Adequacy of maxillary dental arch width in patients with palatally displaced canines

Influence of the maxillary dimensions and lateral incisor anatomy on the palatal impaction of maxillary permanent canines: A three-dimensional case-control study

OBJECTIVE

The diagnosis of impacted upper permanent canines (IUPC) is a relatively common clinical finding. The aim of this study was to investigate associations between the upper permanent canines palatal impaction, lateral incisors morphology and the maxilla bone base.

MATERIAL AND METHODS

Cone-beam tomography files from 62 subjects were divided into 2 groups: impaction group (ICG/n=31; mean age 14.3±2.4) with 45 canines impacted on the palatal side and age- and sex-matched control group (CG/n=31; mean age 14.3±2.3), with 62 normally erupted canines. Linear and volumetric measurements of the lateral incisors, linear transversal measures and the maxillary anterior perimeter were taken. Independent Student's t-test was used for intergroup analysis with correction of Bonferroni.

RESULTS

Significant differences were found for crown length and root diameter (buccal-palatal) (P<0.005). The maxillary anterior perimeter in the ICG was reduced in relation to the GC but not significantly (P=0.008). The transverse skeletal variables of the maxilla were equivalent in the intergroup comparison (P>0.005).

CONCLUSION

Smaller dimensions in the crown length and in the upper permanent lateral incisors root buccal-palatal diameter were associated with the impaction of upper permanent canines on the palatal side. The maxillary transverse morphology did not show any association with the occurrence of this condition.

Statistical shape analysis of maxillary palatal morphology in patients with palatally displaced canines

OBJECTIVE

Maxillary morphology has long been a subject of interest due to its possible impact on palatally and labially displaced canines. This study aims to conduct a comparison of the palate morphology between individuals with palatal and labially displaced canines and control subjects using statistical shape analysis on a coronal cross-sectional of CBCT images.

MATERIALS AND METHODS

Patients aged between 12 and 43 years with palatally or labially displaced canines referred to Hamadan School of Dentistry between 2014 and 2019 were recruited for this retrospective study. The sample included 29 palatally displaced canines (PDC), 20 labially displaced canines (LDC), and 20 control groups (CG). Initially, the maxillary palate coronal section was acquired and landmarked in the region between the right and the left first molar. Procrustes and principal component analyses were used to identify the primary patterns of palatal shape variation. Statistical tests were then performed to examine both shape and size differences.

RESULTS

According to the results of Hotelling's T2 test, there is a significant difference between the mean shape of palate in PDC and CG (P = 0.009), while the difference between the PDC-LDC and LDC-CG groups is not significant. The longest full Procrustes distance was observed between PDC and CG (distance = 0.043), and the shortest full Procrustes distance was observed between LDC and CG (distance = 0.029). The first two principal components accounted for 84.47% of the total variance. The predictive accuracy of the discriminant analysis model showed that 72.46% of cases were correctly classified into the three study groups.

CONCLUSIONS

In terms of centroid size, there was no significant difference in the sectional area between the three groups, but the difference between the mean shape of palate in the PDC and CG groups was significant. The PDC group showed more prominent mid-palatal area in the molar region.

The Relationship between Unilateral Palatal Maxillary Canine Impaction and the Morphology of the Maxilla: A CBCT Study in Eastern Province of Saudi Arabia

OBJECTIVE

 This study aimed to examine the correlation between the morphology of the maxilla and unilateral palatally impacted maxillary canine (PIMC) among the Saudi population in the Eastern Province of Saudi Arabia.

MATERIALS AND METHODS

In this retrospective study, 36 patients' records [(17 PIMC, 8 male, 9 female, mean age 16.75 ± 2.12 years) (19 control; 9 male,10 female, mean age: 17.16 ± 2.12 years)] were included from a teaching dental hospital. On cone-beam computed tomographic images, measurements of maxillary arch length (MAL), palatal vault depth (PVD), intermolar width, sum of widths of 4 maxillary incisors, available arch space (AAS), palatal maxillary width (PMW) in the molar and premolar regions, nasal cavity width (NCW), maxillary arch shape (MAS) (arch length/intermolar width x 100), and palatal vault shape (PVS) (the PVD/intermolar width x100) were performed. Data were analyzed by SPSS-20.0. p-value less than or equal to 0.05 reflected statistical significance.

RESULTS

 This study's findings depicted that AAS (p = 0.012), PVD (p = 0.028), and PMW in the molar and premolar regions at the level of the alveolar crest (p = 0.002 and p = 0.034) and mid-root (p = 0.004 and p = 0.022) were significantly higher in the control compared to the PIMC group. PVS showed a significant difference between the PIMC and control groups (p = 0.037). However, regarding MAS, no significant difference was observed (p = 0.707).

