OBJECTIVES: To investigate the effect of different soft-tissue morphologies on the treatment of skeletal class Ⅰ malocclusion patients by analyzing measurement data before and after treatment. METHODS: Pre- and post-treatment lateral cephalograms of 55 adult female Angle class Ⅰ patients were collected in the Department of Orthodontics, Hospital of Stomatology, Jilin University from January 2012 to December 2020. Chin soft-tissue morphologies in the lateral cranial radiographs were used to divide the patients into an abnormal chin morphology group (flat and retracted chins, n=27) and a normal chin morphology group (rounded and prominent chins, n=28). Relevant soft- and hard-tissue indexes were selected to study in-group varieties and intergroup differences in the varying chin morphologies before and after treatment. RESULTS: The chin-lip angle, mandibular chin angle, mandibular chin vertex angle, PP-MP, LL-E, UL-E, Po-Pos, and B-B' thickness in the abnormal chin morphology group were significantly higher than those in the normal chin morphology group (P<0.05). Furthermore, m∶BMe and n∶B'Mes in the abnormal chin morphology group were signi-ficantly lower than those in the normal chin morphology group (P<0.05). After treatment, the mandibular chin angle, mandibular chin vertex angle, U1-SN, L1-MP, LL-E, UL-E, SNA, SNB, and B-B' thickness of the abnormal chin morphology group significantly decreased (P<0.05), whereas the nasolabial angle, m∶BMe, n∶B' Mes, and Po-Pos significantly increased (P<0.05). In the normal chin morphology group, the U1-SN, L1-MP, LL-E, UL-E, and B-B' thicknesses decreased significantly (P<0.05), whereas the nasolabial angle significantly increased (P<0.05). Among them, m∶BMe and n∶B' Mes were positively correlated. CONCLUSIONS Chin morphology affects the formulation of treatment plans. Compared with the normal chin morphology group, the abnormal chin morphology group required a larger retraction of incisors. Although the chin of soft-tissue morphology is related to the morphology of bones, the changes in soft tissue chin after treatment cannot be directly predicted according to the bone changes. Soft-tissue chin morphology affects the aesthetic assessment of the soft-tissue lateral profile and the change in soft tissue before and after treatment. The method of predicting the change in soft-tissue chin after treatment should consider the morphology of the soft-tissue chin.
Adult ; Humans ; Female ; Chin ; Lip ; Cephalometry/methods* ; Esthetics, Dental ; Mandible

OBJECTIVE: To investigate the efficacy of vertical control by using conventional mini-implant anchorage in maxillary posterior buccal area for Angle class Ⅱ extraction patients. METHODS: Twenty-eight Angle class Ⅱ patients [9 males, 19 females, and age (22.6±2.8) years] were selected in this study. All of these patients were treated by using straight wire appliance with 4 premolars extraction and 2 mini-implant anchorage in maxillary posterior buccal area. In this study, the self-control method was used to measure and analyze the lateral radiographs taken before and after orthodontic treatment in each case, the main cephalometric analysis items were related to vertical changes. The digitized lateral radiographs were imported into Dolphin Imaging Software (version 11.5: Dolphin Imaging and Management Solutions, Chatsworth, California, USA), and marked points were traced. Each marked point was confirmed by two orthodontists. The same orthodontist performed measurement on the lateral radiographs over a period of time. All measurement items were required to be measured 3 times, and the average value was taken as the final measurement result. RESULTS: Analysis of the cephalometric radiographs showed that, for vertical measurements after treatment, the differences of the following measurements were highly statistically significant (P < 0.001): SN-MP decreased by (1.40±1.45) degrees on average, FMA decreased by (1.58±1.32) degrees on average, the back-to-front height ratio (S-Go/N-Me) decreased by 1.42%±1.43% on average, Y-axis angle decreased by (1.03±0.99) degrees on average, face angle increases by (1.37±1.05) degree on average; The following measurements were statistically significant (P < 0.05): the average depression of the upper molars was (0.68±1.40) mm, and the average depression of the upper anterior teeth was (1.07±1.55) mm. The outcomes indicated that there was a certain degree of upper molar depression after the treatment, which produced a certain degree of counterclockwise rotation of the mandibular plane, resulting in a positive effect on the improvement of the profile. CONCLUSION The conventional micro-implant anchorage in maxillary posterior buccal area has a certain vertical control ability, and can give rise to a certain counterclockwise rotation of the mandible, which would improve the profile of Angle Class Ⅱ patients.
Bicuspid ; Cephalometry/methods* ; Female ; Humans ; Male ; Malocclusion, Angle Class II/therapy* ; Mandible ; Maxilla/diagnostic imaging* ; Orthodontic Anchorage Procedures ; Tooth Movement Techniques ; Vertical Dimension

