Reconstruction of a palatomaxillary defect with vascularized iliac bone combined with a superficial inferior epigastric artery flap and zygomatic implants as anchorage

Multiple Buttresses Reconstruction of Maxilla with Fibular Flap Using Computer-aided Design/Computer-aided Manufacturing after Maxillectomy

Background

The maxilla comprises horizontal and vertical buttresses, each with specific functions, supporting various organs, such as the eyes, nose, and oral cavity. Notably, they combine to form a three-dimensional structure, which enables the buttresses to provide their inherent support strength. However, reconstructing the maxilla after maxillectomy by assembling new buttresses is challenging. We successfully reconstructed all the buttresses crucial for facial appearance and dental rehabilitation using a vascularized fibular flap.

Methods

Four patients underwent maxillary buttress reconstruction with a fibular flap after total or subtotal maxillectomy. We used computer-aided design/computer-aided manufacturing digital technology to osteotomize the fibula into multiple segments and assemble them to reconstruct the maxillary buttresses. Each buttress was assembled based on a preoperative simulation.

Results

All patients underwent immediate one-stage maxillary reconstruction. They had good maxillary buttress alignment and acquired good facial appearance, eye position, nasal airway, and prosthetically suitable maxillary alveolus ridge.

Conclusions

The combination of computer-aided design/computer-aided manufacturing digital technology and surgical techniques has enabled novel maxillary reconstruction, providing great hope to patients experiencing facial disfigurement and loss of function after maxillectomy.

Micromotion analysis of immediately loaded implants with Titanium and Cobalt-Chrome superstructures. 3D finite element analysis

Objective

The aim of this study was to evaluate the amount of micromotion of dental implants under immediate loading supported by Titanium (Ti) and Cobalt‐Chrome (Co‐Cr) superstructures.

Material and methods

A model of tridimensional half‐edentulous maxilla with three dental implants was made using the Finite Element Analysis (FEA). Two standard and one zygomatic implants were connected to a superstructure with an elliptic section of 6x 3 mm (mm). Two study models were established. Model A: Titanium (Ti) alloy superstructure; Model B: Cobalt‐Chrome (Co‐Cr) alloy superstructure. To simulate an immediate‐loading situation, a friction coefficient of 0.71 was applied between the implant and the bone surface. An axial load of 252.04 [N] was applied on standard and zygomatic implants.

Results

The Micromotion of dental implants was similar in both superstructure situations. The amount of micromotion was slightly higher in B1 and B3 models (Co‐Cr alloy‐superstructure) compared with A1 and A3 models (Titanium alloy superstructure). The micromotion values in two groups were greater than 150 μm in the incisive region (standard implant) and molar region (zygomatic). In general, the micromotion was higher on the implant that received the load with respect to the other implants. The greater difference was observed when the load was applied on the standard implant A1 (Model A1 = 189.12 μm) compared with standard implant B1(Model B1 = 263.25 μm).

Conclusions

Within the limits of present study, all implants on different load application points showed micromotion; in general, the amount of micromotion was slightly higher in the implants connected with Co‐Cr alloy superstructure.

Zygomatic implant-based rehabilitation for patients with maxillary and mid-facial oncology defects: A review

OBJECTIVES

This literature review reports the current evidence for the use of zygomatic implants in head and neck oncology patients for the prosthetic rehabilitation of defects of the mid-face and maxilla.

METHODS

MEDLINE, Embase and Cochrane databases were searched using strict search terms. Two independent reviewers reviewed the articles and applied inclusion and exclusion criteria.

RESULTS

Literature search revealed 437 articles, and following application of the inclusion criteria, 32 articles were included for analysis. Overall survival rates of 77%-100% were reported with few complications, although only four centres presented data on 20 or more patients. Primary implant placement at time of resective surgery has been shown to be an effective means of accelerating rehabilitation along with early loading protocols. The role of radiotherapy in implant failure has not been fully elucidated, and it is clear that zygomatic implants can be successfully used in the irradiated patient. Providing support for maxillary obturators was the most common use reported with both splinted and unsplinted implants.

CONCLUSIONS

Zygomatic implants provide remote anchorage for a variety of oral and facial prostheses that contribute to the improved function and quality of life for patients being treated for maxillary and mid-facial tumours.

Rehabilitation after maxillectomy in patients with implant-retained obturator: A preliminary report

OBJECTIVE

The aim of this study was to evaluate the clinical outcomes of implant-retained obturator rehabilitation after maxillectomy, based on quality of life (QOL) and masticatory function.

STUDY DESIGN

The present study included 12 patients who underwent dental implant surgery after maxillectomy. Oral health-related QOL and masticatory function before and after completion of implant-retained obturator rehabilitation were evaluated.