CONCLUSION

 MAS was narrower in PIMC compared to the control group. The control group had a deeper palatal vault and greater AAS compared to the PIMC group. However, no significant difference was observed between groups regarding tooth size or NCW.

Investigation of the relationship between maxillary dimensions and labial and palatal maxillary impacted canines using cone beam computed tomography

OBJECTIVES

To compare the maxillary dimensions of individuals with labial and palatal bilateral maxillary canine impaction and a control group of individuals with no impaction using CBCT.

METHODS

45 patients were included in the study with age range of 13 to 18 and consisted of 22 females and 23 males. The sample included three groups of 15 patients as the control, labial and palatal group. The measurements made on the axial and coronal planes were made on the levels of the 1st premolar and the 1st molar. Also nasal cavity and anteroposterior depth were measured.

RESULTS

The maxillary anteroposterior depth, basal first molar width, alveolar first molar and premolar width and first molar palatal vault depth of the control group were significantly higher than labial and palatal groups (p<0.05).The basal first premolar width of the control group was significantly higher than palatal group (p<0.05). The first premolar palatal vault depth and nasal cavity width of the palatal group were significantly lower than other groups (p<0.05).

CONCLUSIONS

The basal and alveolar widths associated with the molars and the palatal depths were lower in the impacted group than control group. The anatomical structures in the female patients were affected by the position of impaction to a higher extent in comparison to the anatomical structures in the male patients.

Maxillary dimensions and arch shape with palatally displaced canines

BACKGROUND/OBJECTIVES

The aim of this study was to explore the effect of palatally displaced canines on maxillary dimensions and arch shape.

METHODS

Occlusal and skeletal landmarks were plotted on cone beam computed tomography (CBCT) images of 156 orthodontic patients: 78 with palatally displaced canines (PDC) (27 left, 28 right, and 23 bilateral) and 78 controls using Mimics™ (Materialise, Belgium). Arch forms were created, and arch width, depth, and skeletal dimensions were measured. T-test (P < 0.05) was used to compare the groups. Geometric Morphometrics (GM) analysis was used to compare the groups and to explore the pattern of covariation between two sets of landmarks.

RESULTS

The unilateral PDC group showed an increased first premolar, second premolar, molar widths, and an increased molar depth. No significant difference was found in arch form. The skeletal measurements were generally larger in the PDC group, but the transverse measurements were the most significant. Discriminant Function Analysis (DFA) with cross-validation allowed an accurate classification of 85.9% of the control group and 66.7% of the PDC group. The Mahalanobis distance displayed significant differences among three combinations of groups. Strong covariance was found between the second premolar and all other landmarks.

LIMITATIONS

The small sample sizes of the stratified groups precluded recognition of statistical significance.

CONCLUSIONS

Patients with unilateral PDC displayed significantly wider first, second premolar, and first molar widths, and increased first molar depths. There were no significant differences in arch form; however, GM showed significant differences between the groups and a prominent covariance function for the 2nd premolars.

Qualitative and quantitative three-dimensional evaluation of maxillary basal and dentoalveolar dimensions in patients with and without maxillary impacted canines

Background

This study aimed to three-dimensionally evaluate the qualitative and quantitative maxillary basal, dentoalveolar, and dental dimensions in patients with unilateral or bilateral maxillary impacted canines relative to their normal peers.

Materials and methods

This is a retrospective comparative study. Cone-beam computed tomography images of one hundred and fifty adult patients were divided into three equal groups: unilateral, bilateral, and control groups. Each had 50 patients that were three-dimensionally analysed. The quantitative measurements involved three basal (molar basal width, premolar basal width, and arch depth), seven dentoalveolar (molar alveolar width, premolar alveolar width, inter-molar width, inter-premolar width, inter-canine width, arch length, and arch perimeter), and two dental (canine length and width) measurements. The qualitative measurements included four bone density areas (buccal, lingual, mesial, and distal) around the maxillary impacted canines.

Result

Differences between the three groups were statistically different for the quantitative measurements involving the two basal variables (molar basal width and premolar basal width) and all measured dentoalveolar variables; these were smaller in the unilateral and bilateral groups compared with the control group (p < 0.001). Unilateral and bilateral impacted canine groups showed significantly wider and shorter canines than the control group (p < 0.001). The qualitative measurements (the four bone density areas) around unilateral and bilateral impacted canine groups showed significantly greater density than the control group (p < 0.001). There was no significant qualitative or quantitative difference between the unilateral and bilateral impacted canines. The three groups had no significant variations in terms of arch depth.

Conclusion

Maxillary unilateral and bilateral canine impactions are associated with reduced basal and dentoalveolar dimensions as well as wider and shorter maxillary canines compared to normal peers. The quality of bone around unilateral and bilateral impacted maxillary canines is higher than in non-impacted cases. Unilateral and bilateral canine impactions have quite similar qualitative and quantitative parameters.

