ObjectiveTo establish a method to prefabricate titanium plate with three-dimensional (3-D) printing technique for correction of mandibular prognathism in sagittal splint ramous osteotomy (SSRO). MethodsBetween January 2012 and May 2013, 12 patients with mandibular prognathism (Angle III malocclusion) were treated. Among them, 9 cases were male and 3 cases were female. Their ages ranged from 19 to 35 years (mean, 25.6 years). With the 3-D facial CT data of these patients, 3-D printer was used to print the models for preoperational simulation. SSRO was performed on 3-D models, and the titanium plates were prefabricated on the models after the distal segments were moved backward and rotated according to occlusal splint. During operations, the proximal segments were fixed to distal segments by the prefabricated titanium plates. 3-D CT scans were taken to examine the temporomandibular joint position changes before operation and at 6 months after operation. ResultsThe skull models were manufactured by 3-D printing technique, and the titanium plates were reshaped on the basis of them. Twenty-four prefabricated titanium plates were placed during operations, and they all matched with the bone segments well. Evaluation of 3-D CT scans showed that the temporomandibular joint position had no change. All patients were followed up 7-12 months (mean, 10.6 months). The face type and dental articulation were improved greatly. All cases obtained satisfactory opening function and occlusion. ConclusionWith the titanium plate fabricated based on 3-D models, surgeons are able to improve or refine surgical planning so that the operation can be performed according to preoperative simulation precisely and the complications, such as dislocation of temporomandibular joint, can be prevented.
To investigate the therapeutic effect of open reduction, bone grafting, and internal fixation with plastic ti-alloy plate on intra-articular calcaneal fracture. Methods From January 2005 to December 2007, 32 patients (37 feet) with intra-articular calcaneal fracture underwent open reduction, bone grafting of autogeneic il ium (30-80 g) and internal fixation of plastic ti-alloy plate. There were 21 males and 11 females aged 18-56 years old (average 42.1 years old). There were 5 cases of bilateral calcaneal fracture and 27 cases of unilateral calcaneal fracture, including 2 cases of open fracture and 30 cases of close fracture. According to Sanders classification system, there were 11 cases of type II, 18 cases of type III and 8 cases of type IV. Preoperatively, Bouml;hler angle was (— 9.6 ± 4.2)° and Gissane angle was (101.4 ± 10.6)°. Nine feet underwent emergency operation and 28 feet received operation 5-7 days after injury. Results The wounds of 34 feet healed by first intention. The wound margin of 3 feet was gray with a small amount of colorless exudates, and healed after dressing change. All patients were followed for 12-24 months (average 16 months). X-ray films displayed that the fracture all healed within 3-4 months after operation. At 6 months after operation, the Bouml;hler angle and the Gissane angle was (28.5 ± 6.1)° and (128.9 ± 4.8)°, respectively, indicating there were significant differences when compared with before operation (P lt; 0.05). According to Maryland foot score system, 15 cases were graded as excellent, 18 cases were good, 4 cases were poor, and the excellent and good rate was 89.19%. Conclusion Open reduction, bone grafting, and internal fixation with plastic ti-alloy plate is an effective method to treat intra-articular calcaneal fracture. Choosing right operational timing, performing subarticular surface grafting when necessary and using appropriate plastic ti-alloy plate internal fixation can minimize the incidence of postoperative compl ications
Objective To investigate the influence of undercorrected orthokeratology on myopia control, and the correlation between target and central corneal epithelial damage. Methods A retrospective study was conducted on 22 undercorrected orthokeratology lens wearers (37 eyes) from January 2016 to February 2017, and 25 full corrected wearers (47 eyes) during the concurrent period were randomly selected as the control group. The changes of axial length before and after orthokeratology lens wearing and the within-6-month central corneal epithelial damage after orthokeratology lens wearing were analyzed. Results The average annual increase of axial length was (0.13±0.15) mm in the undercorrected group, and (0.14±0.16) mm in the full corrected group, the difference was not statistically significant (P>0.05). Multiple linear regression analysis showed that there was no correlation between the axial growth and the undercorrection of the target (P>0.05), but a negative correlation between the axial growth and the age (P<0.01). After using orthokeratology, the average annual growth of the axial length in children aged 7-10 years was (0.25±0.16) mm, and (0.10±0.14) mm in children aged 11-15 years, the difference was statistically significant (P<0.01). The incidence of central corneal epithelial punctate staining in the (–4.25)-(–5.00) D target group was 27.08%, and that in the (–3.00)-(–4.00) D target group was 16.67%, the difference was not statistically significant (P>0.05). Conclusions The effect of orthokeratology on myopia growth is not affected by the undercorrected target, not related to the undercorrection of target, but negatively correlated with the age. Undercorrected orthokeratology can still be used for myopia control in high myopia patients. No correlation is found between the target and central corneal staining.
