生長中大鼠施打肉毒桿菌神經毒素降低咀嚼肌功能後對肌肉萎縮、及骨骼內部結構之影響

Effect on the Muscular Atrophy and Internal Bone Structure of Growing Rats after BTX Injection to Reduce Masticatory Muscle Activity

石逸民(Yi-Ming Shyr)

指導教授 ： 蔡吉陽

臺北醫學大學/口腔醫學院/牙醫學系碩博士班/碩士(2007年)

https://doi.org/10.6831/TMU.2007.00097

摘要

本實驗以肉毒桿菌神經毒素A型(Botox®, Allergan Inc.,Irvine, OCA, USA)注射大白鼠之咬肌與顳肌，造成咬肌與顳肌萎縮，降低咬合功能，藉此觀察其對於老鼠顱顏部肌肉發育的差異，對頭顱骨骼密度的影響、以及皮質骨厚度的改變的比較。
此實驗種所採取的研究方式為：選取60隻30天大的大鼠(Long-Evans) ，隨機分成四組，其中三組為實驗組、另外一組為控制組，依部位注射入大鼠: Group I (Mb+Tn.s.)：雙側咬肌注射肉毒桿菌素 (顳肌則注射入等量生理食鹽水)。 Group II (Mn.s.+Tb)：雙側顳肌注射肉毒桿菌素 (咬肌則注射入等量生理食鹽水)。Group III (Mb+Tb)：雙側咬肌和顳肌注射肉毒桿菌素。Group IV (Control)：雙側咬和顳肌注射入等量生理食鹽水。給予相同飲水與飼料，飼養45天後犧牲，取下咬肌與顳肌測量其重量，並對頭顱骨與下顎骨以「雙能量X光吸收儀」（Dual-energy X-ray absorptiometry, DEXA）進行骨質密度(bone mineral density)掃描。另外，於所有樣本之右側下顎骨選取四處製作骨切片標本，觀察皮質骨(cortical bone)厚度的差異。

本實驗研究結果發現實驗組之大鼠施打肉毒桿菌神經毒素之咬肌和顳肌重量較施打生理食鹽水組顯著較小。咀嚼功能下降，使發育中的大鼠顱顏部骨骼所承受的咀嚼力下降，造成骨骼內部結構上的改變，本實驗發現實驗組之骨密度與對照組相比顯著較低，且於下顎骨皮質骨在不同選取處之厚度顯著較薄。

關鍵字

肉毒桿菌神經毒素 ； 咀嚼功能 ； 生長 ； 下顎 ； 骨骼 ； 鼠

並列摘要

In this study, Botulinum Neurotoxin type A(Botox®, Allergan Inc.,Irvine, OCA, USA) was injected into growing rats’ temporalis muscle and masseter muscle to produce muscular atrophy and to reduce masticatory function. Observations of the muscular volume, skull & mandible bone mineral density, and mandibular cortical bone thickness at selected area were measured.
Method: 60 Long-Evan rats 30 days after birth were divided randomly into 4 groups. Group I (Mb+Tn.s.)：Bilateral injection of Botox in masseter muscle. (Saline of equal amount injected into temporalis muscle). Group II (Mn.s.+Tb)： Bilateral injection of Botox in temporalis muscle. (Saline of equal amount injected into masseter muscle). Group III (Mb+Tb)： Bilateral injection of Botox in temporalis and masseter muscle. Group IV (Control) ：Bilateral injection of saline in temporalis and masseter muscle. All animals were given same food and water under same feeding environment for 45 days. After sacrifice, perfusion with Formalin was performed. Temporalis and masseter muscle were dissected and the volume of each msucle was measured. Bone mineral density of skull and mandible was scanned with DEXA (Dual-energy X-ray absorptiometry). Furthermore, bone biopsies of right half of mandibles were prepared for cortical bone thickness observation.
Result: Temporalis and masseter muscles injected with Botox were lower in volumetric measurements, compared with saline injected ones. Meanwhile,
BTX injected temporalis muscle and masseter muscle reduced masticatory function, which alters the internal structure of the bone: lowered BMD and thinner cortical bone thickness in the experimental groups.

並列關鍵字

Botulinum Neurotoxin ； masticatory function ； rat ； growth ； mandible ； bone

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