J Korean Radiol Soc.  1995 Feb;32(2):215-222.

Masticator Space Lesions: MRI and CT Findings

• Kim KH
• Chang KH
• Yeon KM
• Song JU
• Kim SH
• Jo IC
• Hah MH

Abstract

PURPOSE
We evaluated the MR and CT findings of the masticator space lesions in order to identify the differences among the malignant and benign tumors and infectious conditions.
MATERIALS AND METHODS
MR and CT findings in 46 cases with proven masticator space lesions were reviewed retrospectively. We analysed the involvement of masticator muscles, adjacent spaces, orbit and intracrahium, homogeneity, necrosis, cystic changes, growth patterns, calcifications, enhancement patterns, MR signal intensity, and CT attenuation.
RESULTS
Among the 29 cases of malignant tumors, seven cases were mandibular tumors including four chondrosarcomas, and 22 cases were extramandibular tumors. Malignant tumors of mandibular origin showed large masses with severe bone destruction and epicenter of mandible. Extramandiblular malignant tumors showed the epicenter out of the mandible and less severe bone destruction than mandibular tumors: Among the nine benign tumors, four cases were ameloblastomas which showed the well-defined masses and the expansion of the mandible, and four cases were extramandibular tumors which showed well-marginated extramandibular masses with no bone destruction. Among the eight infectious conditions, five cases were mandibular osteomyelitis with or without abscess formations, and the other three cases were infections from adjacent soft tissue or limited to the soft tissue.
CONCLUSION
By careful observations of growth patterns, involvement of the masticator and adjacent spaces, bone changes, and epicenter of the lesions, one can discriminate a mandibular lesion from an extramandibular lesion. With this approach, it is thought to be easier to suggest a dignosis among a wide spectrum of masticator lesions.

MeSH Terms

Abscess
Ameloblastoma
Chondrosarcoma
Magnetic Resonance Imaging*
Mandible
Muscles
Necrosis
Orbit
Osteomyelitis
Retrospective Studies