Use of a temporary screw for alignment and fixation of sagittal mandibular condylar fractures with lateral screws

Application of Crus of Helix Incision Through the Posterior Parotid Gland Approach in the Mid-Level or High-Level Mandibular Condylar Fractures

OBJECTIVE

This study is to explore the clinical effect of crus of helix incision through the posterior parotid gland approach in the treatment of Mid-or High-Level mandibular condylar fractures.

METHODS

From September 2020 to June 2023, we performed incision reduction internal fixation of 23 patients with mid-level or high-level fractures of the mandibular condylar through the approach of the posterior parotid gland, and observed the effect of the operation.

RESULTS

After a follow-up period of 6 to 12 months, all patients showed no signs of postoperative facial paralysis or salivary gland fistula. In addition, satisfactory scars were observed in the operation area, and the occlusion function had recovered well.

CONCLUSION

The approach of using a crus of helix incision through the posterior parotid gland proved to be an effective method for treating mid-level or high-level fractures of the condylar fractures. This technique offers several advantages, including adequate exposure, minimal facial nerve injury, ease of incision and reduction, inconspicuous scarring, and a more concealed incision.

Biomechanical evaluation of type p condylar head osteosynthesis using conventional small-fragment screws reinforced by a patient specific two-component plate

BACKGROUND

The aim of this study was to evaluate via finite element analysis (FEA) the biomechanical behavior of conventional small-fragment screws reinforced by a patient-specific plate in type p condylar head.

METHODS

A finite element model of the mandible was created using Mimics 12.1 software. A type p condylar head fracture was simulated in the right condyle, and the left condyle was used as a control. Two patterns of fixation were investigated: conventional two-screw fixation and the same fixation system reinforced with a small, patient-specific plate. Surface models were imported into the software Ansys 5.7for further volume mesh generation.

RESULTS

The highest stress gradients were observed in the cortical layer of the lateral fragment, located near the screw. The conventional fixation method resulted in equivalent stresses 2 to 10 times greater than the reinforced method. Rigidity of fixation in the reinforced method increased up to 1.25-3 times compared to the conventional two-screw technique.

CONCLUSION

This study's findings suggest significant benefits in unfavorable biomechanical conditions from reinforcement of the standard two-screw fixation of condylar head fractures with a small, patient-specific plate acting as a washer.

A comparative biomechanical evaluation of different osteosynthesis techniques used for intracapsular condylar head fractures

Purpose

The aim of the present experimental study was to evaluate the biomechanical behavior in different types of osteosynthesis (titanium screws, bioresorbable pins and miniplates) used in management of intracapsular condylar head fractures.

Method

Experimental models of the condylar head fractures were simulated on 15 dry human cadaveric mandibles. Osteotomized mandibles were randomly divided into three groups with different fixation systems used: 1) 15 mm long titanium screws, 2) 15 mm long bioresorbable pins Sonic Pins Rx, 3) T-shaped titanium miniplate and 7 mm long titanium screws. Mandibles were loaded in TIRAtest testing machine (Germany). The main types of deformations, including torsion, bending and shearing, were simulated to study the biomechanical characteristics of the fixation systems.

Results

Titanium bicortical screws demonstrated the highest stiffness in standard loading conditions. The fixation with bioresorbable pins showed lower stiffness in both frontal and sagittal loads. This is indicative of the fact that resorbable pins, which have numerous advantages for clinical usage, cannot provide adequately stable fixation in maximal masticatory loads. The mandibles fixed with T-shaped plate had the lowest stiffness.

Conclusion

Screw or pin fixation, regardless of the material used, was not resistant to rotational loads. On the contrary, the stiffness of T-shaped plates was quite significant. In real clinical conditions, if rotational displacements are not effectively compensated by irregularities in the fracture surface and precise repositioning of the bone fragments, combined use of miniplates and bicortical titanium screws or two screws can be beneficial.

