OBJECTIVES: This study aimed to investigate the feasibility of measuring the soft tissue height of bone cristae around implant by digital method. METHODS: A total of 36 patients with dental implants were selected from the Dental Medicine Center of the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from August 2022 to December 2022. A total of 43 dental implants were enrolled. All postoperative cone beam CT (CBCT) imaging data and intraoral digital impressions obtained before surgery were immediately obtained by the patients on the day of completion of oral implant surgery and they were imported into oral implant surgery planning software for image fitting. Then, virtual implants of the same specification were placed in the planting area, and the implant position was adjusted to overlap with the implant shadow in the CBCT image. Supracrestal tissue height (STH) was measured at the implant view interface (digital group). During the operation, implant holes were prepared step by step in accordance with the standard preparation method, and implants were implanted. The upper edge of the implant was flushed with the crest of the alveolar ridge. STH was measured by perio-dontal probing (periodontal probe group). Paired t-test was used to compare the STH differences between the digital and periodontal probe groups. Bland-Altman test was used to analyze the consistency of the two methods. Intra-group correlation coefficient (ICC) was used to verify the reliability of the results measured by different surveyors using di-gital methods. RESULTS: No statistical significance was observed in the STH difference between the two methods (P>0.05). Bland-Altman test showed good consistency between the two methods, but the measurement of mandibular posterior teeth showed that the results of periodontal probe were greater than those of digital method. The ICC and 95%CI of the STH results measured digitally by different surveyors are 0.992 (0.986-0.996). CONCLUSIONS The digital me-thod is in good agreement with the periodontal probe method in measuring the soft tissue height of the bone cristae around the implant.
Humans ; Alveolar Process/diagnostic imaging* ; Cone-Beam Computed Tomography/methods* ; Dental Implants ; Feasibility Studies ; Reproducibility of Results ; Tooth/diagnostic imaging*

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

OBJECTIVETo investigate the dentoalveolar characteristics in skeletal class I patients with excessive overjet.

METHODSTen cephalometric measurements of 60 skeletal class I patients with excessive overjet were analyzed.

RESULTSCompared with patients with normal overjet, 1-SN, 1-NA and MxAAH were significantly increased in excessive overjet group I (overjet: 3 - 5 mm) and 1-SN, 1-NA and MxAAH were significantly increased in excessive overjet group II (overjet: 5 - 7 mm).

CONCLUSIONSThe protrusion and tipping of maxillary incisor, and absence of compensatory proclination of mandibular incisor may be the factors, caused skeletal class I excessive overjet. Increased height of anterior maxillary anterior alveolar process was the compensatory change in skeletal class I patients with excessive overjet.

Adolescent ; Alveolar Process ; diagnostic imaging ; pathology ; Cephalometry ; Child ; Female ; Humans ; Incisor ; diagnostic imaging ; pathology ; Male ; Malocclusion, Angle Class I ; diagnostic imaging ; pathology ; Radiography

OBJECTIVETo evaluate the mandible angle and to investigate the relationship of angle size to gender, age-group, cortical thickness at the mandibular angle (CTMA), height of mandibular residual body, and edentulous period in the elderly edentulous subjects.

METHODSA total of 356 panoramic radiographs of three groups of subjects were evaluated: the young dentate group, 131 subjects (mean age: 27); the older dentate group, 97 (mean age: 64); and the elderly edentulous group, 128 (ages 76, 81, or 86). Mandibular angle size, CTMA, and height of mandibular residual body were measured from panoramic radiographs. A structured questionnaire was used to determine the history of edentulousness.

RESULTSDifference in angle size was found between dentate men and women (P < 0.05, P < 0.001), but not between the elderly edentulous men and elderly women. The elderly edentulous subjects had larger mandibular angles than did older dentate subjects (P < 0.001). The angle size was negatively related to CTMA only among 76-year-old edentulous women (P < 0.01) and negatively associated with average height of the mandibular residual body in the edentulous men and women (P < 0.01). No association existed between angle size and duration of edentulousness.

CONCLUSIONSElderly edentulous subjects have large mandibular angles and the angle size is correlated with low-height of the mandibular residual body, which suggests that masticatory function of natural dentition and complete denture may influence change of the mandibular angle. The significant relationship of mandibular angle size to CTMA probably indicates the effect of systemic factors on change in the mandibular angle.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Alveolar Process ; diagnostic imaging ; pathology ; Cephalometry ; Female ; Humans ; Jaw, Edentulous ; diagnostic imaging ; Male ; Mandible ; diagnostic imaging ; pathology ; Middle Aged ; Radiography

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*

OBJECTIVETo study the alveolar bone surrounding situation and the length of the root of the maxillary labial inverted impacted incisor in mixed dentition after orthodontic treatment.

METHODSFourteen cases with maxillary labial inverted impacted incisor in mixed dentition were collected. Modified Nance arch and conventional appliance were used. Cone-bean CT (CBCT) was taken after the treatment. Simplant13.0 three-dimensional reconstruction and multi-planer reconstruction (MPR) method were used to observe the labial and lingual alveolar bone crest morphology, besides, the labial and lingual length from the alveolar bone crest to cemento-enamel junction (CEJ) of the impacted incisor and the homonym tooth after treatment, along with their root length and their labial and lingual length ratio of the root surrounded by the alveolar bone to the total root length were measured. The idependent samples t-test were used to analyze the variable differences.

