillary canines and root resorption in the adjacent maxillary lateral incisor was analyzed using SPSS version 22. Results: The mean size of ɑ and ß angles had no significant correlation with the presence/absence, location, or severity of root resorption in the adjacent lateral incisor or the buccolingual position of impacted canine. The ɑ and ß angles in impacted maxillary canines cannot be used to determine the incidence or severity of root resorption in the adjacent lateral incisor. Conclusion: No significant association between ɑ and ß angles and incidence or severity of root resorption in the adjacent lateral incisor was found.

ABSTRACTObjective:The current cross-sectional study aimed to assess the relationship between impacted maxillary canines and their effect on root resorption of neighboring teeth using cone-beam computed tomography (CBCT).Materials and Methods:The study evaluated the effect of 24 impacted maxillary canines on the adjacent tooth roots. We used a CBCT to evaluate the position and size of the dental follicle of impacted maxillary canines and the severity of root resorption on adjacent teeth. We used a t-test to compare the significant differences between the width of the dental follicle and the severity of root resorption. The inter- and intra-rater agreements were assessed.Results:A number of 12 impacted canines had resorbed the roots of adjacent teeth. Lateral incisors were most affected (83.3%), followed by central incisors (16.7%). Mild root resorption was found in 10 cases, while severe resorption was found in two cases. We found no relation between the size of the dental follicle and the degree of root resorption. The inter- and intra-rater agreements were high.Conclusion:In cases with maxillary impacted canines, special consideration should be directed to the roots of the maxillary lateral incisors. Our findings could not confirm any relationship between the size of the dental follicle width of the maxillary impacted canines and the degree of root resorption of the adjacent incisors. More studies are needed to assess the proximity and path of eruption of impacted maxillary canines and their effect on the neighboring teeth.

The management of palatally displaced maxillary canines: Considerations and challenges

Can the severity of root resorption be accurately judged by means of radiographs? A case report with histology

Aim: Through the use of CBCT images, many unidentified features of impacted canines can be easily resolved. The potential collision of impacted maxillary canines and adjacent teeth could lead to root resorption (RR). The aim of this study is to examine the prevalence, location and severity of RR on adjacent teeth caused by impacted maxillary canines and the association between the adjacent teeth and the features of maxillary impacted canines on CBCT. Methods: This study examined 89 subjects with 108 maxillary impacted canines, having had no previous orthodontic treatment (mean age: 18.3 ± 4.1 years). The following impacted-canine-related parameters were analyzed on the CBCT images: location; RR levels on adjacent teeth; occlusal line and midline distances of impacted canines; and the angulations of impacted canines to the midline, lateral incisor and occlusal line. Logistic regression was used to evaluate the association between RR and the measured parameters on CBCT. Results: In this study, we found that the majority of our patients with impacted maxillary canines were female (62.5%). Of the total 108 maxillary impacted canines, 60.2% resorbed the adjacent teeth of the affected quadrants. Lateral incisors were the most affected (34.3%). The mean age of subjects with RR was 16.7 ± 3.5 years. The frequency of RR was statistically significantly higher in female subjects (40.4%). Slight RR was the most frequent (30.5%) and the highest incidence noted at the apical third of the root (29.6%). Regarding the impacted maxillary canine angulation to the midline and adjacent tooth, higher values of angulation caused severe forms of RR (p < 0.05). Conclusion: The sensitivity of CBCT allows for the accurate diagnosis of the location and the degree of RR, alongside the angulation and distance of impacted canines to adjacent teeth. The association between the linear and angular features of the impacted maxillary canines and RR was confirmed.

ABSTRACTObjectivesThis study aimed to assess the predictive factors of root resorption in lateral incisors adjacent to impacted maxillary canines using cone‐beam computed tomography.Material and MethodsIn this retrospective descriptive‐analytic study, 150 samples of impacted canines from 138 CBCT images were collected from the files of 12–35‐year‐old patients. The association between the severity and location of root resorption in lateral incisors adjacent to impacted maxillary canines and the patients’ age, sex, impacted canine's angulation, position, and follicle size was evaluated. Position and angulation of the impacted teeth were measured using the OnDemand3D software. Kruskal–Wallis test, Fisher's exact test, Mann–Whitney test, Kolmogorov–Smirnov test, Spearman's rank correlation coefficient, and multinomial logistic regression were used for data analysis.ResultsThe probability of resorption in the middle‐third of the roots of lateral incisors decreased by 20% with each millimeter of increase in the distance between the impacted canines’ cusp tip from the occlusal plane (p = 0.009). There was a significant association between the severity of lateral incisors’ root resorption and sex; root resorption was significantly more severe in females (p = 0.029).ConclusionsAmong the evaluated variables, the vertical position of the impacted canine influenced the location of the lateral incisors’ root resorption. The severity of root resorption was higher in females.

