Dental anomalies as a microsymptom of palatal canine displacement

Skeletal and dental maxillary morphological characteristics in patients with impacted canines: systematic review and meta-analysis

BACKGROUND

There are a few hypotheses for the origin of palatally impacted canines (PIC). Nevertheless, the results of different studies are controversial.

OBJECTIVE

Considering the evidence available in the literature to determine the skeletal and dentoalveolar dimensions in patients with PIC using cone beam computed tomography (CBCT).

SEARCH METHODS

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement. The literature search with no publication date restriction in five databases and hand searching was performed until April 2023.

DATA COLLECTION AND ANALYSIS

Data assessing the skeletal and dentoalveolar characteristics of subjects with PIC evaluated with CBCT was extracted, and the studies' quality was evaluated with the Newcastle-Ottawa Scale (NOS). Skeletal and dentoalveolar characteristics of subjects with PIC were compared with non-impacted subjects or non-impacted sides. MedCalc software was used to perform the meta-analysis. Statistical heterogeneity was assessed using the chi-square and I-square tests.

RESULTS

The initial database search identified a total of 1153 studies. After applying the selection criteria, nine articles were included in the systematic review and meta-analysis. According to the NOS, all included articles were graded as "Good" quality. The meta-analysis showed a non-significant difference in measuring dentoalveolar height, alveolar first molar width, and basal lateral width. Controversial results were observed when evaluating both basal and alveolar first premolar widths. A significant difference was found when assessing anterior alveolar crest height and basal maxillary width.

CONCLUSIONS

Studies demonstrated the reduction of both dentoalveolar and skeletal maxillary parameters of the patients with PIC. The meta-analysis indicated that PIC correlates to both vertical and transverse skeletal dimensions of the maxilla. However, the results remain controversial. The findings should be interpreted with caution due to different study designs and unbalanced groups in the included studies; therefore, further research is needed for more reliable conclusions.

REGISTRATION

This systematic review and meta-analysis were registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42022362124).

Comparisons of Dental Anomalies in Orthodontic Patients with Impacted Maxillary and Mandibular Canines

To assess the presence and possible associations between the type of dental anomalies and maxillary and mandibular canine impactions in orthodontic patients treated for canine impaction, panoramic radiographs of orthodontic patients treated for canine impaction were assessed for the presence of associated dental anomalies. A random sample of orthodontic patients without canine impaction matched for age and gender served as controls. Descriptive and exact inferential statistics were implemented in order to assess potential associations between canine impaction and dental anomalies. A total of 102 orthodontic patients with 70 maxillary (MaxCI) and 32 mandibular (ManCI) canine impactions were assessed. The control group included 117 orthodontic patients. Dental anomalies were present in more than 50% of patients with impacted canines and in 20% of the controls. Tooth agenesis was significantly more common in the MaxCI group when compared to the ManCI group, while supernumerary teeth and canine transmigration were registered more often in the ManCI group. When compared to the control group, peg-shaped maxillary lateral incisors and tooth agenesis were significantly more prevalent in the MaxCI group, while canine transmigration, supernumerary teeth, the agenesis of mandibular incisors and tooth transpositions were significantly more prevalent in the ManCI group. The impaction of other teeth was significantly more common in both canine impaction groups when compared to the controls. The prevalence of dental anomalies in orthodontic patients with impacted canines was higher than in orthodontic patients without canine impaction. Different types of tooth anomalies were found in the MaxCI and ManCI groups.

Association between maxillary canine impaction and other dental anomalies: radiological study of a mixed dentition children's cohort from an orthodontic clinic

PURPOSE

To investigate the significance of association between maxillary impacted canines and various dental anomalies.

METHODS

Files of 874 orthodontic patients were evaluated for the presence of maxillary impacted canines. From this sample, a group of 97 patients (39 males and 58 females) with at least 1 impacted maxillary canine consisted the study group. This group was compared to a control group of 97 patients (42 males and 55 females) that was created by random selection from the initial sample without maxillary canine impaction. The impaction diagnosis was made from the panoramic radiographs. Chi-square test was used to perform the analysis for significant associations. Stepwise discriminant analysis, binary logistic regression and classification tree were used to identify best combinations.