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.

Comparison between Digital Casts and Cone Beam Computed Tomography for Measuring Maxillary Transverse Dimensions in Patients with Impacted Canines

Cone beam computed tomography (CBTCT) scans (n = 45) and digital dental casts (n = 45) were both used to measure the maxillary transverse dimensions in patients with impacted maxillary canines. The objectives were to explore the associations of these dimensions with the impaction and patient characteristics, and to compare the measurements between these techniques. The maxillary width was measured on scans and casts at the Walaridge, and the intermolar width and interpremolar width levels were measured at the first and second premolars (measured from the buccal grooves and the palatal cuspids, and the palatal and lingual amelocemental junctions). Two examiners independently compared the measurements between the control quadrants (without impaction) and the case quadrants (with impaction) in patients with unilateral impactions, and between the unilateral and bilateral impaction groups. The interclass correlation coefficient (ICC) was calculated to assess the interexaminer reliability and paired or independent Student’s t-tests and ANOVAs were used for comparisons. The ICCs were 0.887 and 0.919, globally, for the measurements on the CBCT scans and casts, respectively, which indicates the excellent interexaminer reliability. On the CBCT scans, statistically significant differences were found between the case and control quadrants in the transverse measurements at the lingual level on the upper first molars, and at the WALA ridge level on the upper second premolars (p < 0.05) in the unilateral impaction group. Significant differences were found between the case quadrants in the unilateral versus the bilateral groups at the WALA ridge on the second premolars in casts (p < 0.05), and at the lingual point on the first molars on the CBCT scans (p < 0.05). No statistically significant differences in the transverse measurements were observed between the impacted buccal and palatal canines on either the casts or CBCT scans. To the best of our knowledge, this is the first study to compare the transverse measurements between digital models and CBCT scans.

Skeletal and Dental Morphological Characteristics of the Maxillary in Patients with Impacted Canines Using Cone Beam Computed Tomography: A Retrospective Clinical Study

The aim of this study is to analyze the skeletal and dentoalveolar morphological characteristics of the maxillary in subjects with a unilateral palatally impacted canine using Cone Beam Computed Tomography (CBCT). A retrospective clinical study was conducted of 100 adult patients divided into two groups: one consisting of patients with a unilaterally palatally impacted maxillary canine (GI), with the subgroups in the right and left hemiarches (GI-R and GI-L), and the second, without impacted canine, as the control group (CG). The CBCT measured skeletal variables (maxillary basal width and alveolar crest height) and dentoalveolar variables (inclination of the upper incisor, tooth lengths of incisors and canines, arch length, tooth size and bone dental discrepancy). In skeletal variables, statistically significant differences were found in alveolar crest height (ACH) in all groups and subgroups (p < 0.01). In the dentoalveolar variables, there were differences in the angle of the upper incisor (II) and lateral incisor length (LLIL) between the GI and GC and the angle of the upper incisor (II′), arch length (AL′) and arch length-tooth size discrepancy (ATD′) among the GI subgroups (p < 0.01). There are skeletal and dentoalveolar differences in patients with unilateral palatally impacted maxillary canines, with lower angular and linear measurements compared with patients without impaction.

Evaluation of facial asymmetry by stereophotogrammetry in individuals with unilateral maxillary impacted canine

PURPOSE

The aim of this study is to compare the symmetry of the facial and dentoalveolar structures of patients with unilateral impacted maxillary canine teeth with a control group of individuals without impacted teeth using three-dimensional face scans.

METHODS

The study included 28 patients (10 females, 18 males) with unilateral impacted maxillary canine teeth and 28 patients (15 females, 13 males) without any impacted maxillary canine between 12 and 25 years of age. The 3dMDface™ (3dMD Inc., Atlanta, GA, USA) imaging system was used to obtain 3D face images. 3dMD Vultus® (3dMD Inc., Atlanta, GA, USA) software was used for the measurements.

RESULTS

According to the study findings, there were differences in linear measurements and volume measurements between the right and left sides of the face in patients with an impacted canine. However, these differences were not statistically significant. In patients with an impacted canine, surface differences between the right and left halves of the face were not found to be statistically different from the control group.

CONCLUSION

There was no difference in the amount of facial asymmetry between patients with unilateral maxillary impacted canine and patients with normal tooth alignment in the control group.

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

OBJECTIVES

To analyse morphological variations of the palate shape and maxillary arch dimension between a group of subjects with unilaterally or bilaterally buccally impacted maxillary canines and a control group (CG) by means of 3D geometric morphometric (GMM).