Objective: To investigate the prevalence of tonsil hypertrophy in patients with different sagittal skeletal craniofacial patterns, as well as the correlation between tonsil hypertrophy and the type of skeletal pattern. Methods: Lateral cephalograms of patients who visited the Department of Orthodontics Division 1, School of Stomatology, Wuhan University during January to August, 2019 were retrospectively collected. Patients (children: age≥6 and ≤12 year; adults: age≥18 year) were divided into three groups according to the ANB (subspinale-nasion-supramental) angle: the skeletal class Ⅰ group (0°≤ANB≤4°), skeletal class Ⅱ group (ANB>4°) and skeletal class Ⅲ group (ANB<0°). Tonsil hypertrophy was diagnosed with lateral cephalogram by two specifically trained orthodontists independently, according to the Baroni's method. The between-group differences in tonsil hypertrophy prevalence were analyzed using chi-square tests with Bonferroni correction (α=0.017). Results: A total of 1 776 patients (593 children and 1 183 adults) were included, among which 672 (37.8%) were with class Ⅰ, 849 (47.8%) with class Ⅱ, and 255 (14.4%) with class Ⅲ skeletal pattern. The prevalence of tonsil hypertrophy in children was 66.3% (393/593). The proportion of children with tonsil hypertrophy in class Ⅲ group [87.0% (60/69)] were significantly higher than that in class Ⅰ [65.6% (145/221), χ²=11.56, P<0.017] and class Ⅱ [62.0% (188/303), χ²=15.69, P<0.017] groups. The prevalence of tonsil hypertrophy in adults was 23.2% (275/1 183). The proportion of adults with tonsil hypertrophy in class Ⅲ group [42.5% (79/186)] was significantly higher than that in class Ⅰ [19.1% (86/451), χ²=36.50, P<0.017] and class Ⅱ [20.2% (110/546), χ²=35.00, P<0.017] groups. However, there was no significant difference in the prevalence of tonsil hypertrophy between class Ⅰ and class Ⅱ groups for both children (χ²=0.70, P>0.017) and adults (χ²=0.18, P>0.017). Conclusions: The prevalence of tonsil hypertrophy in skeletal class Ⅲ patients was significantly higher than that in patients with skeletal class Ⅰ and Ⅱmalocclusion. Tonsil hypertrophy could be an important risk factor for skeletal class Ⅲ patients.
Adolescent ; Adult ; Cephalometry/methods* ; Child ; Humans ; Hypertrophy ; Malocclusion ; Palatine Tonsil ; Retrospective Studies

Objective: To explore the establishment of an efficient and automatic method to determine anatomical landmarks in three-dimensional (3D) facial data, and to evaluate the effectiveness of this method in determining landmarks. Methods: A total of 30 male patients with tooth defect or dentition defect (with good facial symmetry) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to August 2021 were selected, and these participants' age was between 18-45 years. 3D facial data of patients was collected and the size normalization and overlap alignment were performed based on the Procrustes analysis algorithm. A 3D face average model was built in Geomagic Studio 2013 software, and a 3D face template was built through parametric processing. MeshLab 2020 software was used to determine the serial number information of 32 facial anatomical landmarks (10 midline landmarks and 22 bilateral landmarks). Five male patients with no mandibular deviation and 5 with mild mandibular deviation were selected from the Department of Orthodontics or Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June to August 2021. 3D facial data of patients was collected as test data. Based on the 3D face template and the serial number information of the facial anatomical landmarks, the coordinates of 32 facial anatomical landmarks on the test data were automatically determined with the help of the MeshMonk non-rigid registration algorithm program, as the data for the template method to determine the landmarks. The positions of 32 facial anatomical landmarks on the test data were manually determined by the same attending physician, and the coordinates of the landmarks were recorded as the data for determining landmarks by the expert method. Calculated the distance value of the coordinates of facial anatomical landmarks between the template method and the expert method, as the landmark localization error, and evaluated the effect of the template method in determining the landmarks. Results: For 5 patients with no mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (1.65±1.19) mm, the landmark localization error of the midline facial anatomical landmarks was (1.19±0.45) mm, the landmark localization error of bilateral facial anatomical landmarks was (1.85±1.33) mm. For 5 patients with mild mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (2.55±2.22) mm, the landmark localization error of the midline facial anatomical landmarks was (1.85±1.13) mm, the landmark localization error of bilateral facial anatomical landmarks was (2.87±2.45) mm. Conclusions: The automatic determination method of facial anatomical landmarks proposed in this study has certain feasibility, and the determination effect of midline facial anatomical landmarks is better than that of bilateral facial anatomical landmarks. The effect of determining facial anatomical landmarks in patients without mandibular deviation is better than that in patients with mild mandibular deviation.
Adolescent ; Adult ; Algorithms ; Anatomic Landmarks ; Cephalometry/methods* ; Face/anatomy & histology* ; Female ; Humans ; Imaging, Three-Dimensional/methods* ; Male ; Malocclusion ; Middle Aged ; Orthodontics ; Software ; Young Adult

