Zygomatico-maxillary complex fractures

Contents IntroductionEpidemiologyAnatomyClassificationPt evaluationSign and symptomsTreatmentSurgical approaches Complications

Introduction

Epidemiology

Anatomy

ClassificationRowe and Williams

1. Fractures stable after elevationa. Arch only (medially displaced)b. Rotation around vertical axis

i. Mediallyii. Laterally

2. Fractures unstable after elevationa. Arch only (inferiorly displaced)b. Rotation around the horizontal axis

i. Mediallyii. Laterally

c. Dislocation en bloci. Inferiorlyii. Mediallyiii. Posterolaterally

d. Comminuted fractures

Fractures stable after elevation

Fractures unstable after elevation

Arch only Rotation around vertical axis

Inferior displacement

Rotation around horizontal axis

Dislocation en bloc comminuted

Rowe and Killey (1968)

Type I- no significant displacementType II- arch fractureType III- rotation around vertical axis

i. Inward displacement of orbital rimii. Outward displacement of orbital rim

Type IV- rotation around a longitudinal axisiii. Medial displacement of frontal process of zygomatic boneiv. Lateral displacement of frontal process of zygomatic bone

Type V- displacement of complex en blocv. Medialvi. Inferiorvii. Lateral

Type VI- displacement of orbito-antral partitionviii.Inferiorix. Superior

Type VII- displacement of orbital rim segmentsType VIII- complex comminuted fracture

Type II-Fracture of zygomatic arch

Type II-Rotation around vertical axis

Type III- rotation around longitudinal axis

Type V- displacement of complex en bloc

Type VI- displacement of orbito-antral partition

Type VII- displacement of orbital rim segments

Type VIII- complex comminuted fracture

• Rowe (1985)1. Group A : Stable fracture – Showing minimal or no

displacement and requires no intervention.

2. Group B : Unstable fracture – With great displacement and distruption at the frontozygomatic suture and comminuted fracture. Requires reduction as well as fixation

3. Group C : Stable fracture – Other types of zygomatic fractures, which requires reduction, but no fixation.

Fractures of the zygomatic arch alone

4. Minimum or no displacement

5. V type in fracture

6. Comminuted fracture

Larsen and thomsenUndisplaced fracture- this diagnosis is based

on both clinical and radiological examination and is insured by clinical re-examination when traumatic edema has subsided

Displaced unstable fractures- this diagnosis is based on radiological evidence of comminution or wide seperation at zygomaticofrontal suture

Displaced post-reductively stable fractures- this group comprises all other fractures

In 1961, Knight and North proposed an anatomically based classification

system (13) that shed new light on the treatment and prognosis of zygomatic

fractures.

No Changes Made Here

Group I: No significant displacement

Group II: Direct blows that buckle the malar eminence inward

Group III: Unrotated body fractures

Group IV: Medially rotated body fractures

Figure 3 Axial CT scan view of zygomatic fracture.

Zygoma Fractures 365

Group V: Laterally rotated body fractures

Group VI: Complex fractures (presence of additional fracture lines

across the main fragment)

Knight and North found that fractures in some areas were stable after

a closed reduction without the need for fixation 100% of the time (groups II

and V) while others (in groups IV, III, VI) remained unstable after reduction,

so that some form of fixation became necessary.

Further research by Pozatek et al. noted that group V fractures were

unstable about 60% of the time (14). In a study of patients who were submitted

to closed methods of zygomatic elevation, Dingman and Natvig

found that a significant number suffered from redisplacement of the zygoma

if the reduction was not followed by fixation (5). They theorized that redisplacement

took place as a result of the forces applied on the zygoma by the

masseter muscle.

Manson and his colleagues have since developed a classification based

on CT scan analysis (15). In this fractures are divided into low-, medium-,

and high-energy injuries. In low-energy zygoma fractures, there is little or

no displacement, and the incomplete fracture itself provides the stability.

Middle-energy fractures demonstrate fractures at all buttresses, some displacement,

and comminution. These frequently require eyelid and intraoral

exposure to provide the necessary reduction and fixation. High-energy

zygoma fractures are the most severe and often accompany Le Fort of panfacial

fractures. These fractures can involve the glenoid fossa and produce

significant posterior dislocation of the arch and malar eminence.