Use of Two Lag Screws for ORIF of Mandibular Condylar Sagittal Split fracture: An Anti-rotational Concept-A Prospective Clinical Trial

Background

Condylar process fracture is one of the most common mandibular fractures. Approximately 11-16% of all facial fractures and 30-40% of all mandibular fractures are fractures of the mandibular condyle. Treatment can broadly be divided into open or closed, but there are no clear criteria to determine the choice between them. Sagittal split fracture of the mandibular condyle is rare and can be easily missed on conventional radiographs, like OPG and multiple standard films, but because of the high incidence of subsequent ankylosis is an important entity. So a CT scan with axial and coronal cuts is advisable in high condylar or intracapsular fractures of mandibular condyle.

Purpose

The hypothesis in this study is that open reduction and internal fixation (ORIF) of sagittal split mandibular condylar fractures with two lag screws is more stable and there is no rotation of the medial fractured segment of condyle.

Methods

In this prospective clinical trial, ORIF of four patients with sagittal split fracture of mandibular condyle was done using two lag screws. In all the patients, pre-op and post-op clinical and radiological findings were evaluated, with a follow-up of two years.

Results

All the patients were evaluated postoperatively at periodical interval with various clinical parameters, viz. mouth opening, occlusion, pain, deviation of mandible while opening, other complaints (like clicking, tenderness), and radiologically with CT scans. All patients showed good occlusion and adequate mouth opening postoperatively. In this series, there was no pain, deviation of mandible while opening and other complaints like tenderness and clicking. In CT scan, the medial fragment was reduced anatomically in position and the lag screws were not protruding in the TM joint space.

Conclusion

Use of two lag screws for ORIF of sagittal split mandibular condylar fractures is recommended to prevent the rotation of fractured medial condylar segment and for more stable fixation.

Treatment of Sagittal Fracture of the Zygomatic Arch Root Assisted by Surgical Navigation Technology

Sagittal fracture at the temporal root of the zygomatic arch often occurs as a part of zygomaticomaxillary fractures. The authors described the application of computer-assisted navigation in the lag screw insertion for the fixation of sagittal fracture at the temporal root of zygomatic arch. Using the presurgical planning of the computer-assisted navigation system, the trajectory of lag screw insertion was designed, and the insertion depth was calculated. In the presurgical planning, the trajectory of screw insertion was placed with an anterior inclination of 10° to 15° (mean: 12.24°), and the screw insertion depth was 9.0 to 12.0 mm (mean: 10.65 mm). In the operation, the screw insertion in the fixation of the sagittal fracture was performed under the guidance of navigation system according to the presurgical planning. The postoperative CT scan showed exact reduction and fixation of the sagittal fracture in all cases. Computer-assisted navigation is a useful tool for the lag screw insertion in the precise fixation of sagittal fracture at the temporal root of the zygomatic arch in complex zygomaticomaxillary fractures.

[Extramedullary fixation combined with intramedullary fixation in the surgical reduction of sagittal mandibular condylar fractures]

OBJECTIVE

This study aimed to evaluate the clinical effect of extramedullary fixation combined with intramedullary fixation during the surgical reduction of sagittal mandibular condylar fractures.

METHODS

Twenty-four sagittal fractures of the mandibular condyle in18 patients were fixed by two appliances: intramedullary with one long-screw osteosynthesis or Kirschner wire and extramedullary with one micro-plate. The radiologically-recorded post-operative stability-associated com-plications included the screw/micro-plate loosening, micro-plate twisting, micro-plate fractures, and fragment rotation. The occluding relations, the maximalinter-incisal distances upon mouth opening, and the mandibular deflection upon mouth opening were evaluated based on follow-up clinical examination.

RESULTS

Postoperative panoramic X-ray and CT scans showed good repositioning of the fragment, with no redislocation or rotation, no screw/plate loosening, and no plate-twisting or fracture. Clinical examination showed that all patients regained normal mandibular movements, ideal occlusion, and normal maximal inter-incisal distances upon mouth opening.

CONCLUSIONS

Extramedullary fixation combined with intramedullary fixation is highly recommended for sagittal condylar fractures because of the anti-rotation effect of the fragment and the reasonable place-ment of the fixation appliances.

