Measurement of spino-pelvic anatomical parameters and finite element analysis of lower lumbar vertebra in lumbarization patients / 解剖学报

Objective To measure the sagittal anatomical parameters of the spine and pelvis based on EOS imaging system, and to evaluate the stress of the lower lumbar spine by finite element analysis (FEA). Methods A total of 44 subjects examined by EOS imaging system were included, including 11 sacral lumbar vertebra patients and 33 normal subjects. The sagittal plane parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) were measured and compared in both groups. Pearson test was used to analyze the correlation between PI and LL in the two groups. At the same time, the finite element model of the lower lumbar vertebra was established. The stress condition of the lumbar spine model during forward bending, backward extension and left and right bending was evaluated by FEA method. Results The differences of PI, PT, SS and LL between the two groups were statistically significant (P<0.05). The correlation study found that there was a positive correlation between the two groups of subjects' PI and LL, including the lumbarization group (r = 0.69, P<0.05) and the normal group (r = 0.52, P<0.05). Under the conditions of forward bending, backward stretching, left bending and right bending, the bending moment of the model was 2 Nmm, and the stress concentration gradually decreased from bottom to top. The maximum stress concentration point was located at the lower articular process. Conclusion The physiological curvature and stress distribution of the lumbar spine in lumbarization population were different than normal, especially the stress concentration of the transitional intervertebral disc and articular process joint was obvious, and early degeneration of the spine was easy to occur.

Construction of point-based mandibular median sagittal plane / 上海交通大学学报（医学版）

Objective: To develop a new point-based mandibular median sagittal plane (MMSP) by selecting from varied mandibular planes which were formed by combining bony landmarks derived from multiple regions of the mandible. Methods: Forty adult patients were evenly divided into two groups by the degree of chin deviation: mandibular asymmetric group (MA group) and mandibular symmetric group (MS group). Three dimensional (3D) mandibular models were rebuilt by Mimics 19.0 software. In this software, 3D coordinates of 4 central landmarks and 6 pairs of lateral landmarks were collected. Then 120 candidate planes were constructed by point-based method, and compared with the reference plane formed by the iterative closest point (ICP) algorithm. All the planes were reordered and screened by geometric indices such as angle, distance and area in MS group. In addition, the clinical symmetrical indices such as point-to-plane distance, surface area difference, volume difference, and 3D deviation ratio of screened planes were compared in MA and MS groups. Results: The candidate planes co-constructed with landmarks from three mandibular regions (symphysis, mandibular angle and coronoid process) were the top 5% of all the planes. Among them, no statistical difference between B-Cor-Golat plane (constructed with supramentale, coronoid superius and gonion lateralis) and ICP plane was found (P >0.05), while there were significant differences between the rest screened planes and the reference plane (P<0.05). Conclusion: The B-Cor-Golat plane can be used as the mandibular median sagittal plane to reflect the symmetrical degree of the mandible well.

Advances in determination of median sagittal plane of facial soft tissue / 中华口腔医学杂志

Facial symmetry is a crucial component of human facial esthetics. Along with the increasing pursuit of aesthetic, in recent years, more and more researchers have focused on facial asymmetry assessment, of which determining the facial median sagittal plane is the first and most important step, and it will directly affect the accuracy of asymmetry evaluation and clinical treatment outcome. Limited by technical means, the earlier studies of facial soft tissue asymmetry assessment were mainly based on midline from two-dimensional (2D) images. Along with the development of three-dimensional (3D) measurement and data analysis techniques, new methods such as 3D landmark-based method and mirror-original alignment method have become main trend nowadays. This article systematically reviews the methods of determination of median sagittal plane of facial soft tissue, elaborates the developments and the latest research progress in this field, and discusses the advantages and limitations of each method in order to provide reference for clinical application.

Restoration of Sagittal Balance in Spinal Deformity Surgery

The prevalence of patients with adult spinal deformity (ASD) has been reported as high as 68%. ASD often leads to significant pain and disability. Recent emphasis has been placed on sagittal plane balance and restoring normal sagittal alignment with regards to the three dimensional deformity of ASD. Optimal sagittal alignment has been known to increase spinal biomechanical efficiency, reduce energy expenditure by maintaining a stable posture with improved load absorption, influence better bony union, and help to decelerate adjacent segment deterioration. Increasingly positive sagittal imbalance has been shown to correlate with poor functional outcome and poor self-image along with poor psychological function. Compensatory mechanisms attempt to maintain sagittal balance through pelvic rotation, alterations in lumbar lordosis as well as knee and ankle flexion at the cost of increased energy expenditure. Restoring normal spinopelvic alignment is paramount to the treatment of complex spinal deformity with sagittal imbalance. Posterior osteotomies including posterior column osteotomies, pedicle subtraction osteotomies, and posterior vertebral column resection, as well anterior column support are well known to improve sagittal alignment. Understanding of whole spinal alignment and dynamics of spinopelvic alignment is essential to restore sagittal balance while minimizing the risk of developing sagittal decompensation after surgical intervention.

