Discussion
Odontogenic maxillary cysts are managed surgically through intraoral,
sublabial, or transnasal endoscopic (inferior meatal
antrostomy1, middle meatal
antrostomy5, or endoscopic medial
maxillectomy6) approaches.
The intraoral approach by enucleation, curettage, marsupialization, and
tooth extraction is usually associated with potential morbidity;
oroantral fistula, chronic rhinosinusitis, reconstruction, dentition
affection, teeth extraction, and high recurrence
rate1.
The sublabial approach by Caldwell-Luc operation offers the advantage of
wide operative field, but it is associated with co-morbitity; facial
edema, cheek discomfort, dental pain, facial asymmetry, facial
paresthesia, maxillary sinusitis, and partial loss of the anterior bony
wall7.
The endoscopic inferior meatal antrostomy approach is done by resection
of anterior edge of the inferior turbinate and opens the bony wall of
the inferior meatus to observe the cyst wall which is partially or
completely removed1.
In the study of Seno et al1 who used the above
approach the cyst wall was completely removed in only 61.5 % of cases
and partially resected in 38.5 % of cases which is not only increase
the incidence of recurrence rate but also make hazards if the cyst was
neoplastic or have a neoplastic changes.
The endoscopic maxillary antrostomy approach is performed by removal of
uncinate process and unattached portion of the maxillary cyst is
delivered from the lateral and anterior aspect of the sinus then
debulked by using microdebrider, curettes and non-cutting instruments.
In order to access the inferior portion of the maxillary sinus, an
endoscopic maxillary mega-antrostomy is performed5.
In the study of Jain and Goyal 5, they used the above
technique which did not offer complete removal of the cyst wall but only
marsupialization that carries the hazard of recurrence or missing tissue
in neoplastic cyst.
The endoscopic medial maxillectomy approach has been used to achieve
complete cyst removal as described by Nakayama et al.6 however it carries the risk of medial maxillectomy
of nasolacrimal duct, orbit injury and empty nose syndrome.
In our trans-antral endoscopic assisted approach we combined the
endoscopic advantages (better illumination, magnification, and small
approach ) with sublabial approach (wide operative field), while
avoiding their disadvantage; endoscopy (indirect approach, may affect
the drainage and cilliary function of the sinus) , and sublabial
approach by Caldwell-Luc operation (associated co-morbitity).
In this technique we got the advantage of; complete removal of all the
cyst wall without any remnants so avoid any chance of recurrence and
secure removal of any suspected neoplastic tissue, eschew injury of any
nearby structures if there is erosion within the sinus wall, secure
heamostasis, and identify and early management of oroantral fistula.
The World Health Organization classified keratocystic odontogenic tumour
as a benign cystic neoplasm6. Malignant transformation
within the dentigerous cysts has been reported8,9.
Discrimination between keratocystic odontogenic tumors and radicular
cysts before surgery is sometimes difficult10. All the
above justifications beside risk of recurrence make the decision of
complete removal of odontogenic cyst is crucial and marsupialization is
not satisfactory.
The intraoral approach cannot offer complete removal of the cyst with
its wall in all cases as well as it has more co-morbidity.
The inferior meatal antrostomy and wide maxillary antrostomy approaches
cannot offer complete removal of the cyst with its entire wall in all
cases as the anterior and lateral wall of the maxillary sinus are not
feasible accessible endoscopically even with 700telescope in all cases.
Although endoscopic medial maxillectomy approach can offer complete
removal of the entire cyst wall however it is associated with much
co-morbidity with incidence of injury the nearby structures.
The sublabial Caldwell-Luc operation offers direct access, but it needs
more boney removal with no magnification and illumination endoscopic
advantages.
Although the trans-antral endoscopic assisted approach was associated
with some morbidity as temporary cheek edema, however, this edema was
mild and resolved within one week. No permanent parasthesia, sinusitis
or teeth loss was reported in our cases.
The trans-antral endoscopic assisted approach co-morbitity seems to be
the least (small opening of the anterior maxillary wall) comparing to
the benefit of complete excision of the cyst within its entire wall in
all the cases with minimal injury of the unaffected maxillary sinus
mucosa as well as avoidance of injury of any nearby structure if there
is defect in the sinus wall.