Transgingival lag-screw osteosynthesis of alveolar process fracture

New dimensions in alveolar fracture treatment: Open reduction and internal fixation by minimally invasive approach combined with computer-assisted surgery

Alveolar fractures are a common type of maxillofacial trauma, and the conventional treatment involves closed reduction and dental splinting fixation. However, closed treatment is not suitable for some complex segmental alveolar fractures. In this case report, we introduce an innovative method for segmental alveolar fracture by using open reduction and internal fixation by minimally invasive approach combined with computer-assisted surgery. In this case, the new dimensions in the treatment followed AO principles of fracture management, achieving anatomical reduction of the fracture, absolute stability of the fracture ends, proper preservation of vascular supply to soft tissues and bone, and promoting recovery through early postoperative functional training. This case provides new insights into the treatment of the complex segmental alveolar fractures with tenuous vascular supply and cannot be treated by conventional splinting fixation.

Treatment of Sagittal Fracture of the Zygomatic Arch Root

A sagittal fracture at the temporal root of the zygomatic arch (ZAR) often occurs as a component of zygomaticomaxillary complex (ZMC) fractures. However, this area is difficult to access, and anchorage is limited due to the unstable structure around it. Therefore, a preauricular approach using single-screw fixation is proposed, and this study reports its results and usefulness. Forty-four patients with sagittal fractures of ZAR occurring with ZMC fractures were evaluated from 2012 to 2021. Open reduction and internal fixation were performed on all patients with ZMC fractures. Closed reduction using Dingman incision and external finger pressure in group A (indirect approach; 30 patients) and single-screw fixation using a preauricular approach in group B (direct approach; 14 patients) were performed to address sagittal fractures in ZAR. For single-screw fixation, the additional mean operation time was 11.34±3.25 minutes. On postoperative 3-dimensional computed tomography and plain radiographs, group B showed more accurate reduction and less deformity and trismus ( P <0.05). Moreover, a normal diet was initiated more quickly in group B than in group A ( P <0.05). Some cases in group A showed nonunion or malunion. This study revealed that a direct approach (group B) toward sagittal fractures of ZAR is recommended due to more accurate results and fewer complications than those observed with the indirect approach (group A). Moreover, the total operation time and complications may be lesser than those with the bicoronal approach.

Cortical lag screw fixation for the management of mandibular injuries

Objectives

Here, we present cases of mandibular fracture that were managed with the cortical lag screw fixation technique (CLSFT) in order to critically evaluate technique indications and limitations of application at various fracture sites.

Materials and Methods

This was a retrospective cohort study. The study sample was composed of patients suffering from mandibular fractures that were treated by the CLSFT. The outcome variables were fracture type, duration of surgery, number of screws, and pattern of application. Other study categories included patient demographics and causes of injury. Chi-square tests were used to assess descriptive and inferential statistical differences, and the P-value was set at 0.05.

Results

Thirty-three patients were included in the study sample, with a mean age of 30.9±11.5 years and a male predominance of 81.8%. The technique was applied more frequently in the anterior mandibular region (51.5%) than in other sites. Double CLSFT screws were required at the symphysis and parasymphysis, while single screws were used for body and angle regions. No intraoperative and postoperative variables were significantly different except for surgical duration, which was significantly different between the sites studied (P=0.035).

Conclusion

We found that CLSFT is a rapid, cost-effective technique for the fixation of mandibular fractures yielding good treatment results and very limited complications. However, this technique is sensitive and requires surgical expertise to be applied to mandibular fractures that have specialized characteristics.

Comparative Three-Dimensional Finite Element Analysis on Miniplate and Lag Screw Fixation to Symphysis Fractures

The purpose of this study was to compare the amount of stress on the fracture site via three-dimensional finite element analysis between lag screw and miniplate systems. Solid mathematical models were created from the CT of a patient and a fracture observed in the symphysis area. On the fracture site mini plates and lag screws applied to the bone to fixate segments. The physiologic mastication chewing forces were applied for simulation. These 2 fixation methods: were evaluated by their amount of stress values. The maximum Von Misses stress lag screw model was 2727 MPa on the apex of the lag screw and 934 MPa on the fracture site of the screw. At the miniplate model, the maximum Von Misses stress was 571 MPa on the head of the miniplate screw, and it was 202 MPa on the fracture site. Thus, lag screw model causes at least 4 times higher stress values than mini plate model. The stress level of lag screw model is higher than miniplate model. However, when the chewing forces are taken into account, the amount of stress in the lag screw system is also acceptable in clinical applications.

