OBJECTIVES: To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles. METHODS: Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy. RESULTS: A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05). CONCLUSIONS In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.
Humans ; Tooth, Impacted/surgery* ; Incisor ; Alveolar Bone Loss/diagnostic imaging* ; Tooth Root ; Dental Sac ; Maxilla/surgery* ; Esthetics, Dental

Dens invaginatus (DI) is a developmental anomaly as a result of a deepening or invagination of the enamel organ into the dental papilla during tooth development. In addition, DI is a malformation with varying anatomical features, which poses numerous challenges to treatment. Endodontic treatment of dens in dente is one of the most complica-ted cases of DI. Herein, an immature lateral incisor that employed regenerative endodontic treatment was presented. The mentioned tooth was diagnosed with DI, pulp necrosis, and chronic apical periodontitis. Hence, a favorable prognosis has been shown by a 2-year review with cone beam computed tomography. The tooth was functional with normal periodontal parameters and exhibited a normal response to the electric pulp sensibility test. Thus, regenerative endodontic treatment can also be recommended to endodontists for teeth with DI.
Humans ; Regenerative Endodontics ; Incisor/diagnostic imaging* ; Dens in Dente ; Dental Pulp Necrosis/therapy* ; Odontogenesis

Objective: To measure the labial gingival thickness and bone lamella thickness in the maxillary anterior area using digital method, and to analyze the correlation between the two, so as to provide a reference for esthetic restoration and implantation treatment of the upper anterior area. Methods: Fifty-seven patients [23 males, 34 females, (25.8±4.5) years old] who planned to receive posterior dental implant restoration were recruited randomly with the inclusion and exclusion criteria in Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University from May 2020 to October 2020. The 3Shape software was used to perform oral scanning, and cone beam CT (CBCT) was taken for each patient. The image data was fitted and registered by the 3Shape software. The gingival thickness at 2 mm below the gingival margin, bone thickness and gingival thickness at 2 and, 4 mm below the crest of the labial alveolar crest in maxillary central incisors, lateral incisors and canines, were measured. Results: The gingival thickness at 2 mm below the gingival margin of maxillary central incisors, lateral incisors and canines was (1.42±0.21), (1.19±0.17) and (1.23±0.20) mm respectively (F=12.47, P<0.001). The gingival thickness at 2 mm below gingival margin and 4 mm below crest of residual ridge in the male patients were (1.31±0.21) and (0.67±0.22) mm, and those in the female patients were (1.26±0.22) and (0.58±0.19) mm respectively, and there were statistically significant differences in the gingival thickness between the "2 mm below gingival margin" group and the "4 mm below crest of residual ridge" group (t=2.01 and 3.97, P<0.05). There was a positive correlation between gingival thickness and alveolar bone thickness at 2 mm and 4 mm below the crest of residual ridge in maxillary anterior region, and the correlation coefficients (r) were 0.387 and 0.344 respectively (P<0.05). Conclusions: Gingival thickness of maxillary anterior area is related to the tooth position and gender. The gingival thickness of men is greater than that of women.The gingival thickness at 2 and 4 mm below the crest of the alveolar crest is positively correlated with the thickness of the alveolar bone.
Adult ; Alveolar Process/diagnostic imaging* ; Cone-Beam Computed Tomography ; Esthetics, Dental ; Female ; Gingiva/diagnostic imaging* ; Humans ; Incisor/diagnostic imaging* ; Male ; Maxilla/diagnostic imaging* ; Young Adult

OBJECTIVE: To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. METHODS: Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. RESULTS: Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. CONCLUSION In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.
Cone-Beam Computed Tomography/methods* ; Humans ; Incisor/diagnostic imaging* ; Malocclusion, Angle Class III/surgery* ; Maxilla/surgery* ; Root Resorption/etiology*

OBJECTIVE: To measure the three-dimensional morphology of the labial supraosseous gingiva (SOG) and the thickness of related labial bone in maxillary anterior teeth of periodontally healthy Han nationality youth using soft tissue indirect imaging cone-beam computed tomography (CBCT). METHODS: Twenty-five periodontally healthy subjects (11 males and 14 females) with 150 maxillary anterior teeth were involved in this study. A special impression with radiopaque material including the maxillary teeth was made, then a CBCT scan with the elastomeric matrix in position was taken for each subject. The imaging data were generated and transferred to a volumetric imaging software in which three-dimensional reconstruction was conducted and the image analyses were carried out. Measurements were made at the site of labial center of the maxillary anterior teeth. The height of the SOG, the distance between cemento-enamel junction (CEJ) and bone crest, the gingival thickness at the CEJ, and the thickness of bone 2 mm below the labial bone crest were measured and the correlation analysis between the parameters was made. All the data analyses were performed using SPSS 22.0. The data were analyzed with ANVOA and Pearson correlation tests with the significance level at α=0.05. RESULTS: The mean SOG values were (3.49±0.70) mm, (3.48±0.81) mm, and (3.54±0.67) mm for central incisors, lateral incisors and canines, respectively. There were no statistically significant differences among the different sites (P > 0.05). The mean gingival thickness values were (1.45±0.23) mm, (1.13±0.24) mm, (1.14±0.22) mm for central incisors, lateral incisors and canines, respectively. The gingival thickness of the central incisors was the largest among the maxillary anterior teeth with statistically significant difference (P < 0.05). No correlation was found between the SOG and gingival thickness among the maxillary anterior teeth (P > 0.05). CONCLUSION The gingival thickness of central incisors was the largest and the supraosseous gingival height had no correlation with gingival thickness among the periodontally healthy maxillary anterior teeth.
Adolescent ; Cone-Beam Computed Tomography ; Female ; Gingiva/diagnostic imaging* ; Humans ; Incisor/diagnostic imaging* ; Male ; Maxilla/diagnostic imaging* ; Tooth Cervix

