The document describes two classification systems for maxillary defects. The first system by Brown et al classifies defects based on their vertical and horizontal components, with classes 1-6 describing the vertical extent and letters a-d describing the horizontal extent. The second system by Cordeiro and Santamaria is a simplified 4-part classification, with Type 1 being a limited maxillectomy not involving the palate, Type 2 being a subtotal maxillectomy preserving the orbital floor, Type 3 describing total maxillectomies with or without orbital preservation, and Type 4 being an orbitomaxillectomy while preserving the palate.

1. Table
ClassificationofMaxillary Defectsby Brown et ala
Classor Letter Defect
Vertical Component
Class
1 Maxillectomynotcausinganoronasal fistula
2 Not involvingthe orbit
3 Involvingthe orbital adnexae withorbital retention
4 Withorbital enucleationorexenteration
5 Orbitomaxillarydefect
6 Nasomaxillarydefect
Horizontal Component
Letter
a Palatal defectonly,notdental alveolus
b Lessthanor equal to1/2 of the bilateral ortransverse anterior
c Lessthan or equal to 1/2 of the unilateral
d Greaterthan 1/2 of the maxillectomy
,
CordeiroandSantamariadescribe asimplified4-partclassificationscheme:
Type 1 Limitedmaxillectomy,palate isnotinvolved
Type 2 Subtotal maxillectomy,preservationof orbital floor
Type 3 a Total maxillectomywithorbital preservationbTotal maxillectomywithorbital exenteration
Type 4 Orbitomaxillectomy,palateispreserved