Xaismboun special region was created in 1994-06. Change Notice 1 to FIPS PUB 10-4, dated 1998-12-01, lists a division of Laos into 16 provinces, one city, and one special zone. ISO 3166-2 Newsletter Number I-2 was published on 2002-05-21. It showed Xaismboun special region, but called it a province.
THE PARANASAL SINUSES. There are four pairs of paranasal sinuses, the frontal sinuses are located above the eyes, in the forehead bone. The maxillary sinuses (antra of Highmore) are located in the cheekbones, under the eyes. The ethmoid sinuses, also called ethmoid labyrinth are located between the eyes and the nose.here are four pairs of paranasal sinuses, the frontal sinuses are located above the eyes, in the forehead bone. The maxillary sinuses (antra of Highmore) are located in the cheekbones, under the eyes.
1 Frontal- one sinus per side, located within the bone of the forehead above the level of the eyes and nasal bridge (figures 1 and 3).  Sphenoid- one sinus per side, located behind the ethmoid sinuses; the sphenoid is not seen in a head-on view but is better appreciated looking at a side view (figure 3).