Comparison of lag screws and double Y-shaped miniplates in the fixation of anterior mandibular fractures

BACKGROUNDMandibular fractures constitute about 80.79% of maxillofacial injuries inAlexandria University, either as isolated mandibular fractures or as a part ofpanfacial fractures. The combination of symphyseal and parasymphyseal fracturesrepresent 47.09% of the total mandibular fractures.AIMTo compare the effectiveness of lag screws vs double Y-shaped miniplates in thefixation of anterior mandibular fractures.METHODSThis study is a prospective randomized controlled clinical trial, performed onsixteen patients with anterior mandibular fractures. Patients were divided equallyinto two groups, each consisting of eight patients. Group 1: Underwent openreduction and internal fixation using two lag screws. Group 2: Underwent openreduction and internal fixation using double Y-shaped plates. The followingparameters were assessed: operating time in minutes, pain using a visual analogscale, edema, surgical wound healing for signs and symptoms of infection,occlusion status and stability, maximal mouth opening, and sensory nervefunction. Cone beam computed tomography was performed at 3 and 6 mo tomeasure bone density and assess the progression of fracture healing.RESULTSThe study included 13 males (81.3%) and 3 females (18.8%) aged 26 to 45 years(mean age was 35.69 ± 6.01 years). The cause of trauma was road traffic accidentsin 10 patients (62.5%), interpersonal violence in 3 patients (18.8%) and othercauses in 3 patients (18.8%). The fractures comprised 10 parasymphyseal fractures(62.5%) and 6 symphyseal fractures (37.5%). The values of all parameters were comparable in both groups with no statistically significant difference except forthe mean bone density at 3 mo postoperatively which was 946.38 ± 66.29 in group 1 and 830.36 ± 95.53 in group 2 (P = 0.015).CONCLUSIONBoth lag screws and double Y-shaped miniplates provide favorable means offixation for mandibular fractures in the anterior region. Fractures fixed with lagscrews show greater mean bone density at 3 mo post-operation, indicative ofhigher primary stability and faster early bone healing. Further studies with largersample sizes are required to verify these conclusions.

External penetrating laryngeal trauma caused by a metal fragment:A Case Report

BACKGROUND Although external penetrating laryngeal trauma is rare in the clinic,such cases often result in a high mortality rate.The early recognition of injury,protection of the airway,one-stage laryngeal reconstruction with miniplates and interdisciplinary cooperation are important in the treatment of such patients.CASE SUMMARY A 58-year-old male worker sustained a penetrating injury in the left neck.After computed tomography scanning at a local hospital,he was transferred to our hospital,where he underwent tracheotomy,neck exploration,extraction of the foreign object,debridement and repair of the thyroid cartilage using titanium miniplates.An endo laryngeal stent was inserted,which was removed 12 days later.The patient recovered well and his voice rapidly improved after surgery.CONCLUSION Penetrating laryngeal trauma is uncommon.We successfully treated a patient with early laryngeal reconstruction and management by interdisciplinary cooperation.

Three-dimensional Finite Element Analysis of a Newly Designed Onplant Miniplate Anchorage System

The purpose of this research was to evaluate the structural stress and deformation of a newly designed onplant miniplate anchorage system compared to a standard anchorage system. A bone block integrated with a novel miniplate and fixation screw system was simulated in a three-dimensional model and subjected to force at different directions. The stress distribution and deformation of the miniplate system and cortical bone were evaluated using the three-dimensional finite element method. The results showed that the stress on the plate system and bone was linearly proportional to the force magnitude and was higher when the force was in a vertical direction（Y-axis）. Stress and deformation values of the two screws（screw 1 and 2） were asymmetric when the force was added along Y-axis and was greater in screw 1. The highest deformation value of the screws was 7.5148 μm, much smaller than the limit value. The load was decreased for each single miniscrew, and the ability of the new anchorage system to bear the load was also enhanced to some degree. It was suggested that the newly designed onplant miniplate anchorage system is effective, easily implanted and minimally invasive.

