Large defects of jaw caused by tumor, trauma and so on in oral and maxillofacial region lead to facial deformity, language and chewing dysfunction, which severely damage the patient’s life quality. Three-dimensional printing (3DP) is also named additive manufacturing (AM), which can print materials layer by layer to create three-dimensional objects. The complex shape of jaw defects can be accurately reconstructed using 3DP scaffold combined with image data, computer-aided-design and manufacture. It has specific advantages compared with traditional way of jaw reconstruction and has attracted much attention in the field of jaw tissue engineering recently. This article presented the progress of 3DP scaffold and its application in jaw reconstruction, providing a new idea for jaw reconstruction.
Three-dimensional (3D) bio-printing is a novel engineering technique by which the cells and support materials can be manufactured to a complex 3D structure. Compared with other 3D printing methods, 3D bio-printing should pay more attention to the biocompatible environment of the printing methods and the materials. Aimed at studying the feature of the 3D bio-printing, this paper mainly focuses on the current research state of 3D bio-printing, with the techniques and materials of the bio-printing especially emphasized. To introduce current printing methods, the inkjet method, extrusion method, stereolithography skill and laser-assisted technique are described. The printing precision, process, requirements and influence of all the techniques on cell status are compared. For introduction of the printing materials, the cross-link, biocompatibility and applications of common bio-printing materials are reviewed and compared. Most of the 3D bio-printing studies are being remained at the experimental stage up to now, so the review of 3D bio-printing could improve this technique for practical use, and it could also contribute to the further development of 3D bio-printing.
Objective To investigate the effectiveness of using 3 hollow compression screws combined with 1 screw off-axis fixation under the guidance of three-dimensional (3D) printed guide plate with mortise-tenon joint structure (mortise-tenon joint plate) for the treatment of Pauwels type Ⅲ femoral neck fractures. Methods A clinical data of 78 patients with Pauwels type Ⅲ femoral neck fractures, who were admitted between August 2022 and August 2023 and met the selection criteria, was retrospectively analyzed. The operations were assisted with mortise-tenon joint plates in 26 cases (mortise-tenon joint plate group) and traditional guide plates in 28 cases (traditional plate group), and without guide plates in 24 cases (control group). There was no significant difference in the baseline data of gender, age, body mass index, cause of injury, and fracture side between groups (P>0.05). The operation time, intraoperative blood loss, frequency of intraoperative fluoroscopy, incision length, incidence of postoperative deep vein thrombosis of lower extremity, pain visual analogue scale (VAS) score at 1 week after operation, and Harris score of hip joint at 3 months after operation were recorded and compared. X-ray re-examination was taken to check the quality of fracture reduction, fracture healing, and the shortening length of the femoral neck at 3 months after operation, and the incidences of internal fixation failure and osteonecrosis of the femoral head during operation. Results Compared with the control group, the operation time, intraoperative blood loss, and frequency of intraoperative fluoroscopy reduced in the two plate groups, and the quality of fracture reduction was better, but the incision was longer, and the differences were significant (P<0.05). The operation time and intraoperative blood loss were significantly higher in the traditional plate group than in the mortise-tenon joint plate group (P<0.05), the incision was significantly longer (P<0.05); and the difference in fracture reduction quality and the frequency of intraoperative fluoroscopy was not significant between two plate groups (P>0.05). There was 1 case of deep vein thrombosis of lower extremity in the traditional plate group and 1 case in the control group, while there was no thrombosis in the mortise-tenon joint plate group. There was no significant difference in the incidence between groups (P>0.05). All patients were followed up 12-15 months (mean, 13 months). There was no significant difference in VAS score at 1 week and Harris score at 3 months between groups (P>0.05). Compared with the control group, the fracture healing time and the length of femoral neck shortening at 3 months after operation were significantly shorter in the two plate groups (P<0.05). There was no significant difference between the two plate groups (P>0.05). There was no significant difference in the incidences of non-union fractures, osteonecrosis of the femoral head, or internal fixation failure between groups (P>0.05). Conclusion For Pauwels type Ⅲ femoral neck fractures, the use of 3D printed guide plate assisted reduction and fixation can shorten the fracture healing time, reduce the incidence of postoperative complications, and be more conducive to the early functional exercise of the affected limb. Compared with the traditional guide plate, the mortise-tenon joint plate can reduce the intraoperative bleeding and shorten the operation time.
