Position of the maxillary permanent canine in relation to anomalous or missing lateral incisors: a population study

Radiological features and treatment of erupting maxillary canines in relation to the occurrence of dental developmental abnormalities

OBJECTIVE

This study aimed to investigate the radiological features of the permanent canines and the treatment carried out to ensure their eruption relative to certain features involved in Dental Anomaly Patterns (DAP).

MATERIAL AND METHODS

The cross-sectional part of this retrospective register--based study focused on 1,315 dental panoramic tomographs (DPTs) of children aged 8.5-10.5 years, while the longitudinal part involved information on the treatment provided for 1,269 canines after the DPTs and on their eruption into the oral cavity.

RESULTS

The canines of the DAP children more often showed evidence of early treatment (p = 0.014), with girls having more frequently interceptive treatment (p = 0.004) and boys early headgear (p = 0.022). Delayed dental age was associated with early treatment (OR 3.29, 95% CI 1.08-9.99). Either no or clear overlapping of a canine with the lateral incisor occurred more often in the DAP children, whereas canine inclination did not differ between the groups. The root development stage of the canine was more often either beginning or well advanced in the DAP children.

CONCLUSIONS

The children with dental developmental abnormalities more often showed evidence of early treatment for the canines. Monitoring of the erupting canines after the first mixed stage is important to enable timely early treatment.

Evaluation of maxillary transverse dimensions in individuals with a unilaterally impacted canine

INTRODUCTION

The aim of this study was to investigate the maxillary width within individuals with a unilaterally impacted maxillary canine and to determine any association between the impacted canine location and some canine-related variables.

METHODS

A cross-sectional analytical study using a split-mouth design included 22 CBCTs of individuals with unilaterally impacted maxillary canines (a total of 44 sides). The maxillary width was measured and compared in both impacted and non-impacted sides at various levels: basal, alveolar, and dental. The following canine-related variables were analyzed and compared with impaction location: impacted canine angulation, cusp tip distance from the occlusal plane, type of impaction (vertical or horizontal), presence of root resorption, deciduous teeth, or adjacent teeth transposition. Significance was considered at P < 0.05.

RESULTS

There was a significant reduction in maxillary width on the impacted side at the following levels: maxillary first premolar alveolar crest in both coronal and axial sections, dental width measured from the central fossa of maxillary first molar to the midline, and width measured from the canine cusp tip to the midline. Moreover, the distance from the palatally impacted canine cusp tip to the occlusal plane was statistically significantly lower (7.6 ± 1.5 mm) compared to buccal (10.8 ± 3.3 mm) and mid-alveolus (12.0 ± 3.9 mm) impaction, (P values = 0.02).

CONCLUSIONS

There was a significant association between canine impaction and reduction in the maxillary width at least on the dental level. The palatally impacted canine cusp tip was significantly closer to the occlusal plane compared to the buccal and mid-alveolar impaction.

Quality analysis of the clinical practice guidelines for management of impacted maxillary central incisors: a systematic review

PURPOSE

To assess the quality of clinical practice guidelines (CPG) for management of impacted central incisors.

METHODS

Search was performed in PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane databases, and guideline-focused databases/repositories on 15-09-2022 without any limitations and was updated on 15-07-2023. Grey literature search was also performed. Two independent reviewers were involved in the study selection and data extraction. Quality assessment of the included CPG was performed by four independent appraisers using the AGREE-II instrument. The degree of agreement among the appraisers was calculated using the intraclass correlation coefficient (ICC).

RESULTS

Five CPG were included in the review. The Ministry of Health, Malaysia (MHM) guideline obtained the highest scores in all six domains of AGREE-II and an overall score of 73% demonstrating the "highest" quality. The remaining four guidelines obtained overall "low-quality" scores ranging from 34.57-37.52%. The ICC scores ranged from 0.530 to 0.990 for various domains of AGREE-II.

CONCLUSION

MHM guidelines demonstrated high-quality scores in domains of 'scope and purpose', 'clarity of presentation', 'applicability domain', and 'editorial independence', while others were found to have moderate or low quality. This review identified areas that can be addressed by future guideline developers to avoid these discrepancies.

Screening for the risk of canine impaction, what are the presumptive signs and how does it affect orthodontics? A cross-sectional study in France

PURPOSE

The treatment of impacted canines is a challenge for orthodontists. The availability of suggestive clinical signs has become crucial for treatment before the potential for evolution ceases. The main objective was to evaluate the prevalence of the suspected displaced canine (SDC) and to highlight factors easily identifiable from the oral examination.

METHODS

SDC was assessed on panoramic X-rays, on the basis of the angle with the median sagittal plane and the degree of overlap with the permanent lateral incisor. Its association with mesio-distal tooth and palate widths was assessed by univariate analysis. Next, the association of SDC with temporary tooth extraction, expansion and/or premolar extraction was considered using the same modality.

RESULTS

In this retrospective study, the records of 292 patients aged 7 to 13 years were reviewed. SDC was detected in 39% of patients i.e., 28,8% of observed canines. Reduced coronal mesio-distal diameters of permanent maxillary central incisors, 8.7 ± 0.6 mm versus 8.8 ± 0.7 mm (p < .05), and first permanent molars, 10.0 ± 0.7 mm versus 10.2 ± 0.7 mm (p < .001), as well as reduced inter-molar width, 38.7 ± 2.7 mm versus 39.4 ± 2.9 mm (p < .01), were predictive factors. SDC led orthodontists to indicate extraction of maxillary primary canines, OR = 3,32 (p < .001) or even extraction of premolars, OR = 1,66 (p < .05).

CONCLUSION

This study confirmed the interest of panoramic X-rays in detected canines at risk of SDC. Dental factors can be combined to make screening more reliable and predict impaction that makes orthodontics complex.

TRIAL REGISTRATION NUMBER

Opinion n°21.131, dated 09.21.2021, retrospectively registered.

Features of Dental Anomaly Patterns in Finnish children as seen in panoramic radiographs at the late mixed stage

OBJECTIVE

To describe the prevalence of the developmental abnormalities involved in Dental Anomaly Patterns (DAP) and investigate their co-occurrence in an age cohort of children with late mixed dentition.

