TY - JOUR
T1 - The influence of masticatory hypofunction on developing rat craniofacial structure
AU - Tsai, C. Y.
AU - Yang, L. Y.
AU - Chen, K. T.
AU - Chiu, W. C.
N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010/6
Y1 - 2010/6
N2 - The purpose of this study was to use botulinum neurotoxin type A (BoNT/A) selectively to evaluate the influence of localized masticatory atrophy and paresis on craniofacial growth and development. 60 growing rats, 4 weeks old, weighing approximately 120 g, were randomly divided according as follows (Long-Evans, N = 15 per group): I (Mb + Tns); II (Mns + Tb); III (Mb + Tb); IV (Mns + Tns), where Mb or Tb is the BoNT/A-injected masseter or temporalis muscles (1.0 U/muscle, 2.5 ml) and Mns or Tns is the saline-injected muscles (2.5 ml). After 7 weeks, the mature rats were killed, the muscles dissected and mean muscle mass recorded. Anthropometric cranial, maxillary and mandibular measurements were taken from the dried skulls. Changes in animal weight during the growth period were not statistically significant. The mean masticatory muscle mass was smaller for the BoNT/A-injected muscles of Mb and Tb. Anthropometric measurements of bony structures inserted by masseter and temporalis muscles revealed a significant treatment effect. The measurements showed a facial morphology typical of a dolichofacial profile: short upper face accompanied by a long lower face with an extended mandibular length and ramus height and constricted bicoronoidal and bigonial widths. The results suggest that induction of localized masticatory muscle atrophy with BoNT/A alters craniofacial growth and development.
AB - The purpose of this study was to use botulinum neurotoxin type A (BoNT/A) selectively to evaluate the influence of localized masticatory atrophy and paresis on craniofacial growth and development. 60 growing rats, 4 weeks old, weighing approximately 120 g, were randomly divided according as follows (Long-Evans, N = 15 per group): I (Mb + Tns); II (Mns + Tb); III (Mb + Tb); IV (Mns + Tns), where Mb or Tb is the BoNT/A-injected masseter or temporalis muscles (1.0 U/muscle, 2.5 ml) and Mns or Tns is the saline-injected muscles (2.5 ml). After 7 weeks, the mature rats were killed, the muscles dissected and mean muscle mass recorded. Anthropometric cranial, maxillary and mandibular measurements were taken from the dried skulls. Changes in animal weight during the growth period were not statistically significant. The mean masticatory muscle mass was smaller for the BoNT/A-injected muscles of Mb and Tb. Anthropometric measurements of bony structures inserted by masseter and temporalis muscles revealed a significant treatment effect. The measurements showed a facial morphology typical of a dolichofacial profile: short upper face accompanied by a long lower face with an extended mandibular length and ramus height and constricted bicoronoidal and bigonial widths. The results suggest that induction of localized masticatory muscle atrophy with BoNT/A alters craniofacial growth and development.
KW - botulinum neurotoxin
KW - craniofacial growth and development
KW - masseter muscle
KW - masticatory muscle atrophy
KW - temporalis muscle
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U2 - 10.1016/j.ijom.2010.02.011
DO - 10.1016/j.ijom.2010.02.011
M3 - Article
C2 - 20219321
AN - SCOPUS:77953287480
VL - 39
SP - 593
EP - 598
JO - International Journal of Oral and Maxillofacial Surgery
JF - International Journal of Oral and Maxillofacial Surgery
SN - 0901-5027
IS - 6
ER -