ObjectiveTo observe and compare the effects of peptides on the repair of rabbit skull defects through two different binding modes of non-covalent and covalent, and the combination of carboxyl (-COOH) and amino (-NH2) groups with materials.MethodsTwenty-one 3-month-old male ordinary New Zealand white rabbits were numbered 1 to 42 on the left and right parietal bones. They were divided into 5 groups using a random number table, the control group (group A, 6 sides) and the material group 1, 2, 3, 4 (respectively group B, C, D, E, 9 sides in each group). All animals were prepared with 12-mm-diameter skull defect models, and bone morphogenetic protein 2 (BMP-2) non-covalently bound multiwalled carbon nanotubes (MWCNT)-COOH+poly (L-lactide) (PLLA), BMP-2 non-covalently bound MWCNT-NH2+PLLA, BMP-2 covalently bound MWCNT-COOH+PLLA, and BMP-2 covalently bound MWCNT-NH2+PLLA were implanted into the defects of groups B, C, D, and E, respectively. At 4, 8, and 12 weeks after operation, the samples were taken for CT scanning and three-dimensional reconstruction, the ratio of bone tissue regeneration volume to total volume and bone mineral density were measured, and the histological observation of HE staining and Masson trichrome staining were performed to quantitatively analyze the volume ratio of new bone tissue.ResultsCT scanning and three-dimensional reconstruction showed that with the extension of time, the defects in groups A-E were filled gradually, and the defect in group E was completely filled at 12 weeks after operation. HE staining and Masson trichrome staining showed that the volume of new bone tissue in each group gradually increased with time, and regenerated mature bone tissue appeared in groups D and E at 12 weeks after operation. Quantitative analysis showed that at 4, 8, and 12 weeks after operation, the ratio of bone tissue regeneration volume to total volume, bone mineral density, and the volume ratio of new bone tissue increased gradually over time; and at each time point, the above indexes increased gradually from group A to group E, and the differences between groups were significant (P<0.05).ConclusionThrough covalent binding and using -NH2 to bound peptides with materials, the best bone repair effect can be achieved.
ObjectiveTo preliminary study on the feasibility of constructing three-dimensional (3D) hippocampal neural network in vitro by using microfluidic technology.MethodsA network patterned microfluidic chip was designed and fabricated by standard wet etching process. The primary hippocampal neurons of neonatal Sprague Dawley rats were isolated and cultured, and then inoculated on microfluidic chip for culture. Immunofluorescence staining was used to observe the growth of hippocampal neurons at 3, 5, and 7 days of culture and electrophysiological detection of hippocampal neuron network at 7 days of culture.ResultsThe results showed that the number of hippocampal neurons increased gradually with the prolongation of culture time, and the neurite of neurons increased accordingly, and distributed uniformly and regularly in microfluidic chip channels, suggesting that the 3D hippocampal neuron network was successfully constructed in vitro. Single and multi-channel spontaneous firing signals of hippocampal neuronal networks could be detected at 7 days of culture, suggesting that neuronal networks had preliminary biological functions.ConclusionPatterned microfluidic chips can make hippocampal neurons grow along limited paths and form 3D neuron networks with corresponding biological functions such as signal transduction, which lays a foundation for further exploring the function of neuron networks in vitro.
Objective To compare the reduction qualities of three-dimensional visible technique without fluoroscopy and two-dimensional fluoroscopy for unstable pelvic fractures during operations. Methods The clinical data of 40 patients with unstable pelvic fractures, who met the selection criteria in three clinical centers between June 2021 and September 2022, were retrospectively analyzed. According to the reduction methods, the patients were divided into two groups. Twenty patients in trial group were treated with unlocking closed reduction system combined with three-dimensional visible technique without fluoroscopy; 20 patients in control group with unlocking closed reduction system under two-dimensional fluoroscopy. There was no significant difference in the gender, age, injury mechanism, Tile type of fracture, Injury Severity Score (ISS), and the time between injury to operation between the two groups (P>0.05). The qualities of fracture reduction according to the Matta criteria, operative time, intraoperative blood loss, fracture reduction time, times of fluoroscopy, and System Usability Scale (SUS) score were recorded and compared. Results All operations were successfully completed in both groups. According to the Matta criteria, the qualities of fracture reduction were rated as excellent in 19 patients (95%) in trial group, which was better than that in the control group (13 cases, 65%), with a significant difference (χ2=3.906, P=0.048). The operative time and intraoperative blood loss had no significant differences between the two groups (P>0.05). The fracture reduction time and times of fluoroscopy were significantly less in trial group than in control group (P<0.05), and SUS score in trial group was significantly higher in trial group than in control group (P<0.05). ConclusionCompared to using unlocking closed reduction system under two-dimensional fluoroscopy, three-dimensional visible technique without fluoroscopy can significantly improve the reduction quality of unstable pelvic fractures without prolonging the operative time, and is valuable to reduce iatrogenic radiation exposure for patients and medical workers.
