Background and Aim: In contemporary orthognatic surgery, osteotomy and rigid internal fixation procedures are commonly used to restore stability and function of the jaws, and to obtain comfort for patients. Although there are many good reasons for utilization of this type of fixation, in some patients the need to remove plates and screws after surgery may arise due to related complications. The present study investigated plate removal after sagital split osteotomy and its reasons.Materials and Method: In this prospective study, 67 patients in need of sagital spilt osteotomy or bimaxillary osteotomy were selected from two university departments during the period of 2005 to 2007. All patients were followed up for 14 month after surgery and number of plates removed was recorded. In addition, information regarding age, sex, duration of operation, medical condition, splitting during surgery, smoking habits, and need to extract wisdom teeth at the time of surgery were gathered. The data were analyzed using a linear logistic regression model with the SPSS software version 12.Results: Infection was the sole reason for plate removal in this study. From 134 plates used in 67 patients 14 plates (10.5%) were removed in 10 patients. Age was the only statistically significant factor to affect plate removal and the effect of other factors were not statistically significant.Conclusions: According to the findings of this study only a few patients needed plate removal. Routine removal of plate does not appear to be clinically indicated.

Introduction: To determine the most appropriate method for placement of plates and screws in terms of stress in mandibular body fractures using finite element analysis. Materials and Methods: First a model of the mandible reconstructed with Mimics software. This study employed various methods, including plates positioned parallel to the inferior border of the mandible with screws perpendicular to the bone,plates parallel to the inferior border of the mandible fixed with screws oriented at a 45-degree to the fracture line,plates positioned perpendicular to the fracture line fixed with screws perpendicular to the bone,plates perpendicular to the fracture line and fixed with screws oriented at a 45-degree to the fracture line. Then the software measured the stress within the screws and plates in each condition under the maximum bite force. Results: It was observed that in cases of favorable horizontal fractures, the stress exerted on the plates and bones is greater when the plates are aligned parallel to the lower border of mandible, compared to when the plates are positioned perpendicular to the fracture line. In the study of unfavorable horizontal fractures, when the plates were fixed perpendicular to the fracture line, higher magnitudes of stress were recorded compared to the stress observed in the plates positioned parallel to the inferior border of the mandible. Conclusion: In cases of mandibular body fractures with favorable horizontal orientations, the use of fixation techniques involving plates perpendicular to the fracture line is preferred due to the reduced stress exerted on the plates. In the unfavorable horizontal fractures, the stress levels do not exhibit significant variation between different fixations. Finally, it is not advisable to utilize screws positioned at a 45-degree angle to the fracture line, as it can lead to an increase in the displacement of the plates. Keywords: Finite element analysis,Mandibular fracture,Stress and strain,Surgical plates and screws.

Introduction: One of the main purposes of osteotomy is improvement in function and stability after orthognathic surgery. Today with use rigid internal fixation, this function and stability reach to best reasons, but a few complications are appeared, the purpose of this study was to evaluate this situation. Materials and Methods: The study sample consisted of 52 patients who underwent lefort I osteotomy at oral and maxillofacial department between 1998 and 2000. All patients in the study were treated with internal fixation using 2.0 mm plates and screws. All patients were fallowed for 14 months after surgery. Results: 1) A total of 208 plates and screws were placed in 52 patients, 9 (6 female, 3 men) had at least a portion of hardware removed. 2) The percentage of titanium plates removed was greater than the other plates. 3) The reasons for removal include: Palpation by patient, sinusitis, pain - infection, temperature Sensitivity, pain of palption, pain, infection and unknown. Conclusion: Only a small number patient develop complication from plates or screws (16%) that required their removal. In each case after removal of plates and screws, all complication was disappeared.

Background: Previously, absorbable screw and plate systems were widely used in craniosynostosis surgery in Iran, but now, due to the establishment of economic sanctions, the importation of these tools into the country has become difficult. In this study, we compared the short-term complications of cranioplasty surgery in craniosynostosis using absorbable plate screws with absorbable sutures. Methods: In this cross-sectional study, 47 patients with a history of craniosynostosis who underwent cranioplasty at Tehran Mofid Hospital, Tehran, Iran from 2018 to 2021 were divided into two groups. For first group (31 patients) we used absorbable plate and screws, and for the second group (16 patients) absorbable sutures (PDS). All operations in both groups were performed by the identical surgical team. Patients followed up for consecutive post-operative examinations in the first and second weeks and 1, 3, and 6 months. Data were analyzed using SPSS software version 25. Results: The results did not show any short-term or medium-term complications in either group. No recurrences were observed. In Whittaker classification, 63. 8% were Class I, 29. 8% were Class II, 6. 4% were Class III, and 0% were Class IV. There was no statistically significant relationship between the type of treatment (screw and plate or absorbable suture) and higher Whitaker. There was also no statistically significant relationship between type of craniosynostosis and higher Whittaker. Conclusion: The absorbable sutures can be considered as valuable and costeffective tools in the fixation of bone fragments in craniosynostosis surgeries by surgeons.

