Rehabilitation of mandibular resected patients using fixed immediately loaded corticobasal implant -supported prostheses. A case series

INTRODUCTION AND IMPORTANCE

Aliments such as congenital conditions, pathological, and iatrogenic circumstances may result in mandibular defects that can severely disturb the patients' oral health, functions (mastication, speech), aesthetics, and quality of life and present a rehabilitating challenge.

CASE PRESENTATION

we present a multidisciplinary treatment approach for three cases presented with mandibular resection as a consequence of cystic, benign, and malignant tumour eradication that were rehabilitated with immediately loaded fixed corticobasal implant-supported prostheses and a follow-up period of 5,5 and 4 years. The reported cases present with excellent implant survival, along with healthy peri-implant tissues, stable prostheses, enhanced speech, chewing ability, aesthetics, superior patient satisfaction, and improved overall self-esteem.

CLINICAL DISCUSSION

A multidisciplinary oral and maxillofacial team is mandatory for the successful rehabilitation of patients with mandibular resection and to restore soft and hard tissue loss. The reported treatment modality offers the patient immediate fixed implant-supported prostheses omitting the need for a bone grafting procedure, with optimum peri-implant tissue health, excellent biomechanical and prosthetic results, and significant improvement in function and satisfaction.

CONCLUSION

Corticobasal fixed implant-supported prostheses can be a reliable treatment modality for mandibular resection, resulting in notable enhancements in the patients' oral health, appearance, mastication, speech, and self-esteem.

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques

OBJECTIVES

To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images.

METHODS

Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender.

RESULTS

In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively.

CONCLUSIONS

This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

Effect of segmental versus marginal mandibular resection on local and lymph node recurrences in oral squamous cell carcinoma: is tumorous bone infiltration or location and resulting soft tissue recurrences a long-term problem?

PURPOSE

Oral squamous cell carcinomas (OSCCs) adjacent to the mandible or with clinically suspected bone infiltration are surgically treated either with marginal or segmental resections. This retrospective study compared both resections regarding local recurrence and lymph node recurrence or secondary lymph node metastases.

METHODS

All consecutive primary OSCC cases between January 2007 and December 2015 that underwent mandibular marginal or segmental resection were included. Rates of local and lymph node recurrences or secondary metastases and possible risk factors such as tumor localization according to Urken's classification were recorded.

RESULTS

In total, 180 patients with 85 marginal (group I) and 95 segmental (group II) mandibular resections were analyzed. The local recurrence rates were comparable between the groups (28.2% vs. 27.4%; p = 0.897). Lymph node recurrences or secondary metastases were higher in group I (9.4% (n = 8) vs. 6.2% (n = 6); p = 0.001). Tumor localization appears to affect the outcomes. Significantly fewer local and lymph node recurrences/metastases were found for Urken's classification SB and S calculated by two-proportion z-test (p = 0.014 and 0.056, respectively). Local recurrences mostly emerged from soft tissues, which should be resected more radically than the bones.

CONCLUSION

While bone infiltration appears technically well controllable from an oncologic point of view, local recurrences and lymph node recurrences/metastases remain an issue. Regular clinical aftercare with imaging is crucial to detect recurrences.

Inferior alveolar nerve reconstruction in extensive mandibular resection: Technical notes

The inferior alveolar nerve (IAN) is a sensitive branch of the mandibular nerve innervating the lower lip, the chin, the buccal mucosa and the teeths. Lesions of the IAN are reported to occur in the 64,4% of maxillo-facial procedures, leading to anesthesia, hypoestesia and/or neurogenic discomfort. An extensive segment of the nerve can be moreover removed during mandibular resection for benign or malignant pathologies. Nervous grafts can be used in these cases to restore the nerve continuity. In order to optimize the procedure and to allow a concomitant mandibular osseous reconstruction, the Authors identified several standardized steps. The technique described allows to perform confortable and safe nervous anastomoses and to reduce the risk of damage and tension during the flap insetting phases.

Rehabilitation of an irradiated marginal mandibulectomy patient using immediately loaded basal implant-supported fixed prostheses and hyperbaric oxygen therapy: A 2-year follow-up

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Mandibulectomy after oral cancer resection can cause severe facial disfigurement.

