V-shaped outward displacement: a proposed new subtype of isolated zygomatic arch fracture

Existing classification systems for isolated zygomatic arch fractures have substantially advanced clinical management of this injury pattern. However, atypical fracture configurations that do not conform to established subtypes are occasionally encountered in clinical practice. This technical note describes an unusual V-shaped outward displacement fracture of the zygomatic arch and proposes its recognition as a novel subtype within the recently described modified classification system for zygomatic arch fractures. A patient presenting following a motor vehicle accident exhibited an isolated zygomatic arch fracture with outward (lateral) displacement of arch fragments, forming a distinctive V-shaped configuration. Unlike conventional zygomatic arch fractures, which characteristically produce trismus through coronoid process impingement, this variant preserved mouth opening and manifested primarily as an aesthetic deformity. Management considerations for this pattern differ from standard approaches applied to conventional subtypes. The described fracture pattern is clinically and biomechanically distinct from the seven subtypes currently enumerated in the modified classification. Incorporation of this variant as a new subtype would enhance the comprehensiveness and clinical utility of the classification, enabling more accurate diagnosis and tailored surgical planning for atypical isolated zygomatic arch fractures.