MATERIALS

Pre-treatment records of 50 subjects (16 males and 34 females; mean age 13.9 years ± 1.8) with one or both canines buccally displaced were collected retrospectively. A CG of 50 subjects was selected from a list of orthodontic patients at the same dental hospital. The experimental group, buccally displaced canine (BDC) was divided in two groups: unilateral buccally displaced canine (UBDC) and bilateral buccally displaced canine (BBDC). To analyse the palate's shape and maxillary arch dimension, study casts were scanned. To study the entirety of the palatal shape, 3D GMM analysis was used. To analyse the maxillary arch dimension, the virtual three-dimensional models were measured with a specific software (VAM, Vectra, Canfield Scientific, Fairfield, New Jersey, USA).

RESULTS

When comparing the groups with the GMM analysis, patients with BDC showed a statistically significant narrower and higher palatal vault. About the analysis of linear measurements, the intercanine width, the anterior and posterior segment length were significantly smaller in BDC, UBDC, and BBDC subjects when compared with the controls and there were no differences between UBDC versus BBDC groups.

CONCLUSIONS

Patients with buccally displaced permanent canine tended to have maxillary transverse constriction and variation in palatal vault morphology. The morphometric variation of the palatine vault and arch dimensions can be considered a clinical factor associated with the presence of BDC.

Changes in canine inclination after rapid and slow maxillary expansion compared to untreated controls

OBJECTS

Palatally displaced canines (PDC) might represent condition causing several clinical problems, such as roots resorption and malocclusion, and can develop palatal canine impaction. Some interceptive treatments such as rapid maxillary expansion were suggested in order to foster maxillary canine eruption. Among expansion protocols, no data are available about differences between rapid and slow maxillary expansion on maxillary canine eruption. The aim of this study was therefore to evaluate α-angle changes in palatally displaced canines using rapid and slow maxillary expansion compared to untreated control patients.

SETTING AND SAMPLE POPULATION

The final sample comprised 19 patients treated with rapid maxillary expansion (RME group), 17 treated with slow maxillary expansion (SME group) and 22 control patients (Control group).

MATERIALS AND METHODS

α-angle was measured on panoramic films to detect canine inclination at the beginning, and at the end of maxillary expansion treatment or observation, time and changes over time were compared.

RESULTS

In the comparisons among groups, RME group was the only group showing a decrease in α-angle measurements that was statistically significant also when compared to the other groups, except for the left side when compared to SME group.

CONCLUSION

RME treatment significantly and positively affected canine position when compared to SME treatment and control group.

Prediction of maxillary canine impaction based on panoramic radiographs

OBJECTIVES

The objective of this article is to establish a large sample-based prediction model for maxillary canine impaction based on linear and angular measurements on panoramic radiographs and to validate this model.

MATERIALS AND METHODS

All patients with at least two panoramic radiographs taken between the ages of 7 and 14 years with an interval of minimum 1 year and maximum 3 years (T1 and T2) were selected from the Department of Oral Health Sciences, University Hospital Leuven database. Linear and angular measurements were performed at T1. From 2361 records, 572 patients with unilateral or bilateral canine impaction were selected at T1. Of those, 306 patients were still untreated at T2 and were used as study sample. To construct the prediction model, logistic regression analysis was used.

RESULTS

The parameters analyzed through backward selection procedure were canine to midline angle, canine to first premolar angle, canine cusp to midline distance, canine cusp to maxillary plane distance, sector, quadratic trends for continuous predictors, and all pairwise interactions. The final model was applied to calculate the likelihood of impaction and yielded an area under the curve equal to 0.783 (95% CI [0.742-0.823]). The cut-off point was fixed on 0.342 with a sensitivity of 0.800 and a specificity of 0.598. The cross-validated area under the curve was equal to 0.750 (95% CI [0.700, 0.799]).

CONCLUSION

The prediction model based on the above mentioned parameters measured on panoramic radiographs is a valuable tool to decide between early intervention and regular follow-up of impacted canines.

Difficulty of palatal impacted canine treatment in different sagittal and vertical skeletal malocclusions: A retrospective 3D evaluation

OBJECTIVE

To evaluate the difficulty of impacted canine treatment in different kinds of sagittal and vertical malocclusion using the KPG index, a novel 3D classification system for canine impaction.

MATERIALS AND METHODS

In this cross-sectional study, 74 cone-beam computed tomography (CBCT) images of subjects with palatally impacted canines were collected from one dental radiographic clinic. Impacted canines were assessed and KPG index of difficulty of treatment was calculated for each tooth. Lateral cephalograms corresponding with each CBCT were also traced and analysed. To assess the relationship between the level of treatment difficulty and type of malocclusion, the Chi² test was used. The Kruskal-Wallis H test was used to assess the difficulty score between the three classes of malocclusion.

RESULTS

There was no correlation between different sagittal skeletal measurements and treatment difficulty of impacted teeth (P>0.05). A positive correlation was shown between KPG index and linear measurements of A to Pn and facial angle (FH-N Pog) (P<0.05). Difficulty of treatment did not differ among various patterns of vertical growth.