Double J Fixation after Craniotomy: Technical Description of a Modification Method for Bone Flap Fixation (Hiederov Method)

Background: Fixation of bone flap following craniotomy is usually achieved by synthetic materials. In rural and poor funding areas, innovation for cheap, safe and applicable material is needed. Purpose: The aim is to assess our new innovative technique in bone flap fixation against traditional techniques. Patients and Methods: The study was a prospective randomized controlled study enrolled at Al-Amal Hospital and Al-Ahly Bank Hospital from 2014-2019. Forty-eight patients were randomized in the study. Group A (24 patients) underwent titanium miniplate fixation while group B (24 patients) underwent our new technique. The new technique is double J tunnels performed by craniotome on either side of the bone (flap and skull sides), then a Prolene suture is passed through the shared stem of J’ holes and secured in the wrapped side of J’s holes and tying it tightly. Both techniques were examined against fixation time, rigidity, offset and final judgment postoperatively. Result: There was no statistically significant difference in using both techniques as regard fixation time. Our new technique was not inferior to the traditional one in achieving rigidity (p > 0.05). The final postoperative assessment was as equal as that seen in miniplate fixation. Conclusion: This technique is a simple, easy, cheap and effective method of fixing craniotomy bone flap.

Evaluation of labial versus labio-inferior lines of osteosynthesis using 3D miniplate for fractures of anterior mandible:A finite element analysis with a pilot clinical trial

Purpose:The fractures of anterior mandible are subject to severe torsional forces due to muscles acting in opposite directions.3D miniplate has been suggested as a good alternative by some researchers.However,finite element model(FEM)studies indicate that labio-inferior positioning of two miniplates perpendicular to each other offers better stability as compared to labial positioning.This study aims at combining the advantages of a single 3D miniplate and labio-inferior positioning of two conventional miniplates,which was assessed by finite element analysis along with a pilot clinical trial.Methods:Two FEM models were created using CT data of a 24-year-old patient with Angie class I occlusion:control model with labial plating and study model with labio-inferior plating.The models were processed with MIMICS.(materialise,Leuven,Belgium),CATIA.(Dassault Systemes)and finite element analysis softwares.Parameters adopted for analysis were(1)displacement(mm)of fracture fragments during each screw fixation,(2)lingual splay and post fixation stability of fracture fragments with masticatory load,and(3)stress distribution(MPa)across fracture fragments.Moreover,a pilot clinical trial including five patients with anterior mandible fracture was conducted.The fractures were managed by intraoral open reduction and 3D miniplate fixation in labio-inferior position.Intraoperative interfragmentary gap,post fixation lingual splay and radiographic fracture union and complications were assessed clinically.Results:Labio-inferior plating demonstrated less displacement(mm)of fracture fragments during screw fixation(0.059 vs.0.079)as well as after application of masticatory load(1.805 vs.1.860).Negligible lingual splay and less stress distribution(MPa)across fracture fragments(1.860 vs.1.847)were appreciated in the study group as compared to control group.Clinical trial support the favorable outcome related to intraoperative and postoperative assessment parameters.Conclusion:FEM analysis and clinical trial reveal better results with labio-inferior positioning of 3D miniplate when compared to labial positioning.

Facemask therapy with miniplate implant anchorage in a patient with maxillary hypoplasia

A reverse headgear is thought to be an effective .treatment approach for skeletal class Ⅲ malocclusion with retruded maxilla. Clinical studies have shown that the changes of occlusion are a combination of skeletal and dental changes： forward movement of the maxilla, proclination of the maxillary incisors, clockwise rotation of the mandible, and retroclination of the mandibular incisors. However, the undesirable dental effects, such as excessive mesial movement and extrusion of maxillary molars and labial tipping of maxillary incisors, have been reported. Most of previous studies have demonstrated that the best time for maxillary protraction is early mixed dentition. The skeletal effect decreases and the dental effect increases with age. So there is a need for an absolute stable anchorage for maxillary orthopedics to produce more skeletal change and less dental movement.