Mucormycosis or black fungus is one of the most lethal, progressing, and rapid form of deep fungal infections in humans which is caused by group of molds called mucormycetes. It is called black fungus infection due to black nasal discharges and black patches around nose found in the initial stage. The most common variety is rhino-orbito-cerebral-maxillary, although there are also pulmonary, gastrointestinal, cutaneous, and disseminated variations. In recent years, mucormycosis has become increasingly prevalent in immunocompromised individuals, with coronavirus disease 2019 (COVID-19) infection and associated consequences as the primary source of the cause. Rhino-orbito-cerebral-maxillary variety usually involves the nose, paranasal sinuses, brain, and maxilla but the involvement of mandibular bone is exceedingly rare. In this case report, we present a case of a 59-year-old male affected with mandibular mucormycosis in post-COVID scenario which is quite rare situation.

Mucormycosis of the mandible (MOM) is a rare fungal infection, and only 23 cases had been reported during the last 50 years worldwide, from seven different countries. Most of the cases were reported in India (n=8, 34%), followed by the United States (n=5, 22%). It is usually associated with an immunocompromised state and generally occurs after tooth extraction. Radiographically, it presents with the characteristic sign of osteomyelitis. Most of the previous case reports/series on MOM described successful outcomes with the resection of the involved segment. However, our experience in managing these cases was quite different and it was observed that resection is seldom required. It was seen that MOM rarely causes cortical perforation. One of the probable reasons is the thicker cortical bone and well-confined boundary of the mandible. Another reason could be the fulminating nature of the disease that leads it to rapidly spread in less resistant medullary bone before perforating cortical bone. During surgery, a clear line was seen separating necrotic medullary bone from healthy cortical bone. The thicker cortical bone of the mandible was found to be resistant to fungal invasion; however, the medullary bone was rapidly invaded. Therefore, the healthy cortical bone could be saved. The preservation of the cortical parts thus helps in maintaining the continuity of the bone. Surgical curettage of necrotic medullary bone is usually the optimal method to manage MOM affecting the mandibular body or ramus region.