MATERIAL AND METHODS

Retrospective, register-based study focused on 1315 panoramic radiographs of children aged 8.5-10.5 years. The features examined were absent teeth, peg-shaped maxillary lateral incisor, delayed dental age, infraocclusion of primary molars, transposition and distal angulation of unerupted mandibular second premolar.

RESULTS

Feature involved in DAP was detected in 29.8% of the children, most common being infraocclusion of primary molars (17.5%), followed by absent teeth (8.4%), delayed dental age (7.6%), distal angulation of unerupted mandibular second premolar (7.3%), peg-shaped maxillary lateral incisor (2.4%) and transposition (0.5%). Two DAP features occurred together in 4.7% of children, while three occurred in 0.7%. Infraocclusion (p=.040) and absent teeth (p=.001) occurred more commonly in girls. Phenotypic variations in maxillary lateral incisor more often occurred together (p=.004). Absent teeth, peg-shaped maxillary lateral incisor and delayed dental age more often occurred together (p<.01) as did transposition and absent teeth (p=.016).

CONCLUSION

Almost third of the children had dental developmental abnormalities involved in DAP. Absent teeth, peg-shaped lateral incisors and delayed dental age more often occurred together.

Three-dimensional evaluation of social smile asymmetry in patients with unilateral impacted maxillary canine: a 3D stereophotogrammetry study

OBJECTIVE

This study aimed to evaluate social smile asymmetry in patients with unilateral impacted maxillary canine on 3D stereophotogrammetric images.

MATERIAL AND METHODS

The 3D social smile images of participants with unilateral impacted maxillary canine (n:20) and without impaction as a control group (n:20) were included. The images were recorded with a hand-held 3D stereophotogrammetry device (Fuel3D® Scanify®) and Geomagic Essentials 2 reverse engineering software were used for analyses. After the orientation process of the 3D records, the tissues around the smile area were divided into five morphological regions: cheek, upper lip lateral and medial, and lower lip lateral and medial. The deviation margins in the negative and positive directions for the 95% mesh rate and the total percentages of meshes between - 0.5- and + 0.5-mm deviations were calculated. ICC, paired samples t test, independent samples t test, and the Mann-Whitney U test were used for statistical analyses.

RESULTS

In individuals with impacted canine, the amount of maximum positive deviation in the upper lip medial was 5.64 mm ± 1.46 and maximum negative deviation was - 4.6 mm ± 1.17. In the control group, mean of deviation limits for all parameters was less than 1.19 mm ± 2.62, while in individuals with unilateral impacted maxillary canine, the maximum value was 8.34 mm ± 2.23. The mesh percentage between - 0.5 and 0.5-mm deviations was over 95% in all morphological areas in the control group, while in the impacted canine group, the number of meshes within the specified deviation limits was less than 95%.

CONCLUSION

Individuals with unilateral impacted maxillary canine exhibit greater asymmetry in social smile compared to the control group, with the asymmetry being most prominent near the corners of the mouth and cheeks.

CLINICAL RELEVANCE

Amount of asymmetry was higher in impaction group compared to the control group in social smile. The quantification of a possible smile asymmetry due to the impacted canine is crucial for the diagnosis and treatment planning of orthodontic and/or orthognathic cases for ideal aesthetic results. Hence, smile asymmetry should not be overlooked and should be considered in diagnosis and treatment planning.

Association between sella turcica bridging and the impaction severity of palatally displaced canines: A retrospective study

INTRODUCTION

This retrospective study aimed to investigate the association between the extent of the bridging and dimensions of sella turcica and the impaction severity of palatally displaced canines. Secondarily, any possible association between skeletal age and gender was evaluated.

METHODS

Panoramic and cephalometric radiographs of 94 patients (63 female, 31 male; 19 pre-peak, 75 post-peak) with palatally displaced canines were evaluated. Sector classification and α angle were used to determine the impaction severity of palatally displaced canines on panoramic radiographs. The distance from the cusp tip of the palatally displaced canines to the occlusal plane (d) and the extent of the bridging and dimensions of the sella turcica were evaluated on cephalometric radiographs.

RESULTS

Sella turcica bridging and dimensions did not vary regarding the impaction severity of palatally displaced canines, but a significant association was found between sella turcica bridging and skeletal age (P = 0.038). Class II (33.3%) and Class III (12.0%) bridging was higher in postpubertal patients. No differences between females and males were detected for the extent of bridging and dimensions of the sella turcica.

CONCLUSIONS

These findings indicate no association between sella turcica bridging and dimensions and the impaction severity of palatally displaced canines. Sella turcica bridging is more frequent in the postpubertal period, whereas gender does not influence sella turcica bridging. More studies are needed to evaluate if the extent of sella turcica bridging may be indicative of severely impacted palatal canines, which in turn would allow for careful monitoring of patients from an early age and for the clinician to take preventive measures.

Comparison of root apex's position between unilateral and bilateral palatally impacted canines: A pilot study

INTRODUCTION

The purpose was to determine whether the location of the root apices of unilateral palatally impacted canines differs from that of bilateral palatally impacted canines using cone-beam computed tomography.

METHODS

The subjects were divided into 3 groups: a bilateral palatally impacted canine group (BPG; n = 28), a unilateral palatally impacted canine group (UPG; n = 28), and a control group (CG; n = 28) that included contralateral normally erupted canines in the UPG. After selecting the root apex in the onDemand3D program, 3-dimensional coordinates were extracted. These 3-dimensional coordinates were converted using the MATLAB program to 2-dimensional coordinates via projection on the palatal plane. Procrustes analysis was used to superimpose these 2-dimensional coordinates. The x- and y-coordinates of the root apices were used to measure the distance between the origin and root apex.

RESULTS

The distance between the root apex of the canine and the origin was 17.43 ± 1.78 mm in BPG, 17.96 ± 1.87 mm in UPG, and 13.96 ± 0.95 mm in CG. There was no statistically significant difference between UPG and BPG. However, there was a statistically significant difference between the CG and impacted groups (UPG and BPG). The same results were found for the x- and y-coordinates.

CONCLUSIONS

The location of the root apices of unilateral palatally impacted canines is similar to that of bilateral palatally impacted. The location of root apices of palatally impacted canines differs from that of normally erupted canines.

Three-dimensional orthodontic anchorage management of impacted maxillary canines: A systematic review

Objectives:

Our work aims to provide scientific evidence by conducting a serious systematic review of the efficacy of three-dimensional (3D) anchorage devices for orthodontic traction of impacted maxillary canines.

