Root dilaceration in maxillary impacted canines and adjacent teeth: A retrospective analysis of the difference between buccal and palatal impaction

Short-Term Impact of Slow Maxillary Expansion on Labial Ectopic Canine Eruption Pathway in Children: A Retrospective Study

Objectives: This retrospective study evaluated the short-term effects of removable slow maxillary expansion (SME) on eruption patterns of labially ectopic canines in a Chinese pediatric population, comparing treated patients with untreated controls. Methods: Seventy-six patients (mean age 8.38 ± 0.88 years) underwent SME treatment for 11.04 ± 4.44 months. Canine positions were categorized as labial ectopic (TE: n = 40) or normally positioned (TN: n = 112). The TE group was stratified vertically: superior (TES; n = 15, canines above lateral incisors' roots or adjacent to unerupted incisors) and inferior (TEI; n = 25, canines adjacent to erupted lateral incisors' roots). Untreated controls (n = 58; mean age 8.46 ± 0.78 years) included labial ectopic (CE group; n = 32) and normal canines (CN group; n = 84), with CE further divided vertically into CES (n = 24) and CEI (n = 8). Panoramic radiographs at baseline (T0) and follow-up (T1) evaluated sector distribution, midline proximity (3c-ML: canine cusp to midline distance), vertical position (3c-OP: cusp to occlusal plane distance), and angular (3^ML: canine-midline angle). Results: SME significantly improved midline proximity (3c-ML increased) while reducing vertical height (3c-OP decreased) and angulation (3^ML reduced) in the TE group. Notably, TE patients revealed a significantly greater increase in 3c-ML compared to CE. Subgroup analysis showed that TEI canines exhibited significant improvements in all three parameters (3c-OP, 3c-ML, and 3^ML), whereas TES canines displayed minimal changes. The shifts in sector distribution were similar between the treatment and control groups. Conclusions: SME demonstrated short-term efficacy in guiding labially ectopic canines toward more favorable eruption trajectories, particularly when erupted beyond the roots of the lateral incisor. The observed positional improvements underscore SME's potential to optimize eruption outcomes during early orthodontic intervention.

Epidemiological and imaging characteristics of impacted maxillary incisors and effect on root development

Despite extensive research on maxillary impacted canines, studies specifically investigating maxillary impacted incisors remain limited. This retrospective study aimed to determine the prevalence of impacted teeth among adolescent orthodontic patients, analyze the imaging characteristics of maxillary impacted incisors, and evaluate factors influencing root development. From a cohort of 2163 underage patients who attended the children malocclusion special clinic between August 2022 and July 2024, individuals with impacted teeth were identified and their clinical data were collected. Subsequently, detailed analyses were conducted on impacted maxillary incisors using high-quality Cone-beam computed tomography (CBCT). There were 157 patients with 205 impacted teeth observed, presenting a prevalence rate of 7.26%. Maxillary canines were the most popular impacted teeth (39.51%), followed by maxillary incisors (30.24%). The tooth dilaceration demonstrated a significant relationship with the three-dimensional (3D) locations of tooth. Impacted teeth situated in low impacted depth (P < 0.05) and those with buccal-lingual (P < 0.05) or vertical (P < 0.01) orientations showed reduced susceptibility to root dilaceration. A positive correlation was observed between the Upper Incisor to Palatal Plane Angle (UI-PP) and both the probability (P < 0.05) and earlier occurrence (P < 0.01) of root dilaceration. The root length of impacted tooth was positively correlated with age (P < 0.05). Besides, the average root length of the impacted central incisors was 1.84 mm shorter than the contralateral. The prevalence of impacted teeth in our orthodontic specialist clinics was 7.26%, and 69.76% of impacted teeth were maxillary anteriors. The development of tooth roots was mainly influenced by age and 3D location. These findings enhance clinicians' understanding of impacted maxillary incisor characteristics and factors affecting the root development. The UI-PP proves to be an effective 3D location evaluation indicator. Early intervention is recommended for impacted teeth lacking sufficient space for root development, which could facilitate root development and minimize the risk of root dilaceration.

Evaluating the success rates and effectiveness of surgical and orthodontic interventions for impacted canines: a systematic review of surgical and orthodontic interventions and a case series

OBJECTIVES

The goal is to gather more information on orthodontic traction of impacted canines in the arch or their extraction.

METHODS

We focused our search on English-language papers published between January 1, 2004, and July 24, 2024 in PubMed, Scopus, and Web of Science that were relevant to our topic. The search strategy employed the Boolean terms "impacted" AND "canine". In addition to the overview, this article discusses a number of clinical instances involving canine disinclusion.

RESULTS

The study analyzed 2748 papers from databases like Web of Science, PubMed, and Scopus, resulting in 1455 articles after eliminating duplicates. After examining titles and abstracts, 897 entries were removed. The remaining 558 papers were confirmed, with 543 items removed due to being off-topic. The study includes a qualitative analysis of the 15 final articles.