RESULTS

Oral Health Impact Profile-Short Form (OHIP-14) scores showed significant differences in the domain for functional limitation (before, 4.08 ± 2.47; after, 1.33 ± 0.98; P < .01); physical pain (before, 2.75 ± 2.05; after, 0.42 ± 0.51; P < .01); physical disability (before, 3.24 ± 2.11; after, 1.33 ± 1.30; P < .01), psychological disability (before, 3.83 ± 2.48; after, 1.67 ± 2.50; P < .01); social disability (before, 2.17 ± 1.75; after, 1.08 ± 1.38; P < .05); handicap (before, 3.17 ± 1.90; after, 1.08 ± 1.00; P < .01); and total score (before, 22.41 ± 10.17; after, 8.83 ± 6.82; P < .01) Furthermore, masticatory function score was significantly higher after completing implant-retained obturator rehabilitation (before, 38.75 ± 22.97; after, 69.17 ± 21.41; P < .01).

CONCLUSIONS

Implant-retained obturator rehabilitation contributed to improved masticatory function and oral health-related QOL after maxillectomy.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

Oral Rehabilitation of Oral Cancer Patients Using Zygomatic Implant-Supported Maxillary Prostheses with Magnetic Attachment: Three Case Reports

Maxillectomy for malignant tumor often results in a maxillary defect and serious oral dysfunction. A prosthesis is usually provided for postoperative oral rehabilitation of such patients with maxillary defects. However, the further the resected region extends, the less stable the prosthesis becomes, due to insufficient bone and tooth support. Therefore, in many cases, conventional resection dentures may not be adequate to restore the oral function. Effective utilization of dental and zygomatic implants may help to restore oral function in patients with severe maxillary defects. This clinical report describes the management of three patients with severe maxillary defects following cancer ablative surgery who were rehabilitated using maxillary prostheses with magnetic attachments supported by dental and zygomatic implants. Occlusal reconstruction was performed with removable prostheses supported with two or four implants and magnetic attachment. The oral function was evaluated before and after prosthodontic treatment with implants using the Oral Health Impact Profile (OHIP-14) and functional chewing score. Results indicated improvement in all cases. These findings show that quality of life (QOL) and oral function were improved.

Novel Patient-Specific 3-Dimensional Printed Fixation Tray for Mandibular Reconstruction With Fibular Free Flaps

Segmental mandibular defects secondary to infectious, traumatic, and pathologic conditions can be debilitating because of their impact on function and facial esthetics. Several reconstructive techniques are available, with vascularized flaps commonly used for the reconstruction of large bony or composite segmental defects. The free fibular flap for mandibular reconstruction is well documented and remains a commonly used flap because of its bone length, versatility, distant location from the head and neck region that allows for a 2-team approach, and ability to simultaneously place endosseous implants. Virtual surgical planning (VSP) and guided resection and reconstruction of maxillofacial defects have facilitated complex 3-dimensional (3D) reconstruction. The accuracy and fidelity of VSP are dependent on the intraoperative execution of the VSP, with computer-aided design and computer-aided modeling of patient-specific cutting guides and hardware providing a template for its execution. The goal of this report is to describe the authors' experience with the use of a novel 3D printed fixation tray designed from the VSP data. It provides dual functionality by aiding in alignment and stabilization of the fibular segments and concomitantly providing patient-specific anatomic references for indexing of bony and soft tissue components. This tray enables rapid ex vivo configuration of the fibula segment(s) with the reconstruction bar relative to the native mandibular segments and allows the compiled construct to be transferred to the head and neck for insetting as a precisely configured single unit.

Prosthetic versus surgical rehabilitation in patients with maxillary defect regarding the quality of life: systematic review

PURPOSE

To assess the ability of prosthetic rehabilitation versus surgical rehabilitation in improving the QOL for patients with maxillary defects.

MATERIAL AND METHODS

A systematic search of PubMed, Scopus data base, Cochrane database, Ovid database, and Latin America & Caribbean database for articles published before September 2017 was performed by two independent reviewers. A manual search of articles published from January 2000 to September 2017 was also conducted. Only English studies were included which evaluate the QoL in patients with head and neck cancers. Any confusion between the two independent reviewers was resolved by means of a moderated discussion between the reviewers.

RESULTS

Five studies fulfilled the inclusion criteria for this study. Many parameters were used regarding evaluation of QOL as the EORTC Head and Neck 35 assessment, UW-QOL, OHIP-14, VAS, OFS, MHI, HAD, Body Satisfaction Scale, Oral symptom check list, Swallowing, Diet consist, Pain control, Postoperative complication, and Speech. Two studies supported the surgical line of treatment for improving the QOL as compared to the prosthetic one; another two studies showed a statistically insignificant improvement in the patients' QOL with the surgical line, while only one revealed insignificant difference in QoL with both lines of treatment.