Material and Methods:

An electronic search extending from 2012 to 2022, targeting mainly clinical trials was performed on the following databases PUBMED (MEDLINE), The Cochrane Library, SCIENCE DIRECT, EBSCO HOST DATABASES, and GOOGLE SCHOLAR. The search was established on a well-defined research question following the PICO principle: population, intervention, comparator, and outcome. Search evaluation and the assessment of the risk of bias (RoB) were undertaken in each study following its type and design.

Results:

Thirteen studies were included for qualitative analysis, with a low to moderate RoB. Ten studies used only heavy conventional palatal anchorage such as a fixed trans palatal arch (TPA), while one study used skeletal anchorage to manage the orthodontic traction of impacted maxillary canines. Two studies compared trans palatal arch and mini-screws efficiency to treat impacted maxillary canines.

Conclusion:

Studies proved that the trans palatal arch (TPA) presents a particular anchorage unpredictability in the sagittal, transversal, and vertical dimensions. Whereas, anchorage management using mini-screws proved to be very beneficial clinically; however, further studies must be implemented to evaluate the 3D efficacy of skeletal anchorage to place an impacted maxillary canine to its rightful position into the arch.

Associations among the occurrence or types of maxillary canine impaction, labial frenum attachment types, lateral incisor anomalies, and midline diastema in patients with and without impaction: A case-control study

INTRODUCTION

We tested whether the labial frenum attachment types may affect the occurrence or type of maxillary canine impaction.

METHODS

This case-control study was performed on 96 subjects (48 with maxillary canine impaction [20.50±4.99 years, 32 females], 48 controls [21.94±3.79, 31 females]). Types of canine impaction (buccal/palatal, bilateral/unilateral, left/right), types of upper lip middle frenums (mucosal, gingival, papillary), the anatomy of lateral incisors (impacted, peg shaped, small, normal), and the midline diastema were evaluated clinically and radiographically. Associations were examined using multiple binary logistic regression, 3-way repeated-measures ANCOVA, and Fisher tests (α=0.05, β=0.2).

RESULTS

The numbers of mucosal, gingival, and papillary frenums in the case group were '29, 14, and 5', respectively; in the control group, they were '25, 21, and 2' (Fisher, P=0.248). The numbers of mucosal, gingival, and papillary frenums were respectively '25, 11, and 1' in the palatally impacted canine subgroup; they were '4, 3, and 4' in the buccally impacted subgroup (Fisher, P=0.010). Abnormal laterals were present in 12 cases and 4 controls; normal laterals were observed in 36 cases and 44 controls (Fisher, P=0.053). Abnormal laterals were seen in 10 cases with palatally impacted canines and 2 cases with buccally impacted canines; normal laterals existed in 27 cases with palatally impacted canines and 9 cases with buccally impacted canines (Fisher, P=0.705). Lateral anatomy was not associated with frenum attachment (Fisher, P=0.827). Greater midline diastemas were seen in cases with maxillary canine impaction, papillary frenums, and abnormal laterals (ANCOVA, P≤0.016).

CONCLUSIONS

Buccal type of canine impaction is positively associated with papillary labial frenums. Canine impaction is 3.6 folds more prevalent in cases with lateral abnormality. Midline diastema is positively and independently associated with canine impaction, papillary frenums, and abnormal laterals.

Unilateral vs Bilateral Maxillary Canine Impaction: A Cone-Beam Computed Tomography Study of Patterns and Associations

AIM

This retrospective study aimed to compare and evaluate the pattern of maxillary canine impaction and its association with other anomalies using cone-beam computed tomography (CBCT).

METHODS

A total of 59 CBCT records of patients (ages 12 and up) were divided into two groups: A total of 35 subjects with unilateral canine impactions and 24 subjects with bilateral canine impactions. The CBCT data were analyzed for the measurement of qualitative and quantitative variables.

RESULTS

In unilateral canine impaction, the mesiodistal (MD) width of the central incisors and the nasal cavity (NC) width were wider (p < 0.05). The canine-palatal plane (U3-PP) distance was significantly longer in bilateral canine impaction (p < 0.05). The distance of the impacted canines from the palatal and mid-sagittal planes, the anterior dental arch width, and the maxillary skeletal width changed significantly with the position of the impacted canines (p < 0.05). Males had 0.185 odds of presenting with a bilateral canine impaction as compared to females (p = 0.025). The odds of having bilateral canine impaction with a longer canine-midsagittal plane (U3-MSP) distance was 1.30 (p = 0.003).

CONCLUSION

The findings indicate a gender predilection with females showing a greater prevalence of bilateral canine impaction. Supernumerary teeth were associated with unilateral impacted canines and lower canine impaction with bilaterally impacted canines.

CLINICAL SIGNIFICANCE

Anomalies in the form of the maxillary central and lateral incisors, distance from the maxillary canine to the palatal plane and the mid-sagittal plane, NC width, maxillary skeletal width, and gender, are the best discriminating parameters between unilateral and bilateral canine impactions.

The labiopalatal impacted canine: Accurate diagnosis based on the position and size of adjacent teeth: A cone-beam computed tomography study

INTRODUCTION

Labiopalatal impacted canines (L-PICs) occur when the canines lie between central and lateral incisors, with their tip palatal to the central incisor and part of their crown labial to the lateral incisor. Because of their unusual position, they are often misdiagnosed, and their orthodontic resolution fails. This study aims to provide clinicians with pathognomonic features for early and accurate positional diagnosis of L-PICs.

METHODS

The L-PIC sample included 21 subjects with full diagnostic records. The control group of normally erupted canines was taken from a previous study. Clinical photographs, 2-dimensional radiographs, and cone-beam computed tomography were used to evaluate the positions of the adjacent incisors and first premolars, the canine incisor index, and the mesiodistal width of the lateral vs central incisors.

RESULTS

Central incisors adjacent to L-PICs showed significant mesial root angulation, labial root inclination, and mesiolabial crown rotation, whereas lateral incisors presented significant distal root angulation, palatal root inclination, and mesiolabial crown rotation, in comparison to controls. The roots of the central and lateral incisors were divergent, in contrast to the controls, in which they were slightly convergent. The first premolar positions were not affected. The mean canine incisor index was significantly bigger in L-PICs vs the controls, suggesting a palatal canine. The lateral incisor widths were similar between the groups.

