Investigation of the morphometry of the pre-lacrimal recess of the maxillary sinus for the pre-lacrimal approach of the maxillary sinus and paramedian skull base. A computed-tomography study

The pre-lacrimal recess approach is modernly used for lesions of the anterior maxillary wall and for reaching paramedian cranial base regions. In this computed-tomography study, we assessed the pre-lacrimal recess types as well as the angles between the anterior and medial maxillary walls and between the anterior maxillary wall and the lateral margin of the nasolacrimal canal to show the feasibility of the pre-lacrimal recess approach in reaching lesions of the infratemporal and pterygopalatine fossae, using 30 computed-tomography studies (60 sides). A type I pre-lacrimal recess was identified in 22 cases (35%), type II was identified in 31 cases (53.30%), and type III in 7 cases (11.66%). We found that angle 1 (the angle between the anterior maxillary wall and the medial maxillary wall) had a mean value of 80.8° (minimum 75.5°, maximum 85.8°), while angle 2 (the angle between the anterior maxillary wall and the lateral margin of the nasolacrimal canal) had a mean value of 59.1° (minimum 57.6°, maximum 60.1°). We consider the pre-lacrimal recess approach a very good option for the anterior maxillary wall, the alveolar recess, and in reaching the infratemporal fossa and lateral part of the pterygopalatine fossa. In cases where direct visualization of the medial part of the pterygopalatine fossa is needed, the pre-lacrimal recess approach could not be the perfect option.