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Paper text:
very rarely , haemorrhage caused by trauma or bleeding tendency forms cyst - like lesions in the potential space surrounding vessels . in the oral and maxillofacial region , these lesions are known by a variety of names , including traumatic bone cyst , solitary bone cyst and simple bone cyst , and intramedullary haemorrhage of the jaw is the most accepted pathogenetic theory .
most cases of maxillofacial haemorrhagic bone cysts are asymptomatic and do not cause expansion of the cortical bone ; however , expansion of the maxillofacial cyst caused by intra - cystic bleeding presents with serious symptoms . a case of mandibular cyst causing paraesthesia of the mental region
this incidental clinical state was caused by spontaneous haemorrhage into the pre - existing cyst .
we report a case of maxillary cyst presenting with mid - facial deformity where the patient had previously undergone maxillary sinus surgery and later suffered trauma of the cheek region .
we also discuss the pathogenesis of this unusual case and the outcome of our treatment .
epilepsy was diagnosed , and her history included bilateral caldwell  luc surgery 21 years earlier and trauma to the left cheek region 4 years earlier .
nasal endoscopic surgery was performed 2 years after the injury , by an otolaryngologist , but her symptoms persisted after the surgery .
physical examination revealed a non - tender , hard swelling of the left nasal wing from which serosanguineous fluid was aspirated by fine needle ( fig .  1 ) .
intraoral examination showed a soft palatal expansion and on panoramic radiography , the identified cyst had no relation to the neighbouring teeth . computed tomography showed a trilocular cyst in the left maxillary region ( fig .  2 ) .
a clinical diagnosis of surgical ciliated cyst was made , and facial osteotomy and cyst enucleation were performed under general anaesthesia .
lateral rhinotomy provided excellent exposure of the expanded cortical bone , which was removed carefully with a bone chisel .
serosanguineous fluid filled the cyst cavity just below the surface ; however , palatal and nasal cyst cavities contained straw - coloured fluid .
the cyst was enucleated , and the facial wound was closed primarily ( fig . 
histopathological examination showed that all cyst walls were lined by ciliated columnar epithelium , which was consistent with surgical ciliated cyst ( fig . 
the patient showed no signs of recurrence at the end of a 20-month follow - up , and the postoperative appearance was excellent ( fig . 
figure  1:appearance of the swelling in the left nasal wing at the initial examination . 
 figure  2:computed tomographic appearance .
( a ) axial computed tomographic section showed a well - defined trilocular cyst in the left maxillary region extending to the cortical plate .
( b ) three - dimensional computed tomographic image showing a defect in the nasal lateral wall
haematoxylin and eosin staining showing pseudostratified ciliated epithelium lining the cyst wall ( original magnification 200 ) . 

appearance of the swelling in the left nasal wing at the initial examination . computed tomographic appearance .
( a ) axial computed tomographic section showed a well - defined trilocular cyst in the left maxillary region extending to the cortical plate .
( b ) three - dimensional computed tomographic image showing a defect in the nasal lateral wall .
haematoxylin and eosin staining showing pseudostratified ciliated epithelium lining the cyst wall ( original magnification 200 ) .
informed consent was obtained from the patient 's family to publish the details of her case , including photographs and other identifying information .
we report a unique case of a maxillary cyst that deformed the overlying mid - face , with buccal trauma as the initiating cause . based on the patient 's history , it is obvious that the buccal trauma led to the lesion presenting as an unusual tumour .
external injury can cause radicular cysts ; however , in this case , the affected maxillary region was not related to the neighbouring teeth .
histopathology findings confirmed that all cyst walls indicated a surgical ciliated cyst , which is one of the most common maxillary cysts in japan , and it can result from delayed complication of maxillary sinus surgery , trauma or infection . in cases that follow radical sinus surgery ,
the initial presentation is typically expansion of vestibular or palatine bone cortical plates with only mild clinical abnormalities of the face .
because the patient had a previous history of bilateral sinus surgery and 19 years had passed since the maxillary surgical procedure , it seems reasonable that the surgical ciliated cysts were already present at the time of the initial cheek injury .
the lesion consisted of three cavities , and only the facial portion was found to contain haematoid fluid , suggesting that the increased intra - cystic pressure caused by traumatic haemorrhage induced expansion of the lesion . to our knowledge ,
ours is the first report of maxillary haemorrhagic cyst augmentation presenting with mid - facial deformity .
although this is a secondary phenomenon , we consider this is a haemorrhagic cyst in the broadest sense .
there is fairly general agreement that marsupialization is an effective and less invasive treatment for surgical ciliated cyst ; however , complete resolution followed by regeneration of normal bone requires an appreciable period . in our case ,
immediate correction of the facial deformity was absolutely necessary ; therefore , facial osteotomy concurrent with the cyst enucleation was considered the best approach .
usually , resection of maxillary cysts is similar to the technique and approach used with the basic caldwell  luc procedure , which is suitable for treatment of benign maxillary tumours , chronic empyema , fractures and exploration of the maxillary sinus ; however , the caldwell  luc procedure provides an inadequate approach to the nasal cavity . in our case , because the cyst extended to the middle meatus , good exposure of the nasal lateral wall was essential .
the lateral rhinotomy approach allows wide access to the mid - facial region . wide exposure minimizes the surgical invasion , bleeding is readily controlled and the postoperative appearance is excellent .
we found that bleeding in a pre - existing maxillary cyst can potentially lead to expansion of the lesion and deformation of the face .
serious symptoms caused by intra - cystic bleeding are very rare . 
 we describe a case of a maxillary cyst presenting with mid - facial deformity in a japanese woman . 
 she underwent bilateral caldwell  luc procedure 21 years earlier and suffered left cheek trauma 4 years earlier . 
 she presented soon after the trauma complaining of left mid - facial deformity , and computed tomography showed a trilocular cystic lesion in the left maxilla . 
 we performed facial osteotomy concurrent with cyst enucleation with lateral rhinotomy . 
 serosanguineous fluid filled the cyst cavity just below the face ; however , additional cyst cavities contained straw - coloured fluid . she showed no signs of recurrence at the end of a 20-month follow - up , and her postoperative appearance was excellent . 
 histopathological examination showed that all cyst walls were lined by ciliated columnar epithelium , which was consistent with surgical ciliated cyst . 
 we consider that the increased intra - cystic pressure caused by traumatic haemorrhage induced expansion of the pre - existing surgical ciliated cyst .