CONCLUSIONS

This study provides the orthodontist with evidence-based clinical and radiographic red flags for diagnosing L-PIC, which may allow timely initiation of orthodontic treatment and correct planning of mechanotherapy.

Factors That Guide the Diagnosis and Treatment Planning for Impacted Canines Using Three-Dimensional Cone-Beam Computed Tomography: A Cross-Sectional Study

Objective. Impacted canines are one of the significant challenges in orthodontics that should be appropriately assessed to provide the best treatment to the patients. Materials and Methods. In the present study, 57800 patients were examined over six years to investigate the prevalence, diagnostic procedures, and treatment methodologies for impacted canine cases. Prevalence and diagnosis were tested using history taking, clinical examination, and three-dimensional cone-beam radiographs. The cases were tested for impaction site, gender, age, signs, and symptoms. The groups were classified for impaction location according to Mupparapu’s classification. Result. The causative factors and the treatment methodology selected were plotted according to age and gender distribution. The total prevalence was 3.9% of canine impaction cases in relation to the total sample cases. The results showed a strong correlation between the site of impaction toward the upper arch and with distribution following Mupparapu’s classification. The pain was the most detectable complication in all age groups, while root resorption was the least. Conclusion. Most of the younger age groups were sent for exposure and orthodontic traction, while the mid-aged groups elected for observation, and follow-up as their primary concern was esthetics. However, the adult patients were into exposure and traction to improve their function.

Morphological Comparison of the Maxillary Arch in Buccal and Palatal Canine Impaction among Asian Population of Gujarati Origin: A Hospital-Based Study

Aim: To estimate the differences in the maxillary arch morphology in buccal and palatal canine impaction in an Asian population of Gujarati origin. Methodology: An institutional ethics committee’s approval was acquired before the commencement of this study. Sixty subjects were enrolled in the study. Thirty subjects (20 females and 10 males) had a maxillary impacted canine either buccal or palatal and thirty control group participants were selected aged 13 to 18 years who sought orthodontic treatment at the tertiary health care center in Ahmedabad, Gujarat, in western India. Routine pre-treatment radiographs and dental plaster models with good anatomic details were recorded. Measurements of the inter-molar width, palatal depth, arch length, sum of the mesio-distal width of the upper incisors, and available arch space were recorded from prepared orthodontic study models using digital vernier calipers with an accuracy of 0.01 mm and brass wire. The ratio of palatal depth to inter-molar width (Ratio 1), arch length to inter-molar width (Ratio 2), and width of the maxillary incisors to available arch space (Ratio 3) were also secondarily calculated. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21, IBM Inc. The normality of the data was assessed by the Shapiro−Wilk test. As the data was found to be normally distributed, bivariate analyses were also performed (one-way ANOVA test, Bonferroni post hoc correction). The level of statistical significance was set at a p-value less than 0.05. Results: The comparison of the inter-molar width, palatal depth, arch length, sum of the mesio-distal width of the upper incisors, available arch space, Ratio 1, Ratio 2, and Ratio 3 among controls and subjects with buccal and palatal canine impaction showed overall significant differences in the inter-molar width, palatal depth, arch length, sum of the mesio-distal width of the upper incisors, and available arch space when compared using one-way ANOVA as p < 0.05. Ratios 1, 2, and 3 also showed significant differences between the buccal and palatal canine impaction. Conclusion: An inadequate arch length (p < 0.0001) and a higher degree of crowding with reduced available arch space (p < 0.0001) may be considered as early risk factors for buccal maxillary canine impaction. An inadequate inter-molar width (p < 0.0001), and an increased palatal depth (p < 0.0001) with a clinically reduced mesiodistal width of the sum of maxillary incisors may be considered as risk factors for palatal maxillary canine impaction in an Asian population of Gujarati origin.

Prediction methods of maxillary canine impaction: a systematic review

OBJECTIVE

To describe and assess the available evidence of prediction methods of maxillary canine impaction (MCI).

MATERIAL AND METHODS

A systematic search was conducted through PubMed, Cochrane Library, Embase, EBSCOhost, Scopus, ScienceDirect, Bireme and Scielo until December 2020. This systematic review was conducted according to the PRISMA statement. The methodology of the selected studies was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2).

RESULTS

A total of 2391 articles were identified in the first approach and after a 2-phase selection, 11 studies were included in qualitative analysis. Prediction methods were constructed using equation-based models, geometric measurements and computational methods from clinical and imaging data to predict palatal/buccal MCI. The quality of evidence was low to moderate due to the presence of risk of bias in most of the studies included. Three cohort studies with the best methodological quality proposed prediction models based on geometric measurements, canine position and facial growth pattern that would allow predicting MCI from CBCT, lateral and panoramic radiographs.

CONCLUSIONS

The evidence is limited and most of the studies present a low methodological quality. However, it is possible to suggest that some prediction methods based on the position of the canine and facial growth pattern could predict palatal/buccal MCI in mixed dentition. Cohort studies with better methodological quality and long-term follow-up are needed to better validate a prediction model.

Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for surgical exposure, in children aged 9 to 14 years

BACKGROUND

A permanent upper (maxillary) canine tooth that grows into the roof of the mouth and frequently does not appear (erupt) is called a palatally displaced canine (PDC). The reported prevalence of PDC in the population varies between 1% and 3%. Management of the unerupted PDC can be lengthy, involving surgery to uncover the tooth and prolonged orthodontic (brace) treatment to straighten it; therefore, various procedures have been suggested to encourage a PDC to erupt without the need for surgical intervention.

OBJECTIVES

To assess the efficacy, safety and cost-effectiveness of any interceptive procedure to promote the eruption of a PDC compared to no treatment or other interceptive procedures in young people aged 9 to 14 years old.

SEARCH METHODS

An information specialist searched four bibliographic databases up to 3 February 2021 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCT) involving at least 80% of children aged between 9 and 14 years, who were diagnosed with an upper PDC and undergoing an intervention to enable the successful eruption of the unerupted PDC, which was compared with an untreated control group or another intervention.

