OBJECTIVE: To assess the osteogenesis height in maxillary sinus segment one year after zygomatic implantation by imaging methods, and evaluate the influence of patient factors, maxillary sinus anatomical factors and surgical factors on postoperative osteogenesis height. METHODS: This study is a retrospective study, including patients who underwent zygomatic implantation and whose zygomatic implants passed through the maxillary sinus at the Department of Implantology, Peking University School and Hospital of Stomatology from July 2017 to January 2022. Preoperative and postoperative cone beam CT (CBCT)was taken to measure and calculate the average osteogenesis height (AOH) in maxillary sinus segment of the zygomatic implants, then the residual bone height, the width and morphology of the maxillary sinus floor in the buccal and palatal directions were measured. Besides, the integrity of Schneiderian membrane during implant surgery, and the general information of the patients and zygomatic implants were recorded. By comparing anatomical situations and surgical characteristics, the differences of AOH under different conditions were analyzed. Then AOH was divided into two groups (obvious osteogenesis group and non-obvious osteogenesis group) using the median as the threshold, and the influencing factors of osteogenesis were evaluated using mixed effect generalized linear model univariable and multivariable analysis. RESULTS: A total of 47 zygomatic implants were implanted in 24 patients. During the average follow-up period of 12.1 months, there was no implant failure, and the implant survival rate was 100%. Postoperative CBCT showed that 43 zygomatic implants had osteogenic images in the maxillary sinus segment, most of which originated from the floor of the maxillary sinus, and the median AOH was 3.1 mm [interquartile range (IQR): 4.0 mm]. In terms of maxillary sinus width, there were 31 cases (66.0%) of wide type and 16 cases (34.0%) of narrow type. In the aspect of buccal and palatal morphology, 17 cases were taper (36.2%), 20 cases were round (42.6%), and 10 cases were flat (21.3%). The median of residual bone height was 2.8 mm (IQR: 2.2 mm) before operation. Univa-riate analysis of mixed effect generalized linear model showed that postoperative obvious osteogenic rate was related to the residual bone height (OR=2.09, P=0.006). Multivariate analysis showed that the resi-dual bone height (OR=2.55, P=0.022) and the shape of a taper maxillary sinus (OR=11.44, P=0.040) had a significant impact on the postoperative obvious osteogenic rate. CONCLUSION The maxillary sinus floor showed osteogenic images 1 year after the zygomatic implantation surgery. Larger residual bone height and the shape of a taper maxillary sinus may be favorable factors for osteogenesis.
Humans ; Maxillary Sinus/surgery* ; Cone-Beam Computed Tomography ; Retrospective Studies ; Zygoma/diagnostic imaging* ; Male ; Female ; Osteogenesis/physiology* ; Middle Aged ; Adult ; Dental Implants ; Aged ; Dental Implantation, Endosseous/methods*

OBJECTIVEA study was conducted to investigate the relevant applied technique and clinical value of endoscope-assisted repair of zygomatic arch fracture.

METHODSA total of 10 cases of unilateral zygomatic arch fracture and 8 cases ofunilateral zygomatic fracture were included. Reduction and fixation of the zygomatic arch in all cases were performed via asmall face incision by an endoscope. Endoscope-assisted repair allowed exposure of zygomatic arch fracture and ended the anatomy of the reset. Zygomatic arch was stabilized with titanium plates.

RESULTSSymmetric malar was achieved in allcases after operation. Patients did not show difficulty in opening the mouth. No chewing problems or severe complicationswere evident. This method had the advantage of hidden incision, and it did not leave scars on the face. Postoperative CT examination showed excellent reduction of zygomatic arch fracture and good fixed position of titanium plate.

CONCLUSIONEndoscope-assisted repair of zygomatic arch fracture via a small face incision can be an alternative operation for zygomaticarch fracture. Patients are less traumatized. There are fewer complications. A good reduction of fracture is achieved.

Bone Plates ; Endoscopes ; Endoscopy ; methods ; Facial Bones ; Fracture Fixation, Internal ; methods ; Fractures, Closed ; surgery ; Humans ; Titanium ; Tomography, X-Ray Computed ; Treatment Outcome ; Wound Healing ; Zygoma ; injuries ; Zygomatic Fractures ; diagnostic imaging ; surgery

OBJECTIVEThis research aimed to analyze the three-dimensional position of mandibular canal (MC) and man of MC and its relationship with the surrounding structures dibular morphology of normal young males and females by using data from cone beam computed tomography (CBCT), as well as to provide an anatomical basis for clinical surgery of the mandible.