Objective To review the progress and clinical application of malleable bone paste/putty. MethodsRecent literature about malleable bone paste/putty was reviewed and analyzed. ResultsThe preparation and clinical application of malleable bone paste/putty have become increasingly mature. Many kinds of malleable bone paste/putty have been applied extensively and the good clinical results have been achieved in the treatment of the irregular bone defects. The materials and methods for preparing malleable bone paste/putty are different. Then they have different bone repair abilities. ConclusionMalleable bone paste/putty provides effective method to treat irregular bone defects. But the malleable bone paste/putty still has some shortage, so further researches should be carried out.
ObjectiveTo systematically review the efficacy of defocus incorporated multiple segments (DIMS) spectacle lenses and orthokeratology (Ortho-K) in controlling myopia. MethodsThe PubMed, Embase, Cochrane Library, Web of Science, CBM, WanFang Data and CNKI databases were electronically searched to collect clinical studies related to the objectives from January 2000 to June 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed by using RevMan 5.3 software. ResultsA total of 8 RCTs and 7 cohort studies were included. The results of meta-analysis showed that both Ortho-K lens and DIMS had better axial control effects than the single vision control group (MD=−0.18, 95%CI −0.21 to −0.15, P<0.01; MD=−0.21, 95%CI −0.27 to −0.15, P<0.01). The Ortho-K had a smaller one-year growth in axial length compared to the DIMS (MD=−0.06, 95%CI −0.08 to −0.04, P<0.01). ConclusionCurrent evidence suggests that Ortho-K and DIMS have better myopia control effects than single lens lenses, while Ortho-K has better myopia control effects than DIMS, but the advantages are not significant. Due to the limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.
ObjectiveTo investigate the effect of “noncycloplegic retinoscopy for screening myopia + subsequent wearing orthokeratology lens” process for primary and secondary school students based on physical examination center.MethodsA total of 172 primary and secondary school students undergoing vision examination in the Health Management Department (i.e. physical examination center) of the Second Affiliated Hospital of Xi’an Jiaotong University between January 2017 and December 2018 were selected as the research objects. After examination by noncycloplegic retinoscopy in the health management department, they were examined by mydriatic retinoscopy in the ophthalmology department, and then the consistency of the results of the two methods was analyzed. Then 93 students with myopia diagnosed by both methods were randomly divided into control group (n=46) and trial group (n=47), wearing frame glasses and orthokeratology lenses respectively. The diopter, eye axial length, corneal curvature and vitreous cavity depth before wearing glasses, as well as the increment of the above indicators at 3, 6 and 12 months after wearing glasses/lenses were compared between the two groups, and the incidence of complications of the two groups were compared.ResultsCompared with mydriatic retinoscopy, the positive predictive value of noncycloplegic retinoscopy was 88.6%, the sensitivity was 96.9% and the specificity was 84.2%, and the consistency kappa coefficient was 0.821 (P<0.001). Before wearing glasses/lenses, there was no significant difference in diopter, eye axial length, corneal curvature or vitreous cavity depth of both eyes between the two groups (P>0.05); at 3, 6 and 12 months after wearing glasses/lenses, the diopter increment and eye axial increment of both eyes of the trial group were less than those of the control group [left eye diopter increment: (0.48±0.07) vs. (0.73±0.08) D, (0.69±0.13) vs. (1.04±0.11) D, (0.88±0.11) vs. (1.13±0.11) D; left eye axial increment: (0.18±0.05) vs. (0.26±0.04)mm, (0.22±0.04) vs. (0.36±0.04) mm, (0.27±0.05) vs. (0.40±0.05) mm; right eye diopter increment: (0.46±0.10) vs. (0.73±0.09) D, (0.71±0.12) vs. (1.04±0.10) D, (0.90±0.10) vs. (1.17±0.11) D; right eye axial increment: (0.17±0.04) vs. (0.24±0.04) mm, (0.23±0.04) vs. (0.37±0.04) mm, (0.26±0.05) vs. (0.42±0.05) mm] (P<0.05). At 3, 6 and 12 months after wearing glasses/lenses, the changing trends of corneal curvature and vitreous cavity depth in both eyes of the trial group were different from those of the control group (PInteraction<0.05), and the corneal curvature of both eyes at each time point was lower than that before wearing lenses and that of the control group (P<0.05), while the vitreous cavity depth of both eyes was not statistically different from that before wearing lenses (P>0.05) but lower than that of the control group (P<0.05). There was no statistical difference in the incidence of common complications between the two groups (P>0.05).ConclusionIn the physical examination center, the accuracy of noncycloplegic retinoscopy for general survey of myopia in primary and secondary school students is high, and then after the diagnosis by mydriatic retinoscopy in the special department, the use of orthokeratology lens can effectively control the progress of myopia, so the process of “noncycloplegic retinoscopy for screening myopia in physical examination center + subsequent wearing orthokeratology lens in specialty” is feasible.