DATA COLLECTION AND ANALYSIS

Two review authors, independently and in duplicate, examined titles, keywords, abstracts, full articles, extracted data and assessed risk of bias using the Cochrane Risk of Bias 1 tool (RoB1). The primary outcome was summarised with risk ratios (RR) and 95% confidence intervals (CI). We reported an intention-to-treat (ITT) analysis when data were available and a modified intention-to-treat (mITT) analysis if not. We also undertook several sensitivity analyses. We used summary of findings tables to present the main findings and our assessment of the certainty of the evidence.

MAIN RESULTS

We included four studies, involving 199 randomised participants (164 analysed), 108 girls and 91 boys, 82 of whom were diagnosed with unilateral PDC and 117 with bilateral PDC. The participants were aged between 8 and 13 years at recruitment. The certainty of the evidence was very low and future research may change our conclusions. One study (randomised 67 participants, 89 teeth) found that extracting the primary canine may increase the proportion of PDCs that successfully erupt into the mouth at 12 months compared with no extraction (RR 2.87, 95% CI 0.90 to 9.23; 45 participants, 45 PDCs analysed; very low-certainty evidence), but the CI included the possibility of no difference; therefore the evidence was uncertain. There was no evidence that extraction of the primary canine reduced the number of young people with a PDC referred for surgery at 12 months (RR 0.61 (95% CI 0.29 to 1.28). Three studies (randomised 132 participants, 227 teeth) found no difference in the proportion of successfully erupted PDCs at 18 months with a double primary tooth extraction compared with extraction of a single primary canine (RR 0.68, 95% CI 0.35 to 1.31; 119 participants analysed, 203 PDCs; mITT; very low-certainty evidence). Two of these studies found no difference in the proportions referred for surgical exposure between the single and the double primary extraction groups data at 48 months (RR 0.31, 95% CI 0.06 to 1.45).  There are some descriptive data suggesting that the more severe the displacement of the PDC towards the midline, the lower the proportion of successfully erupted PDCs with or without intervention.

AUTHORS' CONCLUSIONS

The evidence that extraction of the primary canine in a young person aged between 9 and 14 years diagnosed with a PDC may increase the proportion of erupted PDCs, without surgical intervention, is very uncertain. There is no evidence that double extraction of primary teeth increases the proportion of erupted PDC compared with a single primary tooth extraction at 18 months or the proportion referred for surgery by 48 months. Because we have only low to very low certainty in these findings, future research is necessary to help us know for sure the best way to deal with upper permanent teeth that are not erupting as expected.

Impacted Canine in Orthodontic Patients of a Tertiary Care Hospital: A Descriptive Cross-sectional Study

INTRODUCTION

Impacted canine is a frequently encountered clinical problem during orthodontic practice with different prevalence in each region. Treatment usually requires an interdisciplinary approach which is difficult and time consuming. Surgical exposure of the impacted tooth and the complex orthodontic mechanisms are used to align the tooth into the arch. This study was designed to find out the prevalence of impacted canine in orthodontic patients.

METHODS

A descriptive cross-sectional study was done with hospital records of patients from 15 to 38 years of age visited department of Orthodontics at a tertiary care hospital from August 2020 to March 2021 after obtaining ethical clearance from the institutional review committee. Convenience sampling method was used. Patients Orthopantomogram and clinical notes were thoroughly evaluated. To locate position of impacted canine cone-beam computed tomography images were used. The data was collected and entered in Microsoft Excel. Point estimate at 99% Confidence Interval was calculated along with frequency and proportion for binary data.

RESULTS

Out of 1008 patients, 44 (4.37%) (2.71-6.03 at 99% Confidence Interval) patients had impacted canines. Among them, maxillary canine impaction was seen in 38 (3.77%) and mandibular canine impaction in 6 (0.60%).

CONCLUSIONS

The overall prevalence of impacted canines was found lower than previous studies done in similar settings. Large number of patients had buccal impaction compared to palatal impaction.

Eruption pattern of the maxillary canines: features of natural eruption seen in PTG at the late mixed stage-Part I

Aim

To describe the variation of eruption pattern of maxillary canines in the late mixed stage of dentition seen in PTG when eruption was later natural.

Methods

Material for this longitudinal and retrospective register-based study consisted of 1454 PTGs of children living in Eastern Finland (mean age 9.3 years, SD 0.6). Natural eruption of a canine consisted of 744 PTGs (336 girls and 408 boys) including 1488 maxillary canines. The variables examined were treatment/natural eruption, overlapping, inclination, dental age, developmental stage of the canine and lateral incisor.

Results

Only 2.0% of maxillary canines had clear overlapping and 56.2% no overlapping was detected at the age of 8.5–10.5 years. Large inclination angle (≥ 25°) was found for 5.5% of examined canines. Overlapping of canine with lateral incisor root decreased as the development of canine root exceeded 1/3. Larger inclinations occurred at earlier stages but decreased significantly as the root developed from 1/3 to 1/2. Mean inclination was significantly larger at children with normal dental age and/or incomplete lateral incisors when overlapping occurred. Regardless overlapping mean inclination was larger if dental age was delayed and/or lateral incisors incomplete.

Conclusion

Some overlapping and larger inclination in maxillary canine are features of normal eruption pattern at an earlier stage of canine development and while lateral incisor is incomplete in PTG (8.5–10.5 years). In addition to the overlapping and inclination, stages of canine and lateral incisor root as well as dental age should be observed radiologically when evaluating erupting maxillary canine in children of this age.

Comparison of Lateral Tooth Volume and Morphology Between Buccally and Palatally Localised Unilateral Impacted Maxillary Canine Cases on Cone-Beam Computed Tomography

ABSTRACT

The aim of this study was to compare the lateral tooth volume and morphology differences between buccally and palatally localized unilateral impacted maxillary canine (IMC) patients with volumetric and linear measurements on cone-beam computed tomography (CBCT) records. CBCT records of 48 individuals with 24-buccally and 24-palatally localized unilateral IMCs were included to the study. The patients comprised 34 females, 14 males, with a mean age of 17.71 (±SD 6.63 years). This split-mouth, retrospective case-control, study consisted of buccally and palatally IMC group, and each group was categorized into 2 sub-groups as impacted and erupted side. Lateral tooth volume, tooth length, mesiodistal-buccolingual crown widths, mesiodistal- buccolingual root widths at cemento-enamel junction (CEJ), at 4 mm apical to CEJ, at 8 mm apical to CEJ, mesiodistal crown-root angle, arch perimeter measurements were performed on CBCT images. The data were analyzed by factorial design repeated measures ANOVA. Bonferroni test was used for post-hoc analysis. The total volume, mesiodistal - buccolingual crown widths, buccolingual root width of lateral incisor at CEJ were statistically smaller in palatally IMC group. The lateral incisor's length, and arch perimeter were statistically shorter, mesiodistal, buccolingual root widths at 8 mm apical to CEJ, and crown-root angle of the lateral were narrower on impacted side than erupted side. The volume and crown widths of lateral incisor are effective in sagittal localization of IMC. The shorter length, narrower apical root morphology and mesially inclined crown-root angle of lateral incisor are noteworthy on impacted sides, regardless of sagittal position of IMC.

