Evaluation of aesthetic outcomes of mandibular reconstruction using artificial intelligence

BACKGROUND

Although vascularized bone graft (VBG) transfer is the current standard for mandibular reconstruction, reconstruction with a mandibular reconstruction plate (MRP) and with a soft-tissue flap (STF) alone remain crucial options for patients with poor general conditions. However, objective aesthetic outcome evaluations for these methods are limited.

METHODS

In a retrospective analysis of 65 patients (VBG, 33; MRP, 19; and STF, 13), mandibular asymmetry value was calculated for each patient's photograph using facial recognition AI, with a higher value indicating worse asymmetry.

RESULTS

The MRP group had a value comparable to the VBG group regardless of mandibular defect types. The STF group had a significantly higher value than the VBG group.

CONCLUSIONS

Regarding cosmesis, STF was inferior to VBG, whereas MRP was comparable to VBG, even for anterior defects for which rigid reconstruction is mandatory. However, MRP's risks of plate-related complications limit its use to cases where VBG is contraindicated or with poor prognosis.

LEVEL OF EVIDENCE: 4

Mandibular reconstruction in head and neck cancer: which is the gold standard?

INTRODUCTION

The aim of this study is to perform a systematic review to compare the outcomes of the different surgical options for mandibular reconstruction in head and neck cancer.

MATERIAL AND METHODS

93 articles were selected. Four groups were identified: titanium plate without flaps, titanium plate covered by soft tissue flap, bone tissue flaps and double flaps. We compared patients' characteristics, site of mandibulectomy, type of reconstruction and complications.

RESULTS

4697 patients were reported. The groups were not homogeneous regarding the type of defect and the treatment history. A significant difference in terms of post-operative complications was found between group 1 and group 2 (p < 0.00001), and between group 2 and group 3 (p < 0.00001). Total complications rate for group 4 was significantly higher when compared to group 3 (p < 0.00001), but no significant difference was found with group 2.

CONCLUSION

These results suggest that mandibular reconstruction using a microvascular bone flap is the best surgical option in patients without significant comorbidities.

Orocutaneous Fistula After Oral Cavity Resection and Reconstruction: Systematic Review and Meta-Analysis

OBJECTIVE

Orocutaneous fistula (OCF) after reconstruction for oral cavity resection can lead to prolonged hospitalization and adjuvant treatment delay. Few studies have examined factors leading to OCF after oral cavity resection. Primary objective: evaluate overall incidence and factors associated with OCF after oral cavity reconstruction.

DATA SOURCES

Scopus 1960-database was searched for terms: "orocutaneous fistula," "oro cutaneous fistula," "oral cutaneous fistula," "orocervical fistula," "oral cavity salivary fistula."

REVIEW METHODS

English language studies with >5 patients undergoing reconstruction after oral cavity cancer resection were included. About 1057 records initially screened; 214 full texts assessed; 78 full-texts included. PRISMA guidelines were followed, and MINORS criteria used to assess risk of bias. Data were pooled using random-effects model. Primary outcome was OCF incidence. Meta-analysis to determine the effect of preoperative radiation on OCF conducted on 12 eligible studies. Pre-collection hypothesis was that prior radiation therapy is associated with increased OCF incidence. Post-collection analyses: free versus pedicled flaps; mandible-sparing versus segmental mandibulectomy.

RESULTS

Seventy-eight studies were included in meta-analysis of overall OCF incidence. Pooled effect size showed overall incidence of OCF to be 7.71% (95% CI, 6.28%-9.13%) among 5400 patients. Meta-analysis of preoperative radiation therapy on OCF showed a pooled odds ratio of 1.68 (95% CI, 0.93-3.06). OCF incidence was similar between patients undergoing free versus pedicled reconstruction, or segmental mandibulectomy versus mandible-sparing resection.

CONCLUSION

Orocutaneous fistula after oral cavity resection has significant incidence and clinical impact. Risk of OCF persists despite advances in reconstructive options; there is a trend toward higher risk after prior radiation.

Comparison of surgical outcomes between primary plate and fibular flap transfer for reconstruction of segmental mandibular defects

PURPOSE

Although two ways of reconstruction have been reviewed for a long period, comparison of large sample size with nearly randomized patient selection is rare. Here, we compare the surgical outcomes of these two methods from two large medical institutes.

METHODS

Totally 176 patients were included from two medical centers with different protocols, 62 patients from MacKay Hospital repair defects with fibula flaps using reconstruction plates. Also 114 patients from Kaohsiung ChangGung Hospital treat with reconstruction plates combine anterior lateral thigh flaps, in which 12 cases had secondary fibula flap after plate exposure. Electronic medical records were reviewed retrospectively. Short (3-12 months) and long-term (>12 months) outcomes were evaluated.

RESULTS

Short-term evaluation revealed that the secondary fibula had a higher rate of vascular complications (33 vs. 6%, p = .02). Primary fibula had a higher risk of post reconstructive surgical debridement (60 vs. 40%, p = .018). Long-term follow-up revealed radiation therapy significantly worsened bone healing (p = .03). Primary fibula had a lower rate of screw loosening (14.0 vs. 40.3%, p = .002). Radiation therapy did not increase the plate exposure rate among the groups (33 vs. 27%, p = .389). Disease free survival showed no significant difference between two groups (53.1 ± 3.5 vs. 47.8 ± 2.8 months, p = .317).

CONCLUSION

Primary fibula reconstruction should be considered whenever possible to reduce the risk of late complications and simplifies the management after a potential plate exposure. Notably, radiation therapy apparently has no significant effect on plate exposure rate both in ALT or fibula groups.

