OBJECTIVETo measure the thickness of facial bone wall of maxillary anterior teeth and premolars based on cone beam computed tomography (CBCT) images.

METHODSCBCT images from 118 patients were collected from the Affiliated Stomatology Hospital of Zhejiang University. The thickness perpendicular to the long axis of facial bone wall was measured at two locations: 4 mm apical to the cementoenamel junction (point 1) and the middle of the root (point 2).

RESULTSThe thickness of the facial bone walls of central incisors, lateral incisors and canines ranged from 0.5 to 1.5 mm. A thin facial bone wall (<1.0 mm) was quite frequent in central incisors (44.1% at point 1, 56.8% at point 2), lateral incisors (65.2% at point 1, 89.8% at point 2) and canines (45.8% at point 1, 61.0% at point 2). In contrast, the majority of examined first premolars (77.1% at point 1, 68.7% at point 2) and second premolars (94.1% at point 1, 94.1% at point 2) exhibited a thick facial bone wall (>1.0 mm).

CONCLUSIONA thin facial bone wall of teeth in the anterior maxilla is common. Radiographic analysis of facial bone wall using CBCT is recommended for selection of appropriate treatment approach.

Adult ; Bicuspid ; diagnostic imaging ; Cone-Beam Computed Tomography ; Female ; Humans ; Incisor ; diagnostic imaging ; Male ; Maxilla ; diagnostic imaging ; Young Adult

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

OBJECTIVETo evaluate the degree and pattern of alveolar bone defect in aggressive periodontitis (AgP) using cone-beam CT (CBCT), and to investigate the distribution of alveolar bone defects in aggressive periodontitis.

METHODSForty AgP patients (age: 14-36 years, male: 15 cases, female: 25 cases) were selected by simple random method and scanned by CBCT. NNT software was applied to measure the average degree of alveolar bone defects and bone loss types in different regions.

RESULTSIn forty AgP patients, 86.6% (3,769/4,352) sites presented moderate and severe alveolar bone defects. In the maxilla, the molar areas presented the heaviest alveolar bone defect [(6.3±0.7) mm], the canine areas showed the lightest bone loss [(4.8±0.8) mm]. In the mandible, the incisal areas presented the heaviest alveolar bone defect [(5.9±0.9) mm], the canine areas showed the lightest bone loss[(5.1±0.7) mm]. The degree of alveolar bone defect in the areas of maxillary canine, maxillary molars, mandibular premolar was significantly different (P<0.05). The degree of alveolar bone defect in mandibular canine and mandibular molars was significantly differenct (P<0.01). The most serious alveolar bone defect was in the mesial side of maxillary molar [(6.9±0.7) mm] and the mesial side of mandibular incisor [(6.5±1.1) mm]. The oblique bone defects were found in the mesial part of the first molars in mandibula [13.6% (42/308)], the first molars in maxilla [12.0% (39/316)] and the first premolar in maxilla [10.8% (34/316)].

CONCLUSIONSThe alveolar bone defects of generalized AgP patients were serious. The most serious areas were located in the mesial side of maxillary molars and the mesial side of mandibular incisor.

Adolescent ; Adult ; Aggressive Periodontitis ; diagnostic imaging ; Alveolar Process ; diagnostic imaging ; Bicuspid ; Cone-Beam Computed Tomography ; Cuspid ; Female ; Humans ; Incisor ; Male ; Mandible ; diagnostic imaging ; Maxilla ; diagnostic imaging ; Molar ; Software

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

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

OBJECTIVETo investigate the features of the fill of interdental spaces by gingival papillae and the associated factors.

METHODSFifteen volunteers with healthy gingiva were involved in this study. The height and thickness on the alveolar crest level of 62 maxillary anterior papilla were measured radiographically with cone-beam computed tomography (CBCT) scans. A standardized periodontal probe with Williams markings was used for measurements of the papilla width on the alveolar crest level.

RESULTSWhen the papilla was complete fill interdentally, the mean height of papillary tissue on the alveolar crest level (equal to contact point-bone crest) was (3.67 ± 0.51) mm. The mean thickness of papilla on the alveolar crest level was (8.38 ± 0.75) mm. The papilla height had a positive correlation with papilla thickness (r = 0.433, P < 0.001).

CONCLUSIONSThe cone-beam computed tomography can be used for clear visualization of the papilla profile and the measurements of papilla height and thickness. Thicker and wider tissue was associated with an increased likelihood of having a complete papilla fill.

Adult ; Alveolar Process ; anatomy & histology ; diagnostic imaging ; Cone-Beam Computed Tomography ; Esthetics, Dental ; Female ; Gingiva ; anatomy & histology ; diagnostic imaging ; Humans ; Incisor ; anatomy & histology ; diagnostic imaging ; Male ; Maxilla ; Odontometry

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

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*

PURPOSE: The research was performed to predict the three dimensional relationship between the impacted mesiodens and the maxillary central incisors and the proximity with the anatomic structures by comparing their panoramic images with the CT images. MATERIALS AND METHODS: Among the patients visiting Seoul National University Dental Hospital from April 2003 to July 2007, those with mesiodens were selected (154 mesiodens of 120 patients). The numbers, shapes, orientation and positional relationship of mesiodens with maxillary central incisors were investigated in the panoramic images. The proximity with the anatomical structures and complications were investigated in the CT images as well. RESULTS: The sex ratio (M : F) was 2.28 : 1 and the mean number of mesiodens per one patient was 1.28. Conical shape was 84.4% and inverted orientation was 51.9%. There were more cases of anatomical structures encroachment, especially on the nasal floor and nasopalatine duct, when the mesiodens was not superimposed with the central incisor. There were, however, many cases of the nasopalatine duct encroachment when the mesiodens was superimpoised with the apical 1/3 of central incisor (52.6%). Delayed eruption (55.6%), crown rotation (66.7%) and crown resorption (100%) were observed when the mesiodens was superimposed with the crown of the central incisor. CONCLUSION: It is possible to predict three dimensional relationship between the impacted mesiodens and the maxillary central incisors in the panoramic images, but more details should be confirmed by the CT images when necessary.
Crowns ; Diagnostic Imaging ; Floors and Floorcoverings ; Humans ; Incisor ; Orientation ; Sex Ratio ; Tooth, Impacted