cephalometry and AHI in children with OSA and to assess the correlations between cephalometric parameters and salivary cortisol level.SUBJECTS AND METHOD: Three parameters of the upper airway were measured by cephalometry: distance from the posterior nasal spine to the hyoid bone (PHy), distance from the mandibular plane to the hyoid bone (MP-Hy), and distance from the posterior nasal spine to the mandibular plane (P-MP). Ratios for each segment were also determined.RESULTS: Subjects with OSAS had longer P-Hy and MP-Hy than the control group. In particular, MP-Hy was significantly longer in the moderate-severe group than the other groups. In the OSAS group, there were significant correlations between MP-Hy, Ratio1, Ratio3 and m-Cor, s-Cor.CONCLUSION: Length of upper airway and ratio parameters of cephalometry may be more useful indices in moderate-severe OSA than absolute distance parameters, and Ratio1 may be valuable for prediction of activating HPA axis.]]>
Airway Resistance ; Cephalometry ; Child ; Humans ; Hydrocortisone ; Hyoid Bone ; Methods ; Sleep Apnea, Obstructive ; Spine

To establish a fetal biparietal diameter (BPD)-gestational age formula based on the data of pregnant women from Xiaoshan District of Hangzhou, and to evaluate its application in prenatal screening.Data of 3500 pregnant women with gestational age between 15 weeks and 19 weeks+6 receiving prenatal screening in Xiaoshan Hospital during May 2014 and May 2015 were collected. BPDs were used to establish a localized BPD-gestational age formula. The localized formula was used to evaluate the prenatal screening risks in 1759 pregnant women with irregular menstrual cycles or uncertain last menstrual period (LMP) in Xiaoshan District, and the results were compared with those calculated using formula in LifeCycle 4.0.With localized formula, the total positive rate of Down syndrome, trisomy 18 syndrome and deformity of neural tube was decreased from 6.96% to 5.85% (<0.05), in which the positive rate of Down syndrome decreased (<0.05), that of deformity of neural tube increased (<0.05), and that of trisomy 18 syndrome remained the same (>0.05). The median MoMs of free-hCG β and α-fetoprotein calculated using localized formula were significantly different from those calculated using the formula in LifeCycle 4.0 (all<0.05), and the former ones were more closer to 1. For women of fetus diagnosed with the above diseases, the positive rate calculated using localized formula was almost the same as that calculated using the formula in LifeCycle 4.0.BPD-gestational age formula should be localized based on the statistical analysis of the local population, which will help to reduce the false positive rate, and make the results more accurate and reliable in prenatal screening.
Adult ; Body Weights and Measures ; standards ; Cephalometry ; standards ; statistics & numerical data ; Chorionic Gonadotropin, beta Subunit, Human ; blood ; standards ; Chromosomes, Human, Pair 18 ; Down Syndrome ; diagnosis ; embryology ; Epidemiologic Measurements ; Female ; Fetal Development ; Gestational Age ; Head ; embryology ; Humans ; Mass Screening ; methods ; standards ; statistics & numerical data ; Menstrual Cycle ; Neural Tube Defects ; diagnosis ; embryology ; Pregnancy ; Prenatal Diagnosis ; methods ; standards ; statistics & numerical data ; Reference Values ; Trisomy ; diagnosis ; Trisomy 18 Syndrome ; alpha-Fetoproteins ; analysis ; standards

OBJECTIVETo evaluate the predictive accuracy of the SurgiCase CMF software in surgical simulation and prediction for mandibular asymmetry with 3-dimensional simulation and measurement.

