Clinical uses of botulinum toxin A in smile aesthetic modification

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 2: cosmetic applications

Objective An evidence-based review on the role of botulinum toxin type A (BoNTA) on diverse cosmetic applications of interest to dental practitioners and allied specialities. In this context, to identify the cosmetic treatments that have an evidence-based rationale against areas requiring further research, with a view to assess the safety and efficacy of BoNTA.Data source and selection A comprehensive search was conducted using Cochrane Library of Systematic Reviews, Cochrane Central Register of Controlled Trials, and PubMed (Medline) electronic databases. Thirty-nine studies of variable quality were included. The Best Evidence Topics (BETs) Critical Appraisal Tool was used to facilitate the quality assessment of relevant studies.Data extraction Based on current level II evidence, BoNTA was safe and effective to improve facial contour, reduce volume and thickness of bilateral hypertrophic masseter. Conservative doses using a combined approach of BoNTA and hyaluronic acid was recommended as a safe and effective treatment for perioral enhancement supported by level II evidence. There was limited evidence, not higher than level III, to support BoNTA effectiveness for gummy smile associated to perioral musculature hyperactivity, while jawline sculpting targeting the platysma muscle had lower level IV evidence up to this date.Conclusion BoNTA has been widely used off-label for the investigated cosmetic orofacial conditions, with reports of 'good patient and practitioner satisfaction'. However, there is limited high-quality evidence to support the long-term safety and effectiveness of repetitive BoNTA injections. Additionally, no studies were found that provided a cost-effectiveness evaluation of BoNTA formulations against other current cosmetic interventions. Well-designed clinical trials, including long-term follow-up, would help to provide robust evidence-based recommendations for clinical practice, supporting BoNTA popularity, independently or in a combined approach.

Long-term Effects of Repeated Botulinum Toxin Injection in Cosmetic Therapeutics

BACKGROUND

Botulinum toxin (BT), a potent neurotoxin, has been used in clinical medicine since the 1970s for cosmetic and therapeutic purposes. Studies have consistently shown positive outcomes with a very limited adverse effect profile and a conventional understanding that results dissipate after 3 to 5 months. However, more recent evidence suggests that changes in muscle composition, function, and appearance persist for much longer, even years. To examine the potential implications of these findings on cosmetic use of BT injections in reduction of skin lines and wrinkles, we first needed to further our understanding of the current literature on long-term outcomes after repeated BT injections.

METHODS

A comprehensive review of the literature on long-term outcomes after repeated BT injections for cosmetic indications was performed. We evaluated the study designs, and results were compared.

RESULTS

A total of 22 publications met our inclusion criteria, of which 14 were clinical trials. Few studies extended outcome measurement past 6 months postinjection, and many were funded or supported by industry. However, the studies that extended follow-up saw persistent changes after BT injection, in some cases as far as 4 years postinjection.

CONCLUSION

The current body of knowledge on the long-term results after repeated cosmetic BT injections is very limited, and the available literature provides insufficient evidence on how prolonged effects could alter clinical use of BT. Further clinical studies with extended follow-up periods with inclusion of both subjective and objective measured outcomes of appearance and muscle function are required to better understand the long-term impacts of repeated BT injections.

The effect of botulinum toxin A in patients with excessive gingival display with and without zinc supplementation: randomized clinical trial

OBJECTIVE

The objective is to determine the effect of oral zinc supplement intake on the clinical efficacy and sustained effect of BTXA injection, in patients with excessive gingival display (EGD).

MATERIALS AND METHODS

Twenty-five participants with excessive gingival display (EGD) were included in this parallel-group RCT, treated with BTXA with and without Zinc supplementation prior to treatment. Participants were assessed for excessive gingival display reduction and results of stability at 2, 6, 12, 18, and 24 weeks. Patient satisfaction questionnaires were filled at 2, 12, and 24 weeks.

RESULTS

The results of this study revealed that after 6, 12, 18, as well as 24 weeks; The control group (BTXA) showed statistically significantly higher median gingival display than the intervention (Zinc supplement with BTXA). In the intervention group, the median gingival display after 24 weeks showed statistically significantly lower median value compared to the baseline measurement CONCLUSIONS: The use of zinc supplementation prior to BTXA injection prolonged its effect and maintained long-term decreased amount of gingival display, and it did not return to baseline measurements. Patients reported high satisfaction levels and self-confidence.

CLINICAL RELEVANCE

Botulinum Toxin A (BTXA) is used to correct gummy smile; however, its main drawback is its short-lasting effect. Oral zinc supplement intake prior to BTXA injection could maintain the effect of BTXA and enhance its clinical efficacy.