RESULTS

Statistically significant difference was found for peg-shaped maxillary lateral incisors and infraoccluded deciduous molars. The presence of peg-shaped upper lateral incisors arises the probability of impacted canine to 83.3%, a distal displaced unerupted second premolar to 63.16% and the impaction of any other teeth to 80% as showed by the classification tree.

CONCLUSIONS

The presence of peg-shaped maxillary lateral incisors and infraocclusion of deciduous molars can be considered major valuable early risk indicators for maxillary canine impaction, because they manifest before the maxillary canine eruption. Special consideration should be given on distal displaced unerupted second premolar and the impaction of any other teeth. Patients with these dental anomalies are candidates for future interceptive treatment for canine eruption.

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.

Orthodontic Treatment for a Patient with Root Resorption of All Four Maxillary Incisors due to Bilaterally Impacted Canines

Maxillary canines require the longest period from the generation of the tooth germ to the completion of eruption, and they have more difficulties in eruption than other teeth. The incisor roots are often resorbed due to malpositioned canines. An 11-year-old girl presented with an extremely rare case of root resorption of four maxillary incisors due to bilaterally impacted maxillary canines, which were located excessively mesially. The case was managed through oral surgery and orthodontic treatment over five years. After extracting the maxillary deciduous canines, the maxillary bilateral canines were surgically exposed. The bimaxillary lateral incisors were extracted, and the canines were orthodontically tracted over 8 months. All teeth were then aligned using edgewise brackets. No further root resorption of the central incisors was observed for 5 years after canine traction. This case demonstrates the importance of early detection of abnormally positioned canines.

Risk Prediction of Maxillary Canine Impaction among 9-10-Year-Old Malaysian Children: A Radiographic Study

Background. Early diagnosis and interceptive treatment of the maxillary canine impaction is crucial as it reduces treatment complexity and decreases complications and adverse outcomes. Aim and Objectives. To determine the mean maxillary canine position among 9-10-year-old children and predict the risk of impaction of the maxillary canines. Methodology. Panoramic radiographs (PANs) of 289 healthy children aged between 9 and 10 years were observed where the average position of maxillary canines was related to the lateral incisor, sector locations, and angulations to the bicondylar line were traced. The average position was obtained by using descriptive statistics. One sample Wilcoxon signed-rank test is done to predict the risk of canine impaction by comparing the data obtained to the average position from prior studies. Results. A total of 289 PANs (126 males and 163 females) were utilized for the analysis. The findings showed that the average position of the maxillary canines in our population was statistically different from the average position of nonimpacted canines in previous studies. However, on average, more than 85% of canines in our population were still located within the safe range of satisfactory position, with females showing slight predominance outside of the acceptable range. The mean scores of the angles between the right canine and lateral incisor were significantly higher among females than males ( $p=0.001$ ). Similarly, females had a significantly higher mean angle of the left canine than males ( $p<0.001$ ). In regard to the angles between the bicondylar line and permanent maxillary canine, the mean scores were not significantly different ( $p>0.05$ ) on both the left and right side. Conclusion. There is a low risk of impaction of maxillary canines in the Malaysian population. However, more retrospective studies using more radiographic and clinical indicators need to be done to confirm the risk of impaction further.

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.

