Objective: To determine the effect of the impacted position of the maxillary canine on the root resorption of the adjacent incisor using Cone-beam Computed Tomography (CBCT) imaging. Methods: This was an analytic quantitative study. The research sample determined CBCT images of treatment patients at the Orthodontic Specialist Policlinic in Dental Hospital of Airlangga University over a three-year period and secondary data taken from Pramita Laboratory. CBCT photos that met the inclusion criteria, including mesially impacted canine or close to central or lateral incisors with completely formed anatomy were then analyzed. Multiple linear regression was used to determine x-axis, y-axis, z-axis position of the impacted canine on the severity of root resorption of the adjacent incisor, and the effect of impacted canines on all axes simultaneously on the severity of root resorption of the adjacent incisors. Results: The position of the impacted canine in the x-axis and z-axis planes had a significant influence on the root resorption of the adjacent incisor. Meanwhile, impacted canine from the y-axis plane showed non-significant influence on the root resorption. Conclusion The position of the impacted canine when viewed in all planes of the tooth axis has a significant effect on the severity of root resorption of the adjacent incisor
Root Resorption ; Cone-Beam Computed Tomography

Background: Cone-beam computed tomography is being utilized in more clinical contexts and determining bone density with this method is becoming more important. Dentists, particularly dentomaxillofacial radiologists, orthodontists, and oral surgeons, must have a solid understanding of gray value. The gray values acquired from conebeam computed tomography images are used to assess dental implant bone density, diagnose dental ankylosis, and diagnose and differentiate pathological lesions. Objective: To determine the difference in the gray value of the trabecular bone in the impacted and normal erupted maxillary canine teeth using cone computed tomography. Methods: We retrospectively evaluated the cone-beam computed tomography images of patients scheduled for orthodontic treatment at the Universitas Airlangga Dental and Oral Hospital. On cross-sectional cone-beam computed tomography images, the region of interest determination of 5 mm2 in the area was placed in the trabecular bone and the gray value measurements were collected using Digital Imaging and Communications in Medicine (OnDemand3D™) dental software. The images were categorized by type of impacted canine teeth after assessing the gray values of all the teeth. Using images on the mesial, distal, buccal, and palatal areas, gray values of impacted and non-impacted teeth were compared. We used the SPSS 24 software. Results: From a total of 13 patient radiographs, we found types I (6/13), II (6/13), and VII (1/13). The mean pixel values of impacted maxillary unilateral canine teeth were 1972.92 (mesial), 2016.55 (distal), 1990.66 (buccal), and 1904.39 (palatal). The mean pixel values of normal erupted maxillary canines were 1754.93 (mesial), 1710.53 (distal), 1852.94 (buccal), and 1674.49 (palatal). There were significant differences between impacted and normal erupted maxillary canines: mesial (P = 0.018), distal (P = 0.000), buccal (P = 0.003), and palatal (P = 0.036). Conclusion There were statistically significant differences between affected and unaffected gray values in the canines in FOV size 51 × 55 mm. However, no statistically significant differences were found in the gray values in trabecular bone of unilateral maxillary impacted canines and normal erupted canines on the mesial, distal, buccal, and palatal sides.
impacted ; canine ; trabecular bone ; maxillary ; cone-beam computed tomography

