Dental considerations and the role of prosthodontics and maxillofacial prosthetics in facial transplantation

The future of maxillofacial prosthodontics in North America: The role of advanced digital technology and artificial intelligence - A discussion document

STATEMENT OF PROBLEM

Maxillofacial prosthodontists were advanced digital technology (ADT) adopters early in the new Millennium. The past two decades saw a range of digital enablers emerge including digital imaging (internal and surface), digital surgical planning, digital functional assessment, subtractive and additive manufacturing, navigation, and robotics among others. Artificial Intelligence (AI) is the latest ADT arrival that will be a challenging disruptive technology. ADT has served as a profound change agent in maxillofacial prosthodontics. The intent was to explore the process and level of ADT engagement in maxillofacial prosthodontics.

PURPOSE

The purpose was twofold. Firstly, to explore maxillofacial prosthodontic engagement of ADT. Secondly, to develop a discussion document to assist the American Academy of Maxillofacial Prosthetics (AAMP) with establishing a collective awareness and considered opinion on the future of maxillofacial prosthodontics in the digital era.

MATERIAL AND METHODS

AAMP member interest in ADT was assessed through analysis of AAMP annual congress programs and publications in the Journal of Prosthetic Dentistry (JPD). The history of the maxillofacial prosthodontic journey to the digital era was undertaken with a selective literature review. The perceptions maxillofacial prosthodontists hold on ADT engagement was assessed through a survey of AAMP members. Developing an understanding of the influence AI was conducted with a review of pertinent literature.

RESULTS

From 2011-2020, an annual mean of 38% of papers published in the JPD involved clinical use of ADT. From 2017-2019, 44% of invited presentations at AAMP annual congresses included clinical use of ADT. The journey to the digital era distinguished three periods with formative and consolidation periods influencing the innovation digital era. The AAMP member survey had a 59% response rate and studied 10 domains through 31 questions. Of the respondents, 89% thought ADT important to the future of maxillofacial prosthodontics.

CONCLUSIONS

The discussion document will assist the AAMP in developing a collective consciousness and considered opinion on ADT in the future of maxillofacial prosthodontics. Members of the AAMP have a developed interest in clinical applications of ADT. A great challenge is that no formal education, training, or clinical competency requirements for ADT could be identified. Clinical competency requirements are important to prepare maxillofacial prosthodontics for the inevitability of a digital era future. The discussion document poses the fundamental question of whether maxillofacial prosthodontists will remain as passive end users of ADT and AI or will they become engaged knowledge workers that have determined clinical competency in ADT and AI in patient care. Without this knowledge worker role, maxillofacial prosthodontists may experience difficulty being part of the inevitable ADT-AI driven future.

Recipient Selection Criteria for Facial Transplantation: A Systematic Review

BACKGROUND

Recipient selection is an important determinant of surgical outcomes in facial transplantation (FT). Appropriately, each FT program develops their own guidelines for recipient selection criteria. Currently, there is no resource to simultaneously assess and identify similarities and differences between these guidelines. Such information could be useful in distinguishing areas of FT that are well understood from those that could benefit from further exploration.

METHODS

We performed a systematic review of the scientific literature from inception to June 18, 2021, using Pubmed, Embase, Cochrane Library, and Scopus to identify articles pertaining to recipient selection criteria. Clinical trials were identified through the Clinicaltrials.gov registry. United States and international program websites were reviewed for patient-facing information.

RESULTS

Our systematic review yielded 90 suitable articles, 8 clinical trials, and 7 program websites containing the recipient selection criteria of 24 different FT programs. The most reported on recipient criteria were age, positive human immunodeficiency viral status (HIV+), positive hepatitis C viral status, psychosocial stability, and medical compliance. Other criteria were rarely addressed, such as blindness and recipient immune status.

CONCLUSIONS

Guidelines among different face transplant programs are changing over time. We found consensus on certain recipient selection criteria, but the majority remain program or surgeon dependent, emphasizing that FT is still an evolving procedure. Although most programs reported on their recipient selection criteria, the rationale was often missing. Further discussion about recipient selection criteria and the reasoning behind employing or changing them will help advance the field.