CONCLUSIONS

This article concludes that both extraction and orthodontic traction are effective treatments for impacted canines, with the choice depending on patient-specific factors. Advances in surgical techniques and imaging technologies have improved outcomes, while a multidisciplinary, patient-centered approach remains essential. Future research should focus on refining treatment selection criteria and integrating genetic and technological advancements.

Prediction of the success of orthodontic treatment of impacted maxillary canines using panoramic radiography parameters: a retrospective cross-sectional study

BACKGROUND

This retrospective study aimed to investigate the relationships between the radiographic features of impacted maxillary canines (IMCs) and traction duration and the factors affecting treatment success.

METHODS

Pre-treatment panoramic radiographs and patient records of 121 consecutive patients with IMCs were analyzed. The measurements included the angle of the IMC with the midline (α-angle), the horizontal position of the IMC relative to the adjacent teeth (S-Sector), the distance from the IMC to the occlusal plane (d-distance), the apex position of the IMC (A), and the vertical height of the IMC relative to the adjacent lateral tooth (V). The measurements were repeated 1 week later. The intraclass correlation coefficient was used to evaluate the relationship between two measurements. Binary logistic regression was performed to determine the factors affecting treatment success. Linear regression was conducted to determine the relationships between traction duration and other parameters. Receiver operating characteristic (ROC) curve analysis was performed to determine the α-angle and the d-distance cutoff values for treatment success. The significance level was set at p < 0.05.

RESULTS

The buccally IMCs were mostly located in sectors 1-2, whereas the palatally IMCs were mostly located in sectors 3-4-5. The effects of the parameters on the treatment success were significant according to the logistic regression of age (p = 0.003), d-distance (p = 0.002), and α-angle (p = 0.001). Linear regression analysis revealed that traction duration was statistically significant (p < 0.001).

CONCLUSION

According to the results of this retrospective study, the α-angle, d-distance, and sector can be used to predict the buccopalatal position of the IMC. The patient's age, d-distance, and α-angle affected the treatment success. The patient's age, d-distance, and the sector of the impacted canine affected the traction duration.

CLINICAL TRIAL NUMBER

Not applicable.

Treatment duration by morphology and location of impacted maxillary canines: A cone-beam computed tomography investigation

INTRODUCTION

This study aimed to identify whether patients with impacted maxillary canines take longer to treat than orthodontic patients without an impacted canine. We also sought to identify factors that are predictive of increased treatment duration in patients with impacted maxillary canines and treated by surgical exposure.

METHODS

A retrospective investigation of 37 patients with an impacted maxillary canine, treated by surgical exposure and fixed appliance therapy, was undertaken. In addition, an age- and sex-matched control group of 39 patients (without impacted canines) was also collected. Patient age, sex, and total treatment duration were recorded. For patients with an impacted canine, patient records and pretreatment cone-beam computed tomography datasets were assessed. Point coordinates identifying relevant landmarks were recorded, and a geometric method was used to calculate variables describing canine location, orientation, and apical morphology.

RESULTS

Controlling for age and sex, linear regression identified a statistically significant increase in treatment duration of 46.7 and 41.5 weeks for palatal and labial/midalveolar impacted canines, respectively, vs controls (P <0.002). Age and sex of patients with impacted canines collectively affected treatment duration (P = 0.04), with females of increased age being treated faster than younger males. Rotation of the impacted canine crown had a highly significant effect on treatment duration, with every degree of rotation increasing treatment duration by 0.32 weeks (P <0.001). There was a significant degree of multicollinearity between the other radiographic variables. Collectively, radiographic variables describing canine displacement significantly prolonged treatment duration (P <0.001) and explained 29.8% of the variability in total treatment time. The apical morphology of impacted maxillary canines was significantly associated with increased treatment duration (P = 0.01) and explained 11.3% of the overall treatment variability (P = 0.01).

CONCLUSIONS

Increased total treatment duration of surgically exposed impacted maxillary canines is associated with increasing mesiopalatal canine crown rotation, worsening displacement, and hooked apical morphology.

Long-term follow-up after the treatment of impacted canines in the maxilla causing severe root resorption of the lateral incisors: two case reports

BACKGROUND

Root resorption of adjacent teeth due to impacted canines is common, and orthodontic treatment often leads to secondary resorption or even loss of adjacent roots. Clinical reports of long-term stability after treatment are rare.

CASE PRESENTATION

This study reports two cases of maxillary impacted canines resulting in severe root resorption of the adjacent lateral incisors. Surgical exposure, orthodontic retraction, and alignment of the impacted canines were successful in both cases, and the resorbed lateral incisors were stable with no significant loosening and normal pulp vitality after treatment and at the 5- and 10-year follow-up appointments.

