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.