Objective To analyze the technical notes, effectiveness, and current issues of real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion. Methods Between April 2020 and October 2021, a total of 27 patients received real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion. There were 18 males and 9 females with an average age of 63.2 years (range, 48-84 years). There were 6 cases of lumbar spinal stenosis, 1 case of lumbar instability, 9 cases of lumbar spinal stenosis with instability, 3 cases of degenerative spondylolisthesis, 6 cases of isthmus spondylolisthesis, and 2 cases of recurrent lumbar disc herniation. All patients showed neurological symptoms before operation (ipsilateral symptom for 15 cases and bilateral symptom for 12 cases). The symptom duration was 1-300 months (median, 24 months). The operations were performed via transforaminal approach in 8 cases, trans-facet joint approach in 18 cases, and combined approaches in 1 case. A total of 32 levels were fused, including 23 single-level cases, 3 two-level cases, and 1 three-level case. Lumbar fusion segment was L2, 3 in 1 case, L3, 4 in 4 cases, L4, 5 in 20 cases, and L5, S1 in 7 cases. The operation time, intraoperative estimated blood loss (IEBL), and perioperative complications were recorded. The improvement of intervertebral space height at fusion level was measured, and the accuracy of percutaneous pedicle screw (PPS) and Cage placement was also evaluated based on CT images performed at 1 week postoperatively. Visual analogue scale (VAS) score for both low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and Oswestry disability index (ODI) were evaluated before operation, at 1 week postoperatively, and at last follow-up. Satisfaction to effectivenss were assessed by patients using modified MacNab criteria at last follow-up. Results The operation time was ranged from 255 to 805 minutes (mean, 424.9 minutes). IEBL was 150-290 mL (mean, 219.3 mL). All patients received follow-up with the duration from 4 to 22 months (mean, 12.4 months). At 1 week postoperatively and last follow-up, VAS scores of low back pain and leg pain, JOA score, and ODI were significantly improved when compared with those before operation (P<0.05). At last follow-up, the clinical indicators were similar in comparison with those at 1 week postoperatively (P>0.05). There were 26 patients and 1 patient who respectively ranked excellent and mild in terms of effectiveness according to the modified MacNab criteria, with the excellent and good rate of 96.3%. There was 1 patient who suffered from incomplete injury of L5 nerve root and partial neurological function recovered after 3-month conservative treatments. There were 118 implanted PPSs, and 116 of them were implanted under navigation. There were 33 Cages that were implanted under navigation. The accuracy of PPS and Cage placement was 99.1% and 97.0% respectively based on CT performed at 1 week postoperatively. The postoperative intervertebral space height was significantly increased in comparison with that before operation (P<0.05). During follow-up, mild Cage subsidence was observed in 1 patient, whereas no fixation loosing was found. Conclusion Real-time three-dimensional CT navigation-guided full-endoscopic lumbar interbody fusion has great safety and effectiveness with satisfactory preliminary clinical results. Design and further improvement of surgical equipment and instruments are expected to resolve the current technical difficulties.