METHODSNormal occlusion and CBCT scans of 29 normal young people were conducted. InVivo 5 software was used to reconstruct the mandible, anchor the points, and measure the jaw shape and three-dimensional course of MC. All measurements were analyzed with SSPS 17.0 software.

RESULTSThe MC lingual bone cortex was thinner than the MC buccal bone cortex, and the distance of the MC to the buccal bone cortex gradually increased. However, the distance of the MC to the tongue bone cortex and alveolar crest gradually decreased from proximal to distal. In addition, the distance of the MC to the mandibular lower margin was minimal at the first molar and reached the maximum at the second premolar. No significant difference was observed among the heights, widths, and thicknesses of the left and right sides of the cortical bone of the mandibular body cross sections. From the midline to the farthest point, the height and lower one-third thickness of the lingual cortical bone of the mandibular body cross sections gradually decreased, whereas the width of the upper cross section and upper one-third thickness of the buccal cortical bone gradually increased. Significant difference was observed in some measured values.

CONCLUSIONAfter MC enter into the mandibular foramen, it moved away from the lingual to the buccal bone but gradually returned to the lingual bone; its general course is closer to the lingual bone. The mandibles of males are thicker than those of females. CBCT can accurately display the course of MC and its relationship with the surrounding structures.

Alveolar Process ; Bicuspid ; Cone-Beam Computed Tomography ; methods ; Dental Pulp Cavity ; Female ; Humans ; Hyoid Bone ; Male ; Mandible ; anatomy & histology ; diagnostic imaging ; Molar ; Software ; Surveys and Questionnaires ; Tongue ; Zygoma

OBJECTIVETo compare the efficacy of computer-navigated surgery and the 3-D skull models and guide plates for the treatment of unilateral delayed zygomatic fractures.

METHODSEleven patients with unilateral delayed zygomatic fractures were treated by computer-navigated surgery (test group) and another 12 patients were treated by 3-D skull models and guide plates as the control group. Quality of reduction was assessed by examination of postoperative axial CT scans through zygomatic arch, the malar prominence and the width of zygomatic arch were measured in both groups.

RESULTSThe difference between bilateral malar prominence was (0.94 ± 0.73) mm in the test group and (1.88 ± 1.82) mm in the control group, there was no significant difference between the two groups (P > 0.05). The difference between bilateral width of zygomatic arch was (0.77 ± 0.51) mm in the test group, less than (3.00 ± 1.81) mm in the control group (P < 0.05). Excessive malar prominence was observed in 6 cases (6/11) in the test group and in 7 cases (7/12) in the control group, whereas malar depression was observed in 5 cases (5/11) in the test group and in 5 cases (5/12) in the control group. Overcorrection of the width of zygomatic arch was observed in 6 cases (6/11) in the test group and in 12 cases (12/12) in the control group, whereas under correction was observed in 5 cases (5/11) in the test group and in 0 cases (0/12) in the control group.

CONCLUSIONSIn the treatment of unilateral delayed zygomatic fractures, symmetry of malar prominence can be achieved by application of computer-navigated surgery or the 3-D skull models and guide plates. Symmetry of the width of zygomatic arch achieved with the computer-navigated surgery is better than that achieved with 3-D skull models and guide plates.

Adult ; Female ; Fracture Fixation, Internal ; Humans ; Male ; Middle Aged ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; Young Adult ; Zygoma ; diagnostic imaging ; surgery ; Zygomatic Fractures ; diagnostic imaging ; surgery

OBJECTIVETo establish the quantitative diagnostic criteria for cranio-orbito-zygomatic deformity (COZD).

METHODSComputer-assisted three-dimensional (3-D) CT measurement was performed in 30 cases with unilateral COZD. The differences of the measurement data between the affected and unaffected sides were analyzed. Then the patients were diagnosed and classified according to the affected bone, soft tissue and conjunctival sac. Based on the quantitative diagnosis, 8 patients underwent surgery to test the clinical practicability of the diagnostic criteria.

RESULTSThe quantitative diagnostic criteria for COZD could reflect the affected area and the corresponding severity of deformity. It helped to preoperative design and to predict movement of osteotomy segment and. the soft tissue volume needed for augmentation. Good postoperative results were achieved.

CONCLUSIONSThe quantitative diagnostic criteria for COZD can describe the affect area and severity of deformity in detail. It is very practical in the guidance of clinical treatment.