The aim of this study was to investigate the effect of impacted maxillary canines on root resorption and periodontal tissues of adjacent central, lateral, and premolar teeth across different age groups using Cone Beam Computed Tomography (CBCT) imaging. CBCT images of 203 impacted maxillary canines from patients of varying ages were retrospectively evaluated. Parameters included eruption stage, localization (right/left and palatal/buccal/central), dental follicle characteristics (shape and width), contact with adjacent teeth, periodontal contour integrity, and degree and location of root resorption. Statistical analyses assessed the relationships between these variables. A total of 203 impacted maxillary canines, including 123 on the right and 80 on the left side, were assessed. Impacted canines were most commonly affected with lateral teeth (57.6%). Root resorption occurred in 33.3% of these lateral teeth, with 14.5% showing severe resorption. Mild resorption was most frequently observed in central incisors and first premolars (16.7% and 12.5%, respectively). Root resorption was significantly more frequent when impacted maxillary canines were in contact with adjacent teeth (p = 0.005 for central incisors, p < 0.001 for lateral incisors, and p = 0.012 for premolars). No significant difference was found between genders in terms of root resorption (p > 0.05). Impacted canines were most commonly located in the palatal position (73.4%), but no statistically significant difference was found in root resorption rates between palatal, buccal, and central positions (p = 0.490). Canine follicle shape, width, and eruption stage did not significantly affect root resorption (p > 0.05). Palatal position and contact of impacted maxillary canines with adjacent teeth increase root resorption frequency, especially affecting lateral incisors. CBCT provides accurate diagnostic information that supports clinical decision-making for impacted canine cases.

The maxillary permanent canine is one of the most frequently impacted teeth, which often requires multidisciplinary management. A common complication of canine impaction is root resorption of the adjacent dentition. The aim of this retrospective study was to report the prevalence of root resorption of maxillary incisors adjacent to impacted maxillary canines from small volume CBCT images by trained clinicians. A secondary objective was to report the location and severity of root resorption. CBCT images of patients with impacted maxillary canines (unilateral and bilateral) who attended a joint orthodontic/surgical multidisciplinary clinic were screened. Descriptive statistics were used to investigate associations of patient characteristics and presence of root resorption. Generalized estimating equations (GEE) logistic regression model were used to identify predictors of root resorption. In all, 148 impacted maxillary canines (122 patients) were analysed. The majority of patients were under 18 years of age (71.6%) with impacted canines present in more females (68.2%) than males (31.8%). Maxillary lateral incisors showed the highest prevalence of root resorption (38.5%). The apical region was the most common location of resorption for lateral incisors (20.9%) with a variable degree of severity evident: slight (10.1%), moderate (15.6%), and severe (12.8%). Although no significant predictors of root resorption were identified, a weak association was evident for age and root development. In this cohort of patients, the roots of maxillary lateral incisors are most likely to suffer from root resorption in the presence of an impacted maxillary canine. Clinicians should consider the extent, location and severity of resorption of adjacent teeth when planning treatment decisions and mechanics in cases of impacted maxillary canines.

Apical root resorption of incisors after orthodontic treatment of impacted maxillary canines: A radiographic study

Objective: To analyze the external root resorption of incisors caused by maxillary canine impaction, and to explore the changes of incisor external root resorption after orthodontic treatment. Methods: Twenty-four patients with impacted maxillary canines leading to external root resorption of incisors treated in Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University from July 2011 to January 2019 were selected. The age ranged from 10 to 14 years [(12.3±1.6) years], including 11 males and 14 females. The maxillary incisors with external root resorption before treatment were included in the resorption group (21 central incisors and 22 lateral incisors), and the maxillary incisors without external root resorption were used as the control group (26 central incisors and 21 lateral incisors). Cone-beam CT was taken before treatment, immediately after treatment and one year after treatment. At the one year follow-up 15 patients were collected (10 central incisors and 12 lateral incisors in the resorption group, while 16 central incisors and 12 lateral incisors in the control group). The root length and tooth volume of maxillary incisors were measured and analyzed before canine traction, after canine traction finished and at the one year follow-up. Results: After the treatment of maxillary impacted canines, the root length and volume of the central and lateral incisors in both resorption group and control group were significantly less than that before treatment (P<0.05). At the one year follow-up, the root length and volume of the incisors (central incisors in the resorption group and the central and lateral incisors in control group) were significantly less than those immediately after impacted canine traction (P<0.05). During the canine traction, the difference of the volume change in lateral incisors between the resorption group [(17±6) mm3] and the control group [(12±5) mm3] was statistically significant (t=2.51, P<0.05). During the one year follow-up period, the difference between the changes of the root length in maxillary central incisors in the resorption group [(0.5±0.4) mm] and in the control group [(0.2±0.1) mm] was statistically significant (t=2.35, P<0.05). Conclusions: For maxillary incisors with external root resorption caused by impacted maxillary canines, the external root resorption could not stop immediately after the treatment of impacted canines. The root resorption in maxillary lateral incisors mainly occured during the traction process, while the root resorption in maxillary central incisors existed during the orthodontic treatment and in the follow-up period.