Orthodontic management of impacted maxillary canines

The prevalence of impacted maxillary canines is 2–3%. In Caucasian populations, it is reported to be more palatally displaced than buccally, with the opposite trend seen in Asian populations. At the ages of 9–11 years, the position of the canine germ should be diagnosed, for most children through clinical supervision. In 7–10% of children, the clinical investigation must be supplemented with radiographic investigation, in most cases with intraoral radiographs. About 50% of impacted canines cause root resorption of the adjacent teeth. To detect the severity of resorption, cone-beam computed tomography is necessary. Root resorptions on incisor roots occur most often at 11–12 years of age. Early diagnosis of ectopically positioned maxillary canines is very important. In cases with palatally displaced canines and no root resorptions, extraction of the primary canines has been found in different studies to give good results. If the permanent canine has not started to normalize its position within 12 months, orthodontic treatment must be taken in consideration. Often, this is done by surgical exposure and orthodontic traction of the canine out into the dental arch.

Implant supported prosthesis on edentulous mandible with multiple impacted teeth - a case report with 5 year follow up

Multiple impacted teeth are quite often syndromically related, which could be hormonal or metabolic. It may be also due to infection, cyst, or trauma. A number of idiopathic multiple impacted teeth cases have been reported in the literature. In most of these situations, the impacted teeth are few in number. Here, we present a case with all mandibular teeth impacted. The number of reports in the literature of rehabilitation of such a clinical situation is very less. Impacted teeth can significantly complicate the rehabilitation of an otherwise straight forward case. When all teeth are impacted, the situation becomes even more complex. This case report illustrates prosthodontic rehabilitation of mandibular arch of a 24-year-old, asyndromic patient with implant-retained dentures following the surgical removal of impacted teeth. The objective of presenting this clinical report is primarily to increase the awareness, with which, the rehabilitation can be handled in a similar situation and also for the fact that such a report is a rarity.

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%.

Three-dimensional evaluations of the digital casts of morphologic maxillary teeth symmetry in patients with unilateral palatally displaced canines

INTRODUCTION

The goal of this study was to compare the size and morphologic symmetry of the maxillary teeth in subjects with and without unilateral palatally displaced canines (PDCs).

METHODS

Plaster casts of 38 subjects (mean age 14.75 ± 0.95 y) with unilateral PDCs were selected (study group [SG]) and compared with casts from an age- and sex-matched control group (CG). Then dental casts of both groups were scanned into 3-dimensional (3D) models. Tooth sizes (mesiodistal [MD] and buccolingual [BL] widths and volumes) for SG and CG were measured. Afterward, 3D deviation analysis was carried out with the use of Geomagic Control X software. All of the data were normally distributed according to parametric tests.

RESULTS

All of the maxillary tooth diameters were smaller in SG than in CG. Statistically significant differences (P ≤ 0.001) were obtained when comparing the widths and volumes of the PDC quadrant and the unaffected quadrant of the same patient. Morphologic tooth symmetry by surface-to-surface matching for SG (PDC side vs non-PDC side) and CG (right vs left quadrant) demonstrated significant (P ≤ 0.001) but small differences, except for the lateral upper incisors (71.27%).

CONCLUSIONS

Unlike control subjects, PDC patients showed high mismatching of lateral incisor crowns of ∼30%.

Third molar tooth agenesis and pattern of impaction in patients with palatally displaced canines

OBJECTIVES

To investigate the association between third molar agenesis and pattern of impaction, missing teeth, and peg-shaped lateral incisor with palatal canine displacement (PDC).

MATERIALS AND METHODS

The pretreatment orthodontic orthopantomograms of 438 patients (122 males and 316 females) diagnosed with PDC were included. A total of 338 patients with normally erupted canines who had a preexisting radiograph as part of their orthodontic treatment (125 males and 313 females) served as controls. Orthopantomograms were evaluated for missing third molars, third molar eruption status, and type of impaction, third molar spaces, third molar width, and angulation.

RESULTS

In the PDC group, at least one third molar was missing in 48% and 19% in the upper and lower arches, respectively. Also, 38% and 67% of PDC patients had at least one third molar impaction in the upper and lower arches, respectively. The difference between the PDC and control groups was significant for both missing and impacted third molars ( P < .001 for each). The most common type of third molar impaction in the upper arch was vertical and distoangular in the PDC and control groups, respectively. Upper and lower third molar width and spaces were reduced in PDC patients when compared with the control group ( P < .001). In PDC patients, missing teeth and peg-shaped lateral incisors were recorded in 5.6% and 9.1%, respectively.