Special Considerations in Face Transplantation: A Systematic Review

ABSTRACT

Vascularized composite allotransplantation of the face is an exceedingly complex procedure, requiring extensive planning and surgical precision in order to successfully manage patients with facial disfigurements. This review aims to present an overview of the salient anatomic considerations in facial transplantation, as well as give attention to unique patient populations and special considerations.A literature review was performed in search of articles pertaining to considerations in facial transplantation using the databases PubMed, Web of Science, and Cochrane. Articles selected for further review included full-text articles with an emphasis on specific anatomic defects and how they were addressed in the transplant process, as well as management of special patient populations undergoing facial transplantation. In total, 19 articles were deemed appropriate for inclusion.The use of computer-assisted technologies for the planning portion of the procedure, as well as intraoperative efficiency, has yielded favorable results and can be considered as part of the operative plan. The ultimate outcome is dependent upon the synchronization of subunits of the allograft and the desired functional outcomes, including osseous, ocular, oral, and otologic considerations. Management of specific pathology and subgroups of patients are critical aspects. Although pediatric face transplantation has not yet been performed, it is a likely a future step in the evolution of this procedure.When performing a face transplantation, many components must be considered pre-, intra-, and post-operatively. This systematic review presents specific anatomic considerations, as well as information about special patient populations within this crosssection of multidisciplinary microsurgery, psychiatry, and transplant immunology.

Maxillofacial Bony Considerations in Facial Transplantation

Alloplastic facial transplantation has become a new rung on the proverbial reconstructive ladder for severe facial wounds in the past couple of decades. Since the first transfer including bony components in 2006, numerous facial allotransplantations across many countries have been successfully performed, many incorporating multiple bony elements of the face. There are many unique considerations to facial transplantation of bone, however, beyond the considerations of simple soft tissue transfer. Herein, we review the current literature and considerations specific to bony facial transplantation focusing on the pertinent surgical anatomy, preoperative planning needs, intraoperative harvest and inset considerations, and postoperative protocols.

Oral findings and treatment of patients with face transplants in Helsinki

OBJECTIVES

Oral health and balanced occlusion are important aspects of a well-functioning face transplant. This study describes the oral and dental status, dental management, and sialoendoscopy of the first 2 patients in Helsinki who underwent face transplantations.

STUDY DESIGN

Two patients received near-full face transplantations in 2016 and 2018, respectively. The transplanted tissues included a Le Fort type II maxilla, angle-to-angle mandible, all oral mucosa, ventral tongue tissue, and the muscles of the floor of the mouth. Comprehensive oral examinations and all required dental treatment, including follow-up examinations, were performed for both patients after the transplantations.

RESULTS

Both patients rehabilitated well, and their quality of life improved. Stable, functioning dentition and occlusion were achieved for both patients. Hyposalivation and dental caries were issues for both patients. Patient 1 also experienced infections in the jaws. Implants were placed in the transplanted jaws of patient 2 with successful osseointegration.

CONCLUSIONS

We report successful tooth-bearing face transplantations in 2 patients. Patient selection, particularly regarding oral health, is crucial in avoiding posttransplantation complications. Moreover, the oral and dental status of the donor should be examined by a dentist before transplantation, and regular follow-up dental examinations should be performed after transplantation.

The future of maxillofacial prosthodontics in North America: Part II - A survey

STATEMENT OF PROBLEM

Head and neck care has been transformed by the introduction of advanced digital technologies that will continue to be important change drivers for maxillofacial prosthodontics. Insight into these changes is important in answering the question of whether maxillofacial prosthodontics is appropriately prepared to contribute effectively to future multidisciplinary care of the head and neck.

PURPOSE

The purpose of this survey was to gain insight into the perception of changes experienced by maxillofacial prosthodontists in relation to clinical practice. The findings of this survey may assist the future development of the subspecialty.

MATERIAL AND METHODS

An exploratory cross-sectional survey was conducted by using a convenience sample of members of the American Academy of Maxillofacial Prosthetics. The survey considered 10 domains and 31 questions. Fully completed surveys (164) provided a 59% response. Descriptive statistics used percentage responses to reduce and characterize perceptions across respondents.

RESULTS

Eighty-four percent of the respondents were from the United States. Results should be interpreted based on this cohort. Respondents reported a change in care delivered over the past 10 years (72%), with the most important causes of change attributed to surgery (60%) and advanced digital technologies (56%). Respondents perceived advanced digital technologies as being central to the future of maxillofacial prosthodontics (89%) and important in attracting younger colleagues (88%). Sixty-three percent believed training programs were not providing adequate education and training in the use of advanced digital technology.

