COVID-19 SARS has swept away mankind off its feet in the last 2½ years. Globally, new treatment modalities, as well as newer medicines to tackle the menace, made way at a breakneck pace. Although the vaccines stemmed the spread of the deadly virus, a new danger was lurking just around the corner. Post-COVID mucormycosis was an untoward unexpected outcome for which the global health fraternity was least prepared.
Multiple etiologies, explanations like the deadly triad of COVID-19 infection, diabetes, and rampant use of corticosteroids were put forth for this fungal infection which spread like wildfire in COVID survivors. However, despite numerous theories, there was no clarity on its occurrence, and contrary to classic mucormycosis presentation, it manifested itself in patients with no comorbidities. The clinical picture of post-COVID mucormycosis also appeared distinct from the classic one in terms of slow disease progression and much lesser tissue damage even in advanced cases.
TACKLING THE MENACE
The mainstay of treatment constituted aggressive debridement and targeted antifungal therapy in the form of amphotericin B. However, the limited availability of therapeutic drugs further made the job of the treating physician difficult and challenging. A plethora of alternate modes, routes, and dosage schedules was suggested globally and tried with moderate success.
Immediate management revolved around drugs like antifungals, and antibiotics, together with aggressive surgical debridement. The extensive debridement and maxillectomies performed on patients who suffered a superinfection of mucormycosis after COVID-19 resulted in a severely disfigured maxillofacial skeleton.
After the tsunami of black fungus aka mucormycosis had run its course, severely mutilated and disfigured faces were posing a new challenge to the prosthodontists, maxillofacial surgeons, and reconstructive surgeons as the magnitude of disability was of hitherto unseen proportions.
The major concerns were multifaceted as the restoration of both soft tissues and hard tissues was indicated in these patients, hence making the task more challenging than routine rehabilitation.
REHABILITATION OPTIONS
Prosthetic rehabilitation of patients with acquired maxillectomy defects secondary to mucormycotic necrosis post-COVID-19 infection involved techniques to overcome complications such as lack of supporting tissues and postsurgical microstomia. Over the years, advanced training in conjunction with the availability of technologically upgraded equipment and materials has immensely improved the treatment outcomes in patients with extreme tissue loss, resorbed alveolar bone ridges, missing basal bones, etc.
Mucormycosis-afflicted maxillofacial defects mandated a holistic and multispecialty synergy to bring back some normalcy in the lives of these ill-fated individuals. The radiologist's opinion prior to any planning of rehabilitation was needed to ensure the elimination of the disease process in order to avoid compromised treatment outcomes subsequently. Apart from the structural rehabilitation, the psychological status of these patients also needed to be taken into consideration by the treating team of specialists.
The spectrum of the Mucor-inflicted maxillofacial skeletonis diverse and needs a team approach whether it is functionalrehabilitation by a prosthodontist, soft tissue coverage by themaxillofacial surgeon and most importantly cognitive therapy by a psychiatrist, as thefacial scars of mucormycosis-induced deformity result inemotionally and mentally shattered individuals.
Hence, the designated members of a postmucormycosis rehab team often consisted of the following:
- Prosthodontist
- Maxillofacial Surgeon
- Radiologist
- Psychiatrist
- Speech therapist.
PROCESSES AND PLANNING
In patients undergoing maxillectomies, the use of immediate surgical obturators has been widespread. The rationale for its use remains threefold:
- Functional (provision to retain the surgical dressing and facilitate speech and swallowing)
- Hygienic (separates the residual maxilla from contents of the oral cavity)
- Psychological (restores patient's self-image by reproducing lost oral structure).
However, once the disease process has ceased and the surgical site stabilized, more definitive modalities are considered:
- Autogenous reconstruction
- Zygomatic implants
- 3D-printed patient-specific implants (PSIs).
AUTOGENOUS RECONSTRUCTION
In the reconstruction armamentarium, autogenous reconstruction has been in vogue for the past century, and with improved visualization of the smallest of the vascular channels, microvascular reconstruction of the maxillofacial region has been the mainstay of the rehabilitation of the grossly mutilated and disfigured maxillofacial skeleton.
The technique despite being in vogue, with encouraging results over the years, requires above-average clinical skills, expensive equipment, and above all a secondary surgical site for donor graft. A suboptimal outcome in terms of graft failure, bulky soft tissue, and inability to achieve sufficient bone stock for subsequent prosthodontic rehabilitation were some of the limitations of even this modality which is considered the pinnacle of the reconstruction ladder.
HOPE FROM TECHNOLOGY
Maxillofacial defects are difficult to treat due to their important functional, esthetic, and psychological aspects. The anatomical complexity of this region has also contributed to the challenge. Traditional premade implants often require many adjustments and usually offer suboptimal results.
The advances made in CAD-CAM technology as well as 3D imaging have contributed greatly to the management of maxillofacial defects. This has facilitated the manufacturing of custom-made PSI that mirrors the healthy side to achieve an extremely satisfactory result.
The inherent advantage of modalities other than autogenous reconstruction of post-Mucor defects lies in better precision and more predictable outcomes. Zygomatic implants provided hope for severely resorbed alveolar ridges and have been popular globally for the past two decades.
However, the absence of any alveolar component in the maxilla limits the scope of their application in most of the defects secondary to Mucor infection.
The only hope for such patients lies in PSIs. With superior software making its way into the health-care microsphere, virtual planning, precise location, and angulation of planned abutments for prosthodontic rehabilitation have made this modality, very popular in the past 3–4 years. Improved metallurgy and the finite element analysis of the 3D printed customized titanium implant for its strength estimation have resulted in improved postoperative stability and results.
The biggest advantage of the PSI is its ability to provide requisite maxillary defect restoration without the need for any donor site for autogenous grafting. However, the cost factor needs to be considered prior to taking up the case for the rehabilitation of a Mucor patient. With 3D printing technology witnessing new horizons and new vistas, it is a matter of time before this cutting-edge treatment modality shall be within the reach of patients regardless of their socioeconomic status.
CONCLUSION
Rehabilitation of post-Mucor maxillary defects is a challenging clinical situation and needs careful patient evaluation including psychological considerations. Whatever the chosen modality of treatment, whether autogenous or alloplastic, should be based on sound clinical judgment, established biomechanics of rehabilitation and above all should follow the age-old Hippocrates dictum of primum non nocere, meaning-first do no harm.
