Surgical management of oral squamous cell carcinoma infiltrating mandible

Progression of recent trends in mandible-preserving operations for
the management of oral squamous cell carcinomas that infiltrate the
mandible is rapid and accompanying studies give invaluable
information concerning behavioral understanding of oral squamous
cell carcinoma within the mandible. However, a large amount of
sound osseous tissue is removed as part of partial mandibulectomy,
because it is difficult to gain direct sight into the medullary
portion and as a result of fear for residual tumor in this
inaccessible space. Thus, needless defects are not seldom. For that
reason, there still exists a strong demand for an operating
protocol regarding precise surgical clearance which fulfills the
surgeons' desire to be more conservative. Twenty-one with evidence
of intraosseous tumor spread of 82 resected mandibles were
radiologically and histologically reexamined to compare
discrepancies among clinical, radiologic and histologic entities of
oral squamous cell carcinoma infiltration. Size and location of
primary tumor were dominant correlating factors of oral squamous
cell carcinoma infiltration into the mandible and were
statistically significant (p < 0.05). Larger tumors are more
likely to infiltrate the mandible. Gingiva and retromolar trigone
were the prevalent locations which facilitated tumor infiltration.
Direct contact of the tumor on the attached mucosa usually provides
portal of entry of the tumor through the cortex into the medullary
space. Periodontal space in the dentate mandible is another
possible portal of entry. Erosive-type infiltration is mostly seen
in the shallower depth in early phase of infiltration and then
followed by invasive type in the deeper portion of mandible.
Infiltrating tumors usually do not exceed the limit of the primary
on the mucosa, but it becomes unpredictable when inferior alveolar
nerve related spread is once initiated. Five to 10 mm of surgical
clearance is applicable to any surgical interventions regarding
mandible infiltrating oral squamous cell carcinoma. However,
thorough pre- and intra-operative attention should be put on the
nerve related spread, extended resection of mandible is inevitable
when nerve involvement is evident. A combination of
orthopantomogram, computerized tomography and Tc-99m skeletal
scintigraphy provide a good assessment of the tumor infiltration in
the mandible. Distance measurement in orthopantomogram is reliable
in localizing the tumor and in planning the surgical margin. An
operating scheme based on the biologic behavior of oral squamous
cell carcinoma within the mandible is devised as a result of this
study.