ObjectiveTo evaluate the correlation between the Mohawk (MKX) expression level and the collagen fiber diameter of autologous hamstring tendon graft during the stable graft remodeling phase after anterior cruciate ligament (ACL) reconstruction.MethodsBetween January 2018 and August 2018, patients who underwent arth-roscopic single-bundle anatomical ACL reconstruction with autologous hamstring tendons for at least 48 months and also underwent second-look arthroscopy were enrolled in study. During the second-look arthroscopic procedures, ACL graft biopsies were performed from the surface of central part of the ligament. MKX expressions of ACL grafts were analysed by real-time fluorescent quantitative PCR (qRT-PCR). The ultrastructure of collagen fibers of grafts were evaluated by transmission electron microscopy, which included average diameter of collagen fibers (Dc), average diameter of large-diameter collagen fibers (DL), average diameter of small-diameter collagen fibers (DS), and large-small collagen fibers ratio (RL/S). The correlation between MKX expression level and graft collagen fiber diameter was calculated.ResultsTwenty-six patients met the selection criteria and their ACL graft specimens were enrolled in the study. The interval between ACL reconstruction and second-look arthroscopy was 52-128 months, with an average of 78.6 months. Arthroscopic graft remodeling score was 3-6 (mean, 4.8). There were 17 cases of excellent remodeling and 9 cases of fair remodeling. All ACL grafts showed typical bimodal distributions of both large-diameter collagen fibers and small-diameter collagen fibers, but the ultrastructural characteristics of the graft collagen fibers were different according to different remodeling status under arthroscopy. The DC, DL, DS, and RL/S of the graft specimens were (65.2±9.3) nm, (91.6±10.5) nm, (45.7±8.6) nm, and 0.73±0.12, respectively. The relative expression level of MKX was 1.42±0.11, which was positively linearly correlated with DC, DL, and RL/S, and the correlation coefficient was statistically significant (r=0.809, P=0.000; r=0.861, P=0.000; r=0.942, P=0.000), while there was no significant correlation between DS and relative expression level of MKX (r=0.147, P=0.238). Regression analysis showed that the relative expression level of MKX could predict the DC, DL, and RL/S results of the ACL graft specimens (P<0.05).ConclusionAfter autologous hamstring tendon grafts stepped into stabilized remodeling phase, MKX expression level could predict the diameter measurement results of collagen fibers and be used as an important evaluation basis for graft collagen anabolic metabolism.
Objective To investigate the morphology and biomechanics of in vivo osteogensis after repairing rabbit skull defects with plastic engineered bone which was prefabricated with alginate gel, osteoblasts and bone granules. Methods Twenty-eight rabbits were divided into group A (n=16), group B(n=8) and group C(n=4).The bilateral skull defects of 1 cm in diameter were made. Left skull defects filled with alginate gel-osteoblasts-bone granules(group A1) and right skull defects filled withalginate gel-bone granules(group A2).The defects of group B was left, as blank control and group C had no defect as normal control. The morphological change and bone formation were observed by methods of gross, histology and biomechanics. Results In group A1, the skull defects were almost entirely repaired by hard tissue 12 weeks after operation. The alginate gel-osteoblasts-bone granule material had changed into bone tissue with fewbone granules and some residuary alginate gel. The percentage of bone formation area was 40.92%±19.36%. The maximum compression loading on repairing tissue ofdefects was 37.33±2.95 N/mm; the maximum strain was 1.05±0.20 mm; andloading/strain ratio was 35.82±6.48 N/mm. In group A2, the alginate and bone granules material partially changed into bone tissue 12 weeks after operation. The percentage of bone formation area was 18.51%±6.01%. The maximum compression loading was 30.59±4.65 N; the maximum strain was 1.35±0.44 mm; and the loading/strainratio was 24.95±12.40 N/mm. In group B, the skull defects were mainly repaired bymembrane-like soft tissue with only few bone in marginal area；the percentage of bone formation area was 12.72%±9.46%. The maximum compression loading was 29.5±2.05 N; the maximum strain was 1.57±0.31mm；and the loading/strainratio was 19.90±5.47 N/mm.In group C, the maximum compression loading was 41.55±2.52 N; the maximum strain was 095±017 mm; and the l oading/strain ratio was 47.57±11.22 N/mm. 〖 WTHZ〗Conclusion〓〖WTBZ〗The plastic engineered bone prefabricated with algina te gelosteoblastsbone granule may shape according to the bone defects and ha s good ability to form bone tissue, whose maximum compression loading can reach 89 % of normal skull and the hardness at 12 weeks after operation is similar to that of normal skull.