CONCLUSIONS

PDC patients showed a high prevalence of third molar agenesis and impaction. Upper and lower third molar width and space were reduced in the PDC patients. There were no significant associations between tooth agenesis (other than third molars) and the PDC anomaly.

Associations between tooth agenesis and displaced maxillary canines: a cross-sectional radiographic study

Background

The aim of present study was to test the association between hypodontia and displaced maxillary canine when compared with a control group.

Methods

The study group was composed of 336 subjects with a mean age of 10.7 ± 1.2 years, presenting with at least one missing tooth. Exclusion criteria included syndromes, craniofacial malformations, extractions and trauma history and previous orthodontic treatment. The control group consisted of 336 subjects with a mean age of 10.7 ± 1.2 years, without agenesis. Stepwise multiple logistic regression using the backwards elimination and the Wald test method was performed to identify the best combination of hypodontia and displaced maxillary canine (P < 0.05).

Results

The most represented category in study group consisted in mild agenesis (86.9%); moderate and severe agenesis groups respectively represented the 11.7 and 1.4% of study group. Agenesis was diagnosed in both arches in 46 subjects. Maxillary hypodontia and mandibular hypodontia was respectively detected in 156 and 134 subjects. The most frequent missing teeth were mandibular second premolars (45.8%), lateral incisors (41.7%) and maxillary second premolars (17.8%). A significant correlation between agenesis and displaced maxillary canine was observed in the study group (P < 0.05). Only the agenesis of maxillary lateral incisors remained in the final model during backward stepwise deletion. Significant association between the severity of dental agenesis and prevalence of displaced maxillary canine was not assessed.

Conclusions

The outcomes revealed no difference related to the severity of dental agenesis and prevalence of displaced maxillary canine. Only the agenesis of maxillary lateral incisors should be considered directly connected with displaced maxillary canine.

Electronic supplementary material

The online version of this article (10.1186/s40510-018-0226-0) contains supplementary material, which is available to authorized users.

Determinants of maxillary canine impaction: Retrospective clinical and radiographic study

Background

The aim of this study is to evaluate determinants of maxillary canine impaction taking into account both canine position related variables and the pattern of facial growth.

Material and Methods

A retrospective clinical and radiographic analysis was carried out on 109 patients aged between 9 and 10 years at the time of first evaluation. At baseline, SN-GoMe angle, the interincisal angle, the canine angle α and the canine distance d were used to characterize canine location and vertical facial growth. At the end of a two years follow up period the eruption state of each canine of each patient was recorded and accordingly classified as erupted or impacted on a clinical and radiographic basis. Univariate and multivariate statistical analyses were performed, including correlation among the studied variables and principal components analysis; several machine learning methods were also used in order to built a predictive model.

Results

At the end of the two years follow up period after the first examination, 54 (24.77%) canines were classified as impacted. Except for Angle α values, there were no statistically significant differences between impacted and erupted canines. The studied variables were not significantly correlated, except for the SN-GoMe Angle and the distance d in the impacted canine group and the angle α and the distance d in erupted canines group. All variables, except for SN-GoMe Angle in erupted canines, have a partial communality with the first two principal components greater than 50%. Among the learning machine methods tested to classify data, the best performance was obtained by the random forest method, with an overall accuracy in predicting canine eruption of 88.3%.

Conclusions

The studied determinants are easy to perform measurements on 2D routinely executed radiographic images; they seems independently related to canine impaction and have reliable accuracy in predicting maxillary canine eruption.

Key words:Canine impaction, Determinants, Facial growth.

Associations between occlusion, jaw relationships, craniofacial dimensions and the occurrence of palatally-displaced canines

BACKGROUND AND PURPOSE

Cephalometric and arch measurements might predict the occurrence of a palatally-displaced impacted maxillary canine (PDC). Despite their clinical importance, studies in this regard are limited and controversial.