Objective: To develop a multi-classification orthodontic image recognition system using the SqueezeNet deep learning model for automatic classification of orthodontic image data. Methods: A total of 35 000 clinical orthodontic images were collected in the Department of Orthodontics, Capital Medical University School of Stomatology, from October to November 2020 and June to July 2021. The images were from 490 orthodontic patients with a male-to-female ratio of 49∶51 and the age range of 4 to 45 years. After data cleaning based on inclusion and exclusion criteria, the final image dataset included 17 453 face images (frontal, smiling, 90° right, 90° left, 45° right, and 45° left), 8 026 intraoral images [frontal occlusion, right occlusion, left occlusion, upper occlusal view (original and flipped), lower occlusal view (original and flipped) and coverage of occlusal relationship], 4 115 X-ray images [lateral skull X-ray from the left side, lateral skull X-ray from the right side, frontal skull X-ray, cone-beam CT (CBCT), and wrist bone X-ray] and 684 other non-orthodontic images. A labeling team composed of orthodontic doctoral students, associate professors, and professors used image labeling tools to classify the orthodontic images into 20 categories, including 6 face image categories, 8 intraoral image categories, 5 X-ray image categories, and other images. The data for each label were randomly divided into training, validation, and testing sets in an 8∶1∶1 ratio using the random function in the Python programming language. The improved SqueezeNet deep learning model was used for training, and 13 000 natural images from the ImageNet open-source dataset were used as additional non-orthodontic images for algorithm optimization of anomaly data processing. A multi-classification orthodontic image recognition system based on deep learning models was constructed. The accuracy of the orthodontic image classification was evaluated using precision, recall, F1 score, and confusion matrix based on the prediction results of the test set. The reliability of the model's image classification judgment logic was verified using the gradient-weighted class activation mapping (Grad-CAM) method to generate heat maps. Results: After data cleaning and labeling, a total of 30 278 orthodontic images were included in the dataset. The test set classification results showed that the precision, recall, and F1 scores of most classification labels were 100%, with only 5 misclassified images out of 3 047, resulting in a system accuracy of 99.84%(3 042/3 047). The precision of anomaly data processing was 100% (10 500/10 500). The heat map showed that the judgment basis of the SqueezeNet deep learning model in the image classification process was basically consistent with that of humans. Conclusions: This study developed a multi-classification orthodontic image recognition system for automatic classification of 20 types of orthodontic images based on the improved SqueezeNet deep learning model. The system exhibitted good accuracy in orthodontic image classification.
Humans ; Male ; Female ; Child, Preschool ; Child ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Deep Learning ; Reproducibility of Results ; Radiography ; Algorithms ; Cone-Beam Computed Tomography

OBJECTIVE: To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF). METHODS: A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists. RESULTS: The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001). CONCLUSION Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.
Animals ; Cone-Beam Computed Tomography/methods* ; Gold ; Gutta-Percha ; Palladium ; Swine ; Titanium ; Tooth Fractures/diagnostic imaging* ; Tooth Root/injuries* ; Reproducibility of Results

OBJECTIVE: To propose a sensitivity test method for geometric correction position deviation of cone-beam CT systems. METHODS: We proposed the definition of center deviation and its derivation. We analyzed the influence of the variation of the three-dimensional spatial center of the steel ball point, the projection center and the size of the steel ball point on the deviation of geometric parameters and the reconstructed image results by calculating the geometric correction parameters based on the Noo analytical method using the FDK reconstruction algorithm for image reconstruction. RESULTS: The radius of the steel ball point was within 3 mm. The deviation of the center of the calibration parameter was within the order of magnitude and negligible. A 10% Gaussian perturbation of a single pixel in the 3D spatial coordinates of the steel ball point produced a deviation of about 3 pixel sizes, while the same Gaussian perturbation of the 2D projection coordinates of the steel ball point produced a deviation of about 2 pixel sizes. CONCLUSION The geometric correction is more sensitive to the deviation generated by the three-dimensional spatial coordinates of the steel ball point with limited sensitivity to the deviation generated by the two-dimensional projection coordinates of the steel ball point. The deviation sensitivity of a small diameter steel ball point can be ignored.
Algorithms ; Calibration ; Cone-Beam Computed Tomography ; Steel