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The use of adjunctive radiotherapy may compromise the success rate of reconstructive implant therapy.

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Hyperbaric oxygen therapy (HBO) can repair tissue damage after radiotherapy.

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Basal implants reduces risk of peri-implantitis and osteoradionecrosis.

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This report describes HBO and basal implant treatment for marginal mandibulectomy.

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HBO and basal implants are successful treatment modalities for these patients.

Introduction

The prosthetic rehabilitation of mandibular defects owing to tumor resection is challenging, especially when the patient has undergone subsequent radiotherapy.

Presentation of case

A 46-year old male presented with a marginal mandibular resection. Following surgery, the patient received adjunctive radiation therapy with a total dose of 70 grays. On clinical examination, the patient presented with severely resorbed edentulous jaws, with an anterior marginal mandibular resection and an obliterated vestibular sulcus. The panoramic radiograph showed a hypocellularity of the maxillary and mandibular bones. A multidisciplinary team was formed, and a treatment plan was formulated which involved the construction of a vestibuloplast stent, and the application of 20 hyperbaric oxygen sessions before implant treatment and 10 more sessions after implant insertion. A total of 16 basal cortical screw implants were inserted to support the fixed prostheses, and a vestibuloplasty was performed to improve esthetics. No complications were observed, and at the 2-year follow-up, the patient presented with excellent peri-implant soft tissue health; increased bone-implant contact; and stable, well-functioning prostheses.

Discussion

The construction of a stable, retentive, well-supported removable prosthesis may be complicated in cases of comprehensive mandibular resection. Basal implants can eliminate the need for bone grafting, and reduce the treatment period required for providing a fixed prosthesis.

Conclusion

To our knowledge this is the first evidence reporting the use of fixed basal implant-supported prostheses in irradiated bone, in conjunction with hyperbaric oxygen therapy. A treatment modality that significantly improves the peri-implant tissue health, and ensures an excellent implant-bone contact.

Full-staged digital and prosthetic guided protocol for the insertion of dental implants in autogenous free bone grafts after reconstruction of segmental mandibular defects

PURPOSE

This study aims to evaluate the clinical and radiographic outcomes of dental implants, inserted in consolidated free bone grafts; postsegmental mandibular resection, after following a fully guided staged protocol, which established a systematic approach that correlates the grafted bone and the enclosed implants to the undisturbed mandibular segments and the maxillary occlusal plane.

METHODS

Seven patients were enrolled in the study; all were diagnosed for mandibular locally aggressive tumors. All of the patients were subjected to computer-guided segmental mandibular resections, secondary free iliac crest bone graft; aided by computer-guided harvest and prosthetic guidance of the graft positioning and fixation. Finally, the guided bone grafts; after being consolidated, received twenty-nine computer-guided dental implants.

RESULTS

By the end of the period of osseointegration, the predetermined criteria of implant success judged the success of twenty-five implants, versus the failure of four implants, with (86.2%) percentage of success.

CONCLUSION

The clinical and radiographic assessments demonstrated sound base bone grafts, which succeeded not only to restore the native mandibular continuity and configuration but also to direct the fair-sized embedded dental implants into favorable coastal locations and axial projections, which influenced a smooth prosthetic rehabilitation.

Use of a CAD-CAM inferior alveolar nerve salvage template during mandibular resection for benign lesions

During surgical procedures involving the mandible, preserving the inferior alveolar nerve (IAN) may be preferable for benign tumours. In this prospective pilot study, we report our experience on the use of a Rapid Inferior Alveolar nerve Customised Salvage (RICS) template. Virtual surgical planning (VSP) of the template is based on a 3D model obtained from the elaboration of DICOM files of the preoperative CT scan. Five patients affected by benign mandibular pathology were included. A total of 7 IANs were exteriorised. The average time of exteriorisation was 23 minutes. All exteriorisations were performed successfully and no damage to the neuro-vascular bundle occurred. All patients showed complete recovery of sensitivity of the IAN within 7 weeks after surgical procedure. In conclusion, RICS template seems to allow faster and safer exteriorisation of the IAN.