METHODSCBCT data of 27 patients with mandibular asymmetry were observed in CMF, and postoperative soft tissue physiognomy were predicted by simulating sagittal ramus osteotomy with or without genioplasty. The measurement parameters representing the symmetry of soft tissue were selected and the horizontal, coronal and sagittal planes were established. The results were analyzed by SPSS 19. 0. The overlap compared color grading charts were observed.

RESULTSAngles between cheilions and the horizonta plane (Ch-Ch-FH) in the simulation and postoperative soft tissues are (2. 35 ± 1. 81)° and (1. 44 ± 1. 13)°. The angles constructed among subnasale, upper lip and lower lip (Sn-UL-LL) are (4. 02 ± 3. 05)° and (2. 59 ± 1. 64)°, showing statistically different (P < 0. 01, P < 0. 05), which means that predictive accuracy of the lip canting and lip vertical deviation is relatively low. Distance between gonioi and sagittal plane (Go'-MS), distance between gonion and pogonion (Go'-Pog') and angle betweer subnasale to menton and the horizontal plane (Sn-Me'-MS) are not statistically different, which mean! high predictive accuracy of mandibular angle and chin. By observing the overlap compared color gradin-) charts, the predictive accuracy is not good in the cheek, especially in the deviate side.

CONCLUSIONSThe predictive accuracy of CMF system for patients with mandibular asymmetry is relatively high, but it is not good in the lip and cheek. The software improvement is still necessary.

Cephalometry ; methods ; Chin ; anatomy & histology ; Cone-Beam Computed Tomography ; methods ; Face ; Humans ; Lip ; anatomy & histology ; Mandible ; abnormalities ; surgery ; Osteotomy ; methods ; Software ; Surgery, Computer-Assisted ; methods

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged <12 years and least distally in cases aged >16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.
Adolescent ; Adult ; Age Factors ; Anatomic Landmarks ; pathology ; Cephalometry ; methods ; Child ; Cohort Studies ; Dentition, Mixed ; Female ; Humans ; Male ; Malocclusion ; classification ; pathology ; Malocclusion, Angle Class I ; pathology ; Malocclusion, Angle Class II ; pathology ; Malocclusion, Angle Class III ; pathology ; Mandible ; pathology ; Maxilla ; pathology ; Maxillofacial Development ; physiology ; Middle Aged ; Molar ; pathology ; Palate ; pathology ; Retrospective Studies ; 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

The aim of this retrospective study was to quantitatively evaluate the treatment effects of intrusion of overerupted maxillary molars using miniscrew implant anchorage and to investigate the apical root resorption after molar intrusion. The subjects included 30 patients whose average ages were 35.5±9.0 years. All patients had received intrusion treatments for overerupted maxillary molars with miniscrew anchorage. There were 38 maxillary first molars and 26 maxillary second molars to be intruded. Two miniscrews were inserted in the buccal and palatal alveolar bone mesial to the overerupted molar. Force of 100-150 g was applied by the elastic chains between screw head and attachment on each side. Lateral cephalograms and panoramic radiographs taken before and after intrusion were used to evaluate dental changes and root resorption of molars. Only 6 of the 128 miniscrews failed. The first and second molars were significantly intruded by averages of 3.4 mm and 3.1 mm respectively (P<0.001). The average intrusion time was more than 6 months. The crown of the molars mesially tilted by averages of 3.1 degrees and 3.3 degrees (P<0.001) for first and second molars. The amounts of root resorption were 0.2-0.4 mm on average. The intrusion treatment of overerupted molars with miniscrew anchorages could be used as an efficient and reliable method to recover lost restoration space for prosthesis. Radiographically speaking, root resorption of molars was not clinically significant after application of intrusive forces of 200 to 300 g.
Adult ; Bone Screws ; Cephalometry ; Dental Implantation ; Female ; Humans ; Male ; Maxilla ; Middle Aged ; Molar ; diagnostic imaging ; surgery ; Orthodontic Anchorage Procedures ; instrumentation ; methods ; Radiography, Dental ; methods ; Retrospective Studies ; Root Resorption ; diagnostic imaging ; surgery ; Tooth Movement Techniques ; instrumentation ; methods ; Young Adult