Longitudinal Assessment of Masseter Muscle Elasticity Changes After BoNT-A Injection Using Ultrasound Elastography: A Prospective Self-Controlled Study.
Abstract
[BACKGROUND] Botulinum neurotoxin type A (BoNT-A) is widely used to treat masseter hypertrophy, but its long-term structural effects remain unclear. While animal studies suggest reversible and irreversible remodeling, human data on microstructural changes are limited. Ultrasound elastography (USE) offers a non-invasive method to quantitatively assess muscle elasticity and detect fibrosis risk.
[METHODS] A prospective self-controlled trial enrolled 14 subjects (28 masseter muscles) aged 21-27 years. Masseter thickness and standardized USE measurements (shear wave velocity, V median) were performed at baseline and 1, 3, and 6 months post-injection. Statistical analysis included paired t-tests and Spearman correlation.
[RESULTS] Masseter thickness decreased significantly by 28.9-31.5% at 1-3 months (p ≤ 0.05), with partial recovery (47.4%) by 6 months. V median (elasticity) declined at 1-3 months (2.53 ± 0.46 m/s to 2.10 ± 0.45 m/s, p ≤ 0.05), but returned to baseline by 6 months (2.70 ± 0.68 m/s, p > 0.05), indicating reversible structural adaptation. Thickness and elasticity changes were uncorrelated, suggesting distinct recovery mechanism.
[CONCLUSION] BoNT-A induces transient masseter atrophy and elasticity reduction, with full elastic recovery by 6 months despite incomplete volume restoration. USE effectively tracks reversible microstructural remodeling, distinguishing atrophy from fibrosis. These findings support USE as a tool for optimizing injection timing and monitoring functional recovery.
[LEVEL OF EVIDENCE II] This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
[METHODS] A prospective self-controlled trial enrolled 14 subjects (28 masseter muscles) aged 21-27 years. Masseter thickness and standardized USE measurements (shear wave velocity, V median) were performed at baseline and 1, 3, and 6 months post-injection. Statistical analysis included paired t-tests and Spearman correlation.
[RESULTS] Masseter thickness decreased significantly by 28.9-31.5% at 1-3 months (p ≤ 0.05), with partial recovery (47.4%) by 6 months. V median (elasticity) declined at 1-3 months (2.53 ± 0.46 m/s to 2.10 ± 0.45 m/s, p ≤ 0.05), but returned to baseline by 6 months (2.70 ± 0.68 m/s, p > 0.05), indicating reversible structural adaptation. Thickness and elasticity changes were uncorrelated, suggesting distinct recovery mechanism.
[CONCLUSION] BoNT-A induces transient masseter atrophy and elasticity reduction, with full elastic recovery by 6 months despite incomplete volume restoration. USE effectively tracks reversible microstructural remodeling, distinguishing atrophy from fibrosis. These findings support USE as a tool for optimizing injection timing and monitoring functional recovery.
[LEVEL OF EVIDENCE II] This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
추출된 의학 개체 (NER)
| 유형 | 영어 표현 | 한국어 / 풀이 | UMLS CUI | 출처 | 등장 |
|---|---|---|---|---|---|
| 해부 | masseter
|
scispacy | 1 | ||
| 해부 | muscle
|
scispacy | 1 | ||
| 해부 | microstructural
|
scispacy | 1 | ||
| 약물 | ± 0.45 m/s, p
|
scispacy | 1 | ||
| 약물 | BoNT-A
→ Botulinum neurotoxin type A
|
scispacy | 1 | ||
| 약물 | [BACKGROUND] Botulinum neurotoxin type A
|
scispacy | 1 | ||
| 약물 | [RESULTS] Masseter thickness
|
scispacy | 1 | ||
| 질환 | masseter hypertrophy
|
scispacy | 1 | ||
| 질환 | fibrosis
|
C0016059
Fibrosis
|
scispacy | 1 | |
| 질환 | masseter atrophy
|
scispacy | 1 | ||
| 질환 | atrophy
|
C0333641
Atrophic
|
scispacy | 1 | |
| 질환 | Masseter Muscle Elasticity
|
scispacy | 1 | ||
| 질환 | masseter muscles
|
scispacy | 1 | ||
| 기타 | Self-Controlled
|
scispacy | 1 | ||
| 기타 | BoNT-A
→ Botulinum neurotoxin type A
|
scispacy | 1 | ||
| 기타 | human
|
scispacy | 1 |
MeSH Terms
Humans; Masseter Muscle; Elasticity Imaging Techniques; Botulinum Toxins, Type A; Female; Adult; Prospective Studies; Male; Young Adult; Elasticity; Neuromuscular Agents; Injections, Intramuscular; Hypertrophy; Longitudinal Studies; Treatment Outcome; Follow-Up Studies
📑 인용 관계
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