CONCLUSION

Treatment of impacted canines is more difficult in patients with maxillary prognathism and it is recommended that these patients be more meticulously evaluated prior to treatment.

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.

Effectiveness of various interceptive treatments on palatally displaced canine-a systematic review

OBJECTIVE

The aim of this systematic review was to assess whether interceptive treatment carried out in the mixed dentition period improves the position of Palatally Displaced Canines (PDC).

MATERIALS AND METHODS

A systematic search was performed on various computerized databases. A hand search was also performed by reviewing the references within the examined studies and titles of the papers published over the last 30 years on various orthodontic journals.

RESULTS

This systematic review analysed eight articles, of which five were Randomized Clinical Trials (RCT) and three were prospective control studies. Qualitative assessment was done for all the eight studies. The effect of interceptive measures such as extraction of primary canine, Rapid Maxillary Expansion (RME), cervical pull headgear and Transpalatal Arch (TPA) on successful eruption of Palatally Displaced Canines was analyzed.

CONCLUSION

Interceptive treatment improves the position of PDC and reduces the chances of impaction. Significant changes in success rate depend on diagnosis at early mixed dentition stage. A combination of interceptive measures which includes extraction of primary canine, cervical pull headgear, TPA and RME aided in successful eruption. However, Randomized clinical trials with increased sample size, proper randomization comparing all the interceptive measures along with assessment of other factors such as patient satisfaction, pain experience and cost factor will yield more evidence based conclusions.

Association between maxillary transverse discrepancy and occurrence of potentially impacted maxillary canines in mixed dentition patients

OBJECTIVE

The aim of this study was to determine the association between transverse maxillary discrepancy and occurrence of potentially impacted maxillary canines in mixed dentition patients.

MATERIAL AND METHODS

This cross-sectional analytical study was conducted on 85 Pakistani subjects (32 males and 53 females) aged between 8 to 13 years, having good quality orthopantomographs and dental casts. Maxillary transverse discrepancy was assessed by subtracting the mandibular intermolar width from the maxillary intermolar width on dental cast. Maxillary lateral incisors and canines were traced from orthopantomographs, and canines were placed into sector classification. Chi-square test was used to determine the difference in the occurrence of potentially impacted maxillary canines between patients with maxillary transverse discrepancy and patients without maxillary transverse discrepancy.

RESULTS

There was no significant difference seen in the occurrence of impacted maxillary canines in patients with and without maxillary transverse discrepancy in mixed dentition patients.

CONCLUSION

Patients with maxillary transverse discrepancy may not be at a higher risk of palatal canine impaction. Radiological presence of canine in sector II, III and IV, pose a higher risk of canine impaction.

Morphology of maxilla in patients with palatally displaced canines

OBJECTIVES

The aim of this study was to investigate the possible relationship between the morphology of maxilla and the palatally displaced canines (PDC).

MATERIALS AND METHODS

In this cross-sectional study, there were 101 patients (45 males, 56 females) aged 12 to 16years, referred to Hamadan school of dentistry in 2014. They were divided into 3 groups: the bilateral PDC (PDCb) group (male=15, female=21), the unilateral PDC (PDCu) group (male=16, female=19), and the control group (male=14, female=16). Five morphology related variables including intermolar width, maxillary arch length, palatal vault depth, palatal intermolar area, and nasal width were measured using CBCT images with Dolphin Imaging software, version 11.5. Statistical analysis was performed with ANOVA and the Dunnett test using SPSS software, version 16.0.

RESULTS

Only the palatal intermolar area and the palatal vault depth values were significantly less in the PDCu and the PDCb groups than those in the control group (the palatal intermolar area: 376.17, 381.93, and 423.75mm², the palatal vault depth: 13.19, 13.42, and 14.59mm; respectively; P<0.05). For all the variables, there was no statistically significant difference between the PDCu and PDCb groups.

CONCLUSION

Decreased palatal vault depth and palatal intermolar area may be correlated with greater chance of palatal displacement of canines. Future prospective studies in mixed dentition patients are needed as a predictive factor to find the probability of PDC.

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.

Early diagnosed impacted maxillary canines and the morphology of the maxilla: a three-dimensional study

BACKGROUND

The aetiology of the canine displacement still remains controversial. Some authors implicated a deficiency in maxillary width as a local mechanical cause for impacted canines. The aim of the study was to examine whether there is a relationship between impacted maxillary canines, early diagnosed by using panoramic radiographs, and the morphology of the maxilla on 3D model casts.

METHODS

The displaced maxillary canines (DMC) group consisted of 24 patients (mean age, 9.1 ± 1.1 years), while the control group consisted of 25 subjects (mean age, 8.7 ± 0.9 years). Seven measurements were calculated on the digital casts of each subject: intermolar width (IMW), arch length (AL), depth of the palatal vault (PVD), available arch space (AAS), the sum of the anterior segments (SAS), the right/affected (R-Af) and left/unaffected (L-Un) available spaces.

