Cone beam computed tomography for Maxillary sinus vascular anatomy

Introduction As well described by all anatomists, the vessels of nose region, maxilla and sinus walls constitute a rich network of arteries and veins. Branches of the ophthalmic, maxillary and facial arteries supply the nose. They form anastomosis plexuses within the nasal mucosa. The anterior and posterior ethmoidal branches of the ophthalmic artery supply the frontal and ethmoidal sinuses and the roof of the nose. The sphenopalatine branch of the maxillary artery supplies conchae, meatus and postero-inferior part of the nasal septum being the principal vessel supplying the nasal mucosa. The greater palatine branch of the maxillary artery supplies the inferior meatus. Its terminal part ascends through the incisive canal to anastomosis on the septum with branches of the sphenopalatine and anterior ethmoidal arteries and with the septal branch of the superior labial artery. The pharyngeal branch of the maxillary artery supplies the sphenoidal sinus. The infraorbital artery and the superior, anterior, and posterior alveolar branches of the maxillary artery supply the mucosa of the maxillary sinus. In particular, the maxillary artery passes through the pterygomaxillary fissure from the infratemporal fossa into the pterygopalatine fossa, where it terminates as the third part of the maxillary artery. This part of the artery gives branches running together with those of the maxillary nerve. The posterior superior alveolar artery arises from the maxillary artery and goes through the pterygo-maxillary fissure into the maxillary tuberosity. It gives off several branches: some of them penetrate the bone to supply the maxillary posterior teeth and the maxillary air sinus, and the other branches supply the buccal mucosa. The infraorbital artery emerges into the face at the infraorbital foramen to supply the lower eyelid, part of the cheek, the side of the external nose, and the upper lip. During its route within the infraorbital canal it gives off the anterior superior alveolar artery directed downwards to supply the anterior teeth and the anterior part of the maxillary sinus. Solar, together with his group, in 1999 was the first one to state and find out that those vessels were poorly described in classical textbooks of dental and human anatomy. In his paper, he showed by a scheme, the course of the anastomosis between the posterior superior antral artery and the infraorbital anatomy. Then Elian in 2005, in his radiological study, observed how the computed tomography is not so sensitive comparing the data to the Solar and Traxler studies that were on human cadavers. However, he provided more data regarding the distribution and the position of the vascular anastomosis, and stated the factors of clinical significance: (i) the pre-surgical evaluation performed by CT scans were useful to spot the intraosseous vessel with a great diameter; (ii) the position of the osteotomy, indicating the safe distance as 15 mm from the alveolar bridge. Mardinger in 2007, using the radiographic method, reported results slightly different from the former authors and how the vessels with a <1 mm diameter do not represent a great risk or bleeding threat or obstacle during the surgical procedures. Rysz in 2009 studied the anastomosis on fetus cadavers, and clearly the results of the prevalence and distributions were different from the ones reported in the previous studies. Rosano in 2009-2010 in his cadaveric study, confirmed the data reported by Solar and Traxler in 1999. Ilguy in 2013 reported measures, septa presence, and that the non-detection of the anastomosis on CBCT is probably caused by the small diameter. The more recent study was by Rysz in 2014, which focused this time on adult CBCT scans. All of these authors reported different data and different methods, but all of them agree on two points: 1. The anastomosis supplies the lower part of the sinus, playing an important role in the graft integration and vascularization; 2. Though its accidental sectioning is not life-threat, the bleeding can make difficult the visibility and the management of the Sneider’s membrane.