Canine sexual dimorphism in crown and root dimensions: a cone-beam computed tomographic study.

The primary step in forensic odontological analysis is sex determination. The present study is one of the few studies that evaluated the accuracy of the combination of canine tooth root length and crown measurements for sex determination. The study sample comprised 196 cone-be am computed tomographic scans of individuals aged 20-80 years distributed in five age categories: 20-29, 30-39, 40-49, 50-59, and 60+ years old. Different parameters, such as width, length, and ratio measurements for the crown and root of each maxillary and mandibular canine tooth, were examined and recorded. The findings indicated that maxillary canines had greater sex dimorphism ability (87.3%) than mandibular canines (80.6%). Total tooth length and root length of maxillary canine were the most pronounced variables in the differentiation of sex groups. When the combination of the mandibular and maxillary measurements was considered, the accuracy for sex dimorphism was 85.7%. By using ratio variables, the accuracy was reduced to 68.9%. According to the findings of this study, total tooth length and root length are the most discriminant variables of canine teeth. These variables are more reliable sex indicators than crown measurements.

A novel acrylic orthodontic device for treatment of linguoverted mandibular canine teeth in small dogs.

Linguoverted mandibular canine teeth (LMC) is a common malocclusion in dogs. Several inclined bite-plane techniques using acrylic resin have been introduced to correct LMC in dogs. Although these techniques have suggested modifications to overcome shortcomings, there are still limitations; e.g., high technical sensitivity, as the viscous acrylic resin must still be fabricated in the oral cavity. The authors developed a novel method for small-breed dogs that uses a doughy acrylic resin form to achieve an easy intraoral design and extraoral fabrication. Eight small-breed dogs were presented to evaluate and treat malocclusion causing palatal trauma. First, a Class-1 malocclusion with linguoversion of the mandibular canine teeth (6 dogs with unilateral LMC and 2 dogs with bilateral) was diagnosed based on oral examination. Dogs were treated with the new method using a doughy acrylic resin form for 6 to 7 wk and had posttreatment follow-up 1 y after the procedure. All treated canine teeth were in correct positions 1 y after the appliances were removed. Key clinical message: The authors believe that the new method using a doughy acrylic resin form could be a good alternative for veterinarians to use when treating LMC.

Un nouveau dispositif orthodontique en acrylique pour le traitement des canines mandibulaires linguoverties chez les petits chiens. Les canines mandibulaires linguoverties (LMC) sont une malocclusion courante chez le chien. Plusieurs techniques de plan de morsure incliné utilisant de la résine acrylique ont été introduites pour corriger la LMC chez le chien. Bien que ces techniques aient suggéré des modifications pour surmonter les lacunes, elles présentent encore des limites; par exemple, une sensibilité technique élevée, car la résine acrylique visqueuse doit encore être fabriquée dans la cavité buccale. Les auteurs ont développé une nouvelle méthode pour les chiens de petite race qui utilise une forme pâteuse de résine acrylique pour obtenir une conception intra-orale et une fabrication extra-orale faciles. Huit chiens de petite race ont été présentés pour évaluer et traiter une malocclusion provoquant un traumatisme palatin. Tout d'abord, une malocclusion de classe 1 avec linguoversion des canines mandibulaires (6 chiens avec LMC unilatérale et 2 chiens avec bilatérale) a été diagnostiquée sur la base d'un examen oral. Les chiens ont été traités avec la nouvelle méthode en utilisant une forme pâteuse de résine acrylique pendant 6 à 7 semaines et ont fait l'objet d'un suivi post-traitement 1 an après la procédure. Toutes les canines traitées étaient dans la bonne position un an après le retrait des appareils.Message clinique clé:Les auteurs estiment que la nouvelle méthode utilisant une forme pâteuse de résine acrylique pourrait être une bonne alternative que les vétérinaires pourraient utiliser lors du traitement du LMC.(Traduit par Dr Serge Messier).

Determining the widths of the maxillary anterior teeth for esthetics: comparison of the Mondelli and Albers formulas, esthetic proportion, and golden ratio.