RESULTS

Both IMW and AL in the DMC group were significantly decreased relative to the control group (P < 0.01), indicating that patients with displaced canines presented a shorter and narrower palate than subjects without eruption problems. Moreover, the values of the SAS and AAS were significantly decreased (P < 0.01) in the DMC group relative to the controls.

CONCLUSIONS

The shape of the maxillary arch was narrower and shorter in the displaced maxillary canines group compared with the control group.

Differences in the Eruption Angle of Palatally Displaced Canines in Klinefelter Syndrome: a Retrospective Study on Panoramic Radiographs

Objective

To investigate the eruption angle of maxillary canine in patients with Klinefelter syndrome (KS) in which high prevalence of palatally displaced canine anomaly (PDC) has been found by clinical assessment.

Subjects and Methods

The sample consisted of 37 KS males aged 20-34 years (mean 27 years) and the control group which consisted of 78 healthy males aged 20-27 years (mean 23 years). A pioneer method was used to measure the eruption angle. It was based on determining the topographic construction of mandibular gonion line called GO-GO method on panoramic radiograph.

Results

The mean of eruption angle was increased for 10.58° in the right side and 9.69 ° in left side in patients with KS compared to those in the control group. The difference of mesioangular inclination of palatally displaced canines in Klinefelter patients was statistically significant (p< 0.01). When eruption angle in the control group was compared to Klinefelter patients, the statistical difference was confirmed for respective sides (P <0.01 for both).

Conclusions

The difference between eruption angle values in KS patients as well as in those belonging to the control group seemed to identify a developmental disturbance, thus confirming the fact that an extra X chromosome has an influence. The GO-GO method might be used for males when it is difficult to define occlusal planes, or for comparison. If this method is used, the eruption angular values should not exceed 56.74°.

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.

The Relationship between Palatal Displacement of Upper Canines and Incisors Widths in a Syrian Sample of Patients with Uncrowded Arches

The aim of this study investigates mesiodistal crown size of the maxillary and mandibular incisors of patients with palatally impacted canines (PDC). Pretreatment dental casts of orthodontic patients with PDC of one or both maxillary canines (N: 33) were collected. This PDC sample was matched according to age and sex with pretreatment dental casts from unaffected orthodontic patients. For the PDC and matched control samples, maximum mesiodistal crown diameters were recorded for the four incisors on the right side only. The results showed that, on average, the mesiodistal crown diameters for the maxillary and mandibular incisors measured smaller in the PDC sample than in the control sample. These findings of statistically significant tooth-size reductions associated with PDC occurrence indicate a generalized pattern of reduced tooth size as a characteristic associated with the PDC anomaly. Further, the presence of generalized tooth-size reduction in cases with palatally displaced canines help explain why most orthodontic treatment plans for PDC patients are of the nonextraction type.

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).

Etiologic factors for buccal and palatal maxillary canine impaction: a perspective based on cone-beam computed tomography analyses

INTRODUCTION

The aim of this research was to identify the etiologic factors associated with palatally impacted canines and buccally impacted canines in a Chinese population by using the cone-beam computed tomography technique.

METHODS

Pretreatment cone-beam computed tomography scans of 170 Chinese subjects with impacted maxillary canines and 170 age- and sex-matched subjects without impaction were used. Impacted canine subjects were divided into 2 groups: those with palatally impacted canines and those with buccally impacted canines. One rater analyzed the cone-beam computed tomography data for qualitative and quantitative variables of the teeth, dental arch, and skeletal components. The measurements were compared by using analytical statistical methods.

RESULTS

The mesiodistal dimension of the lateral incisor was significantly smaller in the palatally impacted canine group than in the other group (by an average of 0.4-0.5 mm; analysis of variance [ANOVA], P <0.001). Both anterior maxillary dental (interpremolar) width and skeletal width (interjugal points) in the buccally impacted canine group were significantly smaller than in the palatally impacted canine and control groups (ANOVA, P <0.001), whereas the intermolar widths and posterior mandibular widths were similar among the groups. The groups with palatally impacted or buccally impacted canines had significantly increased prevalence values of peg-shaped lateral incisors and incisor impaction, respectively (chi-square or Fisher exact tests, P <0.001). After excluding subjects who also had lateral incisor anomalies, the prevalence values of supernumerary teeth, missing premolars, or third molars combined were not different among the impaction and control groups. The average mesiodistal location of the canine cusp tip was significantly different between the buccally impacted canines and the palatally impacted canines groups; it was distal and mesial to the lateral incisor long axis, respectively.