ObjectiveTo investigate the changes of facial soft tissue before and after orthognathic surgery in patients with skeletal Class Ⅲ malocclusion.MethodsBetween August 2016 and April 2017, 30 patients with skeletal Class Ⅲ malocclusion who underwent maxillary LeFort Ⅰ osteotomy and sagittal split mandible osteotomy were selected as study subjects. Among them, 11 were male and 19 were female with an average age of 22.6 years (range, 18-35 years). Full head CT scan and facial soft tissue three-dimensional image scan were performed within 2 weeks before surgery and at 6 months after surgery. A three-dimensional facial image model was established using Artec Studio 11.0 and CMF Proplan 3.0 software to analyze the facial soft tissue changes before and after surgery. The soft tissue anatomical landmarks in each area of the face were measured and compared before and after surgery.ResultsThe area of facial soft tissue change after surgery was the maxillary nose and the lower jaw area, and the two sides did not exceed the vertical boundary of the outer canthus. After surgery, the horizontal points of bilateral alar bases and bilateral cheeks changed significantly (P<0.05). The sagittal points of subnasale, pronasale, bilateral alar bases, upper lip margin significantly forwarded (P<0.05); the sagittal points of the bilateral cheilions, lower lip margin, midpoint of chin-lip groove, pogonion, and menton significantly backwarded (P<0.05). The vertical points of the upper lip margin, bilateral cheilions, lower lip margin, bilateral cheeks, and bilateral inner canthus points significantly descended (P<0.05), and the vertical point of the menton significantly elevated (P<0.05). After surgery, the nasal column was significantly shortened, the upper lip got longer and the alar base widened when compared with those before surgery (P<0.05).ConclusionThe overall change of face after double jaw surgery is shorter and fuller, and the mandible of facial soft tissue change is larger than that of maxillary, which suggests that the postoperative facial changes should be taken into account in the surgical design.
ObjectiveTo investigate the effectiveness of three-dimensional (3D) navigation template in the adult cubitus varus osteotomy.MethodsBetween April 2013 and September 2015, 17 patients with cubitus varus were admitted. There were 6 males and 11 females, aged from 19 to 38 years, with an average age of 26.9 years. There were 10 cases of left elbow joints and 7 cases of right elbow joints. The disease duration was 9-30 years (mean, 18 years). Based on the preoperative X-ray film, the humerus-elbow-wrist (HEW) angle was (−13.2 ±3.3)°, the anteversion angle was (−10.5±2.3)°. The preoperative range of motion (ROM) of flexion was (127.3±7.3)° and ROM of extension was (−10.0±2.5)°. Based on the CT 3D reconstruction, the osteotomy navigation template was designed and printed by 3D printing technique. The cubitus varus osteotomy was assisted by 3D navigation template. The postoperative HEW angle, anteversion angle, and ROMs of the elbow joints of both sides were measured. The elbow function was evaluated based on the Oppenheim elbow function score at 1 year after operation.ResultsAll cubitus varus osteotomies succeeded with the assist of 3D navigation template. All incisions healed by first intention. All patients were followed up 12-15 months (mean, 13 months). X-ray films showed that all osteotomies healed after 9-12 weeks (mean, 11 weeks). At 1 year after operation, the HEW angle was (9.7±1.9)°, the anteversion angle was (20.7±4.3)°, the ROM was (2.6±3.5)° in extension and (139.2±4.8)° in flexion of affected side. The HEW angle, anteversion angle, and ROMs significantly increased compared with preoperative values (P<0.05). And there was no significant difference between affected and normal elbow joints (P>0.05). The elbow functions were excellent in 13 cases and good in 4 cases based on the Oppenheim elbow function score at 1 year after operation. There was no complication such as the nerve injury or osteomyositis of elbow joint during follow-up. ConclusionThe 3D navigation template can provide a personalized and precise osteotomy treatment for adult cubitus varus deformity and obtain a satisfactory effectiveness.
Objective To detect the value of three-dimensional (3D) ultrasound diagnosis in common ocular fundus diseases. Methods Two-dimensional (2D) images of 38 patients with common ocular fundus diseases were three-dimensionally reconstructed via 3D ultrasound workstation. The 3D images reflecting the ocular diseases were analyzed. Result In 38 patients with common ocular fundus diseases, there was vitreous hemorrhage in 16 patients, retinal detachment in 12, choroidal detachment in 5, and intraocular space occupying lesion in 5. Compared with the 2D images, 3D reconstructed images reflect the lesions more intuitionistically, displayed the relationship between the lesions and the peripheral tissues more clearly, and revealed the blood flow more specifically. During a scanning examination, 3D reconstructed technology provided the diagnostic information of section of X, Y and Z axises simultaneously which shortened the time of examination; the condition of any point of lesions and the relation between the lesion and the peripheral tissues could be gotten by the tools like cut and chop provided by 3D imaging software itself, which avoided detecting the same lesion with different angles and lays and proved the diagnostic efficacy. Conclusions 3D ultrasound diagnosis is better than 2D in diagnosis of vitreous, retina, choroid, and intraocular space occupying lesion. 3D ultrasound diagnosis is a complementarity for the 2D one, and the Z axis changes the former observational angles which may provide the new way of precise diagnosis. (Chin J Ocul Fundus Dis, 2005, 21: 381-383)