METHODS

In this case-control study, 35 PDC patients and 77 controls aged over 13 years were examined. Eleven cephalometric measurements: N-S, ANS-PNS, ANS-N, S-N-ANS, facial angle (FH/NPog), SNA, SNB, Y-axis (SN/SGn), gonial angle, Go-Gn/SN, and Jarabak Index were performed. The maxillary and mandibular intermolar and interpremolar widths were measured. Patients' sagittal skeletal relationships and centric occlusions (molar) were measured by radiographic and cast examinations. The differences between the two groups in terms of the above-mentioned cephalometric and anatomic variables were assessed using Chi² and Mann-Whitney U-tests (α=0.05).

RESULTS

Chi² showed a significant negative association between dentoalveolar class I (molar) and PDC occurrence (P=0.018), but not between PDC and skeletal sagittal relationships. Facial angle (FH/NPog) and Y-axis (SN/SGn) were more obtuse in patients with PDC (P<0.05). No arch dimensions differed between the two groups.

CONCLUSIONS

PDC tends to accompany molar class II/III but is not associated with upper or lower jaw widths or lengths. Vertical dimensions might be smaller in PDC patients. Some variables were inconclusive and need future assessments.

Evaluation of dental age and associated developmental anomalies in subjects with impacted mandibular canines

OBJECTIVES

To assess the null hypothesis that there is no difference in the rate of dental development and the occurrence of selected developmental anomalies related to shape, number, structure, and position of teeth between subjects with impacted mandibular canines and those with normally erupted canines.

MATERIALS AND METHODS

Pretreatment records of 42 subjects diagnosed with mandibular canines impaction (impaction group: IG) were compared with those of 84 subjects serving as a control reference sample (control group: CG). Independent t-tests were used to compare mean dental ages between the groups. Intergroup differences in distribution of subjects based on the rate of dental development and occurrence of selected dental anomalies were assessed using χ(2) tests. Odds of late, normal, and early developers and various categories of developmental anomalies between the IG and the CG were evaluated in terms of odds ratios.

RESULTS

Mean dental age for the IG was lower than that for the CG in general. Specifically, this was true for girls (P < .05). Differences in the distribution of the subjects based on the rate of dental development and occurrence of positional anomalies also reached statistical significance (P < .05). The IG showed a higher frequency of late developers and positional anomalies compared with controls (odds ratios 3.00 and 2.82, respectively; P < .05).

CONCLUSIONS

The null hypothesis was rejected. We identified close association of female subjects in the IG with retarded dental development compared with the female orthodontic patients. Increased frequency of positional developmental anomalies was also remarkable in the IG.

Disimpaction of maxillary canines using temporary bone anchorage and cantilever springs

Impacted canines, particularly in the maxilla, are frequently encountered in orthodontic practice. Unfortunately, depending on their position, correction can often be difficult and sometimes unsuccessful. Thorough diagnosis along with orthodontic treatment combining bone-supported anchorage and cantilever springs appears, in our view, to offer the best solution to this tricky orthodontic challenge while limiting, as far as possible, the risk of failure.

Clinical utility of dental cone-beam computed tomography: current perspectives

Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology and forensic dentistry, and its limitations in maxillofacial diagnosis.

Dental anomalies associated with buccally- and palatally-impacted maxillary canines

AIM

The aim of the present study was to determine the association of both buccally- and palatally-impacted canines with other dental anomalies.

METHODS

This retrospective study was conducted on a population of 533 southern Chinese children and adolescents who had impacted maxillary canines that had been treated in the Paediatric Dentistry and Orthodontics Clinic, Prince Philip Dental Hospital, The University of Hong Kong, Hong Kong. Descriptions of the impacted canine and other associated anomalies were obtained from the case notes and radiographs. Clinical photographs and study casts were used, where available.