A bar and ball attachment prosthesis over osseointegrated implants post mandibular resection

Rehabilitation of mandibular resection poses functional, esthetic, and psychological challenges. The deviation and rotation of the mandible toward the resected side leaves the patient with almost no option of chewing. This is aggravated if the patient is edentulous. The case report discussed in this article was an edentulous patient taken up with the primary goal to limit deviation toward resected side and provide a stable and retentive prosthesis to the patient. Two implants were placed anteriorly, splinted with bar and clip supported superstructure. The splinted implants with bar and clip superstructure provided the mandibular prosthesis with retention and some support. A posterior implant was also placed in the region of mandibular first molar on the left side for added support. This provided with a tripod configuration and limited the prosthetic movement of the mandibular prosthesis. This case report highlights an alternate way toward the rehabilitation of edentulous mandible post mandibular resection when surgical reconstruction may not be feasible.

Accuracy of virtually 3D planned resection templates in mandibular reconstruction

OBJECTIVE

Since reconstruction of composite defects in the head and neck region is a challenging and demanding problem for head and neck surgeons, surgical aids have been sought for decades. The purpose of this study was to evaluate the accuracy of prefabricated surgical resection templates used in mandibular segmental resections in comparison to the virtual surgical plan.

MATERIALS AND METHODS

A prospective study was performed in 11 consecutive patients, with a primary T4 oral squamous cell carcinoma or osteoradionecrosis of the mandible. Preoperatively, a CBCT scan was acquired to delineate the size and extension of tumor invasion; a virtual patient-specific resection template was designed based on this information. Intraoperatively, the resection template was positioned on the mandible and secured using four fixation screws. Postoperatively, a CBCT scan was acquired. This scan was superimposed on the preoperative scan. Positioning of the resection template and inclination of the resection planes were evaluated on the virtual head model. In order to test the interobserver reliability of these new measurement methods, two different observers executed all measurements.

RESULTS

The mean shift of the proximal resection templates was 3.76 mm (standard deviation [SD] 3.10 mm). For the distal resection templates, the mean shift was 3.06 mm (SD 1.57 mm) with no significant interobserver difference (ICC = 0.99). An absolute mean deviation of 8.5° (SD 5.3°) was found for the proximal resection angle and 10.4° (SD 5.0°) for the distal resection angle. Again, no significant interobserver differences were found (ICC = 0.98).

CONCLUSION

The resection templates used in this study proved reasonably accurate. Although the concept of virtual surgical planning aids significantly in mandibular reconstruction with microvascular free flaps, further improvement of resection accuracy is necessary for further improvement of reconstruction accuracy.

A two-year audit of non-vascularized iliac crest bone graft for mandibular reconstruction: technique, experience and challenges

Objectives

Non-vascularized iliac crest bone graft (NVIBG) is a known treatment option in mandibular reconstruction following jaw resection, but no documented review of patients treated with NVIBG exists for northern Nigeria. The experience and technique from a Nigerian tertiary hospital may serve as baseline data for comparison and improvement of practice for other institutions.

Materials and Methods

A retrospective review of medical records and patient case files from January 2012 to December 2013 was undertaken. All case files and other medical records of patients who had reconstruction with NVIBG for benign or malignant lesions with immediate or delayed reconstruction were selected for review.

Results

Twenty patients had mandibular reconstruction with NVIBG during the study period. Two patients were excluded because of incomplete medical records. Eighteen patients' (male=14, female=4) records were reviewed. Their ages ranged from 13 to 62 years (mean 26.0±10.6 years). Indications for NVIBG included jaw tumors (n=16; 88.3%), jaw cyst (n=1; 5.6%) and gunshot injury (n=1; 5.6%). Jaw tumors seen were ameloblastoma (n=15; 83.3%) and osteosarcoma (n=1; 5.6%). Treatments done were mandibular resection with condylar resection (n=7; 38.9%), mandibular segmental resection (n=10; 55.6%) and subtotal mandibulectomy (n=1; 5.6%). Patients' postoperative reviews and radiographs revealed good facial profile and continued bone stability up to 1 year following NVIBG.

Conclusion

NVIBGs provide an acceptable alternative to vascularized bone grafts, genetically engineered bone, and distraction osteogenesis for mandibular reconstruction in resource-limited centers.