CONCLUSIONS

Light orthodontic force may be used to move adjacent teeth with root resorption due to tooth obstruction. The path and direction in which the teeth are moved must be specifically designed so that the adjacent roots are not resorbed and so long-term stability can be achieved.

Characteristics of Unilaterally Impacted Maxillary Canines and Effect on Environmental Tissues: A CBCT Study

BACKGROUND

The prognosis of orthodontic treatment for a patient with impacted canine teeth can be affected by many factors and understanding some of the characteristics of impacted teeth can increase the effectiveness and reduce the duration of treatment. This study aims to explore the effects of positions and dentoalveolar morphological characteristics of impacted maxillary canines on the prognosis of orthodontic treatment.

METHODS

In this study, forty-six adolescent individuals who applied for treatment of impacted teeth were divided into three groups: CC (no impacted maxillary canine group), BC (unilateral buccally positioned impacted maxillary canine group), and PC (unilateral palatally positioned impacted maxillary canine group). The impacted canine and adjacent teeth were evaluated in terms of position, angulation, inclination, mesiodistal and buccolingual widths, root length, dilaceration angle, and root resorption.

RESULTS

The mean values of U3 Ang (angulation of the maxillary impacted canine) and U3/U2 angles (maxillary impacted canine and lateral incisor angle) were statistically significantly higher in the BC and PC groups (p < 0.001). The mean values of U2 RL (lateral incisor root length) and U3 RD (canine root dilaceration angle) were statistically significantly lower in the BC and PC groups.

CONCLUSIONS

The results of this study suggest that shorter root lengths and increased angulation values may lead to the ectopic eruption of canines. The higher canine angulations in the PC group increase the degree of root resorption.

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.

Root Dilaceration: A Case Report and Literature Review

The clinical management of impacted incisors affected by root dilaceration is challenging. This case report presents the treatment of an adolescent female patient who presented with a deeply impacted, rotated and dilacerated maxillary central incisor and also reviews the current literature on the definition, prevalence, aetiology, diagnosis, and treatment of the anomaly. The impacted and dilacerated incisor was successfully orthodontically treated following a two-stage surgical exposure and after being rotated 100 degrees in the sagittal plane (due to the deep impaction and severe displacement). A Ballista spring and piggyback appliance technique were used to elevate the tooth. The dilacerated incisor was successfully preserved and relocated in the dental arch. The pre-operative and post-operative CBCT scans showed no significant root resorption of the repositioned tooth.

Root morphology of lateral incisors adjacent to impacted maxillary canines: A cone-beam computed tomography retrospective cross-sectional study

INTRODUCTION

To compare the root morphology of the maxillary lateral incisors (MLIs) adjacent to an impacted (IMC) versus non-impacted maxillary canine (non-IMC).

MATERIALS AND METHODS

This cross-sectional study included cone beam computed tomography (CBCT) images derived from 154 subjects (with unilateral/bilateral impacted maxillary canines or without canine impaction). Each MLI was considered as a unit of analysis. Thus, the study group included 122 MLIs adjacent to impacted maxillary canine (IMCG) and the control group included 122 MLIs adjacent to a non-impacted maxillary canine (CG). Groups were matched by age, sex and evaluation side. Root length, root dilaceration angle and root convergence angle were evaluated in both the coronal and sagittal planes. Comparisons between groups were made with Student's t-test and the chi-square test with Bonferroni correction (P<0.008, P<0.01, respectively).

RESULTS

The root measurements of the MLIs showed some significant differences between the groups. The coronal root length was 0.52mm shorter but not highly significant (P=0.032), the coronal root dilaceration angle was 7.51° smaller (P<0.001), and the coronal root convergence angle was 1.28° greater (P<0.001) in the IMCG compared to the CG. The orientation of root dilaceration in the MLIs showed significant differences between the groups: it was mostly distopalatal in the GC (87.5%), to a lesser extent in the IMCG (58.9%) and also mesiopalatal in the IMCG (22.3%), (P=0.001).

CONCLUSIONS

The root morphology of MLIs adjacent to an IMC showed a tendency of shorter length, smaller root dilaceration and greater root convergence in the coronal section than MLIs adjacent to a non-IMC.

Dental anomalies in non-syndromic orofacial clefts: a clinical approach

Orofacial clefts (OC) represent some of the most common congenital malformations and affect multiple structures in the craniofacial region. There are a wide range of morphological OC types within the spectrum of both non-syndromic OC (NSOC) and syndromic OC, including cleft lip (CL); cleft lip and palate (CLP) and cleft palate (CP). Here, we describe the most frequent dental anomalies seen in the permanent dentition of individuals with NSOC, comparing them between the three main cleft types (CL, CLP, CP). We present these findings from the perspective of prevalence relating to each anomaly, as well as the clinical characteristics and potential impact in the rehabilitation process. The investigation of dental anomalies associated with NSOC is important, helping to expand the phenotypic characterization of NSOC, improve initial diagnostics and establish appropriate rehabilitation and counseling.