The purpose of this study was to compare various formulas for idealized proportions of the maxillary incisors to the actual dimensions of natural teeth. The Mondelli formula 1 (MF1), Mondelli formula 2 (MF2), Albers formula (AF), esthetic proportion (EP) for width and height of anterior teeth, and golden ratio (GR) were calculated for a total of 50 dental students (30 women and 20 men) who participated in the study. The following measurements were obtained directly in the participant's mouth with a digital caliper: the mesiodistal and incisogingival dimensions of the maxillary central incisors, lateral incisors, and canines; the intercanine distance; and the smile width. The participants were photographed, and the smile width was also measured on the photographs. The MF1 and MF2 were each calculated twice, using both direct measurements and photographic measurements. The projected central incisor widths calculated using the MF1, MF2, and AF were compared among themselves and against the actual measurements using analysis of variance and Fisher test for multiple comparisons (α = 0.05). The EP and GR were analyzed using descriptive statistics. There was a statistically significant difference between all of the widths projected by the formulas and the actual widths of the central incisors (P < 0.05). Whether calculated from a direct or a photographic measurement, the incisor widths projected by the MF1 and MF2 were statistically similar to each other (P > 0.05). The EP values were similar to those reported in the literature. Only 2% of the participants had an incisor width ratio (central incisor/lateral incisor) that matched the GR of 1.618, while 86% fell within the range of 1.2 to 1.4. Overall, the proportions calculated with the MF1, MF2, AF, EP, and GR did not exactly match the actual dimensions of natural teeth. The formulas and the proportions available in the literature can assist in esthetic planning, but the individual characteristics of each patient and expertise of the dentist should guide treatment for each case.

In vitro study examines posterior torque impact on 3D mechanics of anterior teeth in clear aligner treatment.

INTRODUCTION: This study utilizes investigate the impact of posterior torques on the three-dimensional force exerted on the lower anterior teeth during the retraction in orthodontic clear aligners treatment. METHODS: Four groups of mandibular dental arch light-cured resin models will be created, including: mandibular posterior teeth with standard torque, mandibular posterior teeth with labial torque, and mandibular posterior teeth with lingual torque. Each group will consist of 12 sets of clear aligners. The aligners will be worn, and measurements will be taken using the six-axis measurement platform to evaluate the three-dimensional force exerted on the lower anterior teeth under various initial torques applied to the mandibular posterior teeth. SPSS 26.0 used for ANOVA analysis, α = 0.05 significance level. RESULTS: Comparing mandibular posterior teeth with standard torque to those with labial torque, no statistically significant changes were observed in buccolingual force. In the mesiodistal direction, mandibular incisors exhibited a significant decrease in distal force, while canines showed a significant increase. Both findings had a significance level of P < 0.05; Lingual torque on mandibular posterior teeth, compared to standard torque, led to a significant increase in lingual force for incisors and a significant increase in labial force for canines in the buccolingual direction (P < 0.05). Additionally, mandibular incisors exhibited a significant decrease in distal force in the mesiodistal direction (P < 0.05). CONCLUSION: Varying initial torques on mandibular posterior teeth significantly impact force on lower anterior teeth. Labial torque reduces lingual force on incisors and increases distal force on canines. Lingual torque increases lingual force on incisors and labial force on canines.

Comparison of the different methods of width estimation in unerupted canine and premolars.

BACKGROUND: There are different methods for determining the required space for unerupted teeth. However, the accuracy of these techniques varies depending on ethnic differences. Therefore, the current study was performed to compare the accuracy of four methods for estimating the mesiodistal width of unerupted canines and premolars in a population of northern Iran. METHODS: The present cross-sectional study was conducted on 50 pairs of dental casts of patients aged 12-24 years old. The mesiodistal width of the teeth was measured with a digital caliper by two observers (ICC < 0.9), and the mean value was recorded. The space required for eruption of canines and premolars was obtained by the Tanaka-Johnson formula and the Moyers tables and compared with the actual value by paired t test. RESULTS: The Tanaka-Johnson formula had overestimation in the maxilla and mandible, which was statistically significant (p < 0.001). The values obtained from the Moyers tables in different confidence levels were not accurate. However, the 65% level for the mandible had almost no difference from the actual value (P = 0.996 and r2 = 0.503). Furthermore, linear regression was obtained based on the total mesiodistal width of the maxillary first molar and mandibular central incisor (maxilla: Yx= 0.613X + 2.23 and mandible: Ym= 0.618X + 1.6) and the total mesiodistal width of the mandibular first molar and maxillary central incisor in each jaw (maxilla: Yx = 0.424X + 5.021 and mandible: Ym = 0.447X + 3.631). CONCLUSION: The Tanaka-Johnson method was overestimated in the population of northern Iran. The 85% and 75% confidence levels of the Moyers table have the best clinical results for the maxilla and mandible, respectively. Regression based on maxillary first molars and mandibular central incisors has better results.

