Effect of Botubinum toxin type A injection into the masseter muscle on mandibular development in rats

黃進(jìn)軍(Huang Jinjun，Dept Plast Surg，Zhujiang Hosp，Southern Med Univ，Guangzhou 510282)…∥Chin J Plast Surg.－2010，26(4).－280～285

Effect of Botubinum toxin type A injection into the masseter muscle on mandibular development in rats

黃進(jìn)軍(Huang Jinjun，Dept Plast Surg，Zhujiang Hosp，Southern Med Univ，Guangzhou 510282)…∥Chin J Plast Surg.－2010，26(4).－280～285

ObjectiveTo investigate the effect of Botulinum toxin type A(Botox)injection into the masseter muscle on mandibular development in rats.Methods12 28 －day-old Wistar rats were divided into two groups as Botox group(n=6)and control group(n=6)which received anesthesia only.InBotox group，Botox was injected into the right masseter muscle，while only sterile saline into the leftmuscle.When the rats were 75 － day-old，CT scan and 3D reconstruction were performed for cephalometry.The masseter muscles at both sides were weighed.Histologic study of masseter muscle and mandible was also performed.ResultsThe weight of right masseter muscle was(0.4575 ± O.0940)g in Botox group，and(0.8899 ±0.1030)g in control group(P ＜0.05).The mandibular heightⅡ and Ⅲ was(10.8 ±0.8)mmand(9.5+0.6)mm in Botox group and(12.5+0.6)mm and(10.7+0.4)mm in control group，respectively(P ＜ 0.05).The intergonial distance was(11.6 ±0.6)mm and(12.4 ±0.6)mm in Botox and control group，respectively(P ＞ 0.05).Conclusion

When the rats receive Botox injection into the masseter muscle at young age，the grown-up rats have a decreased mandibular height，but the mandibular length and intergonial distance are not affected.22 refs，6 figs，1 tab.

(Authors)