CONCLUSIONS

In Chinese subjects, buccal canine impaction is mostly associated with anterior transverse (dental and skeletal) deficiency and incisor impaction, whereas palatal impaction is mostly associated with small or missing lateral incisors, consistent with the guidance theory. Likely, preimpaction migrations of the canines are mainly buccal for buccal impactions and excessively mesiopalatal for palatal impactions.

Dental arch parameters of the displacement and nondisplacement sides in subjects with unilateral palatal canine ectopia

OBJECTIVE

To compare arch perimeter and teeth size, number, and shape between the two sides of the dental arch-the canine displacement side (DS) and the nondisplacement side (NDS)-in subjects with unilateral palatally displaced canine (PDC).

MATERIALS AND METHODS

Orthopantomograms (OPTs) of 240 subjects with unilateral PDC and 240 OPT matching controls were used. Additionally, study casts of 100 study subjects and 100 controls were used. The age of subjects ranged between 14 and 25 years. Dental casts were digitized and several parameters were recorded.

RESULTS

The transverse width from midpalatal line to the buccal segment and the palatal area on the DS was larger than that in the NDS (P < .05 to .001), with no difference in tooth size between both sides. Maxillary second premolars, canines, and lateral incisors in the PDC group were smaller than those in control group. Peg-shaped lateral incisors were significantly more frequent in the study group (P < .001).

CONCLUSIONS

The transverse width of the DS was larger than that of the NDS. Both sides were generally smaller than those of the control group. Tooth size in the DS was comparable to that in the NDS but smaller than those of the control group. A missing or peg-shaped lateral incisor was the most common reported anomaly.

Surgical-orthodontic management of bilateral multiple impactions in non-syndromic patient

Several surgical and orthodontic treatment options are available to disimpact the impacted teeth. But the closed eruption technique has the best long-term prognosis. The tooth is surgically exposed, an attachment is bonded to it, flap is resutured over it and an orthodontic extrusive force is delivered to bring the tooth into occlusion. This case report presents a case with multiple impacted teeth in which no syndrome or systemic conditions were detected. A 20-year-old female patient reported for orthodontic treatment with chief complaint of multiple unerupted permanent teeth and retained primary teeth. Radiographic examination revealed impacted 14, 15, 24, 25, 33, 34, 43 and 44. Surgical exposure of the impacted teeth was done after extraction of retained primary teeth. Forced eruption of these teeth was done by applying traction with closed eruption technique. After careful treatment planning followed by guided eruption of impacted teeth, patient finished with a significantly improved functional and aesthetic result.

Inclination of the infraorbital canal studied on dry skulls expresses the maxillary growth pattern: a new contribution to the understanding of change in inclination of ectopic canines during puberty

OBJECTIVE

The purpose of this study was to analyze the correlation between direction of the infraorbital canal and maxillary width on frontal radiographs of dry human skulls.

MATERIAL AND METHODS

Forty-two symmetrical, dry human skulls (late adolescence and adult) with no dental or skeletal anomalies. Frontal radiographs were taken of each skull placed in the Frankfort horizontal plane, with a radiopaque marker in the infraorbital canal. The maxillary transversal growth pattern was expressed as the infraorbital transversal angle (IOt) formed between a line through the contour of the bilateral orbita (lo) and a line parallel to the infraorbital marker. Three cephalometric widths were measured on the skulls, two anteriorly (the width of the piriform aperture (AP) and the interorbital width (IO)) and one posteriorly (the palatal width (PW)). A general linear model was used for statistical analysis.

RESULTS

The direction of the infraorbital canal (66.08°, 95% CI: 62.53-69.64) depended on the transversal growth: an increased PW of 1 mm resulted in a decreased IOt of 1.84° (p=0.041); an increase in IO of 1 mm resulted in an increased IOt of 2.24° (p=0.017); and an increased AP of 1 mm resulted in a decreased IOt of 3.30° (p=0.066).

CONCLUSIONS

The study indicates that the direction of the infraorbital canal in frontal view reflects the transversal growth of the maxilla. A wide maxilla posteriorly resulted in a small infraorbital transversal angle. These findings might explain the different inclination of ectopic canines.

Interrelationship between the position of impacted maxillary canines and the morphology of the maxilla

INTRODUCTION

The aim of this study was to examine whether there is a relationship between the position of impacted maxillary canines and the morphology of the maxilla.

METHODS

The palatally impacted canine group included 18 boys and 27 girls with an average age of 12 years 9 months (±2 years 1 month). The buccally impacted canine group comprised 19 boys and 26 girls with an average age of 12 years 2 months (±1 year 4 months). Arch length/intermolar width × 100 was used as the value for comparison of maxillary arch shapes, and palatal vault depth/intermolar width × 100 was used to compare the shapes of palate between the 2 groups. Each category was directly measured from the diagnostic model.

