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 investigate the application of osteotomy template manufactured via 3D printing technique in bilateral sagittal split osteotomy (BSSO).

METHODSThe patient group consisted of 32 patients (17 males and 15 females) with mandibular hypoplasia who underwent a BSSO setback (Hunsuck modification; 64 splits). The mean age at the time of surgery was 23.5 years (range 1.9-35 years). All patients were scanned using cone beam computed tomography (CBCT) to create a 3D model of the mandibular, and the osteotomy template of the inner horizontal ramus of mandible bone incision was manufactured via 3D printing technique. All splits underwent operation with or without the osteotomy template by either a young doctor (attending doctor) or a doctor with extensive orthognathic surgery experience (chief doctor). The time it took to perform the mandible bone incision of the inner horizontal ramus of each group was recorded. Postoperative CBCT scan was performed, and the lingual split scale was used to assess the effect of the operation.

RESULTSPrimary healing of incisions was observed in all patients, and no serious complications occurred. The time it took to perform the mandible bone incision of the inner horizontal ramus was significantly different in the four groups (F=30.059, P<0.05), and it was longer in the group of the attending doctor without osteotomy template than in the other three groups (P<0.05). No significant difference was observed in the other groups (P>0.05). Although all splits (n=64) were performed according to the standardized protocol, only 59.38% (38/64) of the fracture lines run according to the Hunsuck's description. By contrast, only 21.88% (14/64) run through the mandibular canal and 18.75% (12/64) was split. The database was analyzed using crosstabs and via Fisher exact test. The split pattern was influenced by the application of an osteotomy template (P<0.05).

CONCLUSIONThe application of osteotomy template manufactured via 3D printing technique in BSSO was effective, which enabled the young doctor to complete the operation faster and with good results.

Cone-Beam Computed Tomography ; Female ; Humans ; Male ; Mandible ; Osteotomy, Sagittal Split Ramus ; Printing, Three-Dimensional

AIM: To investigate the neuroprotective effect of ginsenoside Rg1 on rats with ischemic stroke and to investigate its mechanism of action. METHODS: Eighty-four SPF-grade SD male rats at about 13 weeks of age were randomly divided into 7 groups (n=12): sham-operated group, model group, Rg1 low-dose group, Rg1 medium-dose group, Rg1 high-dose group, Epac1 agonist group, and Epac1 inhibitor group. The model group, Rg1 low, medium and high dose groups, Epac1 agonist group and Epac1 inhibitor group were all used to establish a permanent focal cerebral ischemia rat model. Rats in the Rg1 low, medium and high dose groups were treated with 60, 120 and 240 μmol/L Rg1 administered by gavage at a fixed time every morning. The rats in the Epac1 agonist and Epac1 inhibitor groups were administered intraperitoneally at a fixed time each morning with a concentration of 1.0×10

OBJECTIVE: This study aimed to investigate the application of an osteotomy template and a repositioning template manufactured by three-dimensional (3D) printing technique in maxillary LeFortⅠosteotomy. METHODS: The patient group consisted of eight patients with maxillary hypoplasia who underwent LeFortⅠosteotomy. The mean age at the time of surgery was 25.6 years old. All patients were scanned using cone beam computed tomography (CBCT) to create a 3D model of the maxillary. The osteotomy and repositioning templates of the LeFortⅠosteotomy were manufactured by 3D printing technique. All bones were cut by the same doctor with extensive orthognathic surgery experience. One part of the template guided the osteotomy, and the other repositioned the maxilla during operation. Postoperative CBCT scan was performed, and the virtual plan was compared with the postoperative surgical result using an image fusion of the CBCT dataset by analyzing measurements between six landmarks relative to three reference planes. Statistical analysis was performed, and accuracy was reported using SPSS 16.0 software package. RESULTS: Primary healing of incisions was observed in all patients, and no serious complications were observed. The maximum mean values were 1.35 mm, and the displacement error was UL6 to the coronal plane. The maximum standard deviation was 0.85, and the maximum standard error was 0.30, which was acceptable by clinical standards. CONCLUSIONS The application of osteotomy and repositioning templates manufactured by 3D printing technique in maxillary LeFortⅠosteotomy was safe and can enable doctors to complete a surgery accurately.
Adult ; Cone-Beam Computed Tomography ; Humans ; Imaging, Three-Dimensional ; Maxilla ; Orthognathic Surgical Procedures ; Printing, Three-Dimensional