Adolescent ; Adult ; Bone Diseases, Developmental ; diagnostic imaging ; Child ; Diagnosis, Computer-Assisted ; standards ; Humans ; Imaging, Three-Dimensional ; Male ; Orbit ; abnormalities ; Tomography, X-Ray Computed ; methods ; Young Adult ; Zygoma ; abnormalities

PURPOSE: Malignant fibrous histiocytoma (MFH) is mainly a soft tissue sarcoma containing fibroblast-like cells and histiocytic cells. MFH in bone accounts for 5% of all malignant bone tumors. MFH of the maxilla is extremely rare and difficult to diagnose due to its scarcity. Treatment mainstay is a complete surgical excision. Radiation therapy is also available when surgery alone is incomplete. Prognosis is not clear but can be devastating. Authors report one case of MFH developed in the maxilla. METHODS: A 24-year-old man firstly diagnosed as fibrous dysplasia based on CT findings. Considering facial contour, partial excision was done. But pathology report confirmed malignant fibrous histiocytoma and secondary wide excision was done including zygoma and grossly all affected area. After surgery, radiation therapy was continued. RESULTS: There are no evidence of tumor recurrence after clinical and radiological treatment. CONCLUSION: MFH of maxilla is very rare and this can leads to misdiagnosis in many clinicians. Surgeon should differentiate this disease from fibrous dysplasia and pathology and MRI are accurate methods for diagnosis of MFH.
Diagnosis ; Diagnostic Errors ; Facial Bones ; Histiocytoma, Malignant Fibrous* ; Humans ; Magnetic Resonance Imaging ; Maxilla* ; Pathology ; Prognosis ; Recurrence ; Sarcoma ; Young Adult ; Zygoma

OBJECTIVE: To explore the methods for sex determination on head CT film. METHODS: To establish the sex determination equations by binary regression analysis of cranial skeletal indices obtained on head CT film. RESULTS: A single element equation by applying the index of the width of ansa capitis and a multi-element equation by applying multitude indices were established. CONCLUSION The equations for sex determination on head CT film were established.
Adult ; Aged ; Aged, 80 and over ; Algorithms ; Facial Bones/anatomy & histology* ; Female ; Forensic Anthropology ; Head/diagnostic imaging* ; Humans ; Logistic Models ; Male ; Middle Aged ; ROC Curve ; Sex Determination by Skeleton/methods* ; Tomography, X-Ray Computed/methods* ; Zygoma/anatomy & histology*

OBJECTIVETo discuss the technique of installation of zygomatic implants in severely resorbed edentulous maxillae, and maxillary defect.

METHODSFive patients received 8 zygoma implants and 11 dental implants. On the basis of an axial spiral CT data, anatomical models of natural size were manufactured using CAD/CAM system and before operation preoperative measurements of relevant parameters (length, areas, and volumes) carried out. Theses maxillary and zygomatic measurements obtained were referred for installing zygomatic implants.

RESULTSThe ideal direction and position of installation of the 8 zygomatic fixtures were obtained in 5 patients. The anatomical model and surgical plate were used for preoperative planning and intraoperative control of the insertion of zygomatic fixtures. The implants could be positioned precisely as preoperatively planned. The length of the zygomatic implants was between 40 mm and 50 mm.

CONCLUSIONSThe use of surgical drilling guides should be encouraged for zygomatic implant placement. 3-D image data and anatomical models improves preoperative planning and facilitates clinical procedure.

Adult ; Alveolar Bone Loss ; diagnostic imaging ; surgery ; Dental Implantation, Endosseous ; methods ; Dental Implants ; Female ; Humans ; Male ; Maxilla ; diagnostic imaging ; injuries ; surgery ; Middle Aged ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; Zygoma ; diagnostic imaging ; surgery

OBJECTIVETo provide objective data for position and orientation of zygomatic-area implant used in zygo-buccal flange osseointegrated implant obturator for patients with large maxillary defect.

METHODSFifty cases of normal unilateral zygomatic body with dentition were measured on three-dimensional spiral CT images. Measurements included the slope angle of zygomatic body on sagittal sectional image, the maximal horizontal distance from the buccal boundary of maxillary alveolar to outboard of maxillary sinus. Furthermore, the configuration of zygomatic body was observed on coronal sectional image.

RESULTSThe average rearward slope angle of zygomatic-body was 80.03 degrees. Forty-eight cases showed straight zygomatic-body configurations and two cases quite curvy. The maximal horizontal distance from the buccal boundary of maxillary alveolar to outboard of maxillary sinus was 6.77 mm.

CONCLUSIONSIn a normal condition, implants can be upright inserted tilting about 10 degrees ahead to utilize much zygomatic bone-volume in high site. In order to improve security and validity of implantation, it is better to take spiral CT examination to evaluate the bone volume and shape of zygomatic body before zygomatic-area implant.

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Maxillofacial Prosthesis Implantation ; methods ; Middle Aged ; Tomography, Spiral Computed ; Young Adult ; Zygoma ; diagnostic imaging ; surgery