الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Middle meatal antrostomy is not enough to access all walls of the maxillary sinus and should be combined with another approach like prelacrimal recess approach especially in cases where the origin of the lesion is from the anteromedial wall of the maxillary sinus.
Preoperative radiological evaluation of the prelacrimal recess area is a crucial step when we pretend to apply prelacrimal recess approach on the maxillary sinus lesions.
Degree of pneumatization of the anteroposterior diameter of prelacrimal recess is inversely related to the rate of postoperative complications and directly related to the feasibility and accessibility of all walls of the maxillary sinus even with the use of less angled endoscopes and instruments.
Prelacrimal recess anteroposterior diameter is not enough to reflect the accessibility and maneuverability of the prelacrimal recess approach and we need to combine this parameter with angle of pyriform notch (APN) parameter.
Ideal situations in which prelacrimal recess approach is highly indicated and can be performed effectively and safely:
• When prelacrimal recess anteroposterior diameter is of Type III >7 mm. In this situation we can access the maxillary sinus without causing injury to pyriform aperture anteriorly or to the nasolacrimal duct posteriorly.
• When angle of pyriform notch is of type c >60, so the incidence of postoperative numbness associated with ASAN injury decreases significantly.
• When the origin of the lesion is from the anteromedial or anterolateral walls inside the maxillary sinus which are difficult areas to be approached by traditional middle meatal antrostomy technique.
• When the bone occupying the medial wall of the maxillary sinus is of average thickness. Therefore, drilling of bone in this area is technically easy and the chance of ASAN affection due to heat injury is significantly decreased.