RESULTS

A total of 253 (47.5%) patients with impacted maxillary canines were diagnosed with other dental anomalies. Microdontia was the most frequently-occurring anomaly reported in these patients, with the maxillary lateral incisor the most commonly affected tooth. Other odontogenic anomalies that were associated with both buccally- and palatally-impacted canines included hypodontia, supernumerary teeth, transposition of other teeth, enamel hypoplasia, other impacted teeth, and dens invaginatus.

CONCLUSION

Both buccally- and palatally-impacted canines were found to be associated with other odontogenic anomalies.

Skeletal features in patient affected by maxillary canine impaction

Objective: To analyze the skeletal features of patients with maxillary canine impaction. Material and Methods: The complete pre-treatment records of 1674 orthodontic patients were examined. From the subjects with maxillary impacted canine 12 patients were excluded , remaining 108. The subjects with maxillary impacted canine were divided into two study groups: a palatally displaced canine group (PDCG) (77 patients) and a buccally displaced canine group (BDCG) (31 patients). The values of the skeletal features measured on the lateral cephalometric radiograph were compared with a control group (CG) of 121 subjects randomly selected from the initial sample without maxillary canine impaction. The statistical analysis of the difference between the study groups and the CG was tested using ?2 test and Fisher’s exact test. The level of significance was set at P ?0.05. Results: The CG was characterized by increased values of A point-Nasion-B point angle (ANB) and by a retro-positioned or smaller lower jaw. PDCG patients showed normal skeletal features compared to the CG, presenting mainly I class and lower rank of II and III sagittal skeletal features. PDCG subjects presented also normal values of the Steiner vertical skeletal relationship angles with normal facial divergence compared to the CG. PDCG cases were also characterized by horizontal and prognathic growth. BDCG did not present significant differences in skeletal features compared to the CG, except for an increased ANB. Conclusions: Palatally displaced canine (PDC) was frequently the only orthodontic problem of patients and was not associated whit altered skeletal features. The frequent absence of malocclusion in PDC patients explains the delayed identification of this problem. BDCG patients did not present significant differences in skeletal features with respect to the orthodontic population. The presence of both buccally displaced canine (BDC) and malocclusion makes the patient with BDC both aware of the need for, and motivated to undergo, orthodontic treatment.

Key words:Canine impaction, palatal displacement, buccal displacement, skeletal features.

Triplets with bilateral palatally displaced canines in association with third molar agenesis: an example of biologically related dental anomaly patterns?

This case series shows male triplets with similarly positioned palatally displaced canines and agenesis of third molars. It supports findings reported previously in the literature suggesting a genetic origin for the palatally displaced canine and other dental anomalies which may be biologically related.

Evaluation of tooth size in patients with congenitally-missing teeth

Background and aims

Hypodontia is a common developmental abnormality of dentition. This study aimed to determine tooth width in patients affected with mild hypodontia and compare the results with a control group without tooth agenesis.

Materials and methods

The orthodontic records of 25 patients with congenital missing of one or two teeth (hypodontia group), and 25 subjects with full dentition (control group) were selected. The greatest mesiodistal width of each tooth was measured on the study models by a digital caliper. Tooth width measurements were compared between the groups using a student t-test at p < 0.05 of significance.

Results

Patients with hypodontia showed narrower teeth than the control subjects. The differences in tooth size between the two groups were statistically significant for the first and second premolars and first molar in the maxillary right and for the second premolar in the maxillary left quadrants (p < 0.05). In the lower arch, the first and second premolars and also first molar in both sides of hypodontia patients demonstrated significant reduction in tooth size compared to the control group (p < 0.05).

Conclusion

These findings suggest that patients with mild hypodontia have narrower teeth than normal subjects especially in posterior segments, which may have clinical implications during the orthodontic treatment process.

Dental anomalies and clinical features in patients with maxillary canine impaction

OBJECTIVE

To analyze the prevalence, distribution, clinical features, and relationship with dental anomalies of maxillary canine impaction.

