The sphenopalatine foramen (SPF) represents an opening on the lateral nasal wall that is present at the articulation between the superior aspect of the vertical portion of the palatine bone and the inferior projection of the sphenoid bone. The sphenopalatine foramen connects the nasal cavity to the pterygopalatine fossa of the skull and houses the sphenopalatine artery (SPA) and vein, the posterior superior lateral nasal nerve, and the nasopalatine nerves. Moreover, the sphenopalatine foramen provides an important anatomical landmark for those who perform procedures where knowledge of the sphenopalatine foramen and its contents remains critical, including the creation of a nasoseptal flap for nasal reconstruction or skull base repairs, posterior epistaxis control, and functional endoscopic sinonasal surgery. Herein we discuss the anatomy of the sphenopalatine foramen, including its structure, function, contents, embryology, anatomical variations, and clinical relevance.
Boundaries of the sphenopalatine foramen:
The foramen can be found at the posterior-superior-medial corner of the maxillary sinus, just deep to the attachment of the middle turbinate, but exists in a variety of locations:
The sphenopalatine foramen forms from the fusion of the palatine bone and the sphenoid bone around the sphenopalatine artery; thus, a description of the embryology of the structures, as mentioned earlier, will provide a better understanding of the development of the sphenopalatine foramen.
In summary, the subsequent fusion of the palatine and sphenoid bone around the sphenopalatine artery result in the formation of the sphenopalatine foramen.
The neural contents of the sphenopalatine foramen include the posterior superior lateral nasal nerve and the nasopalatine nerve.
As mentioned previously, several studies have reported that approximately 10 to 20% of individuals have an accessory sphenopalatine foramen, generally located anterior and inferior to the natural sphenopalatine foramen. This variation is thought to be due to the variable branching of the sphenopalatine artery. Additionally, it merits noting that the foramina can range in size, shape, and location, as mentioned above (see STRUCTURE AND FUNCTION).
The sphenopalatine foramen remains an important surgical landmark for a variety of procedures. For instance, knowledge of the sphenopalatine foramen’s location is useful when performing endoscopic sinus surgery, as the sphenopalatine foramen can be infiltrated with local anesthetics and vasoconstricting agents to provide better anesthesia and hemostasis, respectively. Knowledge of the sphenopalatine foramen’s location proves particularly important when performing a nasoseptal flap for nasal reconstruction or skull base repairs, as the sphenopalatine artery represents the major blood supply to this versatile flap. Also, knowledge of the sphenopalatine foramen and its contents proves useful when performing endoscopic ligations for posterior epistaxis control where the sphenopalatine artery is targeted.
Reliable landmarks for identifying the sphenopalatine foramen have been delineated above (see Endoscopic landmarks for sphenopalatine foramen localization), though landmarks often used during surgery include the posterior portion of the middle turbinate and the ethmoid crest (i.e., crista ethmoidalis). During endoscopic sinus surgery, an incision can be made 1 cm anterior to the posterior aspect of the middle turbinate, and a mucoperiosteal flap can be raised posteriorly to identify the ethmoid crest. The sphenopalatine foramen and its contents should be located posterior to this landmark in over 95% of cases, allowing for the safe identification and/or preservation of the contents of the sphenopalatine foramen.
The sphenopalatine foramen provides an essential anatomical landmark for multiple surgical procedures of the head and neck, including the creation of a nasoseptal flap for nasal reconstruction or skull base repairs, posterior epistaxis control, and functional endoscopic sinonasal surgery. Sound knowledge of the sphenopalatine foramen anatomy, including its structure, function, contents, and anatomical variations, is required to optimize success when performing such procedures.
|||Kim JH,Oka K,Jin ZW,Murakami G,Rodríguez-Vázquez JF,Ahn SW,Hwang HP, Fetal Development of the Incisive Canal, Especially of the Delayed Closure Due to the Nasopalatine Duct: A Study Using Serial Sections of Human Fetuses. Anatomical record (Hoboken, N.J. : 2007). 2017 Jun; [PubMed PMID: 27860365]|
|||Pothier DD,Mackeith S,Youngs R, Sphenopalatine artery ligation: technical note. The Journal of laryngology and otology. 2005 Oct; [PubMed PMID: 16259659]|
|||The Endoscopic Prelacrimal Recess Approach to the Pterygopalatine Fossa and Infratemporal Fossa., Gao L,Zhou L,Dai Z,Huang X,, The Journal of craniofacial surgery, 2017 Sep [PubMed PMID: 28863111]|
|||Prades JM,Asanau A,Timoshenko AP,Faye MB,Martin Ch, Surgical anatomy of the sphenopalatine foramen and its arterial content. Surgical and radiologic anatomy : SRA. 2008 Oct; [PubMed PMID: 18648719]|
|||Wentges RT, Surgical anatomy of the pterygopalatine fossa. The Journal of laryngology and otology. 1975 Jan; [PubMed PMID: 1113030]|
|||Wareing MJ,Padgham ND, Osteologic classification of the sphenopalatine foramen. The Laryngoscope. 1998 Jan; [PubMed PMID: 9432081]|
|||Scanavine AB,Navarro JA,Megale SR,Anselmo-Lima WT, Anatomical study of the sphenopalatine foramen. Brazilian journal of otorhinolaryngology. 2009 Jan-Feb; [PubMed PMID: 19488558]|
|||El-Shaarawy EAA,Hassan SS, The sphenopalatine foramen in man: anatomical, radiological and endoscopic study. Folia morphologica. 2018; [PubMed PMID: 29131280]|
|||Resection of the ethmoidal crest in sphenopalatine artery surgery., Saraceni Neto P,Nunes LM,Caparroz FA,Gregorio LL,de Souza RP,Simões JC,Kosugi EM,, International forum of allergy & rhinology, 2017 Jan [PubMed PMID: 27513601]|
|||Pádua FG,Voegels RL, Severe posterior epistaxis-endoscopic surgical anatomy. The Laryngoscope. 2008 Jan; [PubMed PMID: 18025950]|
|||Demiralp KÖ,Kurşun-Çakmak EŞ,Bayrak S,Sahin O,Atakan C,Orhan K, Evaluation of Anatomical and Volumetric Characteristics of the Nasopalatine Canal in Anterior Dentate and Edentulous Individuals: A CBCT Study. Implant dentistry. 2018 Aug; [PubMed PMID: 30028392]|
|||Catala M, [Embryology of the sphenoid bone]. Journal of neuroradiology = Journal de neuroradiologie. 2003 Sep; [PubMed PMID: 14566186]|
|||BURDI AR, SAGITTAL GROWTH OF THE NASOMAXILLARY COMPLEX DURING THE SECOND TRIMESTER OF HUMAN PRENATAL DEVELOPMENT. Journal of dental research. 1965 Jan-Feb; [PubMed PMID: 14245486]|
|||Konno A,Togawa K, Role of the vidian nerve in nasal allergy. The Annals of otology, rhinology, and laryngology. 1979 Mar-Apr; [PubMed PMID: 443720]|
|||Honkura Y,Nomura K,Oshima H,Takata Y,Hidaka H,Katori Y, Bilateral endoscopic endonasal marsupialization of nasopalatine duct cyst. Clinics and practice. 2015 Jan 28; [PubMed PMID: 25918636]|
|||Anatomy of the sphenopalatine artery and its implications for transnasal neurosurgery., Eordogh M,Grimm A,Gawish I,Patonay L,Reisch R,Briner HR,Baksa G,, Rhinology, 2018 Mar 1 [PubMed PMID: 29166425]|