Osteosynthesis of segmental alveolar fractures by internal fixation and the prognosis of the fractures and teeth

BACKGROUND/AIMS

Fracture of the alveolar process is a common injury, but the traditional splinting fixation may not be possible in some cases. The aim of this study was to describe the osteosynthesis performed in segmental alveolar fractures by internal fixation and evaluate the prognosis of the fractures and teeth involved.

MATERIALS AND METHODS

Twenty-two patients who were identified as having segmental alveolar fractures treated with osteosynthesis by internal fixation at the authors' department from January 2007 to December 2016 were included with 90 traumatized teeth. The prognosis of the fractures and teeth involved in the fractures was evaluated by the post-operative computed tomography combined with a follow-up study.

RESULTS

All patients achieved healing and consolidation of the alveolar fractures. Furthermore, the occlusion was restored and the wounds healed. During the surgical procedures, no observed iatrogenic dental damage caused by the interdental drilling was found. Eventually, only 15.6% of the teeth had pulp necrosis, whereas the other healing complications were rare or not observed in the study.

CONCLUSIONS

Osteosynthesis by internal fixation is an effective and safe treatment for some segmental alveolar fractures. The teeth involved in these fractures also have good prognosis.

Use of Transgingival Lag Screw Osteosynthesis in the Management of Alveolar Process Fracture

The purpose of this study is to check the efficacy of transgingival lag screw osteosynthesis in alveolar process fractures of maxilla and mandible. A single-arm nonrandomized observational study was performed for the treatment of alveolar process fractures of maxilla and mandible. In this study, 20 mixed age group patients with alveolar process fracture were included. All the patients were treated by a 2.0-mm transgingival screw fixation under local or general anesthesia. All the patients were evaluated for fracture stability, anatomical reduction, bone loss and bone resorption of alveolar process, tooth loss, and wound infection at 3 months of follow-up. A simple descriptive statistical analysis was done to evaluate the parameters and it was shown that the treatment of alveolar process fracture with two or three lag screws provides adequate fracture stability and anatomical reduction with no signs of bone loss and tooth loss, and wound infections were noted post lag screw fixation. The study concludes that transgingival lag screw fixation is a suitable alternative for alveolar process fractures in all the age groups and two to three lag screws are generally sufficient to fix fractured alveolar process either under local anesthesia or general anesthesia.

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.

Diagnosis of alveolar and root fractures in macerated canine maxillae: a comparison between two different CBCT protocols

OBJECTIVES

To compare two small-field-of-view (FOV) CBCT protocols with different voxel sizes and number of frames for the diagnosis of root and alveolar fractures in macerated canine maxillae.

METHODS

80 incisor teeth from the canine species were inserted in 80 anterior alveolar sockets of 20 canine maxillae. An operator randomly divided each maxilla site (80 sites in total) into 4 equal groups of 20 sites: 1 (sound tooth and non-fractured alveolar socket); 2 (sound tooth and fractured alveolar socket); 3 (fractured root and non-fractured alveolar socket); and 4 (fractured root and fractured alveolar socket). The CBCT images were obtained using two different protocols: normal (N) (voxel 0.20 mm, 400 frames and radiation exposure 5.6 mGy) and high definition (HD) (voxel 0.15 mm, 500 frames and radiation exposure 7.0 mGy).

RESULTS

Sensitivity numbers for alveolar fractures were lower than specificity, resulting in comparable areas under the receiver operating characteristic curves (AUC) for both protocols. Sensitivity, specificity and AUC for N and HD protocols were very similar for root fractures. When comparing AUC for both N and HD protocols by submitting them to Student's t-test, the comparison among the curves produced statistically non-significant results for alveolar fractures and root fractures likewise.

CONCLUSIONS

Our findings demonstrated that the elected protocol for the diagnosis of root and alveolar fractures was N. This protocol allowed similar diagnosis results than HD protocol; however, with a lower amount of radiation exposure for the patient (5.6 mGy for N vs 7.0 mGy for HD).