The aim of this study was to retrospectively determine the prevalence of severe external root resorption in maxillary inci- sors during fixed orthodontic treatment and to evaluate the possible predisposing factors. The treatment records of 7000 patients who had been treated between 1990 and 2019 at the Department of Orthodontics Faculty of Dentistry Marmara University were examined, and a total of 120 patients with severe root resorption in at least one of their upper incisors were identified. The following data were retrieved from the patients' records and radiographs: gender, root morpholo- gy, overjet, overbite, treatment modality (extraction, non-extraction), treatment duration, buccal and palatal alveolar bone thickness for the maxillary incisors, and amount of movement of the incisal root apices and incisal edges. These data from a group of 90 patients with severe root resorption were compared with the data from a control group of 90 patients with minimal root resorption. The Chi- square test, the Mann-Whitney U-test, and the independent t-test were used for statistical analysis. The prevalence of severe external root resorption was 3.23%, and the results demonstrated significant difference between the groups for the variables of treatment modality (extractions), treatment duration, thickness of the alveolar bone, and amount of incisor movement at the end of the treatment. It can be concluded that extractions, increased treatment duration, thin alveolar bone, and excessive incisor movement represent risk factors for severe root resorption in maxillary incisors following orthodontic treatment.

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BackgroundThis study aimed to investigate the potential associations between alveolar bone thickness, bucco-palatal inclination of maxillary lateral incisors, and lateral incisor root resorption in patients with unilateral maxillary impacted canines (UMICs).MethodsA total of three hundred and five subjects (120 males, 185 females; mean age, 16.39 years; standard deviation, 4.04) with UMICs were included. Canine position and root resorption were assessed using CBCT. UMICs were divided into palatal, buccal and mid-alveolus groups (PICs, BICs and MAICs), with 117, 137 and 51 subjects, respectively. Alveolar bone thickness and bucco-palatal inclination of lateral incisors were measured using the Dolphin software.ResultsThe prevalence of lateral incisor root resorption was significantly lower in the BICs (13.9%) than MAICs (29.4%) and PICs (29.1%). Alveolar bone thickness of the apical area was smaller in UMICs with lateral incisor root resorption than no resorption in both PICs (8.33 ± 1.64 vs 10.53 ± 2.55 mm) and BICs (8.94 ± 1.85 vs 10.76 ± 2.28 mm). Furthermore, lateral incisors on the impacted side were more buccally inclined in PICs with lateral incisor root resorption than no resorption, while in both BICs and MAICs, there was no statistical difference between lateral incisor root resorption than no resorption. Moreover, alveolar bone thickness of the apical area, rather than bucco-palatal inclination of lateral incisors, was significantly correlated with lateral incisor root resorption both in PICs and BICs.ConclusionsLateral incisor root resorption is less common in BICs. Thinner alveolar bone thickness at the apical area of lateral incisors can be considered as a potential risk factor for lateral incisor root resorption in UMICs.

Influence of impacted maxillary canine orthodontic traction complexity on root resorption of incisors: A retrospective longitudinal study.

Introduction The aim of this study was to determine the incidence of lateral incisor root resorption associated with impacted maxillary canines and determine predisposing factors that may be used to predict its occurrence. Methods Cone beam computerised tomographic images of 133 patients presenting with 186 impacted canines were examined for lateral incisor root resorption. A control sample consisted of 30 lateral incisors on the side of the non-impacted canine. The studied canine-associated variables were gender, type of impaction, location of the canine both meso-distally and vertically and the long axis angulation to the midline. Axial images were primarily used to diagnose resorption. Results The estimated percentage of lateral root resorption in the sample was 17% (range 11.8– 23.9%) confirmed at a 95% confidence interval. A significant association was observed between the level of overlap of the canine across the lateral incisor, measured in sectors, and the probability of lateral incisor root resorption. The probability approximately doubled for each additional sector of canine overlap. No other significant association was noted related to all the other variables examined. Conclusions The incidence of lateral incisor root resorption associated with impacted maxillary canines was lower in the present study compared with many previous reports. However, resorption remains a common clinical finding. In order to screen for lateral incisor resorption, it is recommended that a cone beam image be prescribed when there is a mesial overlap of an impacted canine across the lateral incisor midline.