Effectiveness of a low-intensity static magnetic field in accelerating upper canine retraction: a randomized controlled clinical trial.

INTRODUCTION: Neodymium-iron-boron magnets have been suggested as a contemporary method for accelerating the process of orthodontic tooth movement (OTM). A limited number of clinical trials evaluated their effectiveness in accelerating OTM which is desirable for both orthodontists and patients. The present study aimed to investigate the effectiveness of a low-intensity static magnetic field (SMF) in accelerating upper canine retraction movement. MATERIALS AND METHODS: Seventeen patients (mean age 20.76 ± 2.9 years) with their orthodontic treatment decision to extract the upper and lower first premolars due to bimaxillary protrusion malocclusion were included in this split-mouth study. Canine retraction was performed using Nickel-titanium (Ni-Ti) closed-coil springs (150 g of force on each side). The experimental side received SMF via an auxiliary wire that carried 4-neodymium iron-born magnets with an air gap of 2 mm between the magnets to produce a magnetic field density of 414 mT in the region corresponding to the lateral ligament of the upper canine. To determine the rate of upper canine retraction and upper molar drift, alginate impressions were taken once a month to create plaster casts, which were analyzed digitally via a three-dimensional method. RESULTS: The rate of upper canine retraction was significantly greater (P < 0.05) on the SMF side than that on the control side during the first and second months, with an overall duration (19.16%) that was greater than that on the control side. The peak acceleration occurred during the second month (38.09%). No significant differences in upper molar drift were detected between the experimental and control sides (P > 0.05). CONCLUSION: A low-intensity static magnetic field was effective at accelerating upper canine retraction. The difference between the two sides was statistically significant but may not be clinically significant. The SMF did not affect upper molar drift during the upper canine retraction phase. TRIAL REGISTRATION: The trial was retrospectively registered at the ISRCTN registry ( ISRCTN59092624 ) (31/05/2022).

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

BACKGROUND: Root resorption of adjacent teeth due to impacted canines is common, and orthodontic treatment often leads to secondary resorption or even loss of adjacent roots. Clinical reports of long-term stability after treatment are rare. CASE PRESENTATION: This study reports two cases of maxillary impacted canines resulting in severe root resorption of the adjacent lateral incisors. Surgical exposure, orthodontic retraction, and alignment of the impacted canines were successful in both cases, and the resorbed lateral incisors were stable with no significant loosening and normal pulp vitality after treatment and at the 5- and 10-year follow-up appointments. CONCLUSIONS: Light orthodontic force may be used to move adjacent teeth with root resorption due to tooth obstruction. The path and direction in which the teeth are moved must be specifically designed so that the adjacent roots are not resorbed and so long-term stability can be achieved.

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

OBJECTIVE: This study aimed to investigate the radiological features of the permanent canines and the treatment carried out to ensure their eruption relative to certain features involved in Dental Anomaly Patterns (DAP). MATERIAL AND METHODS: The cross-sectional part of this retrospective register--based study focused on 1,315 dental panoramic tomographs (DPTs) of children aged 8.5-10.5 years, while the longitudinal part involved information on the treatment provided for 1,269 canines after the DPTs and on their eruption into the oral cavity. RESULTS: The canines of the DAP children more often showed evidence of early treatment (p = 0.014), with girls having more frequently interceptive treatment (p = 0.004) and boys early headgear (p = 0.022). Delayed dental age was associated with early treatment (OR 3.29, 95% CI 1.08-9.99). Either no or clear overlapping of a canine with the lateral incisor occurred more often in the DAP children, whereas canine inclination did not differ between the groups. The root development stage of the canine was more often either beginning or well advanced in the DAP children. CONCLUSIONS: The children with dental developmental abnormalities more often showed evidence of early treatment for the canines. Monitoring of the erupting canines after the first mixed stage is important to enable timely early treatment.

Variations in the Root Form and Root Canal Morphology of Permanent Mandibular canine.

