Objective To observe the morphology of the superficial,middle,and deep layers of the masseter muscle and related bony structures in the lateral facial region of adults through gross anatomy,and to probe into the effects of these muscle layers on the bony structures of the lateral facial region.Methods The bilateral masseter muscles of 12 adult cadavers were exposed,and the superficial,middle,and deep layers were separated and measured for muscle length,tendon length,and muscle belly length.After the masseter muscles were stripped,the total thickness was measured,and the mandible and zygomatic arch were exposed to measure the angle of the mandibular angle,thickness of the zygomatic arch,and width of the zygomatic arch.Observations were made of the masseter tuberosities,and statistical analysis was conducted on their interrelations.Results The zygomatic arch thickness was positively correlated with the length of superficial,middle and deep masseter muscles and the length of superficial and middle masseter belly(r superficial masseter length=0.624,r middle masseter length=0.787,r deep masseter length=0.423,r superficial masseter belly length=0.493,r middle masseter belly length=0.548).The width of the zygomatic arch was positively correlated with the lengths of the superficial and middle muscle layers and the middle muscle belly length(r superficial masseter length=0.527,r middle masseter length=0.521,r middle masseterbelly length=0.437).The angle of the mandibular angle was only negatively correlated with the middle muscle belly length(r=-0.422).The tuberosities of the superficial and middle masseter muscles were not affected by the corresponding muscle layers;However,the tuberosity of the deep masseter was negatively correlated with the length of the deep muscle and the length of the deep tendon(r deep masseter length=-0.543,r deep masseter tendon length=-0.443).Conclusion In the masseter muscle layers of Chinese individuals,the superficial and middle layers have the most significant impact on the bony structures structures of the lateral facial region.These findings are of guiding significance for the remodeling of structures in the lateral facial region.

OBJECTIVETo evaluate the implication of Fletcher and Miettinen biologic potential grading criteria in native localized gastrointestinal stromal tumors (GISTs).

METHODSTwo hundred and twenty localized GISTs with complete clinicopathologic and follow-up data were evaluated for their biologic potential by Fletcher and Miettinen grading criteria. The implication of the two grading criteria were compared by survival analysis.

RESULTSEvaluated by Fletcher grading criteria, the overall and disease-free survival rate of high risk GISTs was lower than that of very-low, low and intermediate GISTs; while the overall and disease-free survival rate of very-low, low and intermediate risk GISTs had no statistical diffence. In the high risk GISTs, the overall and disease-free survival rate of small intestinal and rectal GISTs was lower than that of gastric GISTs; while in the intermediate risk GISTs, the disease-free survival rate of small intestinal GISTs was lower than that of gastric GISTs. Evaluated by Miettinen grading criteria, the overall and disease-free survival rate of high risk GISTs was lower than that of very-low, low and intermediate GISTs; while the overall and disease-free survival rate of very-low, low and intermediate risk GISTs had no statistical difference. In the risk subgroup of GISTs, the overall and disease-free survival rate of gastric, small intestinal and rectal GISTs had no statistical difference.

CONCLUSIONSFletcher grading criteria is simple and easy to use; while Miettinen grading criteria for evaluating biological potential by anatomic site is more critical and has important reference implication for the selection of high risk patients for targeted adjuvant treatment.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Disease Progression ; Disease-Free Survival ; Female ; Follow-Up Studies ; Gastrointestinal Stromal Tumors ; pathology ; Humans ; Ileal Neoplasms ; pathology ; Jejunal Neoplasms ; pathology ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Rectal Neoplasms ; pathology ; Risk Assessment ; methods ; standards ; Stomach Neoplasms ; pathology ; Survival Rate ; Young Adult