title: Modular Endoscopic Medial Maxillectomies: Quantitative Analysis of Surgical Exposure in a Preclinical Setting.
abstract: BACKGROUND
  The nomenclature adopted for endoscopic medial maxillectomies (EMMs) is exceedingly heterogeneous. The aim of this study was to objectively measure surgical exposure in a preclinical anatomic setting to validate a classification for modular EMMs.
  
  
  METHODS
  Computed tomography was used to scan 6 cadaver heads, and images were uploaded on dedicated software. A neuronavigation system was used to measure areas and volumes of surgical corridors during dissection. Differences of >10% of area exposed and >3 cm3of volume were considered to define incremental types of EMM. Specific anatomic targets were assessed on the axial and sagittal planes. Influence of anatomic variants on surgical exposure was evaluated.
  
  
  RESULTS
  There were 4 types of EMMs (A-D), with a transseptal variant for each, identified. In the axial plane, type A exposed the vidian canal and foramen rotundum, type B exposed the foramen ovale and foramen spinosum, and transseptal type C or type D exposed the coronoid process. In the sagittal plane, type A exposed the vidian canal, and type B exposed the foramen ovale and styloid process. Transseptal type C exposed the pterygomaxillary fissure, and type D exposed the inferior border of the lateral pterygoid plate. The nasal floor limits the downward angle in transseptal approaches. The width of the piriform aperture independently influenced surgical volume of types B and C.
  
  
  CONCLUSIONS
  This modular classification of EMMs, based on quantitative analysis in a preclinical setting, should allow for better personalized preoperative surgical planning and provides standardization of nomenclature.
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy. Electronic address: dottor.schreiber@gmail.com.
authors.forename: Alberto
authors.initials: A
authors.lastname: Schreiber
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rampinelli
authors.affiliation: Unit of Neurosurgery, University of Brescia, Brescia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Doglietto
authors.affiliation: Unit of Neurosurgery, University of Brescia, Brescia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Belotti
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lancini
authors.affiliation: Unit of Radiology, University of Brescia, Brescia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ravanelli
authors.affiliation: Section of Anatomy and Physiopathology, University of Brescia, Brescia, Italy.
authors.forename: Luigi Fabrizio
authors.initials: LF
authors.lastname: Rodella
authors.affiliation: Unit of Neurosurgery, University of Brescia, Brescia, Italy.
authors.forename: Marco Maria
authors.initials: MM
authors.lastname: Fontanella
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Nicolai
mesh_terms: D063405:Anatomic Variation; D002102:Cadaver; D004724:Endoscopy / Q000379:methods*; D006801:Humans; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D038361:Neuronavigation; D019291:Skull Base / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: Endoscopy; Maxillectomy; Skull base