Location of the infraorbital foramen with reference to soft tissue landmarks

The location of the infraorbital foramen and its variations are important during periorbital, dental, plastic, and oromaxillofacial surgeries. The aim of this study is to document the most practical anatomical soft tissue landmarks for defining the location of infraorbital foramen and infraorbital nerve for effective nerve blockade and to decrease its risk of injury during periorbital surgeries.

Forty sides from 20 adult fixed cadavers were used for this study. The position of the infraorbital nerve was determined in reference to the lateral edge of the ala of the nose, medial and lateral palpebral commissures. All these three soft tissue landmarks were then connected to each other forming a triangular shaped region.

In 75 % of the cases the infraorbital foramen was located on the line which is connecting the lateral palpebral commissure to the ala of the nose. The closest distance of infraorbital foramen to the inferior orbital margin and to facial midline was also measured. The infraorbital foramen was located outside the previously defined triangular region in 20 % and inside the triangle in 5 %. The closest mean distance between the infraorbital foramen and the infraorbital margin was measured as 8.8 ± 1.0 mm and the distance between the medial wall of the infraorbital foramen and the facial midline was measured as 30.3 ± 2.7 mm.

The triangular region and the soft tissue landmarks we offered in this study may facilitate prediction of the locations of the infraorbital foramen thus, the infraorbital nerve.