CONCLUSIONS

Surgical rehabilitation provides a better line of treatment in improving the QOL for patients with maxillary defects. On the other hand, prosthetic has proved effectiveness in the immediate post-surgical times as temporary strategy, and it has represented a good alternative when the surgical obturation is compromised.

Advantages and disadvantages of 3-dimensional printing in surgery: A systematic review

BACKGROUND

Three-dimensional (3D) printing is becoming increasingly important in medicine and especially in surgery. The aim of the present work was to identify the advantages and disadvantages of 3D printing applied in surgery.

METHODS

We conducted a systematic review of articles on 3D printing applications in surgery published between 2005 and 2015 and identified using a PubMed and EMBASE search. Studies dealing with bioprinting, dentistry, and limb prosthesis or those not conducted in a hospital setting were excluded.

RESULTS

A total of 158 studies met the inclusion criteria. Three-dimensional printing was used to produce anatomic models (n = 113, 71.5%), surgical guides and templates (n = 40, 25.3%), implants (n = 15, 9.5%) and molds (n = 10, 6.3%), and primarily in maxillofacial (n = 79, 50.0%) and orthopedic (n = 39, 24.7%) operations. The main advantages reported were the possibilities for preoperative planning (n = 77, 48.7%), the accuracy of the process used (n = 53, 33.5%), and the time saved in the operating room (n = 52, 32.9%); 34 studies (21.5%) stressed that the accuracy was not satisfactory. The time needed to prepare the object (n = 31, 19.6%) and the additional costs (n = 30, 19.0%) were also seen as important limitations for routine use of 3D printing.

CONCLUSION

The additional cost and the time needed to produce devices by current 3D technology still limit its widespread use in hospitals. The development of guidelines to improve the reporting of experience with 3D printing in surgery is highly desirable.

Advances in oncologic head and neck reconstruction: systematic review and future considerations of virtual surgical planning and computer aided design/computer aided modeling

BACKGROUND

Mastery of craniomaxillofacial reconstruction has been traditionally considered to be learning curve dependent, often with inconsistent results during the skill acquisition phase. Until recently, the overall success in bony oncologic reconstruction of the craniomaxillofacial skeleton has relied mainly on the use of 2D imaging modalities, as well as surgical trial-and-error. Virtual surgical planning (VSP) and computer aided design (CAD)/computer aided modeling (CAM) are gaining traction in oncologic applications and offers opportunity for increased accuracy, improved efficiency, and enhanced outcomes. Its role in oncologic head and neck reconstruction has not been formally evaluated.

METHODS

A systematic review of the current literature was conducted by three independent reviewers. Three separate search schemes were utilized to identify cases incorporating VSP-CAD/CAM technology in head and neck reconstruction for an oncologic indication. Inclusion and exclusion criteria were applied; articles that met criteria were evaluated for cohort demographics, osteocutaneous flap type and usage, oncologic indication, recipient bone reconstructed, flap survival, follow up, VSP technology usage, specific reported benefits of the technology, and qualitative and quantitative outcome assessments.

RESULTS

The systematic literature review yielded 87 articles; of these, 33 met inclusion criteria describing a total of 220 cases of oncologic head and neck reconstruction incorporating virtual planning technology. Numerous qualitative benefits of VSP were reported including increased accuracy of the reconstruction (93%), decreased intraoperative time (80%), and ease of use (24%) among others. However, quantitative results using survey data or preoperative/postoperative CT scan comparisons were given for only 33% (3%, 30% respectively) of cases.

CONCLUSION

VSP represents an evolving technology that ushers oncological craniomaxillofacial reconstruction into a modern era that holds potential to advance the field with increased reconstructive accuracy, expedition of the surgical phase, and improved outcomes. While qualitative improvements from the technology are delineated, specific quantifiable benefits and cost-benefit analysis are limited and need to be further investigated.

Finite element analysis of three zygomatic implant techniques for the severely atrophic edentulous maxilla

STATEMENT OF PROBLEM

A variety of zygomatic implantation techniques currently exist; however, a consensus regarding the most suitable method has not yet been reached.

PURPOSE

The purpose of this study was to evaluate and compare 3 zygomatic implantation techniques and to clarify the optimal number and position of zygomatic and dental implants for the reconstruction of the severely atrophied edentulous maxilla.