Reinforcement of glulam beams to prevent an increase in the volume of the structural element and to reduce wood consumption is inevitable. The increased strength of these engineered products along with the limited use of other materials provides this issue. Comparing the strength of glulam beams with adhesive or screw connection was operated by making a variety of reinforcement designs. Glulam specimens of adhesives groups and screws were reinforced with straps and rebars. Prestressing was performed in one of the bolt screw treatments with an approximate amount of 5 kN. Calculations and statistical analysis show the significant effect of reinforcement designs and increase the strength of various types of adhesive beams. End holder sheets on glulam beams using steel straps play an effective role. Slip diagrams show that as the load increases, the slip increases almost uniformly. Next, the partial movement of the layers on each other is controlled by the end holder sheet and prevents the growth of the graph. However, the slip diagram of unreinforced glulam beams shows that the slip in the first part of the diagram has more growth than in the second area.

Introduction & Objective: Fronto-orbital remodeling is the procedure of choice for the treatment of craniosynostosis, affecting the anterior area of the skull and orbital regions. The resorbable plating systems provide rigid fixation while potentially minimizing the long term drawbacks of permanent plating systems. However, plate palpability, visibility, skin breakdown over the plate, encapsulated foreign body and osteolytic changes have been reported. The absorbable fixation systems are composed of either a plate or a mesh and screws. In this clinical trial, we have used plates prepared by cutting a row of mesh for fixation, reducing the palpability and visibility of the implant.Materials & Methods: In this Q experimental study from May 2006 to May 2009, 20 patients (14 males, 6 female) aged 4 to 19 months (mean 6±3 months) underwent operation. Indications for operation were Metopic suture in 8 patients, unicoronal suture in 5 patients, Bicoronal suture in 3 patients, Sagittal suture in 1 patients, Multiple suture suture in 3 patients.All patients underwent fronto-orbital remodeling with cranial reshaping .Through bicoronal approach, once the supra orbital bar is remodeled, a new forehead is created by remodeling the rest of it. Symmetrical repositioning and fixation of supraorbital bar was done, and frontal bone segments were fixed in to position by handmade resorbable mesh plates and screws. The temporal muscle was then advanced to lateral orbital rim and temporal crest, and the priosteum was advanced for the coverage of reconstructed forehead region. The results of treatment, at aminimal follow-up of 6 months were assessed, based on preoperative and postoperative photographs and direct patient examination.Results: The follow-up of the patients ranged from 6 to 36 months (mean 15±6 months). All patients were studied, using photography, radiography, and 3-D CTscans preoperatively and were visited in the clinic 1, 2, 3, 6 week and up to36 months after their operations.During the observation period of up to 36 months, no infection, visibility, exposure, instability or dislocation was observed. The results aesthetically were satisfactory in 90% and good in 10% of patients, according to Bartlett categorization.Conclusions: Absorbable fixation devices in the fronto-orbital remodeling surgery of patients affected by craniosynostosis provides secure fixation while avoiding the potential and well-documented problems with rigid metal fixation. Using a row of absorbable mesh, instead of conventional plate, could effectively reduce visibility and even the palpability of the normal fixation device.

Background and Aim: Due to the complications associated with fixation by titanium screws and plates in BSSRO surgery, the use of resorbable polymers have been increasingly recommended. Since there is not enough studies on this issue through the literature, this study aimed to assess the most appropriate stress distribution in fixation with resorbable plates after BSSRO surgery by FEA.Materials and Methods: This experimental study was performed on simulated human mandible using Ansys and CATIA softwares. The osteotomy line was applied to the simulated model and experimental loads of 75, 135 and 600 N were respectively exerted according to the natural direction of occlusal force. The distribution pattern of stress was assessed and compared for fixation with four-hole resorbable miniplate, two-hole resorbable miniplate and parallel miniplate using Ansys software.Results: Among the four simulated fixations, parallel miniplates showed the highest primary stability. Four-hole resorbable plates were also associated with sufficient primary stability and less trauma and cost for patients. Two-hole resorbable plates did not provide enough stability under 600 N.Conclusion: Polymer-based resorbable plates and screws (polyglycolic acid and D, L polylactide acid) in every three patterns, on masticatory loads after surgery, provides satisfactory primary stability in BSSRO surgery and the displacement of the osteotomy site fixed with this system was inconsiderable. the plates should at least have four holes and adjust in appropriate position (neutral zone) to provide sufficient primary stability. Therefore resorbabale fixation can be a good alternative for titanium fixation in BSSRO surgery.