Restoration of Sagittal Balance in Spinal Deformity Surgery

The prevalence of patients with adult spinal deformity (ASD) has been reported as high as 68%. ASD often leads to significant pain and disability. Recent emphasis has been placed on sagittal plane balance and restoring normal sagittal alignment with regards to the three dimensional deformity of ASD. Optimal sagittal alignment has been known to increase spinal biomechanical efficiency, reduce energy expenditure by maintaining a stable posture with improved load absorption, influence better bony union, and help to decelerate adjacent segment deterioration. Increasingly positive sagittal imbalance has been shown to correlate with poor functional outcome and poor self-image along with poor psychological function. Compensatory mechanisms attempt to maintain sagittal balance through pelvic rotation, alterations in lumbar lordosis as well as knee and ankle flexion at the cost of increased energy expenditure. Restoring normal spinopelvic alignment is paramount to the treatment of complex spinal deformity with sagittal imbalance. Posterior osteotomies including posterior column osteotomies, pedicle subtraction osteotomies, and posterior vertebral column resection, as well anterior column support are well known to improve sagittal alignment. Understanding of whole spinal alignment and dynamics of spinopelvic alignment is essential to restore sagittal balance while minimizing the risk of developing sagittal decompensation after surgical intervention.

Effect of single open-door laminoplasty with mini titanium plate implantation for neurological function and parameters of vertical plane of cervical vertebra of patient with cervical spondylosis / 中国医学装备

Objective:To investigate effect of single open-door laminoplasty with mini titanium plate implantation for neurological function of patient with cervical spondylosis, and analyze the correlation-ship between the parameters of clinical effects and parameters of vertical plane of cervical vertebra.Methods: 90 patients with ossification of posterior longitudinal ligament (OPLL) of cervical vertebra or multi-segment cervical spondylosis were enrolled in the research. All of them were implemented the treatment of single open-door laminoplasty with mini titanium plate implantation, and they were followed up for more than 6 months. The iconography parameters and clinical effect parameters of patients among pre-operation, post-operation and last follow up were compared and analyzed.Results: The C2~C7 axial distance of vertical plane, visual test analogue scores of neck and JOA scores of 90 patients at the last follow-up were significant higher than that of preoperative results(t=-2.371,t=3.914,t=22.345,P<0.05), respectively, and the dysfunction index of cervical vertebra of the last follow up were significant lesser than that of pre-operation (t=6.323,P<0.05). There were no correlations-ship between the clinical effect parameters and vertical plane parameters of cervical vertebra of 90 patients.Conclusion: The single open-door laminoplasty with mini titanium plate implantation can significantly improve the neurological function of patients with cervical spondylosis, and there is no significant correlation-ship between clinical effect parameter and sagittal view parameter.

