A simple method for bone positioning of mandibular segments

Controlling and Stabilising Mandible During Reconstruction: Significance and Techniques

Objective

Stable and accurate positioning of condyle in the glenoid fossa is necessary for maintaining occlusion, facial symmetry and normal function of the temporomandibular joint following segmental resection of mandible. In non-reconstructed mandibular segments or those with fractured reconstruction plates the bony defect gets altered due to contraction or inadvertent muscular pull. This paper describes various techniques used to control dentate and edentate segments of the mandible during reconstruction following an ablative procedure.

Discussion

Secondary mandibular reconstruction has always been a tedious task for the surgeons. Several techniques have been described in literature ranging the use of external fixators, gunning splints and dentures for stabilising mandibular segments. Use of a pre-bent and adapted reconstruction plate is a common practice but may not be feasible in malignancies, benign tumours causing expansion and secondary reconstruction. The current advances in virtual surgical planning allows mandibular reconstruction to be performed in a simpler yet predictable manner.

Conclusion

The paper describes techniques ranging from twin K-wire placement to occlusal wafers, 3D printed splints and patient specific implants to enable accurate positioning of the segments and achieve pre-operative form. Advances in virtual surgical planning will continue to allow this field to evolve and to improve the quality of life of the patients.

Infrazygomatico-coronoid fixation in a segmental mandibular reconstruction with a free vascularized flap: A simple and correct repositioning method without interfering with reconstructive and microsurgical procedures

BACKGROUND

In a segmental mandibular reconstruction with a free vascularized flap, reproducing the optimal relationship between the condyle and glenoid fossa, and maintaining correct occlusion are important. We examined the practicality of a repositioning technique that combined bone plate fixation of the infrazygomatic crest and the coronoid process (infrazygomatico-coronoid fixation [IZCF]) with maxillo-mandibular fixation (MMF).

METHODS

Eight patients were treated with this method. To investigate masticatory function, the status of the dental and temporomandibular joints were examined, and a food scale questionnaire was administered.

RESULTS

IZCF and MMF resulted in correct repositioning of the segmented mandibles and enabled accurate reconstructions. Most patients recovered to be able to ingest the same preoperative food in scale with stable occlusion.

CONCLUSION

This method is a simple and correct repositioning method without interfering with reconstructive and microsurgical procedures. We propose this technique as a reliable method for obtaining a functional outcome in mandibular reconstruction. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

CAD/CAM splint based on soft tissue 3D simulation for treatment of facial asymmetry

BACKGROUND

Most cases of facial asymmetry involve yaw deformity, and determination of the yaw correction level is very difficult.

METHODS

We use three-dimensional soft tissue simulation to determine the yaw correction level. This three-dimensional simulation is based on the addition of cephalometric prediction to gradual yaw correction. Optimal yaw correction is determined visually, and an intermediate splint is fabricated with computer-aided design and computer-aided manufacturing. Application of positioning devices and the performance of horseshoe osteotomy are advisable.

RESULTS

With this procedure, accurate repositioning of jaws was confirmed and patients obtained fairly good facial contour.

CONCLUSIONS

This procedure is a promising method for a widespread, predictable treatment of facial asymmetry.

A novel modification of a bone repositioning device and a new technique for reestablishing facial contours after mandibular resection surgery

A novel modification of a bone repositioning device previously published by the same authors is introduced. A flexible tube to define the intersegmental bony relationship is filled with light-cured resin. It solidifies following exposure to strong visible light for about 1 min. This technique can be used for bone positioning after mandibular resection surgery and during positioning of the proximal segment after sagittal split ramus osteotomy. The authors also propose a simple method for determining the contour of the reconstructed mandible to regain the original shape and form. The advantage of this technique is its simplicity and flexibility compared with other methods of bone positioning during mandibular segmental surgery.