Clinical Study of Reconstruction Plates Used in the Surgery for Mandibular Discontinuity Defect

BACKGROUND/AIM

Postresective mandibular reconstruction is common in cases of oral and mandibular tumors. However, complications such as plate fracture and/or plate exposure can occur. The purpose of this study was to analyze complications and survival of reconstructive plates used to correct mandibular defects caused by oral cancer.

PATIENTS AND METHODS

Clinical and radiological data from 34 patients were analyzed. Only discontinuous mandibular defect cases were included in this study. All cases were classified using the Hashikawa's CAT and Eichner's classification methods. Then, we determined whether these classifications and clinical treatment methods were significantly related to complications.

RESULTS

Complications after mandibular reconstruction occurred in 10 of 34 patients, specifically, two plate fractures, one screw fracture, and seven plate exposures occurred. The plate fractures occurred 5 and 6 months after operation, and the screw fracture occurred 39 months after operation. Using the Hashikawa's CAT classification, the two cases of plate fracture were one of AT type and the other of T type, and the screw fracture was AT type. Using Eichner's classification, all three cases of plate and screw fractures were B2 type.

CONCLUSION

We suggest that plate and screw fractures were caused by the type of mandibular defect and bite force.

Mandibular reconstruction in elderly patients

BACKGROUND AND OBJECTIVES

The choice of reconstructive technique for a segmental mandibular defect in elderly patients is controversial. The aim of this study was to establish an algorithm for selecting a method of mandibular reconstruction in elderly patients.

METHODS

We retrospectively evaluated 121 patients aged ≥65 years who underwent immediate microvascular mandibular reconstruction after oncologic resection. Patients were divided into three groups based on method of reconstruction: vascularized bone graft (n = 49), mandibular reconstruction plate and soft tissue flap (n = 22), and soft-tissue flap (n = 50). We compared perioperative outcomes among groups and investigated factors affecting the choice of reconstructive technique.

RESULTS

Rates of postoperative complications did not differ significantly among groups. Mandibular reconstruction plate was indicated only for anterior mandibular defects. Soft-tissue flap was indicated for posterior mandibular defects in patients aged ≥75 years or with a poor postoperative Eichner index.

CONCLUSIONS

Mandibular reconstruction plate and soft-tissue flap can be good alternatives to vascularized bone graft in the elderly. Our algorithm uses defect type, patient age, and postoperative Eichner index to determine reconstructive technique.

A "no-touch-technique" in mandibular reconstruction with reconstruction plate and free flap transfer

OBJECTIVE

Mandibular reconstruction with a mandibular reconstruction plate (MRP) and free flap transfer can involve serious plate-related complications. The aim of our study is to present our new "no-touch-technique" which keeps an MRP not contaminated to saliva during the entire operation for the reduction of plate-related complications.

PATIENTS AND METHODS

Data were retrospectively collected on 29 patients who had undergone segmental mandibulectomy for head and neck tumor and mandibular reconstruction with an MRP and free flap transfer from 2004 to 2013; 12 patients were reconstructed with our no-touch-technique from 2010 to 2013 (no-touch-technique group), and 17 patients with the conventional technique from 2004 to 2009 (conventional group). A rectus abdominis musculocutaneous flap or anterolateral thigh flap was transferred in all patients. The rates of perioperative recipient site complications including total flap necrosis, partial flap necrosis, wound infection, fistula formation and wound dehiscence, and reoperation for complications were compared between the groups.

RESULTS

All flaps were successfully transferred although one venous thrombosis formation occurred in the conventional group. The rate of wound infection in the no-touch-technique group (8.3%) was significantly lower than that in the conventional group (47.1%) (P = 0.04). Additionally, the rate of fistula formation in the no-touch-technique group (8.3%) tended to be lower than that in the conventional group (29.4%) (P = 0.35).

CONCLUSION

The results of our study showed that our no-touch-technique may be a safe and effective procedure for the prevention of perioperative plate-related complications for mandibular reconstruction with an MRP and free flap transfer.

Single versus dual venous anastomoses of the free fibula osteocutaneous flap in mandibular reconstruction: a retrospective study

OBJECTIVE

The present study was to compare the success rates of single venous anastomosis with dual venous anastomoses of the free fibula osteocutaneous flap in mandibular reconstruction.

PATIENTS AND METHODS

Retrospective review of all cases of mandibular reconstruction using free fibula osteocutaneous flaps performed by a single surgeon in our department during the period January 2005 to April 2012. All the flaps were harvested and transplanted by the standard protocols. Microvascular anastomosis of either one or two veins was performed. In addition to routine clinical evaluation, the viability of the flap was evaluated by a portable Doppler at the tenth day after surgery.

RESULTS

Two hundred and one free fibula osteocutaneous flaps were performed during this time period. Single venous anastomosis was performed in 112 flaps and dual venous anastomoses were performed in 89 flaps. The overall incidence of vascular thrombosis was 3%, and the success rate of the transplantation was 98.5%. Six cases developed vascular thrombosis postoperatively. One was arterial thrombosis that occurred 12 hours after initial operation in the dual venous anastomoses group. Three venous thrombosis occurred 24 hr after the operation in the single venous anastomosis group. In dual venous anastomoses group, two venous thrombosis occurred 3-4 days after initial operation and attempt to salvage failed in both the cases. Fisher's exact test showed that there was no significant difference of the success rate between single and dual anastomoses groups (P = 0.59).

CONCLUSIONS

There is no difference in success rates between single venous anastomosis and dual venous anastomoses for mandibular reconstruction with free fibula osteocutaneous flap.