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.

Orthodontic traction of impacted maxillary canines using segmented arch mechanics

The principles of orthodontic mechanics strongly influence the success of impacted canine traction. The present study discusses the main imaging exams used for diagnosis and localization of impacted canines, the possible associated etiological factors and the most indicated mechanical solutions.

Morphometric analysis of the palatal shape and arch dimension in subjects with palatally displaced canine

OBJECTIVES

The aim of this study is to analyse the morphological variations of the palate shape and maxillary arch dimension in a group of subjects with unilaterally or bilaterally impacted maxillary canines compared with a control group, using three-dimensional (3D) geometric morphometric.

MATERIALS

The subject of this study consisted of pre-treatment records of 46 (18 males and 28 females) patients with one or both canines palatally displaced. A control group of 26 subjects was selected from a list of orthodontic patients at the same dental hospital. The subjects were divided in two study groups: unilateral palatally displaced canine (UPDC) and bilateral palatally displaced canine (BPDC). Study casts were scanned to analyse the palate's shape and maxillary arch dimension. The 3D geometric morphometric analysis was used to study the entirety of the shape of the palate. The virtual 3D models were measured with a specific software to analyse the maxillary arch dimension. (VAM, Vectra; Canfield Scientific, Fairfield, New Jersey, USA).

RESULTS

When comparing the groups with the geometric morphometrics analysis, no significant palatal shape change was found. For the analysis of linear measurements, only a significant reduction of intercanine width was found in the UPDC and BPDC groups when compared with the control subjects.

CONCLUSIONS

Patients with palatally displaced permanent canine showed no maxillary transverse constriction or variation in palatal vault morphology but the absence of permanent teeth was associated with a reduction in the intercanine width.

Prevalence of impacted maxillary canines—an epidemiological study in a region with systematically implemented interceptive treatment

Background

In dentistry, epidemiological studies are important for establishing high-quality care for the individual patient as well as for socio-economic reasons.

Objective

The aim of this epidemiological study was to evaluate the prevalence of impacted maxillary canines in a geographical region in which interceptive treatment is implemented systematically. Furthermore, the aim was to study the age and gender of the patients, and the location and surgical technique used for the impacted maxillary canine.

Method

The study was based on 54 716 adolescents in the Region Västra Götaland, Sweden who were born in the period 1996–98. All patients in the three cohorts who had impacted maxillary canines treated with surgical exposure or surgical removal were identified in the dental record system used in the region.

Results

The prevalence of impacted maxillary canines when interceptive treatment was systematically implemented was 1.1% (N = 601). Overall, the cohorts of patients with impacted canines comprised 65% girls and 35% boys. Most of the canines were palatally impacted and the most common surgical technique was closed exposure.

Conclusion

The prevalence of impacted maxillary canines in a geographical area in which interceptive treatment is systematically implemented is lower than that reported previously. The distributions of impacted canines with respect to gender and location are in accordance with those reported previously in similar studies.

Mind the gap: A novel technique for space closure - a case report

Patients presenting with severe hypodontia can be challenging to manage. They often present with significant spaces within the dental arches and the lack of permanent teeth can make anchorage control difficult. This case report demonstrates a novel technique for diastema closure in a 14-year-old with severe hypodontia. The technique allows maintenance of root parallelism during space closure in cases with reduced anchorage support. The treatment plan was agreed on a multidisciplinary hypodontia clinic and involved an upper sectional fixed orthodontic appliance to close a 7-mm midline diastema aiding subsequent partial denture provision. Treatment commenced by bonding upper primary canines and central incisors. However, attempting space closure on a 0.019 × 0.025-inch stainless-steel working archwire resulted in tipping of the incisor crowns. Two brackets were therefore placed on the labial surface of each central incisor (one incisal and one gingival). Subsequently two stainless steel working archwires and elastomeric chain were used for diastema closure. This four-bracket system provided superior control allowing space closure by bodily tooth movement. Excellent root parallelism was achieved with this innovative technique.

Patterns and prevalence of canine anomalies in orthodontic patients

Objective

The aim of the present study was to present detailed information regarding the impacted maxillary and mandibular canines and their patterns of presentation into the oral cavity and to evaluate the prevalence of different canine anomalies, such as ectopic canine, transmigration, transposition and agenesis of permanent canines among central Indian population.

Method

A total of 1593 patients OPG’s were thoroughly evaluated and the prevalence of different canine anomalies like impacted maxillary and mandibular canine, transmigration, transposition, agenesis and ectopic canine eruptions were evaluated. The canine angulation, vertical position in relation to occlusal surface of adjacent tooth’s and the overlapping of adjacent teeth’s crown by impacted canine was evaluated by tracings.

Result

Out of 1593 subjects, 22 patients had impacted canines. The prevalence of canine impaction was1.38%, with maxillary canine impaction of 0.93%, mandibular canine impaction of 0.37%, canine agenesis 0.06%, transmigration 0.12%, canine transposition 0.18% and the ectopic canine was 5.5%.

Conclusion

There is no gender difference in canine impaction. The prevalence of canine impaction is 1.38%.

The orthodontic-oral surgery interface. Part two: diagnosis and management of anomalies in eruption and transpositions

The orthodontic-oral surgery interface is important for the multidisciplinary management of patients presenting with complex dental anomalies. This article provides an overview of anomalies of eruption and transpositions, their diagnosis, aetiology, presenting features and the different management options. It also highlights the role of the general dental practitioner (GDP) in identifying such anomalies and the importance of timely referral to specialist care.