Influence of positional relationship between the long axis of the mandibular anterior teeth and the alveolar bone on the treatment design of dental implants / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed at investigating and measuring the positional relationship between the long axis of the mandibular anterior teeth and the alveolar bone using cone beam computed tomography (CBCT) to provide reference data for implant treatment.</p><p><b>METHODS</b>From the CBCT image database, 150 cases of radiographic data were selected according to the inclusion criteria and then were divided into six groups: males' mandibular central incisors, males' mandibular lateral incisors, males' mandibular canines, females' mandibular central incisors, females' mandibular lateral incisors, and females' mandibular canines. The angle (β) formed by the long axis of the mandibular anterior teeth and the corresponding alveolar bone was measured and recorded. Based on the long axis of alveolar bone, if the teeth incline to the lingual side, the value of the angle (β) was positive; otherwise, the value was negative. The resultant data were analyzed by SPSS 19.0.</p><p><b>RESULTS</b>The β of the mandibular central incisors presented a mean value of 4.77° (range: -8.17°-16.10°) for male subjects and 5.38° (range: -5.63°-12.93°) for female subjects. The β of the mandibular lateral incisors exhibited a mean value of 6.12° (range: -2.87°-
17.57°) for male subjects and 5.81° (range: -7.70°-15.70°) for female subjects. Finally, the β of the mandibular canines presented a mean value of 5.01° (range: -8.13°-17.67°) for male subjects and 6.21° (range: -7.70°-17.87°) for female subjects. The percentages of the β between -10° and 10° of males' mandibular incisors, mandibular lateral incisors, and mandibular canines were 87.34%, 80.67%, and 88.00%, respectively and those of females were 90.67%, 82.66%, and 82.66%, respectively. Whether male or female, the percentages of the β between -10° and 10° of the mandibular anterior teeth were more than 80%. The β that inclined to the lingual was not more than 20° and to the labial did not exceed 10°.</p><p><b>CONCLUSIONS</b>The long axis of the mandibular anterior teeth was almost consistent with the long axis of the alveolar bone. Therefore, the positional relationship could be referred to make reasonable implants treatment plan.</p>

Evaluation of three methods for constructing craniofacial mid-sagittal plane based on the cone beam computed tomography / 北京大学学报(医学版)

Objective:To compare the accuracyof interactive closet point (ICP)algorithm,Procrustes analysis (PA)algorithm,andalandmark-independent method to construct the mid-sagittal plane (MSP)of the cone beam computed tomography.To provide theoretical basis for establishing coordinate systemof CBCT images and symmetric analysis.Methods:Ten patients were selected and scanned by CBCT before orthodontic treatment.The scan data was imported into Mimics 10.0 to reconstructthree dimensional skulls.And the MSP of each skull was generated by ICP algorithm,PA algorithm and landmark-independ-ent method.MSP extracted by ICP algorithm or PA algorithm involvedthree steps.First,the 3D skull processing was performed by reverse engineering software geomagic studio 2012 to obtain the mirror skull. Then,the original and its mirror skull was registered separately by ICP algorithm in geomagic studio 2012 and PA algorithm in NX Imageware 1 1 .0.Finally,the registered data were united into new data to calcu-late the MSP of the originaldata in geomagic studio 2012.The mid-sagittal plane was determined by SEL-LA (S),nasion (N),basion (Ba)as traditional landmark-dependent methodconducted in software InVivoDental 5.0.The distance from 9 pairs of symmetric anatomical marked points to three sagittal plane were measured and calculated to compare the differences of the absolute value.The one-way ANOVA test was used to analyze the variable differences among the 3 MSPs.The pairwise comparison was performed with LSD method.Results:MSPs calculated by the three methods were available for clinic analysis,which could be concluded from the front view.However,there was significant differences among the distances from the 9 pairs of symmetric anatomical marked points to the MSPs (F=10.932,P=0.001).LSD test showed there was no significant difference between the ICP algorithm and landmark-independent method (P=0.1 1 ),while there was significant difference between the PA algorithm and landmark-independent methods (P =0.01 ).Conclusion:Mid-sagittal plane of 3D skulls could be generated base on ICP algorithm or PA algorithm.There was no significant difference between the ICP algorithm and landmark-independent method.For the subjects with no evident asymmetry,ICP algorithm is feasible in clinical analysis.

Application study of an intelligent three-dimensional ultrasound imaging in obtaining for fetal cranial mid-sagittal view / 中华超声影像学杂志

Objective To evaluate the feasibility of an intelligent three-dimensional ultrasound technique (Smart mid-sagittal planes,Smart MSP) in automatically detecting the fetal cranial mid-sagittal view.Methods Two hundred and forty pregnant women with singleton pregnancies were imaged to display the mid-sagittal view of fetal head using the Smart MSP by six doctors divided into three groups according the different experiences.Another two doctors were then invited to score the images acquired and to compare the successful rates of 6 doctors for acquiring fetal cranial mild-sagittal view according to the doctors' experience.Results The overall successful rate of acquiring the mid-sagittal view was 97.08％ (233/240) with the bipartial diameter plane (BPD plane) as the starting plane and 98.33(237/240) with the trans-cerebellum plane as the starting plane by using Smart MSP program.The successful rates in three groups were similar but the consumed times were different(P ＜0.05).The experienced doctors consumed less time than non-experienced doctors.The scores were also different in three groups.The scores of experienced doctors (group B and C) were significantly higher than that of non-experienced doctors (Group A) (P ＜0.05).There was no significant difference in the scores between experienced doctors (group B and C) (P＞0.05).Conclusions Smart MSP is a novel and feasible method for the automatic visualization of fetal cranial mid-sagittal plane,which may become an effective tool to screen the fetal midline anomalies in future.