RESULTSThe labial and lingual alveolar bone of fourteen cases crest of the diseased tooth after treatment presented general symmetry U shape from qualitative observation through the three-dimensional reconstruction. The labial and the lingual length of the diseased incisor from alveolar bone crest to CEJ [(2.47 ± 1.35) and (1.47 ± 0.84) mm] was significant increased than those of the homonym incisor [(1.03 ± 0.35) and (0.90 ± 0.37) mm] (P < 0.05); the length of the diseased incisor's post-treatment root [(9.82 ± 2.82) mm] was no statistically significant decreased than that of the homonym incisor root [(10.28 ± 1.38) mm, P = 0.59]; the labial and the lingual length ratio of the impacted tooth's root surrounded by the alveolar bone to the total root length [(72.83 ± 17.16)% and (85.32 ± 5.98)%] was statistically significant decrease than those of homonym teeth[(89.66 ± 3.98)% and (90.84 ± 4.61)%] (P < 0.05).

CONCLUSIONSThe diseased tooth's root had gotten enough length after the treatment. The labial and lingual alveolar bone of the maxillary labial inverted impacted incisor in mixed dentition can't offer sufficient adaptive hyperplasia after treatment, of which labial alveolar bone is more apparent, prompting careful protection when they were used.

Alveolar Process ; diagnostic imaging ; pathology ; Child ; Cone-Beam Computed Tomography ; Dentition, Mixed ; Female ; Follow-Up Studies ; Humans ; Incisor ; diagnostic imaging ; pathology ; surgery ; Male ; Maxilla ; diagnostic imaging ; pathology ; surgery ; Orthodontic Extrusion ; Tooth Root ; diagnostic imaging ; pathology ; Tooth, Impacted ; diagnostic imaging ; surgery

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

OBJECTIVES: To explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition. METHODS: Multi-slice computed tomography (MSCT) was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age. RESULTS: There was no significant difference in the height of alveolar bone resorption between sex (P>0.05). The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites (y=2.569x₁+3.106x₂+4.108x₃+1.451x₄-0.082, R²_max=0.756)had a better ability to infer age than that of combining two sites (y=5.942x₁+4.489x₂+0.612, R²_max=0.706) and a single site (R²_max=0.638). CONCLUSIONS The height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.
Humans ; Adolescent ; Child ; Young Adult ; Adult ; Alveolar Process/diagnostic imaging* ; Cone-Beam Computed Tomography ; Bone Resorption/diagnostic imaging* ; Tomography, X-Ray Computed

To investigate the biomechanical influences on two different cleft maxillary 3D finite element models pre- and post-alveolar bone graft, we developed a cleft palate bony model from a 17 year cleft palate male CT scan data and built an alveolar bone-grafted cleft maxillary 3D finite element model through gluing the graft model. Apply vector lip force on the anterior face of the models. Study the press (including S3 principal, S1 principal, von Mises and shear) distribution properties and localized area. The results suggested that the press principal spreads along the alveolar ridge and formed several focused areas. After bone grafted, the shear stress tends to be evenly. The grafted alveolar could resist the medially deformation of alveolar crest and the shear stress to the nasal base bony structure. The conclusions from results demonstrated that the deformation of alveolar ridge is possibly due to the lip pressure after the lip repair. The shear stress along the alveolar ridge could cause the severity of the dentition. The grafted bony structure could even the shear stress distribution evenly other than the distribution properties.
Adolescent ; Alveolar Process ; surgery ; Alveolar Ridge Augmentation ; methods ; Biomechanical Phenomena ; Bone Transplantation ; Cleft Palate ; diagnostic imaging ; physiopathology ; surgery ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Male ; Maxilla ; diagnostic imaging ; physiopathology ; surgery ; Models, Biological ; Tomography, Spiral Computed

OBJECTIVETo determine the agreement between two-dimensional radiograph and three-dimensional CT in the evaluation of the secondary alveolar bone grafting.

METHODSNine complete cleft lip and palate patients (8 UCLP, 1 BCLP) at least 6 months post secondary alveolar bone grafting were selected. The mean age of the patients was 15.5 years with a range of 12 to 26 years. Occlusal radiographs were taken and the interdental septal height was determined using Bergland criteria. There were 2 type I sites, 2 type II sites, 5 type III sites and 1 type IV site. All the patients had undergone CT scan of the cleft within two months after the radiograph was taken. The plane of scan was parallel to the occlusal plane. Cuts of 2 mm were taken from the infraorbital rim to the gingival third of the crown of the teeth. Three-dimensional reconstruction was performed.

RESULTSThe interdental septal height on the occlusal radiograph was conformed by the CT scan. Labial and palatal notch was found on CT scan at two grafting sides.

CONCLUSIONSThe study provided some evidence to support the continued cautious use of anterior occlusal radiograph in the evaluation of bone-graft success before the orthodontic treatment. When the X-ray examination is not in line with the clinical examination, CT scan is indicated.

Adolescent ; Adult ; Alveolar Process ; diagnostic imaging ; surgery ; Bone Transplantation ; Child ; Cleft Lip ; surgery ; Cleft Palate ; surgery ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Tomography, X-Ray Computed ; methods