Space conditions, palatal vault height, and tooth size in patients with and without palatally displaced canines: A prospective cohort study

OBJECTIVES:

To assess palatal vault height, tooth size, and dental arch dimensions in patients with unilateral and bilateral palatally displaced canines compared with a control group.

MATERIALS AND METHODS:

A sample of 66 patients (mean age: 11.5 ± 1.0 years) with 22 unilateral palatally displaced canines (UPDCs), 22 bilateral palatally displaced canines (BPDCs), and 22 controls (C) were consecutively recruited. All three groups had dental casts that were scanned digitally using the OrthoX three-dimensional model scanner. Tooth size, palatal vault height, dental arch width, dental arch depth, dental arch length, and dental arch space were measured by the same examiner using the GOM software. Remeasurements were made in 10 randomly identified patients.

RESULTS:

The palatal vault height was significantly lower in the BPDC group compared with controls. A significantly smaller mesial-distal crown width and, in general, more spacing in the maxilla were found in the UPDC and BPDC groups. No differences in arch length or arch width at the molar region were seen between the groups, while the arch length at the canine region was smaller in the UPDC and BPDC groups. However, this was observed in BPDC patients with both deciduous canines present and in most UPDC patients where the deciduous canine was present, compared with the control group, who had more permanent canines present.

CONCLUSIONS:

Patients with PDC had greater reduction in tooth size compared with the control group. The arch length and arch width were similar in patients with and without PDC.

The restorative management of microdontia

Microdontia is a dental abnormality that will often present to the dental practitioner due to the aesthetic concerns of the patient. Treatment is therefore aimed at addressing the aesthetics issue of the patient and this can present a number of challenges which may require a multidisciplinary approach in its management. This article presents the restorative management of localised and generalised microdontia.

WITHDRAWN: Extraction of primary (baby) teeth for unerupted palatally displaced permanent canine teeth in children

BACKGROUND

The permanent canine tooth in the maxillary (upper) jaw sometimes does not erupt into the mouth correctly. In about 1% to 3% of the population these teeth will be diverted into the roof of the mouth (palatally). It has been suggested that if the primary canine is removed at the right time this palatal eruption might be avoided. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the effect of extracting the primary maxillary canine on the eruption of the palatally ectopic maxillary permanent canine.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 20 April 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1946 to 20 April 2012) and EMBASE via OVID (1980 to 20 April 2012). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Trials were selected if they met the following criteria: a randomised or quasi-randomised controlled trial, involving the extraction of the deciduous maxillary canine and assessing eruption/non-eruption of the palatally displaced maxillary permanent canine.

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two review authors. The primary outcome was the reported prevalence of eruption or non-eruption of the ectopic permanent canine into the mouth following observation or intervention. Results were to be expressed as risk ratios for dichotomous outcomes with 95% confidence intervals and mean differences for continuous outcomes. Heterogeneity was to be investigated, including both clinical and methodological factors. Authors of trials were contacted to request unpublished data.

MAIN RESULTS

Reports of two randomised controlled trials previously excluded from an earlier version of the review due to "deficiencies in reporting, insufficient data" have now been included. These two trials included approximately 128 children, with more than 150 palatally displaced canine teeth, and both were conducted by the same research group. Data presented in the trial reports are either incomplete or inconsistent. Both trials are at high risk of bias. It must be emphasised that both trials have serious deficiencies in the way they were designed, conducted, and reported, and attempts to contact the authors to obtain detailed information and clarify inconsistencies have been unsuccessful. Allocation to treatment appears to be at the level of the individual, but outcomes of successful treatment relate to included teeth and data are not reported for each treatment group. Adverse effects are not reported. Neither trial provides any evidence to guide clinical decision making.

AUTHORS' CONCLUSIONS

There is currently no evidence of the effects of extraction of primary canine teeth in 10-13 year old children with one or two palatally displaced permanent canine teeth.

"Maxillary lateral incisor partial anodontia sequence": a clinical entity with epigenetic origin

The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a “syndrome”. Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called “Maxillary Lateral Incisor Partial Anodontia Sequence.”

Morphological relationship analysis of impacted maxillary canines and the adjacent teeth on 3-dimensional reconstructed CT images

OBJECTIVE

To examine whether there is a relationship between maxillary canine impaction and the morphologic characteristics of the maxillary dentition, especially the root of the lateral incisor.

MATERIALS AND METHODS

In this study, we selected only patients with unilateral maxillary canine impaction to compare the morphologic characteristics of the dentition on the impaction side and the clinically normal eruption side. The sample size was decided to be 40 based on the pilot study. To minimize bias depending on sex and location of the maxillary canine impaction, we selected equal numbers (20) of boys and girls, and equal cases (20) of buccal impaction and palatal impaction. Under the aforementioned conditions, the mean age was 13.5 ± 2.3 years. The multislice spiral computed tomography images of these 40 subjects were converted into three-dimensional (3D) reconstructed images using the OnDemand 3D program (Cybermed Co, Seoul, Korea). Then we measured the morphologic characteristics of the individual teeth on the obtained 3D teeth images.

RESULTS

Length and volume of the maxillary lateral incisor's roots were significantly smaller on the impaction side compared with the normal eruption side (P = 0.001 and P = 0.006, respectively). The width and volume of the canine's crown were significantly greater on the impaction side compared with the normal eruption side (P = 0.020 and P < .0001, respectively).

CONCLUSION

These results might help to prove the hypothesis that the smaller-sized lateral incisor roots and greater-sized canine crowns are the influential etiologic factors in maxillary canine impaction.

Frequency of impacted teeth and categorization of impacted canines: A retrospective radiographic study using orthopantomograms

OBJECTIVE

The objective of this study is to determine the frequency of impacted maxillary canines using seven subtype classification system. For this purpose, impacted maxillary canines have been divided into seven various subtypes.

MATERIALS AND METHODS

This is a descriptive, cross-sectional, and retrospective study conducted using radiographic data of residents of Madinah, Al Munawwarah. Radiographic data of 14,000 patients, who attended College of Dentistry, Taibah University, from January 2011 to February 2015, were screened against the selection criteria for the presence of impacted teeth. The individuals with maxillary impacted canines were matched to maxillary canine impaction. The occurrence of each subtype of impacted canines was calculated.