Accurate rebuilding of sagittal plane radian measure for treatment of thoracolumbar vertebrate fracture: A comparative study / 第二军医大学学报

Objective To conduct a comparative study on the middle- and long-term efficacies of individualized titanium stick angular designs for treating thoracolumbar vertebrate fractures. Methods A total of 96 patients were divided into two groups,with 50 in the treatment group and 46 in the control group. The titanium stick in the treatment group was folded based on the numerical value which had been obtained by measuring and calculating the standard lateral projection of thoracolumbar vertebrate before the operation; the numerical value on sagittal plane was the sum of the average angle of its upper and subtus athletic segment, the angulation of subtus athletic segment and the angle of subtus vertebral body. The titanium stick in the control group was folded based on experience during the operation, with other treatments being the same. The patients were followed-up for at least 6 months, with an average of (18±5) months. All the patients received radiography examination pre- and post-operatively. And 42 patients received CT examination before and at the last follow-up; another 30 patients received MRI examination at last follow-up. Results At the final follow-up, the anterior, posterior vertebral heights were (1.06±0.46) mm and (0.42±0.26) mm for the treatment group and (2.37±0.86) mm (P<0.05) and (0.79±0.46) mm for the control group, respectively. The average loss of Cobb angle was (1.57±0.51)° in the treatment group and (2.49±0.89)° in the control group at final follow-up (P<0.05). The treatment group had 21 cases with fish tail and the control group had 25. The failure rate of internal fixation was 6% in the treatment group and 13% in the control group. The eggshell phenomenon on CT findings was found in 10 of the 22 patients in the treatment group and in 9 of the 20 cases in the control group at final follow-up. The neurological status was improved at least by 1 Frankel grade in the patients who had preoperative incomplete paraplegia. The scores of Oswestry Disability Questionnaire for the treatment group were: 0 in 17 cases, 2 in 15 cases, 4 in 11 cases, 6 in 2 cases, 8 in 2 cases, 56 in 1 case,80 in 1 case, and 88 in 1 case; for the control group were 0 in 10 cases, 4 in 15 cases, 6 in 11 cases, 8 in 2 cases, 10 in 2 cases,18 in 2 cases, 50 in 2 cases, and 80 in 2 cases. There were significant differente between the two groups (34% vs 21.74%, P<0.05). Conclusion When transpedicle vertebral arch internal fixation system is used for treatment of thoracolumbar vertebrae fractures via posterior approach, individualized titanium stick angular design can accurately regain the physiologic curve of the fixed thoracolumbar segment,reducing operational time,loss of vertebral height correction, failure rate of internal fixation, incidence of backache, and degeneration of adjacent segment.

Measurement of the Weight-bearing Standing Coronal and Sagittal Axial Alignment of Lower Extremity in Young Korean Adults / 대한정형외과학회잡지

PURPOSE: The aim of this study was to establish a measurement standard for the weight-bearing axial alignment of the lower extremities when performing a lower extremity reconstruction. MATERIALS AND METHODS: Among 274 patients (147 males and 127 females) in their 20s to 30s without any physical disabilities, and who had undergone weight-bearing full leg standing radiographs, 188 patients (100 males and 88 females) were examined this study. The data was analyzed further according to their age and gender using the radiographic value on the coronal and sagittal alignment of the lower extremities. RESULTS: The weight bearing ratio was 38.47+/-10.52% on the coronal plane and 36.11+/-7.88% on the sagittal plane. Both the mechanical axis and the the weight bearing axis were not identical due to their 0.68+/-0.89degrees difference on average. The most adjacent point of the femoral condyles to the tibial plateau on the sagittal plane was assigned to the center of the knee joint. The difference between the mechanical axis and weight bearing axis was 0.04degrees, which was not significant. CONCLUSION: There is a difference between the mechanical axis, which consists of both a line from the center of the femoral head to the center of knee joint and a line from the center of the knee joint to the center of ankle joint, and the weight bearing axis, which is linked directly from the center of the femoral head to the center of the ankle joint. Furthermore, the weight bearing axis passes through the anteromedial part in the knee joint. The center of the knee joint is defined as the most adjacent point of both femoral condyle to the tibial plateau on the sagittal plane.

