TY - JOUR
T1 - Histochemical characteristics of masseter and temporalis muscles after 5 weeks of maxillomandibular fixation-An investigation inMacaca mulatta
AU - Mayo, Kathleen H.
AU - Ellis, Edward
AU - Carlson, David S.
N1 - Funding Information:
This research was supported by NIH-NIDR DE06874 and a grant from The Chalmers J. Lyons Academy-James R. Hayward Research Fund.
PY - 1988/10
Y1 - 1988/10
N2 - This study describes the histochemical characteristics and cross-sectional areas of the superficial masseter and temporalis muscles in juvenile rhesus monkeys after 5 weeks of maxillomandibular fixation. Four juvenile maleMacaca mulatta underwent mandibular surgery and 5 weeks of maxillomandibular fixation as part of a study of temporomandibular joint (TMJ) adaptations after condylar replacement. Immediately before the time the animals were killed (5 weeks postsurgically), biopsies of the masseter and temporalis muscles were obtained and submitted to histochemical analysis and calculation of muscle-fiber areas. The data were compared to histochemistry from 12 juvenile controlMacaca mulatta. Significant decreases in mean cross-sectional area were exhibited in both type I (p < 0.05) and type II (p < 0.01) fibers in all muscles when compared to controls (n = 12). The ratio of type I to type II fibers, however, remained constant during maxillomandibular fixation in masseter and temporalis muscle samples, indicating no change in relative types of fibers. We conclude from this experimental investigation that (1) significant atrophy occurs in the temporalis and masseter muscles after 5 weeks of maxillomandibular fixation, and (2) this atrophy occurs in both type I and type II fibers, indicating that overall recruitment of the muscle (and not just of one fiber type of motor unit) was affected during fixation.
AB - This study describes the histochemical characteristics and cross-sectional areas of the superficial masseter and temporalis muscles in juvenile rhesus monkeys after 5 weeks of maxillomandibular fixation. Four juvenile maleMacaca mulatta underwent mandibular surgery and 5 weeks of maxillomandibular fixation as part of a study of temporomandibular joint (TMJ) adaptations after condylar replacement. Immediately before the time the animals were killed (5 weeks postsurgically), biopsies of the masseter and temporalis muscles were obtained and submitted to histochemical analysis and calculation of muscle-fiber areas. The data were compared to histochemistry from 12 juvenile controlMacaca mulatta. Significant decreases in mean cross-sectional area were exhibited in both type I (p < 0.05) and type II (p < 0.01) fibers in all muscles when compared to controls (n = 12). The ratio of type I to type II fibers, however, remained constant during maxillomandibular fixation in masseter and temporalis muscle samples, indicating no change in relative types of fibers. We conclude from this experimental investigation that (1) significant atrophy occurs in the temporalis and masseter muscles after 5 weeks of maxillomandibular fixation, and (2) this atrophy occurs in both type I and type II fibers, indicating that overall recruitment of the muscle (and not just of one fiber type of motor unit) was affected during fixation.
UR - http://www.scopus.com/inward/record.url?scp=0024094732&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024094732&partnerID=8YFLogxK
U2 - 10.1016/0030-4220(88)90258-7
DO - 10.1016/0030-4220(88)90258-7
M3 - Article
C2 - 2972982
AN - SCOPUS:0024094732
SN - 0030-4220
VL - 66
SP - 421
EP - 426
JO - Oral Surgery, Oral Medicine, Oral Pathology
JF - Oral Surgery, Oral Medicine, Oral Pathology
IS - 4
ER -