OBJECTIVE: To evaluate the changes of periodontal phenotype (width of keratinized gingiva, thickness and height of alveolar bone) of lower anterior teeth in patients with skeletal class Ⅲ malocclusion before and after the periodontal-orthodontic-orthognathic combined treatment. METHODS: In the study, 20 patients with skeletal class Ⅲ malocclusion (6 males and 14 females) completed the periodontal-orthodontic-orthognathic combined treatment were included from March 2017 to June 2022, with 39 central incisors, 40 lateral incisors and 40 canines. The mean age was (25.40±4.27) years (20-34 years). The mean follow-up time was (3.70±1.05) years from the beginning of periodontal corticotomy regenerative surgery (PCRS) to the end of the combined treatment. Cone-beam computed tomography (CBCT) was used to measure the thickness, area and height of alveolar bone by the same researcher, taken before the PCRS (T0), 6 months after the PCRS (T1), 12 months after the PCRS (T2), before the orthognathic surgery (T3), and after the periodontal-orthodontic-orthognathic combined treatment (T4). The periodontal clinical parameters were used to evaluate changes in the soft tissue by another researcher, measured before the PCRS (T0) and after the combined treatment (T4). Changes of soft and hard tissue were evaluated by the periodontal phenotype. RESULTS: The width of keratinized gingiva increased significantly (all P < 0.001) in lower anterior teeth, the central incisors, lateral incisors and canines increased by (1.82±1.57) mm, (2.03±1.48) mm and (2.05±1.27) mm, respectively. The proportion of thick periodontal biotype in the central and lateral incisors increased significantly (all P < 0.001), while the changes of periodontal biotypes in the lower canines were not obvious. The thickness of labial alveolar bone of lower anterior teeth all increased significantly after periodontal corticotomy regenerative surgery and the combined treatment (all P < 0.001). The area of labial alveolar bone of lower anterior teeth also increased significantly after the combined treatment (all P < 0.001). The whole area of labial and lingual alveolar bone of central and lateral incisors increased (P < 0.001), while the whole area of canines remained the same. All The height of the alveolar bone increased (all P < 0.001) on the labial side after the treatment. CONCLUSION The periodontal phenotypes of lower anterior teeth were significantly improved after the periodontal-orthodontic-orthognathic combined treatment in patients with skeletal Angle class Ⅲ malocclusion. The improvement was long-termly stable, and the periodontal risk was reduced.
Male ; Female ; Humans ; Malocclusion, Angle Class III/surgery* ; Oral Surgical Procedures ; Incisor ; Cone-Beam Computed Tomography/methods*

OBJECTIVE: To evaluate the decompensation effectiveness and alveolar bone remodeling of mandibular anterior teeth after preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusion using lateral cephalogram and cone-beam computed tomography (CBCT). METHODS: Thirty high-angle patients with skeletal class Ⅱ malocclusion who had received preoperative orthodontic treatment and orthognathic surgery in Peking University School and Hospital of Stomatology between Ja-nuary 2017 and August 2022 and had taken lateral cephalogram and CBCT before and after preoperative orthodontic treatment were selected. Items were measured with lateral cephalogram including: The lower central incisor (L1)-Frankfort plane angle (L1-FH), the L1-mandibular plane angle (L1-MP), the L1-nasion-supramental angle (L1-NB) and the vertical distance from the incisal edge of lower central incisor to NB line (L1-NB distance), etc. The incidence of dehiscence/fenestration and the length of dehiscence at labial side (d-La) and lingual side (d-Li) were measured using CBCT. Pearson correlation analysis was used to evaluate the correlation between the changes of d-Li of L1 and age, duration of preoperative orthodontic treatment and the cephalometric measurements before preoperative orthodontic treatment to screen out risk factors affecting the periodontal risk of preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusions. RESULTS: After preoperative orthodontic treatment, L1-FH, L1-MP, L1-NB and L1-NB distances changed by 11.56°±5.62°, -11.13°±5.53°, -11.57°±5.43° and (-4.99±1.89) mm, respectively, and the differences were all statistically significant (P < 0.05). Among the 180 measured mandibular anterior teeth, 45 cases with labial dehiscence/fenestration before preoperative orthodontic treatment (T0) had no longer labial dehiscence/fenestration after preope-rative orthodontic treatment (T1); 142 cases without lingual dehiscence/fenestration at T0 had lingual dehiscence/fenestration at T1. After preoperative orthodontic treatment, the d-La of lower lateral incisors (L2), lower canines (L3) and lower anterior teeth (L1+L2+L3) decreased by (0.95±2.22) mm, (1.20±3.23) mm and (0.68±2.50) mm, respectively, and the differences were statistically significant (P < 0.05); the d-Li of L1, L2, L3 and L1+L2+L3 increased by (4.43±1.94) mm, (4.53±2.35) mm, (3.19±2.80) mm and (4.05±2.46) mm, respectively, and the differences were statistically significant (P < 0.05). The increase of d-Li of L1 was positively correlated with L1-FH (r=0.373, P=0.042). CONCLUSION This study showed that high-angle patients with skeletal class Ⅱ ma-locclusion could achieve ideal decompensation effect of mandibular anterior teeth after preoperative orthodontic treatment with bilateral mandibular first premolars extracted, but the lingual periodontal risk of mandibular anterior teeth was increased. This risk could be correlated to L1-FH before preoperative orthodontic treatment, which should be paid more attention in the design of orthodontic-orthognathic surgical treatment.
Humans ; Malocclusion, Angle Class III ; Malocclusion, Angle Class II/surgery* ; Facial Bones ; Incisor ; Orthognathic Surgical Procedures ; Cone-Beam Computed Tomography ; Mandible