Radiologic Analysis of Postoperative Sagittal Plane Correction in Lumbar Degenerative Kyphosis (LDK) / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study OBJECTIVES: We radiologically analyzed the correction of the sagittal imbalance and the proximal fusion level to prevent correction loss and the usefulness of iliac screws in LDK. SUMMARY OF THE LITERATURE REVIEW: Complications can be encountered during fixation and fusion as most of the LDK patients are aged, and the osteoporosis that causes fixation loss is known to affect the loss of correction. MATERIALS AND METHODS: We analyzed the cause of correction loss among 35 patients who underwent surgery and who were followed up for at least 1 year. All the patients had performed gait analysis before operation. The operative techniques were pedicle subtraction osteotomy and fixation to S1. For analyzing causes of correction loss, we analyzed the degrees of lumbar lordosis for the sagittal correction and the degrees of the preoperative thoracolumbar kyphosis for the proximal fusion range. For analyzing the usefulness of iliac screws, the subjects were divided into two groups: 1) the -iliac screw (23cases) group for the patients who were fixed without iliac screws and 2) the +iliac screw (12cases) group for the patients who were fixed with iliac screws. RESULTS: There were no patients who had marked anterior pelvic tilt. It is important to correct the lumbar lordosis over 20degrees compared with the preoperative thoracic kyphosis. There are 10 cases of preoperative thoracolumbar kyphosis > or = 10degrees and 25 cases of preoperative thoracolumbar kyphosis or = 10degrees, 4 cases that were fixed to T10 had no sagittal correction loss, and 2 of the 6 cases that were fixed to T11 or T12 had sagittal correction loss. For the 25 cases of preoperative thoracolumbar kyphosis < 10degrees, 5 cases that were fixed to T10 had no sagittal correction loss and 1 of the 20 cases that were fixed to T11 or T12 had sagittal correction loss (p<0.05). 6 cases (26%) in the -iliac screw group (23 cases total) and 1 case (8%) in the +iliac screw (12 cases total) showed sagittal correction loss (p<0.05). CONCLUSIONS: It is important to make the postoperative lumbar lordosis over 20degrees compared with the preoperative thoracic kyphosis for correcting sagittal imbalance, to decide on the proximal fixation level according to the preoperative thoracolumbar kyphosis and to fix with iliac screws.

Sagittal Plane Lumbar Responses after Anterior Selective Thoracic Fusion for Main Thoracic Adolescent Idiopathic Scoliosis

STUDY DESIGN: A retrospective radiographic study. PURPOSE: To verify the correlation of sagittal and coronal plane changes after selective thoracic fusion in main thoracic (MT) adolescent idiopathic scoliosis (AIS). OVERVIEW OF LITERATURE: Sagittal plane deformity is known to be essential in the evolution of scoliosis. METHODS: Twenty-eight MT AIS patients treated by anterior selective thoracic fusion were evaluated after minimal follow-up of two years. The unfused lumbar area was divided into proximal and distal parts by the lumbar apex in the coronal plane, and into proximal and distal lumbar lordosis by L2 in the sagittal plane. Surgical motion (the difference between preoperative and postoperative values) and follow-up motion (the difference between postoperative and the last follow-up values) were compared. RESULTS: Immediately after surgery, as thoracic kyphosis increased, lumbar lordosis decreased (r=0.734); proximal lumbar lordosis increased, and distal lumbar lordosis decreased. The proximal lumbar area was mobilized in the sagittal plane, and was straightened in the coronal plane. However, the distal lumbar area was stabilized in the sagittal plane, and showed resistant motion against MT translation in the coronal plane. The surgical motion was correlated to the follow-up motion, i. e., was regulated during follow-up, and the regulatory motion was more precise in the distal than proximal lumbar area in both sagittal and coronal planes. CONCLUSIONS: Sagittal and coronal motions were co-related; optimal sagittal motions were necessary for optimal coronal motions after anterior selective thoracic fusion for MT AIS. Proximal and distal lumbar motions were different for different roles; the proximal lumbar area played a role as a bumper to absorb the MT translatory force, and the distal lumbar area played a role of resistance against MT translation.