MATERIALS AND METHODS

The complete pretreatment records of 1674 orthodontic patients were examined. Subjects with maxillary impacted canines were divided into two study groups: a palatally displaced canine (PDC) group (114 patients) and a buccally displaced canine (BDC) group (37 patients). These were compared to a control group of 151 patients who were randomly selected from the initial sample without maxillary canine impaction. The significance of associations between canine impaction and dental and clinical features and anomalies was examined with the chi-square test.

RESULTS

PDC patients presented with normal overjet and facial profile and a lower degree of dental arch crowding in comparison to the control patients. PDC patients showed a higher prevalence of impaction of other teeth, dental aplasia, transposition, and peg-shaped maxillary lateral incisors (odds ratios 3.3, 2.6, 8.3, and 5.8, respectively).

CONCLUSION

PDC was frequently the only orthodontic problem of patients. BDC group patients did not present with notable differences in clinical and dental features or dental anomalies compared to control subjects.

Relation between agenesis and shape anomaly of maxillary lateral incisors and canine impaction

OBJECTIVE: The purpose was to obtain information about the relation between agenesis and shape anomaly of maxillary lateral incisors and canine impaction. METHODS: Seventy-three patients with canine impaction and 73 control patients, without canine impaction, were evaluated. The mesiodistal distances of the maxillary lateral incisors adjacent to the impacted canines and the correspondent mandibular lateral incisors were measured. The adjacent lateral incisors were classified in: 1 - absent, 2 - small, 3 - peg-shaped, 4 - standard. RESULTS: The results showed that among the patients with impacted canines, there were 21 anomalous teeth (small and peg-shaped) and among the control patients there were only three small and peg-shaped teeth, with a statistically significant difference (p = 0.001). No patients were found with impacted canines and absent lateral incisors. CONCLUSION: It was concluded that in patients with anomalous lateral incisors (small and peg-shaped) there is a probability to present impacted canines and this must be considered.

Comparison of two cone beam computed tomographic systems versus panoramic imaging for localization of impacted maxillary canines and detection of root resorption

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

Three-dimensional assessment of impacted canines and root resorption using cone beam computed tomography

OBJECTIVE

The objective of this study was to localize impacted canines in 3 dimensions and determine the most common location of impaction using cone beam computed tomography (CBCT). We also assessed root resorption of adjacent teeth. The cusp tip of each impacted canine was located and digitized using Dolphin 3D imaging, after viewing sagittal, coronal, and axial views. The position on the occlusal plane where the normally erupted canine cusp tip should be located was used as a control reference point. The degree of impaction was defined by the difference between the impacted canine cusp tip and reference cusp tip positions.

MATERIALS AND METHODS

CBCT scans of 29 consecutive individuals with impacted canines undergoing orthodontic treatment at the UCSF Orthodontic Clinic were included in this study.

RESULTS

The average degree of mesial impactions was 10.1 mm, of distal impactions was 4.2 mm, of facial impactions was 4.16 mm, of palatal impactions was 1.8 mm, and of gingival impactions was 10 mm; 40.4% had no root resorption, 35.7% showed slight root resorption, 14.2% showed moderate resorption, and 4% showed severe root resorption of the adjacent lateral incisor.

CONCLUSION

We reliably assessed the position of impacted canines in 3 dimensions using CBCT, thereby improving accuracy of location and facilitating precise surgical and orthodontic management. In our study 40.4% had no root resorption, 35.7% showed slight root resorption, 14.2% showed moderate resorption, and 4% showed severe root resorption of the adjacent lateral incisor. The most frequent location of impacted canines was palatal, mesial, and gingival.

Vertical periodontal ligament distraction--a new method for aligning ankylosed and displaced canines

OBJECTIVE

In the course of a clinical pilot study we tested the vertical periodontal ligament (V-PDL) distraction as a means of aligning ankylosed upper canines. The objective of this study was to analyze the appropriateness und effectiveness of this method.

