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

This study sought to measure accurately the thickness of the frontal, parietal and occipital bones of the alive human skull based on CT images. The images were treated with a series of processes by coding into a program: image segmentation and binary coding; eliminating edge interference; rectifying image deviation and clarifying boundary edge; redrawing the boundary and reference point fixing; and finally thickness measurement. The new method can measure not only the different points in one CT image but also the same point in massive CT images. The measurement results are of great practical value in the fields of anatomy, clinical medicine, biomechanics study, head injury analysis, etc.
Cephalometry ; methods ; Humans ; Radiographic Image Enhancement ; methods ; Skull ; anatomy & histology ; diagnostic imaging ; Tomography, X-Ray Computed

OBJECTIVETo compare the effects between mini-screw implant and transpalatal arch (TPA) on dentofacial morphology in extraction cases.

METHODSForty-two cases were divided into two groups. One group (n = 19) had been treated with mini-screw implants and the other group (n = 23) treated with TPA as anchorage control. Sliding technique was used to close extraction space in the two groups. Cephalometric analysis was performed before and after the treatment. The data were analyzed by using independent-samples t test.

RESULTSIn the mini-screw implant group, the maxillary incisors were retracted (7.05 +/- 1.89) mm and intruded (1.71 +/- 2.33) mm, The maxillary first molars were distalized (0.45 +/- 3.32) mm and intruded (1.74 +/- 2.66) mm. While in the TPA group, the upper incisors were retracted (4.59 +/- 1.78) mm and extruded (0.93 +/- 1.77) mm. The maxillary first molars were moved (1.65 +/- 1.87) mm mesially and extruded (0.52 +/- 1.59) mm. All the relevant results between the two groups were significantly different (P < 0.05).

CONCLUSIONSAs orthodontic anchorage, mini-screw implants were different from TPA. Mini-screw implant could not only retract the upper incisors but also slightly intrude upper incisors and upper molars.

Bone Screws ; Cephalometry ; Humans ; Incisor ; Maxilla ; Molar ; Orthodontic Anchorage Procedures ; Tooth Extraction ; Tooth Movement Techniques ; methods

OBJECTIVETo establish the differential templates of the skeletal profiles for Shanghainese with normal occlusion in early permanent dentition.

METHODS71 lateral cephalometric radiographs of subjects with normal occlusion in early permanent dentition, aged from 11 - 15 years (37 females and 34 males) were traced. 23 skeletal landmarks were identified on the tracings, which afterwards were scanned on the computer. An x-y coordinate system was established: the tracing superimposed on sella rotated 7 degrees down from the sella-nasion line as the x axis and the vertical line through sella perpendicular to the x axis as the y axis. A special length/depth ratio was designed. The length/depth ratio of each graph were calculated. Steiner analysis was applied to check the difference between genders.

RESULTSThere was no difference between genders. The tracings were divided into three categories: short face, normal face and long face according to the mean and standard deviation of the ratio. The three types of tracings were superimposed on the x axis with sella registered. Three templates were created.

CONCLUSIONSThe differences were apparent when the three templates were superimposed.

Adolescent ; Cephalometry ; methods ; Child ; Dental Occlusion ; Face ; anatomy & histology ; Facial Bones ; anatomy & histology ; Female ; Humans ; Male

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

Modern photo-mechanics testing techniques are widely used in industrial circles and academic circles. In order to solve the problem of biomedical engineering, shadow moiré method is used in oral and dental area in our study. A molar tooth was tested by phase shift shadow moiré method. Through testing molar tooth, the results show that shadow moiré method could be used for measuring the appearance of the oral area and concave and convex parts of molar tooth could also be distinguished and shown by interference patterns. The characteristics of shadow moirh are that it does't need exerting load on the specimen and could realize non-contact measurement.
Cephalometry ; methods ; Humans ; Moire Topography ; instrumentation ; statistics & numerical data ; Molar ; anatomy & histology ; Photography

OBJECTIVETo evaluate a finite element method (FEM) for analysis of the cranial-facial morphology.

METHODSThe two-dimensional finite element analysis system was established and used to analysis the lateral side morphology of the soft tissue by the change of each finite unit of the soft tissue in a X-ray cranial-facial lateral cepholometrics film.

RESULTSThe finite element analysis system was showing very well in the figures and data made by the system.

CONCLUSIONFinite element analysis system may be a good supplement of the traditional X-ray cephalometrics to the soft tissue of orthognatics.

Cephalometry ; methods ; Face ; anatomy & histology ; Finite Element Analysis ; Humans ; Orthognathic Surgery

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

OBJECTIVETo establish a convenient and rapid method for constructing a digital model of the maxillofacial soft tissue based on three-dimensional laser surface scanning to allow direct and accurate observation of the soft tissue changes in the course of orthodontic treatment.

METHODSThe point cloud data of three-dimensional laser scanning of the maxillofacial region were acquired from a healthy woman with Angle Class I occlusion, who maintained a horizontal Frankfort plane during scanning with the scanner placed at a distance of 80 cm. The scanning was repeated twice after wearing the dental cast for an Angle Class I occlusion. The three-dimensional digital model of the maxillofacial soft tissue was constructed based on the point cloud using GeoMagic10.0 software.

RESULTSThe high-resolution three-dimensional model of the maxillofacial soft tissue reconstructed allowed accurate observation of the distinct facial anatomical landmarks and represented directly the soft tissue changes in the process of orthodontic treatment by merging the models. Using the analytic tool provided by the software, this model also allowed direct quantitative measurement of the nasolabial angle and the distances from the esthetic plane to the upper lip, labral inferior, and mentolabial sulcus, which were 111.86°, -3.57 mm, -2.54 mm, and 3.95 mm before orthodontic treatment as compared to 114.31°, -2.73 mm, -1.06 mm, and 3.46 mm during treatment, and 116.53°, -0.15 mm, 0.64 mm, and 3.11 mm after the treatment, respectively.

CONCLUSIONThree-dimensional laser surface scanning enables accurate and rapid construction of the digital model of the facial soft tissues, which may provide valuable assistance in orthodontic treatment.

Adult ; Cephalometry ; methods ; Face ; Female ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; methods ; Lasers ; Orthodontics, Corrective ; methods ; Software

OBJECTIVETo evaluate the outcome of the treatment of malocclusion with mandibular congenital missing teeth guided by Bolton index.

METHODS26 class I and II cases (males 10, females 16) were chosen in this study. Guided by Bolton index, enamel stripping, denture and two types of tooth extraction were used in the treatment.

RESULTSNormal Bolton index was achieved and the results of treatment were satisfactory.

CONCLUSIONSMalocclusion with mandibular congenital missing teeth can be treated successfully guided by Bolton index.

Adolescent ; Adult ; Anodontia ; complications ; Cephalometry ; methods ; standards ; Child ; Female ; Humans ; Male ; Malocclusion ; etiology ; therapy ; Orthodontics, Corrective ; methods ; standards ; Treatment Outcome