Radiographic study and clinical significance about sagittal plane curves in the adjacent segments of the thoracic and lumbar spine / 中国矫形外科杂志

[Objective]To study the anatomy about the sagittal plane curves of the adjacent segments of the thoracic and lumbar spine on the radiographs of standing position,in order to provide anatomical evidence for clinical operation. [Methods]Seventy-five standing posture radiographs about normal adult were obtained,the sagittal plane curves of the adjacent segments of the thoracic and lumbar spine were obtained by measuring the angles between perpendicular of adjacent superior end plate.The normal value and rule about sagiital plane curves were determined by statistical method.Fifty patients received operation according to these measures.The Cobb's angle of sagittal plane(T12-S1) at 0,3,12 months postoperatively,Denis scores at 12 months postoperatively and the cases in which breaking or loosening internal fixation occurred at 12 months postoperatively were recorded.[Results]The 95% confidence interval of about sagittal plane curves was obtained.There was no statistical significance for sex and age.It would improve function postoperatively and decrease the broken or loosened internal fixation.[Conclusion]It's important to recover the Cobb's angle in the short segmental internal fixation with pedicle screws through posterior approach.

Evaluation of Rotational Displacement of the Posterior Facet on the Sagittal Plane in Computed Tomographic Images of Calcaneal Fractures

PURPOSE: To find out whether or not the computed tomographic (CT) classification systems of the calcaneal fracture are efficient in illuminating displaced posterior facet fragment and the degree of displacement can be evaluated by analyzing serial CT images. MATERIALS AND METHODS: Seventy-seven hundred calcaneal fractures were classified by CT classification systems including Sanders classification, and the sagittal rotation angle of the posteior facet fragment was measured on the plain lateral radiograph. Among the serial axial CT images, a number of images with the cortical bone embedded in the cancellous portion were recorded and any significant relationship between each data were evaluated. RESULTS: The conventional CT classification systems are rather insufficient in illuminating the extent of sagittal rotatory displacement. However, the number of CT images in which the cortical radiodensity was observed showed a significantly related with the degree of displacement. CONCLUSION: The conventional CT classification of the calcaneal fractures is unsatisfactory in expressing the degree of sagittal rotatory displacement of the posterior facet fragment; this problem may be alleviated by observing the number of axial CT images in which cortical radiodensity was revealed within the calcaneal body.

Analysis of Radiologic Factors Affecting Longterm Surgical Results of Anterior Cervical Fusion Patients

OBJECTIVE: Anterior cervical discectomy and fusion is accepted as appropriate surgical intervention for disease processes of the ventral cervical spine. In some cases, however, improvement of symptom following operation develop myelopathy or rhizopathy at longterm follow-up. We studied to clarify the correlation between clinical results and plain radiologic findings at long term follow-up. METHODS: A total of 86 patients who underwent anterior cervical discectomy and fusion were grouped into deteriorated and good recovery group. These two groups were compared in lateral functional roentgenograms on the cervical kyphosis and disc height at fused level, sagittal plane rotation and dynamic sagittal canal diameter at adjacent level. RESULTS: The presence of cervical kyphosis and disc height at fused level do not correlate with long term follow-up results. Sagittal plane rotation of more than 20 degrees were identified in 36% of the cases in deteriorated group, whereas the same findings were identified in 15% of the cases in good group. Sagittal diameter of less than 12mm were identified in 48% of the cases in deteriorated group, whereas the same finding were identified in 8% of the cases in good group. Preoperatively, sagittal plane rotation of more than 20 degrees at adjacent level were identified in 28% of the cases in deteriorated group, whereas the same findings were identified in 13% of the cases in good group. Preoperatively sagittal diameter of less than 12mm at adjacent level were identified in 40% of the cases in deteriorated group, whereas the same finding were identified in 7% of the cases in good group. CONCLUSION: Large sagittal plane rotation and small dynamic sagittal diameter at adjacent level were factors that might be associated with later clinical deterioration after cervical anterior fusion.

A computerized tomographic study on the structure of the mandibular ramus

0.05).2. On horizontal section, The distance between the inferior alveolar canal and the lateral cortical plate of the mandibular ramus were 6.73+/-1.24mm minum, 7.70+/-1.44mm maximum.3. On coronal section, Outer mandibular angle were 4.84+/-2.37degrees right side, 4.93+/-2.12degrees left side.4. The design of the ideal true sagittal split ramus osteotomy is that posterior border of osteotomy must be limited vertically, at the right posterior point of lingula mandibularis and anterior border of osteotomy must be extended to mandibular body, anteroinferiorly.