METHOD AND MATERIALS

The ankylosed upper canines of five female patients aged between 16 und 19 years were surgically exposed, luxated, and after a latency period of 5 to 7 days, distracted at a rate of 0.5 mm per day. The installed distractors were borne by the periodontal-mucosa, the periodontal-mucosa and the bone, or by the bone exclusively. We evaluated the distraction distance and time and degree of hard and soft tissue generation present in the region surrounding the distracted teeth.

RESULTS

All canines were aligned after a mean distraction period of 43.2 days (+/- 3.6 days). The mean distraction distance was 10.8 mm. Three canines had defects at the cemento-enamel junction, and one canine had to be extracted due to a large defect at the root.

CONCLUSIONS

Vertical PDL distraction is a minimally-invasive therapy to align ankylosed impacted canines. Even if the long-term prognosis of distracted canines with defects is uncertain, the patient benefits from the vertical PDL distraction because both hard and soft tissues are generated in the vicinity of the distracted canine.

Dens invaginatus. Part 1: classification, prevalence and aetiology

AIM

To review and discuss the aetiology, prevalence and classification of this dental anomaly together with the morphology of an invagination and the most appropriate nomenclature.

SUMMARY

This review considers the different possible nomenclatures and concludes that dens invaginatus is the most appropriate description. The paper highlights the different reported prevalence figures and concludes that the problem is probably one of the most common of the dental developmental abnormalities with maxillary lateral incisors most commonly affected. The paper suggests that the classification system described by Oehlers (1957a) is probably the most clinically relevant and that the morphological features associated with this problem may increase the risk of pulpal pathology developing and complicate any possible endodontic treatment.

KEY LEARNING POINTS

* The aetiology of dens invaginatus is still unknown, although there is some evidence that it may be genetic in origin. * The problem is probably more prevalent than most clinicians are aware of and this is because of the diagnostic difficulties associated with the anomaly. * The nature of the problem may increase the risk of pulp disease and complicate any root canal treatment.

Radiographic assessment of dental anomalies in patients with ectopic maxillary canines

BACKGROUND

The aetiology of palatally and labially located ectopic maxillary canines is multifactorial. Accordingly, early prediction of this eruptional disturbance is in most cases not possible.

AIM

The purpose of this study was to analyse dental deviations in cases with either palatal or labial ectopic canines.

DESIGN

Panoramic and intra-oral radiographs from 50 patients with palatally located (38 females and 12 males) and 19 patients with labially located ectopic canines (11 females and 8 males), aged 10 years, 2 months-18 years, 1 month, were analysed. Dental deviations registered were crown and root malformations, agenesis, and eruption deviations. Registrations were performed in the maxillary incisor field and in the dentition in general.

RESULTS

The study documented that palatally as well as labially located ectopic canines can occur in dentitions without other dental deviations. Dental deviations occurred in approximately two-thirds of all cases, more often in females and in cases with palatally located canines. More than half of the females with palatally located canines had deviations in the maxillary incisors and in the dentition in general.

CONCLUSION

Dental deviations may be considered a risk factor for maxillary canine ectopia. Early identification of patients at risk and appropriate interceptive treatment may reduce ectopic eruption of maxillary canines.

Treatment of a patient with multiple impacted teeth

An impacted or missing permanent tooth can add significant complications to an otherwise straightforward case. When multiple impacted teeth are present, the case complexity increases further. Developing a treatment sequence, determining appropriate anchorage, and planning and executing sound biomechanics can be a challenge. The following case report illustrates a patient reportedly diagnosed with mild scleroderma as an adolescent. He presented for orthodontic treatment as an adult with multiple retained primary teeth and multiple impacted teeth. Diagnosis, treatment planning, and various methods of managing guided eruption of impacted teeth will be discussed. Following orthodontic treatment that required extraction of multiple primary and permanent teeth as well as exposure and ligation of multiple permanent teeth by an oral surgeon, the patient finished with a significantly improved functional and esthetic result.