CONCLUSIONS

The perception of maxillofacial prosthodontists regarding changes taking place in care delivery was that the most important changes in the past 10 years were attributed to surgery and advanced digital technologies, that persisting pressures related to few institutional positions, that the subspecialty was poorly visible, that remuneration for care was inadequate and referring disciplines did not understand the subspecialty, that advanced digital technologies were considered central to the future of maxillofacial prosthodontics and important to attract younger colleagues to the subspecialty, that barriers to advanced digital technology use included funding for equipment acquisition, institutional funding support, and remuneration for their use in care delivery, and that maxillofacial prosthodontic programs were not providing adequate education and training in advanced digital technologies.

The future of maxillofacial prosthodontics in North America: Part I-Journey to the present

STATEMENT OF PROBLEM

Understanding how maxillofacial prosthodontists are perceiving changes in head and neck care and the impact of advanced digital technologies on maxillofacial prosthodontics is important. However, no studies could be identified that specifically addressed these subjects.

PURPOSE

The purpose of this review of selected literature was to identify issues that guided the development of maxillofacial prosthodontics and the concerns that persist. The review also considered contemporary influences that will affect the future of maxillofacial prosthodontics. The conclusions of the review were used to interpret the results of the exploratory survey reported in Part II.

MATERIAL AND METHODS

The review of selected literature was related to the development of maxillofacial prosthodontics in North America between 1950 and 2018. Literature that was considered relevant to the purpose of the review was included.

RESULTS

The review yielded 37 references of interest: 34 peer-reviewed publications, 1 guideline, 1 historical publication, and 1 website. Periods in the development of maxillofacial prosthodontics in North America were identified as formation, consolidation, and innovation.

CONCLUSIONS

It was concluded that concerns in subspecialty programs and clinical practice had origins in the formation and consolidation periods. These persisting concerns extended into the innovation period. Contemporary influences in head and neck surgery will continue to affect the future of maxillofacial prosthodontics. Advanced digital technologies appeared to be central to driving change. Understanding the evolution of maxillofacial prosthodontics was an important first step in providing context when interpreting the results of a survey of maxillofacial prosthodontists reported as Part II of this work.

Enhancing Face Transplant Outcomes: Fundamental Principles of Facial Allograft Revision

Facial transplantation (FT) has become a feasible reconstructive solution for patients with devastating facial injuries. Secondary revisions to optimize functional and aesthetic outcomes are to be expected, yet the optimal timing and approach remain to be determined. The purpose of this study was to analyze all facial allograft revisions reported to date, including the senior author's experience with 3 FTs.

Methods

A literature review was performed, with 2 reviewers independently conducting title and abstract screening, followed by a full-text review. All articles mentioning FT revision surgeries were evaluated. The medical records of the senior author's 3 FT recipients were additionally reviewed.

Results

Initially, 721 articles were captured and 37 were included in the final analysis. Thirty-two FTs were reported to have involved posttransplant allograft revisions, with FT recipients undergoing a mean of 4.8 ± 4.6 revision procedures. The mean duration between FT and the first revision procedure was 149 ± 179 days. A wide spectrum of revisions was identified and categorized as involving the soft tissues, craniofacial skeleton, dentition, oronasal cavity, salivary glands, facial nerve, or ocular region. In the senior author's experience, when indicated, posttransplant occlusal changes and integrity of the donor-recipient intraoral interface were successfully addressed with secondary procedures without allograft compromise or loss.

Conclusions

The worldwide experience shows that secondary procedures are nearly ubiquitous after FT and can be safely performed at various timepoints. The authors thereby establish 5 distinct categories of facial allograft revisions and define 7 critical principles to optimize posttransplant procedures.

Otologic considerations in a full face transplant recipient

Facial transplantation provides a functional and aesthetic solution to severe facial disfigurement previously unresolved by conventional reconstruction. Few facial allografts have been ear containing; hence, there is limited knowledge of the postoperative otologic considerations. We describe the case of a 44-year-old man who underwent transplantation of the total face, eyelids, ears, scalp, and skeletal subunits in 2015 after an extensive thermal injury. We detail the patient's transition from osseointegrated prosthetic ears to an ear-containing facial allograft, and describe the unique surgical approach and challenges encountered. Subsequent bilateral revision meatoplasties were performed, which provided relief from stenosis of the external auditory meatus. Laryngoscope, 129:2008-2011, 2019.