OBJECTIVES: To compare the root length of maxillary and mandibular anterior teeth between open bite patients and normal overbite patients via cone-beam computed tomography (CBCT) as well as the root length of anterior teeth in different degree of open bite patients, and to analyze the correlation between the degree of open bite and root length. METHODS: A total of 106 untreated patients were enrolled retrospectively (53 anterior open bite patients and 53 normal overbite patients).Three-dimensional position of the CBCT image for the patient's teeth was performed using Dolphin software. The median sagittal plane of the tooth was used as the measurement plane, and the line connecting the apical point and the midpoint between the labial and lingual cementoenamel junctions was defined as the root length. Independent RESULTS: Significant differences were found in the root length of maxillary and mandibular anterior teeth between the open bite group and the normal overbite group ( CONCLUSIONS The root length of maxillary and mandibular anterior teeth in the open bite patients is shorter than that in the normal overbite patients, and the severer the degree of open bite, the shorter the root length of the mandibular central incisor tends to be. There is a certain relationship between maxillary anterior teeth and the root length of anterior teeth.
Cone-Beam Computed Tomography ; Humans ; Incisor/diagnostic imaging* ; Maxilla/diagnostic imaging* ; Open Bite/diagnostic imaging* ; Retrospective Studies

OBJECTIVE: To evaluate the difference of features of alveolar bone support under lower anterior teeth between high-angle adults with skeletal class II malocclusions and high-angle adults presenting skeletal class III malocclusions by using cone-beam computed tomography (CBCT). METHODS: Patients who had taken the images of CBCT were selected from the Peking University School and Hospital of Stomatology between October 2015 and August 2017. The CBCT archives from 62 high-angle adult cases without orthodontic treatment were divided into two groups based on their sagittal jaw relationships: skeletal class II and skeletal class III. vertical bone level (VBL), alveolar bone area (ABA), and the width of alveolar bone were measured respectively at the 2 mm, 4 mm, 6 mm below the cemento-enamel junction (CEJ) level and at the apical level. After that, independent samples t-tests were conducted for statistical comparisons. RESULTS: The ABA of the mandibular alveolar bone in the area of lower anterior teeth was significantly thinner in the patients of skeletal class III than those of skeletal class II, especially in terms of the apical ABA, total ABA on the labial and lingual sides and the ABA at 6 mm below CEJ level on the lingual side (P<0.05). The thickness of the alveolar bone of mandibular anterior teeth was significantly thinner in the subjects of skeletal class III than those of skeletal class II, especially regarding the apical level on the labial and lingual side and at the level of 4 mm, 6 mm below CEJ level on the lingual side (P<0.05). CONCLUSION The ABA and the thickness of the alveolar bone of mandibular anterior teeth were significantly thinner in the group of skeletal class III adult patients with high-angle when compared with the sample of high-angle skeletal class II adult cases. We recommend orthodontists to be more cautious in treatment of high-angle skeletal class III patients, especially pay attention to control the torque of lower anterior teeth during forward and backward movement, in case that the apical root might be absorbed or fenestration happen in the area of lower anterior teeth.
Adult ; Alveolar Process/diagnostic imaging* ; Cephalometry ; Cone-Beam Computed Tomography ; Humans ; Incisor ; Malocclusion, Angle Class III/diagnostic imaging* ; Mandible/diagnostic imaging*