OBJECTIVE: To investigate the clinical application of cone-beam computed tomography (CBCT) among endodontic practitioners, and to analyze the indications and reasonability of CBCT in the diagnosis and treatment of pulpal and periapical diseases. METHODS: The clinical data were collected from patients who visited the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and underwent CBCT examination from January to December, 2021. The data with their complete clinical information (including clinical records, radiology request forms/reports, two-dimensional and three-dimensional imaging data) were included. Those who underwent CBCT examination for orthodontic or prosthodontics were excluded. The experience and training background of the endodontic specialists, the number of patients treated in the whole year, the objective and region of interest (ROI) of CBCT examination, technical parameters, such as machine type, field of view (FoV) and radiographic reports were collected and analyzed to evaluate the impact on diagnosis. Wilcoxon and Mann-Whitney tests were used to compare the distribution of CBCT ROI. Chi-squared test and pairwise comparison were used to compare the application of CBCT by endodontic specialists with different clinical experience (senior, middle and junior). RESULTS: In 2021, a total of 3 308 CBCT scans were prescribed by 61 endodontic specialists who treated 34 952 patients throughout the year. 3 218 patients (male ∶female about 1 ∶2) amounting for 10% of the patients treated in the whole year who received CBCT scans with an median age of 35 years (28, 49). Around 98% CBCT examinations were performed after clinical examination and two-dimensional periapical radiographs were taken. The FoV of CBCT scanning less than 10 cm×10 cm accounted for 96% of the total number of the images. Among the 3 308 CBCT scans, 83% of the ROI were in posterior teeth, with a higher number of anterior teeth (Z=-2.278, P < 0.05). Maxillary and mandibular first molars accounted for 35% of the examined teeth. The objectives of CBCT scanning included three aspects: clarifying clinical diagnosis, guiding surgical and non-surgical endodontic treatment (including management of endodontic complications), and outcome assessment, accounting for 1 111 (34%), 1 745 (54%), 311 (10%), respectively. and the others 2%. In the diagnosis process, CBCT was mainly used for the diagnosis of chronic periapical periodontitis, root fracture, root resorption and dental trauma. In the study, 353 CBCT were used in the diagnosis of root fracture, with a positive diagnosis rate of 35% (125/353). 846 CBCT used to reveal the anatomy of the root canal system, of which 297 cases were used to find missed/extra canals after treatment failure, and 58% (171/297) were used to confirm the missed/extra canals. In the management of complications or errors, CBCT was mainly used to assist the diagnosis of perforation and to locate the separated instruments. In the study, 311 CBCT scans were used for outcome assessment, including 240 cases related to non-surgical treatment and 71 cases related to surgical endodontic treatment for follow-up or presence of clinical symptoms, and persistent lesions on 2D films. Among the 61 endodontic specialists who used CBCT, 23 (45%) were with senior experience, 15 (30%) with middle experience, and 23 (25%) with junior experience. The proportion of senior or junior experience prescribing CBCT examination was 10%, higher than that of middle experience (8%, χ₁²=39.4, χ₂²=29.1, P < 0.001). The application rate of chief endodontists was 18%, which was higher than that of associate chief endodontists (9%, χ₁²=139.4, P < 0.001). 31% (1 109/3 308) cases of diagnosis or treatment plans were changed after CBCT was taken. CONCLUSION Use of CBCT in endodontic practice could provide more clinical information, which is helpful for diagnosis, accurate treatment and prognosis evaluation.
Humans ; Male ; Adult ; Prevalence ; Root Canal Therapy/methods* ; Cone-Beam Computed Tomography/methods* ; Tooth ; Imaging, Three-Dimensional

