Sequential application of novel guiding plate system for accurate transoral mandibular reconstruction

Combined Use of Endoscopic Techniques and Virtual Surgical Planning for Intraoral Approach for Hemi-mandibular Resection and Reconstruction

Background

The study aimed to describe our experience in using endoscopic procedures to aid hemi-mandibular reconstruction with bone flaps through transoral approach.

Methods

Five patients with huge benign mandibular tumors underwent transoral mandibulectomy and hemi-mandibular reconstruction, using endoscopy. Facial symmetry, occlusion, bone healing, and mandibular similarity were all evaluated postoperatively. The paired-samples t test was used to compare quantitative data, and a P value less than 0.05 was considered a significant difference.

Results

All five patients who received transoral mandibular surgery recovered in terms of TMJ functionality, facial symmetry, and aesthetic results. Endoscopy monitored and ensured that bone flaps were correctly connected and fixed. The accuracy of endoscopy-guided mandibular reconstruction was confirmed by quantitative examination for four cases, which revealed no statistically significant variations between postoperative CT analysis and preoperative virtual surgical planning data.

Conclusions

Endoscopy-assisted virtual surgery may resolve concerns with transoral hemi-mandibular reconstruction and broaden indications for mini-invasive mandibular reconstruction. However, only patients with benign mandibular tumors were included in our study, so surgeons should be very cautious if applying this technique to malignant lesions or bony tumors invading soft tissues.

Planning of physiotherapeutic procedure in patients after mandible reconstruction taking into account donor site: a literature review

BACKGROUND

Mandible tumors are very rare. One of the main methods of the treatments is resection of the tumor and then reconstruction of the mandible. The donor site is often distant tissue-fibula or ilium. Following this, it is necessary to improve the patient in two ways, on one hand restoring the function of the mandible, and on the other hand, improving the donor site area. For that reason, physiotherapy after tumor resection and reconstruction of the mandible is very complicated. The aim of this bibliographic review was to find the methods of the reconstruction of the mandible in the context of patients' functional assessment after surgeries to create effective physiotherapeutic procedures in the feature.

METHODS

PEDro, Medline (PubMed), Cochrane Clinical Trials were searched.

RESULTS

767 articles were found. 40 articles were included to this literature review.

CONCLUSIONS

Authors showed different kinds of surgeries strategy for patients with tumors of the mandible. They also showed manners of patients' functional assessment in the localization of transplantation and donor site. It could be useful for physiotherapists during planning of comprehensive physiotherapy.

A 3D segmentation network of mandible from CT scan with combination of multiple convolutional modules and edge supervision in mandibular reconstruction

Mandibular reconstruction is a very complex surgery that demands removing the tumor, which is followed by reconstruction of the defective mandible. Accurate segmentation of the mandible plays an important role in its preoperative planning. However, there are many segmentation challenges including the connected boundaries of upper and lower teeth, blurred condyle edges, metal artifact interference, and different shapes of the mandibles with tumor invasion (MTI). Those manual or semi-automatic segmentation methods commonly used in clinical practice are time-consuming and have poor effects. The automatic segmentation methods are mainly developed for the mandible without tumor invasion (Non-MTI) rather than MTI and have problems such as under-segmentation. Given these problems, this paper proposed a 3D automatic segmentation network of the mandible with a combination of multiple convolutional modules and edge supervision. Firstly, the squeeze-and-excitation residual module is used for feature optimization to make the network focused more on the mandibular segmentation region. Secondly, the multi atrous convolution cascade module is adapted to implement a multi-scale feature search to extract more detailed features. Considering that most mandibular segmentation networks ignore the boundary information, the loss function combining region loss and edge loss is applied to further improve the segmentation performance. The final experiment shows that the proposed network can segment Non-MTI and MTI quickly and automatically with an average segmentation time of 7.41s for a CT scan. In the meantime, it also has a good segmentation accuracy. For Non-MTI segmentation, the dice coefficient (Dice) reaches 97.98 ± 0.36%, average surface distance (ASD) reaches 0.061 ± 0.016 mm, and 95% Hausdorff distance (95HD) reaches 0.484 ± 0.027 mm. For Non-MTI segmentation, the Dice reaches 96.90 ± 1.59%, ASD reaches 0.162 ± 0.107 mm, and 95HD reaches 1.161 ± 1.034 mm. Compared with other methods, the proposed method has better segmentation performance, effectively improving segmentation accuracy and reducing under-segmentation. It can greatly improve doctor's segmentation efficiency and will have a promising application prospect in mandibular reconstruction surgery in the future.