OBJECTIVE: To evaluate the accuracy and reliability of detecting alveolar bone dehiscence and fenestration of maxillary anterior teeth of Angle class III by cone-beam computed tomography (CBCT). METHODS: Eighteen Angle class III patients with 108 maxillary anterior teeth were included (3 males and 15 females) who accepted modified corticotomy in orthodontic therapy. The mean age was 23.6 years (18-30 years). The clinical detection of dehiscence and fenestration was done when modified corticotomy was performed by the same periodontist. The CBCT examination was conducted pre-operation and the detection of dehiscence and fenestration by CBCT was done by two periodontists. The data in modified corticotomy were used as the golden standard to calculate the parameters, such as sensitivity, specificity, positive and negative predictive values, Youden index (YI), positive and negative likelihood ratio. Kappa statistic was used to analyze the agreement between the clinical detection and the CBCT detection. RESULTS: The incidence of dehiscence and fenestration was about 10.19% and 13.89% respectively, which mainly occurred on lateral incisors and canines. The median values of length and width of dehiscence were about 5 mm and 4 mm, and the median values of length and width of fenestration were 3 mm and 2 mm, respectively. Most fenestrations were detected on the middle third to the apical third of the root. For dehiscence, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). For fenestration, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). The values of sensitivity and specificity for detecting dehiscence were more than 0.7. The values of positive and negative predictive values for detecting dehiscence were 0.44 and 0.97. The values of sensitivity and specificity for detecting fenestration were 0.93 and 0.52. The values of positive and negative predictive values for detecting fenestration were 0.24 and 0.98. CONCLUSION For dehiscence, the agreement between clinical detection and CBCT detection was good. For fenestration, the agreement between clinical detection and CBCT detection was general. Detection of dehiscence and fenestration of maxillary anterior teeth of Angle class III by CBCT had limited diagnostic value in clinical practice with overestimation of dehiscence and fenestration incidence.
Adolescent ; Adult ; Alveolar Bone Loss/diagnostic imaging* ; Alveolar Process/diagnostic imaging* ; Cone-Beam Computed Tomography ; Female ; Humans ; Incisor ; Male ; Malocclusion, Angle Class III/diagnostic imaging* ; Reproducibility of Results ; Young Adult

OBJECTIVETo evaluate the orthodontic treatment outcome in patients with impacted maxillary central incisor in the mixed dentition.

METHODSNine patients, aged 8 to 11 years, with impacted maxillary central incisor were treated orthodontically. The cone-beam CT(CBCT) was taken before treatment, after treatment and one year out of retention to evaluate the root length, root canal wall thickness, width of the apical foramen, and degree of root bending, alveolar bone height and thickness. The crown-to-root ratio was calculated. The periodontal and endodontic conditions were evaluated. The parameters of the treated incisors and contralateral ones served as controls were compared.

RESULTSNine impacted teeth were treated successfully. Throughout the treatment, the root of impacted central incisor continued to develop and the alveolar bones also continued to develop and remodel. The condition of the alveolar bone of vertically impacted teeth was better than that of horizontally impacted ones. No periodontal pocket or pulp necrosis was found after treatment. Seven patients were examined one year after treatment. No significant difference was found in root length, palatal alveolar bone level and palatal alveolar bone thickness. The control group root length was (13.07±2.15) mm, the treatment group root length was (12.06±2.00) mm. No further alveolar bone loss, gingival recession and pulp necrosis were found. The control group labial and palatal alveolar bone levels were (0.90±0.62), (0.45±0.52) mm, labial and palatal alveolar bone thickness were (0.85±0.14), (1.21±0.41) mm. The treatment group labial and palatal alveolar bone levels were (2.18±1.59) mm, (0.57±0.71) mm, labial and palatal alveolar bone thickness were (0.48±0.29), (1.43±0.31) mm.

CONCLUSIONSOrthodontic therapy for impacted maxillary central incisor in the mixed dentition could promote root development and alveolar bone remodeling. Good periodontal and endodontic conditions were achieved.

Alveolar Bone Loss ; diagnostic imaging ; Child ; Cone-Beam Computed Tomography ; Dentition, Mixed ; Gingival Recession ; diagnostic imaging ; Humans ; Incisor ; diagnostic imaging ; Maxilla ; Orthodontics ; methods ; Tooth Apex ; diagnostic imaging ; Tooth Crown ; diagnostic imaging ; Tooth Root ; diagnostic imaging ; Tooth, Impacted ; diagnostic imaging ; therapy ; Treatment Outcome

The purpose of this study was to develop a new way to localize the impacted canines from three dimensions and to investigate the root resorption of the adjacent teeth by using cone beam computed tomography (CBCT). Forty-six patients undergoing orthodontic treatments and having impacted canines in Tongji Hospital were examined. The images of CBCT scans were obtained from KaVo 3D exam vision. Angular and linear measurements of the cusp tip and root apex according to the three planes (mid-sagittal, occlusal and frontal) have been taken using the cephalometric tool of the InVivo Dental Anatomage Version 5.1.10. The measurements of the angular and linear coordinates of the maxillary and mandibular canines were obtained. Using this technique the operators could envision the location of the impacted canine according to the three clinical planes. Adjacent teeth root resorption of 28.26 % was in the upper lateral incisors while 17.39% in upper central incisors, but no lower root resorption was found in our samples. Accurate and reliable localization of the impacted canines could be obtained from the novel analysis system, which offers a better surgical and orthodontic treatment for the patients with impacted canines.
Adolescent ; Adult ; Cephalometry ; methods ; Child ; Cone-Beam Computed Tomography ; methods ; Cuspid ; diagnostic imaging ; Female ; Humans ; Imaging, Three-Dimensional ; methods ; Incisor ; diagnostic imaging ; Male ; Maxilla ; diagnostic imaging ; Reproducibility of Results ; Root Resorption ; diagnostic imaging ; Tooth, Impacted ; diagnostic imaging ; Young Adult