Giant follicular cysts of the upper jaw invading pterygo-maxillary fossa, sinus-nasal cavities and ethmoidal-orbital structures in young patients. Diagnostic- surgical strategies and long term follow-up.

Aim and Study Design. Dentigerous (follicular) cysts develop from follicular epithelium and they are more potential for growth, differentiation and degeneration than radicular cysts. Due to their tendency to expand rapidly and greatly to displace teeth germs , when they are associated with impacted superior third molars, it' s possible a massive invasion of antral cavity and other surrounding anatomical structures with nasal, orbital, nervous and sometimes inflammatory complications. Especially deep impacted third molars have a high risk of developing these pathological conditions. Possible complications of infections of the orbital cavity are eyesight reduction, including blindness, and disseminated infections. In these cases routine radiological examination often fails to describe the extent of the lesion . We describe two cases of giant follicular cysts of the maxilla involving meso- and sovrastructure. Clinical Cases . Case 1 - Young female, 16 years old with swelling of the right cheek and oral vestibule, right exophtalmos and diplopia. Spiral CT showed a massive lesion occupying the whole maxillary sinus with extension into the pterygo-maxillary space, due to the destruction of the posterior antral bone wall. Above the lesion compressing the orbital floor. Anatomo-clinical study was completed by MR imaging that showed good the interface cyst / soft tissues of the pterygo-maxillary space and orbital structures, and the characteristics of the wall, useful for surgical planning. Transantral surgical excision was performed with approach to the pterygo -maxillary space and orbital structure also using the operating microscope. The cyst measured over 4 cm in diameter; open, about7 cm and was listing on the collar of 1.8.Histological diagnosis was follicular cysts, characterized by the absence of inflammatory cells in the pattern. Five years follow-up (clinical, radiological and MR imaging examination) shows a good restore of antro-pterygo-maxillary and orbital structures without relapse. Case 2 - Young female, 20 years old with swelling of the left cheek and oral vestibule, left nasal obstruction, orbital pain. The integrated study Spiral CT-MR in this case also allowed a very accurate study: the lesion occupied the entire maxillary sinus, the pterygo-maxillary space, the adjacent left nasal cavity, ethmoidal structures with posterior orbital compression. Transantral surgical excision was performed with approach to the pterygo-maxillary space; nasal-ethmoidal and orbital structures were approached by endoscopic technique. The cyst measured about 4 cm in diameter; wide open, about 8 cm and was listing on the collar of 2.8. Follow-up shows a good clinical, anatomical and functional conditions. Histological examination showed a pattern of follicular dentigerous cyst. Conclusions. Giant follicular cysts in the maxilla, especially in young subjects, pose the need for accurate preoperative study in relation to the delicate structures involved and interested. Inflammatory complications make excision even more laborious. In these cases, operating microscope and endoscopic surgical procedures are necessary in certain surgical passages in order to perform the operation safely since the lesion must be detached in deep areas, not easily accessible and very delicate. REFERENCES 1. Hirose K, Suzuki S, Kuroda T. A long-term follow-up case of multiple impacted teeth associated with large follicular cyst in maxilla. Kokubyo Gakkai Zasshi. 2000 Jun;67(2):213-20. 2. Metzger MC, Wagner KW, Hohlweg-Majert B, Voss PJ, Schoen R, Schmelzeisen R. Diplopia and acute rectus muscle palsy as symptoms of an infected follicular cyst of a maxillary right third molar: a case report. Quintessence Int. 2007 Jul-Aug;38(7):571-4. 3. Mesgarzadeh AH, Esmailzadeh H, Abdolrahimi M, Shahamfar M. Pathosis associated with radiographically normal follicular tissues in third molar impactions: a clinicopathological study. Indian J Dent Res. 2008 Jul-Sep;19(3):208-12.