Botulinum toxin related research in maxillofacial plastic and reconstructive surgery

The effect of botulinum toxin A in unilateral cleft lip scar: comparison of results with different sites of injection

Botulinum toxin type A (BTA) injections into the subjacent orbicularis oris muscle have been shown to improve appearance and produce narrower cheiloplasty scars. This study was performed to determine the effect of BTA injected at different sites on the unilateral cleft lip scar and cleft side nostril width. A double-blind, randomized prospective trial was conducted involving 64 consecutive patients with unilateral cleft lip undergoing primary cheiloplasty between September 2016 and January 2019. The patients were randomized to receive BTA injections either into the subjacent orbicularis oris muscle (4 points group) or into the bilateral nasolabial fold region (6 points group) during cheiloplasty. The scars were assessed by photographic scar width measurements and Vancouver scar scale assessment tool. The cleft side nostril width was compared to the non-cleft side width. Fifty-six patients completed the trial, 24 in the 4 points group and 31 in the 6 points group. There was no significant difference in scar width or nostril width measurements between the groups at the end of follow-up. The Vancouver scar scale assessment was also similar between the groups. There was no significant difference in scar width or nostril width measurements after cleft lip repair between patients treated with botulinum toxin injections to the subjacent orbicularis oris muscle and patients treated with injections in the nasolabial region.

Botulinum Toxin for a Better Scar in Cleft Lip Surgery: A Prospective Randomized Control Trial

INTRODUCTION

An unsightly scar following cleft repair can undo the good work of even an experienced surgeon. A functioning orbicularis oris muscle beneath the lip scar maintains a zone of dynamic tension resulting in a stretched scar. Botulinum toxin type A (BTA) can be used to create a temporary paralysis of the orbicularis muscle during the healing phase. This may lead to better scar formation after a cleft lip repair.

METHOD

The present prospective randomized control trial enrolled 28 infants with unilateral cleft lip undergoing primary lip repair. They were randomized to receive injection of either BTA (botox group) or normal saline (control group) intraoperatively into adjacent orbicularis oris muscle immediately after completion of cleft lip repair. Blinded experts reassessed the scar after 6 months. Objective assessment was undertaken employing Visual Analogue Scale (VAS), Vancouver Scar Scale (VSS), and photographic scar width measurements.

RESULTS

Twenty-two subjects were able to complete a follow-up duration of 6 months. Children in the BTA (Botox Group) had a statistically significantly better VAS score and lesser scar width compared to the control group. However, the difference in the VSS score between both groups was not statistically significant. On comparing patients with cleft lip alone with cleft lip and palate, no statistically significant difference was found in VAS, VSS, and scar width. There were no complications associated with the use of botulinum toxin A.

CONCLUSIONS

Botulinum toxin type A injection is a safe and effective addition to improve scar appearance following cleft lip repair. There was improvement in appearance of the scar in terms of width, but no improvement was seen in the scar pigmentation. The scar outcome is independent of cleft lip classification.

Application of botulinum toxin in maxillofacial field: Part III. Ancillary treatment for maxillofacial surgery and summary

Botulinum toxin (BTX) has various therapeutic indications: bruxism, square jaw, facial wrinkle, oral ulcer and maxillofacial pain, etc. In this paper, we will discuss the effectiveness of using BTX in dental implant surgery and orthognathic and orthodontic treatment. We summarized the clinical application of botulinum toxin in the maxillofacial field at the finale.

Application of botulinum toxin in maxillofacial field: part I. Bruxism and square jaw

The application of botulinum in oral and maxillofacial surgery begins in 1982, where Jan Carruthers started using it for reducing the muscle mass and smoothing the skin, and since then it has been used for cosmetic purposes. In Korea, it is already being used by various specialties including dentistry (oral and maxillofacial surgery, oral medicine), plastic surgery, dermatology, ophthalmology, general surgery, and orthopedic surgery, etc. Each specialty approaches to Botox with its own medical indications. In this article, we will discuss the maxillofacial application of botulinum toxin, which includes theoretical and practical aspects of such as bruxism and square jaw.

Botulinum toxin A injection into the anterior belly of the digastric muscle increased the posterior width of the maxillary arch in developing rats

Background

The purpose of this study was to evaluate the effects of botulinum toxin A (BTX) injection into the anterior belly of the digastric muscle on a growing rat.

Methods

Ten Sprague Dawley rats were used in this study. When the rats were 13 days old, 0.5 units of BTX was injected into the anterior belly of the digastric muscle for the experimental group (n = 5). For the control, the same volume of normal saline was injected (n = 5). The rats were sacrificed at 60 days old, and the skulls were harvested for micro-computed tomography (μCT) analysis.

Results

In anthropometric analysis, the zygomatic arch and mandibular bi-condylar width were significantly lower in the experimental group than those in the control group (P = 0.025 and 0.027, respectively). The maxillary point width was significantly higher in the experimental group than that in the control group (P = 0.020).

Conclusion

BTX injection into the anterior belly of the digastric muscle had effects on the maxillofacial bony width in growing rats.

Effect of the masseter muscle injection of botulinum toxin A on the mandibular bone growth of developmental rats

Background

The objective of this study was to evaluate the influence of masticatory muscle injection of botulinum toxin type A (BTX-A) on the growth of the mandibular bone in vivo.

Methods

Eleven Sprague-Dawley rats were used, and BTX-A (n = 6) or saline (n = 5) was injected at 13 days of age. All injections were given to the right masseter muscle, and the BTX-A dose was 0.5 units. All of the rats were euthanized at 60 days of age. The skulls of the rats were separated and fixed with 10% formalin for micro-computed tomography (micro-CT) analysis.

Results

The anthropometric analysis found that the ramus heights and bigonial widths of the BTX-A-injected group were significantly smaller than those of the saline-injected group (P < 0.05), and the mandibular plane angle of the BTX-A-injected group was significantly greater than in the saline-injected group (P < 0.001). In the BTX-A-injected group, the ramus heights II and III and the mandibular plane angles I and II showed significant differences between the injected and non-injected sides (P < 0.05). The BTX-A-injected side of the mandible in the masseter group showed significantly lower mandibular bone growth compared with the non-injected side.

Conclusion

BTX-A injection into the masseter muscle influences mandibular bone growth.