it is caused by fungi , which may be found in decaying food , in the soil , or other organic matter , such as animal excreta .  
immunocompromised patients are especially susceptible , and timely diagnosis as well as intervention are of utmost importance for successful management .
because of atypical initial symptoms , such as facial pain , earache , sinus pain , or odontalgia , patients may seek dental treatment initially .
dental care may also precede such an infection , by means of a creation of a postextraction or postcurretage wound , which may be susceptible to fungal infection .
the aim of this case report is to present a patient with rhinocerebral mucormycosis who was successfully treated due to timely diagnosis , effective surgical intervention , and intravenous antifungal treatment .
a 22-year - old woman was transferred to the oral and maxillofacial department for facial pain , oedema , and double vision , following extraction of the upper right third molar tooth three days earlier .
the patient had initially visited an ear - nose - throat specialist because of diffuse pain of the midface a week previously .
the general dental practitioner had decided to extract the patient 's upper right third molar tooth , which was in close contact to the inferior wall of the maxillary sinus , assuming that the symptoms were odontogenic .  
the patient had been hospitalized for generalized facial oedema and pain in a regional hospital but was transferred to our institution twenty - four hours later , when she developed double vision due to paralysis of the right lateral rectus muscle .
the patient 's medical history included diabetes mellitus type i , which was poorly controlled . on clinical examination , she presented slight hemifacial oedema of the right side , inward gaze of the right eye because of paralysis of the abduscent nerve ( vi cranial nerve ) , as can be seen in figures 1 and 2 . neurological examination also revealed hypaesthesia of the area of distribution of the maxillary nerve ( 2nd branch of the v cranial nerve ) .
the right side of the palate was red with an ulcer of 1  cm diameter , near the second upper molar tooth ( figure 3 ) .  
generally , the patient was an undernourished young woman , with normal vital signs , and unwilling to provide information regarding her diabetes or the reason for dental care . undertaken investigations at admittance included blood count , serum electrolytes , urea , kreatinin , glucose , and c - reactive protein .
furthermore , glycated haemoglobin ( glycohemoglobin , hba1c ) was raised to 12.3% , with the normal range between 45.9% ( table 1 ) .
opthalmological examination showed palpebral oedema of the right side , no lesions of the retina or optic nerve , but diplopia at the right outward gaze , which confirmed the paralysis of the right lateral rectus muscle .  
further imaging with magnetic resonance imaging also showed involvement of all paranasal sinuses of the right side , however , without involvement of the central nervous system ( figure 4 ) .
a biopsy of the palatal ulcer showed fungal infection by species of mucorales ( figure 5 ) .
the patient was initiated with intravenous antifungal agents ( amphotericin b 300  mg qd and posaconazole 200  mg tid ) , and three days later she underwent subtotal right maxillectomy and reconstruction with an obturator .
the paralysis of the right lateral rectus muscle progressively recovered , so the patient was dismissed from the hospital 2 months later , free of any infection , and has recently returned for definitive reconstruction ( figure 6 ) . during her hospitalization , our patient was also accustomed to more effective blood glucose management ( table 1 ) .
the species of mucorales invade blood vessels and cause necrosis of vessel walls and mycotic thrombi . while healthy humans are resistant to such an infection , immunocompromised patients are generally much more vulnerable to the angioinvasive hyphal forms of these fungi .
diabetes mellitus , neutropenia , severe trauma , immunosuppression following transplantation of bone marrow , or solid organs are all predisposing factors for mucormycosis [ 1 , 3 , 4 ] .
the host - specific condition may however render the host susceptible to different types of the infection .
mucormycosis is classified according to the anatomic site of occurrence in ( 1 ) rhinocerebral , ( 2 ) pulmonary , ( 3 ) cutaneous , ( 4 ) gastrointestinal , and ( 5 ) disseminated .  
rhinocerebral or sino - orbital types are common among diabetic patients , especially those who are poorly controlled
. the above - mentioned types of infection may present with various and atypical symptoms of sinusitis [ 1 , 6 ] .
nasal congestion , headache , earache , or facial pain are some of the most common features , which are not at all characteristic .  
depending on the affected site , adjacent structures like the orbit or the central nervous system may be involved .
similarly , extension to the cavernous sinus may cause cavernous sinus thrombosis [ 1 , 2 ] or affect cranial nerves . through the cribriform plate of the ethmoid bone or the supraorbital fissure , the infection may spread intracranially and cause abscesses or sagittal sinus thrombosis .
the affected area is initially clear of any signs , but soon may appear reddish with or without necrotic eschars [ 1 , 4 ] .
ct and mri are within normal limits initially , which are followed by signs of sinusitis , such as congested sinus or thickened mucosal lining .
repetition of the investigations is necessary for close followup of the advancement of the disease .
a histopathological diagnosis is generally considered more precise than simple culture , as the latter may be unyielding due to the depth of invasion of the infection [ 1 , 8 , 9 ] .  
as soon as the clinical suspicion has risen , it is imperative to perform a biopsy of the area and initiate intravenous antifungal treatment [ 1 , 2 , 9 ] . early intervention with ablative surgery is generally recommended [ 1014 ] .   especially considering rhinocerebral or rhino - orbital mucormycosis , enucleation of the eye
although the internal medicine faculty strongly suggested total maxillectomy and removal of the eye , because of the aforementioned evidence , the absence of vision disturbance , severe conjunctival infection , or even optic nerve involvement in a young patient led to a more conservative maxillectomy .
this fact is probably due to early intervention as well as no participation of the contents of the orbit , but cranial nerves .
however , signs of involvement of the orbital area should always direct to a total maxillectomy , including the globe .  
the differential diagnosis of such a peculiar condition should initially include cocaine abuse , fasciitis , or other opportunistic infections of an immunocompromised host , such as aspergillosis , herpes simplex , or herpes zoster .  
dental practitioners should be aware of rhinocerebral mucormycosis , specifically in cases of diabetic and other immunocompromised patients .
atypical symptoms such as facial pain , sinus pain , or unexpected odontalgia of otherwise healthy teeth should alert clinicians .
moreover , when a patient seems to deteriorate after dental therapeutic interventions , one should consider rare conditions , such as mucormycosis , and promptly urge the patient to seek medical advice .
particularly , meticulous intraoral examination should be performed to all patients , as atypical lesions may thus be revealed and estimated . in the case presented , a slight change of the mucosal colour or dehiscence of the palate   might have been noticed .
similarly , it is imperative that all general dental practitioners note the patients ' medical history and modify their diagnostic or therapeutic actions accordingly .
as known , a raised glycated haemoglobin level is indicative of a poor blood glucose control by the diabetic patient .
if the dentist had required a serum glucose or glycated haemoglobin test , he might have estimated the poorly controlled diabetic condition and might have avoided the unnecessary extraction of the upper right third moral tooth . instead , a more precise dental examination might have shown the need for further investigation of the patient 's facial pain .
 this paper presents a case of rhinocerebral mucormycosis in a 22-year - old female patient with type i diabetes mellitus , who was successfully treated with surgery and long - term antifungal medication . 
 the patient had initially been submitted to extraction of an upper third molar by a general dental practitioner but was referred to our department three days postoperatively because of double vision . immediately following histopathological confirmation of the infection , 
 the patient was administered amphotericin b and posaconazole intravenously . 
 surgical excision of the affected site was relatively conservative . 
 the patient was free of the disease 15 months after initial admission to the hospital and has recently returned for reconstruction . 
 the aim of this paper is to increase 
 the awareness of general dental practitioners regarding uncommon serious conditions in diabetic patients , which may be confused with periodontal or dental diseases . 