RESULTS

Both the arch length/intermolar width × 100 and the palatal vault depth/intermolar width × 100 formulas showed statistically significant differences (P <0.0001), indicating differences in the shape of maxillary arch and the palatal vault between the 2 groups.

CONCLUSIONS

The shape of the maxillary arch was narrower and longer in the palatally impacted canine group compared with the buccally impacted canine group, and the palatally impacted canine group had a deeper palatal vault than did the buccally impacted canine group.

Incidence and effects of genetic factors on canine impaction in an isolated Jewish population

INTRODUCTION

The etiology of palatal canine impaction is multifactorial and includes a genetic contribution. The aim of this study was to find the incidence and effects of genetic factors on palatally impacted canines in a genetically isolated community of ultraorthodox Hassidic Jews of Ashkenazi decent.

METHODS

For this study, we retrospectively evaluated 1000 charts of Hassidic Jewish patients. Their distribution was 58% female and 42% male, with a mean age of 14 years.

RESULTS

From those patients, 49 (4.9%) were determined to have canine impaction. Of these 49, 69.4% had unilateral palatal impaction, 26.5% had bilateral palatal impaction, and 4.1% had unilateral labial impaction. The z-test of proportion showed that female patients have a greater percentage than males for unilateral palatal impaction (P <0.01) with left-side dominance (P <0.01).

CONCLUSIONS

Our results imply that genetics plays a significant role in maxillary canine palatal impaction. A genetically isolated Hassidic Jewish community can be a useful group to study the effects of genetic factors on various dental anomalies, including palatally displaced canines.

A review of early displaced maxillary canines: etiology, diagnosis and interceptive treatment

Impaction of maxillary canines is a frequently encountered clinical problem the treatment of which usually requires an interdisciplinary approach. Surgical exposure of the impacted tooth and the complex orthodontic mechanisms that are applied to align the tooth into the arch may lead to varying amounts of damage to the supporting structures of the tooth, not to mention the long treatment duration and the financial burden to the patient. Hence, it seems worthwhile to focus on the means of early diagnosis and interception of this clinical situation. In the present article, theories related with the etiology of impacted canines and predictive variables of canine impaction in the mixed dentition are reviewed with an insight into current interceptive treatment modalities.

Maxillary expansion as an interceptive treatment for impacted canines

DESIGN

This was a randomised controlled trial.

INTERVENTION

Patients in the control group received no treatment, whereas the patient treatment group had a rapid maxillary expander soldered to bands placed on the second deciduous molars or the first permanent molars. Activation of the screw was continued until the palatal cusps of the maxillary posterior teeth were in contact with the buccal cusps of the mandibular posterior teeth. Once the required expansion was achieved, the expansion screw was locked in position. After expansion, all patients were retained with the expander in place for 6 months after which the patients wore a retention plate at night for 1 year.

OUTCOME MEASURE

The main outcome was successful or unsuccessful eruption of the maxillary permanent canines.

RESULTS

The sample comprised 54 patients (32 in the treatment group and 22 in the control). No statistically significant differences were found for any variable at baseline. The prevalence rates of successful eruption of the maxillary canines were 65.7% (21 subjects) in the treatment group and 13.6% (three subjects) in the control. The comparison was statistically significant (chi-square, 12.382; P >0.001).

CONCLUSIONS

The use of rapid maxillary expansion (RME) in the early mixed dentition appears to be an effective procedure to increase the rate of eruption of palatally displaced maxillary canines (PDC) compared with an untreated control group.

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.

Maxillary Transverse Discrepancies and Potentially Impacted Maxillary Canines in Mixed-dentition Patients

OBJECTIVE

To investigate the correlation between maxillary transverse discrepancy and the occurrence of impacted canines in patients during the mixed-dentition stage.

MATERIALS AND METHODS

Panoramic radiographs and dental casts were evaluated of randomly selected patients in the mixed dentition. The experimental group consisted of 84 orthodontic patients with a maxillary transverse discrepancy. The control group included 100 orthodontic patients without a maxillary transverse discrepancy. Intermolar widths of the experimental group were measured and recorded. The permanent canines of both groups were placed into a sector classification by using a panoramic radiograph. The experimental group was then analyzed to identify whether these patients had an impacted maxillary canine associated with the transverse discrepancy. The results were further evaluated based on type of impaction (unilateral or bilateral).

RESULTS

Results of this study showed that patients with a transverse discrepancy are more likely to have an impacted canine than those patients without a transverse discrepancy, with the impaction more likely being unilateral. However, patients with a transverse discrepancy do not have a greater likelihood of having a bilateral impaction compared with patients without a transverse discrepancy.

CONCLUSIONS

There appears to be an association between potentially impacted canines and transverse discrepancies. Identification can be made early based on proper panoramic evaluation and clinical detection. If a possibly impacted canine is detected early, appropriate treatment should be taken to minimize complications and avoid definitive impaction.