BACKGROUND: Mandibular canines are recognized as usually having one root and one root canal in most cases. However, many investigators have reported the anatomical variations associated with mandibular canines. Thus; the objective of this study is to determine the number of roots and morphology of the root canal system of permanent mandibular canine in a Nepalese population. METHODS: Cone Beam Computerized Tomography images of 390 patients in a Nepalese population were selected, and a total of 780 mandibular canines were analyzed. The number of root and the canal configurations were investigated. Data were analyzed with descriptive analysis and Chi-square tests using the Statistical Package for the Social Sciences (SPSS) software version 20 (SPSS Inc, Chicago, IL, USA). RESULTS: Out of the 780 mandibular canines, 741(95%) were single-rooted canines while only 39 (5%) were double-rooted canines. The most common type of Vertucci in single-rooted canines was Type I (1-1) in the percentage of 85.6% and the least type was Type IV (1-2) in the percentage of (2.5%). The Chi-square tests showed no significant association between gender and number of roots (P = 0.87) and gender and root canal configuration in single-rooted canine (P = 0.52). CONCLUSIONS: All mandibular permanent canines were single rooted but 5.2% of the permanent mandibular canines had two roots.

Accuracy comparison of single- and double-sleeve endodontic guides for fiber post removal.

BACKGROUND: This study aimed to assess the accuracy of two different endodontic guides for fiber post removal. METHODS: In this in vitro study, 54 maxillary canine fiber posts were mounted on 36 maxillary stone casts; 18 teeth were mounted unilaterally, and 36 teeth were mounted bilaterally. Static endodontic guides were fabricated according to baseline cone-beam computed tomography (CBCT) and intraoral optical scans using Blue Sky software. In the single-sleeve endodontic guides group (SSG), two anterior and two posterior teeth were included in a 5-unit guide. In the double-sleeve endodontic guides group (DSG) group, the guide was passed through the midline to include both canine teeth and extended by 2 teeth posterior to the canine teeth bilaterally (a 10-unit guide). After drilling, postoperative CBCT scans were taken and superimposed on the virtually designed path, and the maximum coronal deviation (MCD) at the marginal entry point of the tooth, maximum apical deviation (MAD) at 10 mm apical to the tooth margin, and maximum angular deflection (MAnD) of the drill were calculated. RESULTS: The mean MCD, MAD, and MAnD were 0.34 mm, 0.6 mm, and 2.32 degrees, respectively, in the SSG and 0.31 mm, 0.7 mm, and 2.37 degrees, respectively, in the DSG. The two groups were not significantly different from each other in terms of MCD (P = 0.573), MAD (P = 0.290), or MAnD (P = 0.896). CONCLUSIONS: The accuracies of the two techniques, the extended double sleeve guide and the single sleeve guide, were comparable and thus DSG may be used for removal of fiber posts in adjacent or distant teeth.

Effectiveness of low frequency vibration on the rate of canine retraction: a randomized controlled clinical trial.

To investigate the effectiveness of AcceleDent Aura vibrating device on the rate of canine retraction. Thirty-two patients requiring extraction of upper first premolars and canine retraction were randomly allocated with a 1:1 ratio into either no-appliance group or the AcceleDent Aura appliance group. Canine retraction was done applying 150gm of retraction force using NiTi coil springs on 16 × 22 stainless steel archwires. The duration of the study was 4 months. Models were collected and digitized directly after extraction of upper first premolars and at monthly intervals during canine retraction for recording the monthly as well as the total distance moved by the canine. Digitized models were superimposed on the initial model and data were statistically analyzed. Anchorage loss, rotation, tipping, torque and root condition were evaluated using cone beam computed tomography imaging. Pain was evaluated by visual analog scale. No patients were dropped-out during this study. There was no statistically significant difference between both groups regarding the total distance travelled by the canine (P = 0.436), as well as the rate of canine retraction per month (P = 0.17). Root condition was the same for the two groups. Regarding the pain level, there was no statistically significant difference between the two groups at day 0 (P = 0.721), after 24 h (P = 0.882), after 72 h (P = 0.378) and after 7 days (P = 0.964). AcceleDent Aura was not able to accelerate orthodontic tooth movement. Pain level couldn't be reduced by vibrational force with an AcceleDent device during orthodontic treatment. Root condition was not affected by the vibrational forces.

Dental transpositions: An update for clinicians.

