Korean J Orthod.  2017 Jul;47(4):222-228. 10.4041/kjod.2017.47.4.222.

Repeated injections of botulinum toxin into the masseter muscle induce bony changes in human adults: A longitudinal study

• Lee HJ
• Kim SJ
• Lee KJ
• Yu HS
• Baik HS

• KMID: 2379554
• DOI: http://doi.org/10.4041/kjod.2017.47.4.222

Abstract

OBJECTIVE
To evaluate soft- and hard-tissue changes in the mandibular angle area after the administration of botulinum toxin type A (BoNT-A) injection to patients with masseteric hypertrophy by using three-dimensional cone-beam computed tomography (3D-CBCT).
METHODS
Twenty volunteers were randomly divided into two groups of 10 patients. Patients in group I received a single BoNT-A injection in both masseter muscles, while those in group II received two BoNT-A injections in each masseter muscle, with the second injection being administered 4 months after the first one. In both groups, 3D-CBCT was performed before the first injection and 6 months after the first injection.
RESULTS
Masseter muscle thicknesses and cross-sectional areas were significantly reduced in both groups, but the reductions were significantly more substantial in group II than in group I. The intergonial width of the mandibular angle area did not change significantly in either group. However, the bone volume of the mandibular gonial angle area was more significantly reduced in group II than in group I.
CONCLUSIONS
The repeated administration of BoNT-A injections may induce bone volume changes in the mandibular angle area.

Keyword

Computed tomography; Soft tissue; Botox; Bony change

MeSH Terms

Adult*
Botulinum Toxins*
Botulinum Toxins, Type A
Cone-Beam Computed Tomography
Humans*
Hypertrophy
Longitudinal Studies*
Masseter Muscle*
Volunteers
Botulinum Toxins
Botulinum Toxins, Type A

Figure

• 

  Figure 1 A, Cone-beam computed tomography (CBCT) image cut at levels C5, C10, C15, C20, C25, and C30. Mandibular CBCT images are digitally cut into 5-mm-thick sections parallel to the mandibular plane. B, The thickness and crosssectional area of the masseter muscle at each cut level. The arrows indicate the maximum thickness of the masseter muscles, and the indicated areas represent the cross-sectional area of the masseter muscles.

• 

  Figure 2 A, Reference points for the width and volume of the mandibular angle area; Go post (Gonion posterius), Go inf (Gonion inferius), and distobucco-occlusal point angle. B, Inter-Go post right-left (Rt-Lt) and inter-Go inf Rt-Lt widths. C, Reference points for the volume of the mandibular angle area; Go post, Go inf, distobucco-occlusal point angle, and distolinguo-occlusal point angle of second molar. D, Volume of the mandibular angle area.

Reference

1. Moss ML. The primacy of functional matrices in orofacial growth. Dent Pract Dent Rec. 1968; 19:65–73.

2. Collins HB. The origin and antiquity of the Eskimo. Washington, D.C.: Smithsonian Institution;1951.

3. Proffit WR, Fields HW, Nixon WL. Occlusal forces in normal- and long-face adults. J Dent Res. 1983; 62:566–570.

4. Burgen AS, Dickens F, Zatman LJ. The action of botulinum toxin on the neuro-muscular junction. J Physiol. 1949; 109:10–24.

5. Klein AW. Complications, adverse reactions, and insights with the use of botulinum toxin. Dermatol Surg. 2003; 29:549–556. discussion 556.

6. Kim NH, Chung JH, Park RH, Park JB. The use of botulinum toxin type A in aesthetic mandibular contouring. Plast Reconstr Surg. 2005; 115:919–930.

7. To EW, Ahuja AT, Ho WS, King WW, Wong WK, Pang PC, et al. A prospective study of the effect of botulinum toxin A on masseteric muscle hypertrophy with ultrasonographic and electromyographic measurement. Br J Plast Surg. 2001; 54:197–200.

8. Kiliaridis S, Engström C, Thilander B. The relationship between masticatory function and craniofacial morphology. I. A cephalometric longitudinal analysis in the growing rat fed a soft diet. Eur J Orthod. 1985; 7:273–283.

9. Kün-Darbois JD, Libouban H, Chappard D. Botulinum toxin in masticatory muscles of the adult rat induces bone loss at the condyle and alveolar regions of the mandible associated with a bone proliferation at a muscle enthesis. Bone. 2015; 77:75–82.

10. Matthys T, Ho Dang HA, Rafferty KL, Herring SW. Bone and cartilage changes in rabbit mandibular condyles after 1 injection of botulinum toxin. Am J Orthod Dentofacial Orthop. 2015; 148:999–1009.

11. Rafferty KL, Liu ZJ, Ye W, Navarrete AL, Nguyen TT, Salamati A, et al. Botulinum toxin in masticatory muscles: short- and long-term effects on muscle, bone, and craniofacial function in adult rabbits. Bone. 2012; 50:651–662.

12. Raphael KG, Tadinada A, Bradshaw JM, Janal MN, Sirois DA, Chan KC, et al. Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study. J Oral Rehabil. 2014; 41:555–563.

13. de Paiva A, Meunier FA, Molgó J, Aoki KR, Dolly JO. Functional repair of motor endplates after botulinum neurotoxin type A poisoning: biphasic switch of synaptic activity between nerve sprouts and their parent terminals. Proc Natl Acad Sci U S A. 1999; 96:3200–3205.

14. Hambleton P. Clostridium botulinum toxins: a general review of involvement in disease, structure, mode of action and preparation for clinical use. J Neurol. 1992; 239:16–20.

15. Park MY, Ahn KY, Jung DS. Botulinum toxin type A treatment for contouring of the lower face. Dermatol Surg. 2003; 29:477–483. discussion 483.

16. Kim HJ, Yum KW, Lee SS, Heo MS, Seo K. Effects of botulinum toxin type A on bilateral masseteric hypertrophy evaluated with computed tomographic measurement. Dermatol Surg. 2003; 29:484–489.

17. Shim WH, Yoon SH, Park JH, Choi YC, Kim ST. Effect of botulinum toxin type A injection on lower facial contouring evaluated using a three-dimensional laser scan. Dermatol Surg. 2010; 36:Suppl 4. 2161–2166.

18. Lee HH, Kim ST, Lee KJ, Baik HS. Effect of a second injection of botulinum toxin on lower facial contouring, as evaluated using 3-dimensional laser scanning. Dermatol Surg. 2015; 41:439–444.

19. Chappard D, Chennebault A, Moreau M, Legrand E, Audran M, Basle MF. Texture analysis of X-ray radiographs is a more reliable descriptor of bone loss than mineral content in a rat model of localized disuse induced by the Clostridium botulinum toxin. Bone. 2001; 28:72–79.

20. Warner SE, Sanford DA, Becker BA, Bain SD, Srinivasan S, Gross TS. Botox induced muscle paralysis rapidly degrades bone. Bone. 2006; 38:257–264.

21. Kim HY, Kim SC. Bone cutting capacity and osseointegration of surface-treated orthodontic mini-implants. Korean J Orthod. 2016; 46:386–394.