MATERIAL AND METHODS

A 3-dimensional finite element analysis craniofacial model was constructed from the computed tomography data of a selected patient with a severely atrophic edentulous maxilla. Modeled zygomatic implants were inserted into the craniofacial model with 3 surgical techniques (classic Brånemark, exteriorized, and extramaxillary), and with 3 model variations that involved the number and position of zygomatic and dental implants. The zygomatic implants were loaded with a vertical force of 150 N and a lateral force of 50 N. The stresses on and deformations of the bones and implants were then observed and compared.

RESULTS

No obvious differences in the amount and distribution of stress on the external craniofacial bones were detected in the models. The lowest stresses on the zygomatic implants were observed in the exteriorized technique group. The lowest deformations of the bone that surrounds zygomatic implants and dental implants were observed in the exteriorized technique and classic Brånemark technique groups. For the exteriorized technique group, the model with 1 dental implant in the site of the maxillary lateral incisor exhibited the lowest stress on the zygomatic implants and the least deformation of the bone surrounding the zygomatic and dental implants.

CONCLUSIONS

All 3 zygomatic implant techniques resulted in more or less homogeneous transference of force and thus could reconstruct the edentulous maxilla; however, the exteriorized technique with 1 dental implant in the lateral incisor appeared to be the most appropriate reconstruction method for the severely atrophied edentulous maxilla.

Evaluation of the effect of computed tomography scan protocols and freeform fabrication methods on bone biomodel accuracy

OBJECTIVE

To assess the effect of computed tomography (CT) scan protocols (radiation amounts) and fabrication methods on biomodel accuracy and variability.

SAMPLE

Cadaveric femur of a Basset Hound.

PROCEDURES

Retroreconstructions (n = 158) were performed of 16 original scans and were visually inspected to select 17 scans to be used for biomodel fabrication. Biomodels of the 17 scans were made in triplicate by use of 3 freeform fabrication processes (stereolithography, fused deposition modeling, and 3-D printing) for 153 models. The biomodels and original bone were measured by use of a coordinate measurement machine.

RESULTS

Differences among fabrication methods accounted for 2% to 29% of the total observed variation in inaccuracy and differences among method-specific radiation configurations accounted for 4% to 44%. Biomodels underestimated bone length and width and femoral head diameter and overestimated cortical thickness. There was no evidence of a linear association between thresholding adjustments and biomodel accuracy. Higher measured radiation dose led to a decrease in absolute relative error for biomodel diameter and for 4 of 8 cortical thickness measurements.

CONCLUSIONS AND CLINICAL RELEVANCE

The outside dimensions of biomodels have a clinically acceptable accuracy. The cortical thickness of biomodels may overestimate cortical thickness. Variability among biomodels was caused by model fabrication reproducibility and, to a lesser extent, by the radiation settings of the CT scan and differences among fabrication methods.

[Reconstruction after maxillectomy using the temporalis muscle flap--our experience]

THE AIM OF STUDY

The study presents a method of a reconstruction of the palatum after maxillectomy. This method is choosen in selected cases of malignant tumors of the maxilla.

MATERIAL AND METHODS

The method is combined of preparation of the temporalis muscle flap and its dislocation it under arcus of zygoma into the oral cavity. The surface of the flap covered with temporal fascia is oriented into the oral cavity and has been stitched in the hole of the palatum. The surface of the flap covered with periostium is connected to postoperative cavity of the maxilla. The flap covered the palatum tightly divides oral cavity from postoperative cavity of the maxilla. The vascular pedicle of the flap, with deep temporal vessels supply blood for proper healing of the palatum. Oncologic control of the postoperative cavity is performed using imaging investigation (computer tomography, magnetic resonance). The loss of tissue in the temporal fossa is covered by temporal fossa fat or synthetic material.

RESULTS AND CONCLUSIONS

The reconstruction method brings satisfactory functional result. The method allows to avoid using inconvenient prostheses--obturators of palatum--in patients after maxillectomy. Complications in this method as postoperative perforation of the palatum and necrosis of the muscle flap are rare--less than 5% cases.

[Typical surgical reconstruction for nose and paranasal sinuses oncology]

The main problem for nose and paranasal sinuses oncology is not the high incidence but the poor oncological and functional results of the treatment.

AIM

The aim of the work was presentation the patients and reconstruction methods after oncological ablation of nose and paranasal sinuses area.

MATERIAL AND METHOD

The study wa carried out on 14 patients treated in Department of Otolaryngology of The Military Clinical Hospital in Krakow. The patients were divided into groups considering size and localization of the tumor.

RESULTS

All the patients are in observation without recurrence untill now. Cosmetic and functional results are satisfed. The main problem is total reconstruction of the nose where the cosmetic results are not satisfied.

CONCLUSIONS

The main difficulty is the total and near total reconstruction of the nose especially if it is necessary to reconstruct all nasal structures. From quality of life point of view the cooperation with dental prosthetic doctor is obligated for maxillectomy.