Extra corporeal fixation of fractured mandibular condyle

Condylar fracture is the second most common site in the mandibular fractures. Motor vehicle accident and fall are the major causes of such fractures. Because of the anatomical weakness of the condyle and the shape of the condylar head the antero-medial dislocation of the condyle is common. Open reduction and closed reduction is always debatable. The open reduction will bring back the normal function much earlier than closed reduction. Medially dislocated condylar fracture fragments are always managed with open method. In superior or high condylar fractures,exact reduction with conventional open reduction can be difficult due to the limited surgical and visual fields. In such cases extracorporeal fixation of condyle using vertical ramus osteotomy may be better choice to achieve perfect alignment and absolute maintaince of vertical height of the ramus and facial symmetry. We here present a case of extracorporeal fixation of unilateral left high condylar fracture.

Clinical and radiological outcomes after treatment of sagittal fracture of mandibular condyle (SFMC) by using occlusal splint in children

This study was designed to investigate the effects of occlusal splints in the treatment of sagittal fractures of the mandibular condyle in children. From January 1995 to December 2011, 37 sagittal fractures of the mandibular condyle in 30 patients aged 4-8 years old were included in this study. All the patients were treated with 1-2mm occlusal splints in the molar region. The mouths of the patients were kept slightly open by the occlusal splints for 3-6 months, and we reviewed the clinical and radiological remodelling of the affected condyles after treatment. Excellent (n=20) and good (n=10) clinical outcomes were achieved with full radiological remodelling seen in 19 and partial remodelling in 11. Treatment with occlusal splints is effective in delivering good results and function with minimal morbidity in children with sagittal fractures of the condyle, while permitting ongoing remodelling and growth in the short term.

Computer-assisted virtual technology in intracapsular condylar fracture with two resorbable long-screws

Our aim was to fix intracapsular condylar fractures (ICF) with two resorbable long screws using preoperative computer-assisted virtual technology. From February 2008 to July 2011, 19 patients with ICF were treated with two resorbable long screws. Preoperatively we took panoramic radiographs and spiral computed tomography (CT). Depending on their digital imaging and communications in medicine (DICOM) data, the dislocated condylar segments were restored using the SimPlant Pro™ software, version 11.04. The mean (SD) widths of the condylar head and neck from lateral to medial were 19.01 (1.28)mm and 13.84 (1.13)mm, respectively. In all patients, the mandibles and the ICF seen intraoperatively corresponded with the preoperative three-dimensional and virtual reposition. All patients were followed up for 6-46 months (mean 21). Occlusion and mouth opening had been restored completely in all but one patient, and absolute anatomical reduction was also achieved in most cases. Computer-assisted virtual technology plays an important part in the diagnosis of ICF, as well as in its preoperative design. Fixation with only two resorbable long screws is an effective and reliable method for fixing ICF.

Minimally-invasive open reduction of intracapsular condylar fractures with preoperative simulation using computer-aided design

Reduction of intracapsular condylar fractures is difficult, so we have based our technique on preoperative simulation using computer-aided design (CAD), which has proved useful in other surgical specialties. We have treated 11 patients with intracapsular condylar fractures. Before the operation the procedure was shown on the computer using a three-dimensional simulation system. The relation between the stump and the fragment of the condyle, and assessment of the position and the size of the screw, were made preoperatively to obtain a perfect fit. The displaced fragment was reduced by elevators, and fixed with a bicortical screw through a minimised preauricular incision under general anaesthesia. The fragments and the location of the screws were similar on the preoperative simulation and on the postoperative computed tomographic (CT) scan. The reduction and fixation of the fracture showed a perfect fit on the same view in the preoperative CAD simulation in the Mimics 10.01 software and postoperatively. Postoperative clinical examinations showed good occlusion and satisfactory mouth opening. Two patients had temporary paralysis of the occipitofrontalis muscle that recovered within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months' follow up. The technique of CAD simulation could help to improve the accuracy during open treatment for intracapsular condylar fractures.