Bone fractures in dogs and cats are usually see and we concern with those in the clinic. Usually, fractures occur after a traumatic accident such as being hit by a car or falling from a height, some fractures occur following pathological bone weakening, which is seen with some neoplastic conditions such as osteosarcoma. The main goals of fracture stabilization; Immobilization of broken parts, quick repair of the damaged bone, return of primary mobility, full function and stability to weight bearing of the bruise limb. All internal and external fixation methods that allow significant intersegmental motion under weight bearing are considered flexible fixation. The best important point in the stabilization of fractures is that a possibility of repair, that is, the blood supply to the place is maintained and the fixation is not so tight that it leads to a delay in bone fusion. Open fixation and internal fixation have been used to restore bone anatomy and original mobility and to overcome the limitations encountered when treating fractures with skeletal traction or cast immobilization. The main goal of internal fixation is to achieve rapid and, if possible, full function of the affected limb with rapid rehabilitation of the patient. The selection of the internal fixation method is based on the classification of the fracture, break bone, synchronize injuries, open fracture, and of course the forces that are neutralized by the fixation method. Internal stabilization implants are made of stainless steel and include; There are intramedullary pins, orthopedic wire, plates and screws.

Objective: Bioresorbable and titanium plates/screws are considered as a standard treatment for fixation of the bone segments of craniofacial area and paying attention to their biocompatibility is an important issue along with other aspects of application. The purpose of the study was to evaluate the cell viability of two types of plate and screw used in maxillofacial surgeries in contact with gingival fibroblasts and bone marrow stem cells. Materials and Methods: In this experimental study after extraction and cultivation of cells from healthy human gingival tissue and alveolar bone of jaw, cytotoxicity of device was evaluated. In direct contact method, samples had near vicinity contact with the both cell lines and in indirect contact method, by-products released, like ions, from samples after 8 weeks were used to assess cytotoxicity. Then cytotoxicity was evaluated on the 2nd, 4th and 6th day with MTS tests and microscopy. The data were analyzed by one-way ANOVA and independent t tests. Results: There was a statistically significant difference between the German plate and screw and all the samples studied on day 6 (P<0. 05). Furthermore, a statistically significant difference was observed between both metal samples and both bio-absorbable samples on day 6 and both cell lines (P<0. 05). Comparisons between the two groups with each other for both cell lines on the 6th day were statistically significant (P<0. 05). Conclusion: Our results suggest that that cytotoxicity of biomaterial, from different brands, were not similar and some of the biomaterial showed lower degree of toxicity compared to others and specialist using these products showed be aware of this differences. Our investigation indicates more biocompatibility of bioresorbable plates and screws compared to titanium. In addition our results suggest that biomaterials were not completely neutral.

until the completion of healing process, which has its own complications in some critical fractures. To overcome this drawbacks bone adhesives are developed for the immobilization of fractured bones. Objective: In this in-vitro study we compared the bond strength obtained by immobilization of the bone fragments using plates and screw and new adhesive containing BTDMA monomer. Materials and Methods: In this experimental in-vitro trial, bone fractures were simulated in bovine’ s mandibular bone using an electrical saw. The bone fragments were randomly allocated in different groups and were immobilized with either plate and screws and adhesive containing 0, 10, 15% BTDMA. After 24 hours tensile bond strength was calculated using universal testing machine. One-way ANOVA and Tukey post hoe test were used for statistical analysis. Results: Mean (± standard deviation) of tensile bond strength of bone fixation using adhesive containing 15% (W/W) BTDMA monomer were 176. 0 (± 18. 89) N. These values were 149. 1 (± 23. 88) N for adhesive containing 10% BTDMA; 102 (± 17. 99) N for the base adhesive and 278. 9 (± 24. 12) N for the screw and plate technique. Significant differences were found regarding bond strength of bone fixation in 4 groups using bone adhesives or plate technique (P<0. 001). The highest bond strength was recorded for the plate group and the least was related to the base adhesive. Significant differences existed between all bone adhesives as declared by paired comparison (p<0. 05). Conclusion: Despite the lower bond strength in adhesive groups in comparison with screw and plate, with regards to possible complications of screw and plate technique, it seems bone adhesives containing BTDMA monomer can be used for bone fragment fixation. However, bond strength is just one of the numerous properties that an adhesive should have and more studies must be done on these kinds of adhesives.