This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach (lSFE) and to determine the factors that influence the stability of the grafted area in the sinus cavity. Thirty patients (30 implants) treated with lSFE using minimally invasive techniques from 2015 to 2019 were included in the study. Five aspects of the implant (central, mesial, distal, buccal, and palatal bone heights [BHs]) were measured using cone-beam computed tomography (CBCT) before implant surgery, immediately after surgery (T0), 6 months after surgery (T1), and at the last follow-up visit (T2). Patients' characteristics were collected. A small bone window (height, (4.40 ± 0.74) mm; length, (6.26 ± 1.03) mm) was prepared. No implant failed during the follow-up period (3.67 ± 1.75) years. Three of the 30 implants exhibited perforations. Changes in BH of the five aspects of implants showed strong correlations with each other and BH decreased dramatically before second-stage surgery. Residual bone height (RBH) did not significantly influence BH changes, whereas smoking status and type of bone graft materials were the potentially influential factors. During the approximate three-year observation period, lSFE with a minimally invasive technique demonstrated high implant survival rate and limited bone reduction in grafted area. In conclusion, lSFE using minimally invasive techniques was a viable treatment option. Patients who were nonsmokers and whose sinus cavity was filled with deproteinized bovine bone mineral (DBBM) had significantly limited bone resorption in grafted area.
Humans ; Animals ; Cattle ; Maxillary Sinus/surgery* ; Retrospective Studies ; Sinus Floor Augmentation ; Bone Resorption ; Cone-Beam Computed Tomography

Objective: To measure and analyze the morphometric changes in the anterior alveolar bone during treatment and retention stage after retraction in bimaxillary adults using cone-beam CT(CBCT). Methods: Fifteen adult patients, four males and 11 females, aged 19 to 28 years[(22.2±3.1) years], who have completed orthodontic treatment and extracted four first premolar teeth for retraction in the Department of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University from January 2016 to December 2018 were selected. CBCT was taken to assess the labial and palatal vertical bone level, total bone thickness at crest area, middle root area and apical area in pre-treatment (T1), post-treatment (T2) and at follow-up (maintained for more than two years) (T3). The differences in alveolar bone morphology at different stages were compared by single factor repeated measure ANOVA, and Pearson correlation analysis was performed on the amount of alveolar bone change in treatment stage and retention stage. Results: There were statistically significant differences in the alveolar bone height of the palatal side of maxillary anterior teeth, the labial side of maxillary lateral incisors and canine among three time points (P<0.05). The height difference of palatal alveolar bone of anterior teeth in T1-T2 stage was statistically significant (P<0.05). Palatal alveolar bone of upper and lower central incisors decreased by (1.52±0.32) and (4.96±0.46) mm, respectively. The height difference of anterior palatal alveolar bone was statistically significant in T2-T3 stage(P<0.05), the palatal alveolar bone height of central incisors increased by (1.20±0.27) and (3.14±0.35) mm respectively. The height difference of palatal alveolar bone in the anterior teeth of T1-T3 stage was statistically significant (P<0.05), and the height of palatal alveolar bone of central incisors was decreased (0.33±0.11) and (1.82±0.39) mm, respectively. There were statistically significant differences in the thickness of the cervical and middle root alveolar bone of anterior teeth among three time points (P<0.05). The difference of alveolar bone thickness of the cervical and middle root of anterior teeth at T1-T2 was statistically significant (P<0.05). decreased by (0.63±0.10) and (0.67±0.09) mm in lateral incisors, respectively. In the T2-T3 stage, the alveolar bone thickness of the crest area of the lower anterior teeth was significantly different (P<0.05), the alveolar bone thickness of mandibular central incisor crest area increased (0.09±0.03) mm. There were statistically significant differences in alveolar bone thickness in crest area and middle root of the incisors during T1-T3 stage (P<0.05), among which the middle root decreased by (0.38±0.16) mm and (0.63±0.13) mm, respectively. There was no statistically significant difference in other areas (P>0.05). The change of alveolar bone height in palatal side of upper anterior teeth at T2-T3 was very strongly negatively correlated with the change in T1-T2. The change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor root and neck were moderately strongly negatively correlated (r≤-0.8, P<0.001), the change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor crest area were moderately strongly negatively correlated (-0.8<r≤-0.4, P<0.05). Conclusions: For adult patients after retraction, anterior alveolar bone decreased significantly. In the retention stage, the same degree of bone apposition will occur, but still have alveolar bone loss compared with pre-treatment. The amount of alveolar bone change in the retention stage correlated with the amount of alveolar bone change in the treatment stage.
Male ; Female ; Humans ; Maxilla/diagnostic imaging* ; Cone-Beam Computed Tomography ; Tooth Root ; Malocclusion ; Palate