Six years of experience using an advanced algorithm for botulinum toxin application

Botulinum Toxin Injection into the Digastric Muscle: Current Clinical Use and a Report of Five Cases

The present research aimed to review the clinical applications of botulinum toxin-A (BTX-A) injection into the anterior belly of the digastric muscle (ABDM) and to highlight the potential role of the BTX-A injection into ABDM in preventing postsurgical relapse. Five Class II malocclusion patients who underwent orthognathic surgery received BTX-A injections into both ABDM for the prevention of postoperative relapse. The relapse was evaluated using lateral cephalometric radiographs by comparing the postoperative cephalometric analyses at two different time points, postoperatively at 2 weeks (T1), and long-term, at 9 months after the surgical intervention (T2). The results demonstrated no significant differences between T2 and T1 for the Selle-Nasion-point A (SNA) angle, Selle-Nasion-point B (SNB) angle, point A-Nasion-point B (ANB) angle, mandibular length, and sagittal mandibular position. The patients exhibited stable occlusion without any signs of relapse after the surgery. A single BTX-A injection into the ABDM can effectively prevent postoperative relapse in Class II malocclusion patients, following orthognathic surgery. From a clinical perspective, in case of optimal dosage and procedure, BTX-A injection could be considered as the primary option for the prevention of postsurgical relapse for Class II malocclusion patients.

Influence of botulinum toxin type A esthetic injections on facial expressions

BACKGROUND

Botulinum toxin type A (BoNT-A) injection remains the leading medical cosmetic procedure worldwide, with a high rate of patient satisfaction. However, it still suffers from patients' fear of being unable to transmit their emotions and of looking frozen from unnatural results.

AIM

This study aimed to determine whether BoNT-A can decrease the intensity of emotions in facial expressions.

PATIENTS/METHODS

In this single-center prospective study, 42 patient investigators assessed four patients' facial expressions for six emotions and neutral faces, before and after injection of 36 IU or 48 IU of onabotulinumtoxinA, using photographs. Photographs were presented on a tablet to the investigators.

RESULTS

There were no statistical differences between the before and after photographs for the intensity of emotions for all expressions (P > .05) except for the expression of surprise in the group of patients that received 48 IU of the injection (protocol with injection of the frontalis muscle). All patient investigators answered negatively to the question "Do you think that this patient has a 'frozen face'?".

CONCLUSION

This study shows that esthetic injection of BoNT-A in the upper face has no negative effects on facial expressions and does not lead to the feared "frozen face" when it is injected with respect for best practice guidelines. This study can be used as an example for patients who have some reticences against BoNT-A injection.

Immunohistochemical evidence of striated muscle cells within midfacial superficial musculoaponeurotic system

INTRODUCTION

The superficial musculoaponeurotic system (SMAS) is a controversial functional fibro-adipose layer that connects the mimic muscles to the skin and is involved in a variety of facial mimic expressions. The presence of muscle fibers within SMAS fibrous septa is hypothetical. The present study analyzed SMAS fibrous septa composition for the existence of striated muscle cells.

METHODS

Histological serial sections of the sample borders (n=107) of 19 in sano-resected and diagnosed cutaneous tumors of the midfacial region were investigated. Immunohistochemical (actin and myosin) and hematoxylin and eosin staining were performed to detect striated muscle cells in SMAS fibrous septa.

RESULTS

A fibro-neuro-musculo-vascular functional unit within SMAS fibrous septa was demonstrated. SMAS striated muscle cells were morphologically independent from preparotideal and periorbital mimic muscles. Intraseptal blood vessels draining the superficial and deep SMAS vascular system were described.

CONCLUSIONS

Striated muscle cells were demonstrated within SMAS fibrous septa. Nerve cells and vascular tissue together with the SMAS fibro-muscular meshwork demonstrated an autonomous operating functional unit that hypothetical modulated individual mimic expression contributing to the diversity of mimic expression. The SMAS develops with mimic muscle contractions as a synergetic effect during facial crease and fold formation processes.

An Italian experience of a new personalized injective protocol (Botutouch) for botulinum toxin application in aesthetic medicine

Botulinum toxin typeA (BoNTA) is widely used in aesthetic medicine as primary treatment to reduce facial wrinkles. Major unmet needs in the field of the injection techniques include dilution factor, injected volume and site. Since 2013, an innovative protocol has been developed in our clinic that works on a double dilution volume, identifies the injection site according to the specific anatomical-functional characteristics of each patient's musculature and applies a gentle massage to the injected area to optimize the toxin spread in the muscle. We retrospectively retrieved medical records of subjects that underwent aesthetic treatments in our outpatient Italian clinics from 2013. In cobotulinum toxin A was used in double dilution (100 AU in 5 mL of physiologic solution) and followed by a gentle massage after the injection to increase the distribution into the muscle. 197 subjects, most of them drug-naïve (81.7%), underwent 869 BoNTA treatments. On average, higher total units and volumes were applied in first visits or older subjects whereas the lower ones were preferred in following visits or younger subjects. As perceived by the patients, the effects of BoNTA lasted more than 6 months in about 38% of the cases. 95.9% of subjects declared to be satisfied,whereas 5.2% of adverse events were observed (4.8% hematoma, 0.2% ptosis, and 0.2% tenderness). To date, we offer a BoNTA treatment with the aim to maximize the results and consequent patient's satisfaction, with low incidence of complications.

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.