Transposition of teeth may present to the general dental practitioner and in some circumstances transposed teeth may present with other dental anomalies. Although dental transpositions are rare anomalies, management of transposed teeth can often be complex, requiring multidisciplinary management. It is therefore important for dentists to be familiar with the clinical and radiographic presentation of transpositions and understand the aetiology to aid early diagnosis and appropriate management.Clinical relevance: Dentists are best placed to detect transposed teeth and should be familiar with the clinical and radiographic presentation, aetiology, and classification of transpositions in order to aid early diagnosis and their subsequent management.

Comparative evaluation of volumetric changes following rotary and hand files' canal preparation of primary maxillary canine: an in vitro nano-CT analysis.

PURPOSE: To evaluate the volumetric changes of two recently introduced paediatric rotary file systems in comparison with conventional hand file systems in primary maxillary canines using an ultra-high-resolution nano-computed tomography. METHODS: This in vitro study was performed in extracted primary maxillary canines based on certain inclusion and exclusion criteria. Samples were prepared, and working length was determined after the pre-operative scan using a high-resolution nano-CT device (SkyScan 2214, Bruker, Kontich, Belgium). A single well-experienced paediatric dentist prepared the canals using three file systems: Kedo-S plus, Kedo-SG blue and hand K-files. All samples were subjected to post-operative scans performed similar to pre-operative scans. Image reconstruction was performed with NRecon software for 3D volumetric visualisation and analysis of the root canals. RESULTS: Kedo-SG blue file systems had the highest mean difference in the canal volume (4.05%). Hand K-files had the least difference at (3.71%) of canal volume. Kedo-S plus file system had a moderate mean canal volume difference (3.82%) which is closer to hand K-files. Intergroup comparison between the three groups showed that the mean difference in canal volume was statistically significant between all three file systems (p = 0.000). CONCLUSION: Within the limitations of the current study, rotary file systems produced a significant enlargement of canals as compared to hand files. Kedo-SG blue created a uniform preparation of the canal cervico-apically. Kedo-S plus files were prepared more coronally with minimal preparation apically as close to the preparation of hand files. TRIAL REGISTRATION: Trial registration number: IHEC/SDC/PEDO-2103/22/651, Date of registration: 2022.

Evaluation of stress and displacement of maxillary canine during the single canine retraction in the maxillary first premolar extraction cases- A finite element study.

OBJECTIVES: This finite element study aimed to simulate maxillary canine movement during anterior teeth retraction. MATERIALS AND METHODS: Three methods of maxillary canine movement including miniscrew sliding with high hooks (MSH), miniscrew sliding with low hooks (MSL), and the traditional sliding method (TS) without using miniscrews were simulated using three-dimensional finite element analysis. The initial displacement of the maxillary canine, the maximum principal stress of the periodontal ligament and the Von Mises stress were calculated. RESULTS: The distolingual tipping movements of the canine were shown in three movement modes. MSH showed a small tendency to lingual tipping movement and a extrusion movement while MSL had the largest lingual inclination. TS demonstrated a tendency toward distolingual torsion displacement. Compressive stress values were mainly concentrated in the range - 0.003 to -0.006 MPa. For tensile stress, the distribution of MSH and MSL was concentrated in the range 0.005 to 0.009 MPa, TS was mainly distributed about 0.003 MPa. Von Mises equivalent stress distribution showed no significant difference. CONCLUSIONS: The loss of tooth torque was inevitable, irrespective of which method was used to close the extraction space. However, miniscrew application and higher hooks reduced the loss of torque and avoided lingual rotation. CLINICAL RELEVANCE: This study shows that miniscrew implants with different hooks can better control the movement of the maxillary canines. The non-invasive nature of the finite element analysis and its good simulation of dental stress and instantaneous motion trend have a clinical advantage in the analysis of tooth movement.

Influence of alveolar bone thickness and bucco-palatal inclination on root resorption of lateral incisors in unilateral maxillary impacted canines: a retrospective observational study.

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

The ectopic mandibular canines can start tooth formation in three different locations: a case series study based on single orthopantomograms from 47 individuals.