RESULTS

Impacted teeth are more common in the maxilla compared to mandible. The impacted canine represented the highest proportion of all impacted maxillary teeth followed by the second premolars and the central incisors. According to the classification system represented, Type II of canine impaction comprised the highest proportion (51%) while Type IV (0.5%) comprised the lowest frequency. The maxillary canine is the most frequently impacted tooth followed by mandibular canines.

CONCLUSIONS

Although there are many variations, the majority of impacted canines fall into Type II of the classification of impacted canines.

Are patients with impacted canines referred too late?

Objective To establish the appropriateness of timing of referrals for patients referred for the management of ectopic maxillary canines, and to evaluate the success of previous recommendations to educate referrers.Design Retrospective clinical re-audit.Setting Royal Surrey County Hospital NHS Foundation Trust.Subjects and methods Data were collected retrospectively for 220 consecutive patients between January 2013 - December 2014 and compared to the gold standard based on the clinical guidelines for management of the palatally ectopic maxillary canine published by the Royal College of Surgeons of England in 2010 which states that all patients with an impacted canine should be referred by 12 years of age.Results Ectopic maxillary canines represent a significant number of referrals to district general hospitals. One hundred and sixty-seven patients (76%) were referred late (>12 years) at a mean age of 14.1 years, >2 years later than the recommendations made in the Royal College Guidelines. Seventy-six percent of patients were not referred by 12 years of age compared to an audit in 2002 which found 45% delayed referral.Conclusion Timing of referral was delayed compared with the Royal College Guidelines. An increase in delayed referral suggests that local education programmes introduced after the previous audit did not have a lasting effect.

Etiology of maxillary canine impaction: a review

This article is a review that enumerates the causes of impaction of the maxillary permanent canines, including hard tissue obstructions, soft tissue lesions, and anomalies of neighboring teeth, and discusses the much-argued relationship between environmental and genetic factors. These phenomena have been shown in many investigations to accompany the diagnosis of canine impaction and have been presented as unrelated anomalous features, each of which is etiologically construed as genetic, including the aberrant canine itself. While in general the influence of genetics pervades the wider picture, a guidance theory proposes an alternative etiologic line of reasoning and interpretation of these studies, in which the same genetically determined anomalous features provide an abnormal milieu in which the canine is reared and from which it is guided in its misdirected and often abortive path of eruption.

Relationship between the maxillary transverse dimension and palatally displaced canines: A cone-beam computed tomographic study

OBJECTIVES

To examine the relationship between palatally displaced maxillary canines (PDC) and the maxillary transverse dimension using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Thirty-three patients (11 males and 22 females, mean age 18.2 years) with PDC were matched to 66 patients (22 males and 44 females, mean age 18.1 years) without PDC (control) by gender, age, and posterior occlusion. A CBCT image was taken on all the patients prior to any orthodontic treatment. For each patient the maxillary basal bone widths and interdental widths at the maxillary first molars and first and second premolars were measured on axial and coronal sections of CBCT images. In addition, the presence of permanent tooth agenesis and the widths of maxillary incisors were recorded.

RESULTS

Similar maxillary transverse dimensions, both skeletally and dentally, were found between the PDC and control groups. In the PDC group, the number of patients with permanent tooth agenesis was six times higher than in the control group. In addition, the maxillary lateral incisors on PDC-affected sides were smaller than those of control group (P < .05).

CONCLUSIONS

The maxillary transverse dimension, both skeletally and dentally, had no effect on the occurrence of PDC. The higher prevalence of permanent tooth agenesis was found in the PDC group. Moreover, the mean mesiodistal width of maxillary lateral incisors in the PDC group was significantly smaller than in the control group (P < .05).

Root resorptions related to ectopic and normal eruption of maxillary canine teeth - A 3D study

OBJECTIVE

To assess the incidence and severity of root resorption of maxillary incisors caused by ectopically and normally erupting maxillary canines and to analyse factors influencing root resorption of incisors using cone beam computed tomography.

SUBJECTS AND METHODS

The study sample comprised 59 patients with a total of 80 canines. Forty-six of the canines, in 37 patients, were defined as ectopic and 34 canines, in 22 patients, were defined as normal. The severity of root resorptions were analysed according to studies by Ericson and Kurol. Multiple logistics regression was used to evaluate the association between various factors and root resorptions.

RESULTS

The prevalence of root resorptions was significantly higher in the ectopic canine group, 11.0% of the central incisors and 67.6% of the lateral incisors in comparison to 0% and 36.2% in the normal erupting group. Most resorptions were defined as 'slight' and were located in the middle third of the root. There was a statistically significant relationship between canines located mesial to the midline of the lateral incisor and root resorption on the maxillary incisors.

CONCLUSION

The present results show that root resorption of maxillary lateral incisors was common in patients referred to CBCT imaging due to maxillary canine eruption disturbances. Although significantly more frequent in patients with ectopically erupting canines, lateral incisor resorption was also found in association with approximately every third of the normally erupting canines. The best predictor for root resorption seemed to be location of the canine mesial in relation to the midline of the lateral incisor root.

Comparison of the dental anomalies found in maxillary canine-first premolar transposition cases with those in palatally displaced canine cases

AIM

To compare the developmental dental anomalies associated with maxillary canine-first premolar (MxCP1) transposition and those of palatally displaced canine (PDC) with each other and with the background prevalence in the Maltese population in order to elucidate whether the two conditions have similar or differing genetic backgrounds.

MATERIALS AND METHODS

Dental records of 477 subjects with PDC, 57 subjects with MxCP1, and a control group of 500 subjects with no history of a PDC or tooth transposition were compared for canine eruption anomalies and hypodontia.

RESULTS

A high frequency of bilateral occurrence was present for both canine malpositions and when unilateral, a trend to right-sided occurrence was evident. The occurrence of transpositions in the PDC group and of PDC in the MxCP1 group was higher than expected. The prevalence of incisor hypodontia was significantly higher in subjects with PDC and MxCP1, as compared to the control group.

LIMITATIONS

The size of the MxCP1 group is relatively small. The study population is a small isolated Caucasian population and the results may not be applicable to other populations.

CONCLUSIONS

There is no significant difference between the MxCP1 and PDC groups in the prevalence or distribution of hypodontia and each of these groups exhibits a higher prevalence of the other canine anomaly. These findings support the theory that PDC and MxCP1 form part of a group of interrelated dental anomalies that share a common genetic basis.