INTRODUCTION: A former study on orthopantomograms from young children with abnormal dental development (not canine ectopia) demonstrated that the tooth bud of the mandibular canine, compared to a stable longitudinal canine axis, could be located normally, anteriorly or posteriorly, with close relation to the first premolar. AIM: The aim of the present study is to analyse on orthopantomograms if the canine axis can demonstrate where the ectopic mandibular canine started tooth formation. MATERIALS: The material consists of orthopantomograms with ectopic mandibular canines and presence of primary mandibular canines from 47 cases (29 cases 9-21 years old and 18 cases with unknown ages). The primary canines demonstrated from minor apical resorption to more severe apical resorption. METHODS: Based on canine maturity, location of the canine axes and the interrelationships between the roots of the permanent canine and first premolar, the location from where the canine started tooth formation was determined. Canine maturity. Maturity stage below half root length and maturity stage above half root length revealed that 11 ectopic canines had less than half root length and 36 cases more than half root length. Canine axes. The canine axis, through the length of the primary canines Ax, is inserted on drawings of the orthopantomograms using the tracing programme Inkscape®. Interrelationship between roots. By visual inspection, the distance between the canine and first premolar was designated close distance, normal distance and extended distance. RESULTS: The results are divided into 3 groups. Group 1: The initial site of the permanent ectopic canine is located within the canine axis (6 cases). Group 2: The initial site of the permanent ectopic canine is located posterior to the canine axis (36 cases). Group 3: The initial site of the permanent ectopic canine is located anterior to the canine axis (5 cases). CONCLUSION: The study explained that the canine axis could divide cases of ectopic canines into three groups according to the location from where tooth formation starts. For getting closer to the pattern of the ectopic canine eruption, it is necessary to analyse series of orthopantomograms taken from the same individual over several years.

Three-dimensional evaluation of secondary alveolar bone grafting in patients with unilateral cleft lip and palate: A 2-3 year post-operative follow-up.

OBJECTIVES: The present study aims to quantitatively assess secondary alveolar bone graft (SABG) resorption in unilateral cleft lip, alveolus and palate (UCLAP) patients in a 2-3 year longitudinal follow-up setting by using a validated 3D protocol. Furthermore, the potential relation of SABG resorption with maxillary canine position and a number of patient-related factors was investigated. METHODS: UCLAP patients who underwent SABG and had good quality CBCT images at the following timepoints were included in the study: pre-operative (T0), immediate (T1), 6 months (T2) and either 1-2 years (T3) or 2-3 years (T4) post-operative. The final bone grafted region was defined on the T1 scans and refined in the registered T0 scans. The bone graft after resorption was determined by applying threshold-based segmentation on the registered T2, T3 or T4 scans within the segmented bone graft volume. The position of the canines was determined at every timepoint at the cleft and non-cleft side. RESULTS: Forty-five UCLAP patients (mean age 9.0 ± 1.3 years) were included. In the first 6 months after SABG, 43.6% bone resorption was recorded. 2-3 years post-operative, 56% bone resorption was found if the maxillary canine was not yet erupted and 42.7% if it erupted through the graft. The vertical position of the canines was significantly higher on the cleft side at T3. CONCLUSIONS: The present study reports significant SABG resorption over time. However, no correlation was found between SABG resorption and canine position, nor between other patient-related factors.

Local factors relating to mandibular canine impaction: A retrospective study.

INTRODUCTION: This study aimed to investigate the characteristics of impacted and transmigrated mandibular canines and the association existing between them and some local factors, such as degrees of axial inclination of mandibular incisors, skeletal Class, and mandibular symphysis width. METHODS: A retrospective observational study was performed on the medical records and radiographic examination (panoramic radiographs and lateral cephalograms) of 102 orthodontic patients divided into a study group, with at least 1 impacted mandibular canine (51 subjects) and a control group, without mandibular impaction (51 subjects). A chi-square test, t test, and analysis of variance test analysis were used to analyze the data. RESULTS: Unilateral and buccal impaction and the presence of the deciduous canine were the more prevalent characteristics of impacted canines, whereas 39.2% presented transmigration. Furthermore, the persistence of the deciduous canine on the impaction side (P <0.0001) and the mesial axial inclination of the impacted canine (P <0.0001) were found to be statistically significant characteristics. A statistically significant association was found between the impaction of the mandibular canine and mandibular incisor to the mandibular plane angle (IMPA) (IMPA, 95.8°; P = 0.009). An additional statistically significant association was found with transmigrated canines (IMPA, 96.8°; P = 0.024). CONCLUSIONS: The mesialization of the canine cusp and the persistence of the mandibular deciduous canine are characteristics frequently found in the impaction of the mandibular canine. An accentuated vestibular inclination of the mandibular incisors is significantly associated with mandibular canine impaction.