Individual Factors of Botulinum Type A in Treatment of Gummy Smile: A Prospective Study

A Systematic Review and Meta-Analysis Comparing Surgical and Nonsurgical Treatments for Excessive Gingival Display

Excessive gingival display (EGD) is defined as more than 2 mm of gingiva display above the maxillary incisors at maximum smile. Various skeletal, dental, and soft tissue etiological factors for EGD have been suggested. This study assessed the effectiveness and stability of surgical (SX) and nonsurgical (NSX) interventions for correction of EGD through a systematic review and meta-analysis following PRISMA 2020 guidelines. An electronic search of Ovid MEDLINE, EMBASE, CENTRAL, Scopus, Web of Science, and LILACS was conducted (2010-2023). Results were expressed as mean change in gingival display using the random-effects model at 1, 3, 6, and 12-month follow-up. At 1 month, SX and NSX treatments yielded a comparable mean reduction of 3.50 mm (2.13-4.86) and 3.43 mm (2.67-4.19) in gingival display, respectively. However, by 6 months, NSX treatments showed a reduction of 0.51 mm compared to 2.86 mm with SX treatments. SX outcomes remained stable past 6 months, while NSX outcomes partially relapsed at 6 months and returned to baseline levels at 12 months. Notably, NSX treatments were more effective in cases with mild initial EGD, while SX treatments showed a better outcome in severe cases. To draw more robust conclusions regarding the treatment outcomes, future primary studies of greater rigor are required.

Application of Botulinum Toxin at the Yonsei Point for the Treatment of Gummy Smile: A Randomized Controlled Trial

BACKGROUND

Demand for less-invasive procedures for treating gummy smile, such as botulinum toxin A injections, has increased substantially over the years. Meanwhile, the optimal injection site for botulinum toxin A injection is debated. The authors aimed to investigate the efficacy of botulinum toxin A injection at the Yonsei point for treating gummy smile.

METHODS

In this double-blind, single-site, randomized clinical trial, healthy participants with a gummy smile (anterior gingival exposure of ≥3.0 mm) were enrolled and randomized (1:1 ratio) into two groups. The experimental group was administered 6 U of botulinum toxin A at the Yonsei point (a single-site injection of 3 U to the right Yonsei point and 3 U to the left Yonsei point), and the control group received the same dose in the bilateral levator labii superioris alaeque nasi muscle sites. The patients were assessed at baseline and 4, 12, 24, and 48 weeks after the first injection using a digital vernier caliper.

RESULTS

A total of 49 participants were enrolled. Anterior and bilateral posterior gingival exposure were reduced at 4, 12, and 24 weeks ( P ≤ 0.05) and returned to baseline at 48 weeks in both groups; there was no difference between the groups at these time points. The increase in satisfaction among patients was significant, and few adverse events were observed.

CONCLUSION

Both the Yonsei point and the levator labii superioris alaeque nasi muscle site can be used as botulinum toxin A injection sites for treating gummy smile.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Neuromodulator Injection for Gummy Smile

SUMMARY

Neuromodulators have become a treatment of choice for the management of excess gingival show, or "gummy smile." There have been many proposed algorithms for the optimal placement and dosage of neuromodulator to inject in these locations. The authors aim to clarify these points and provide surgeons with a reliable way to manage the gummy smile that results from hyperactive muscles of the midface.

Non-Surgical Management of the Gingival Smile with Botulinum Toxin A-A Systematic Review and Meta-Analysis

Currently, concern about facial attractiveness is increasing, and this fact has led to orthodontics in adult patients being an increasingly demanded treatment, and with it, multi-disciplinary work. When it is caused by a vertical excess of the maxilla, the ideal solution is orthognathic surgery. However, in borderline cases and when the cause is hyperactivity of the upper lip levator muscle complex, alternative conservative solutions can be considered, such as the application of botulinum toxin A (BTX-A). Botulinum toxin is a protein produced by a bacterium and causes a reduction in the force of muscle contraction. The multi-factorial nature of the smile requires an individualized diagnosis in each patient, since there are multiple ways to treat the gummy smile (orthognathic surgery, gingivoplasty, orthodontic intrusion). In recent years, interest has grown in the simplest techniques that allow the patient to quickly return to their usual routine, such as lip replacement. However, this procedure shows recurrences in the first 6-8 post-operative weeks. The main objective of this systematic review and meta-analysis is to analyze the effectiveness of BTX-A in the treatment of gummy smile in the short term, to study its stability, and to evaluate potential complications. A thorough search of the PubMed, Scopus, Embase, Web of Science, and Cochrane databases and a grey literature search were conducted. The inclusion criteria were studies with a sample size greater than or equal to 10 patients with gingival exposure greater than 2 mm in smile, treated with BTX-A infiltration. Those patients whose exclusive etiology of their gummy smile was related to altered passive eruption, gingival thickening, or overeruption of upper incisors were excluded. In the qualitative analysis, the mean pre-treatment gingival exposure ranged between 3.5 and 7.2 mm, reaching a reduction of up to 6 mm after infiltration with botulinum toxin at 12 weeks. Although multiple muscles are involved in the facial expression, the muscles par excellence selected for blockade with BTX-A were levator labii superioris, levator labii superioris ala nasalis, and zygomaticus minor, infiltrating from 1.25 to 7.5 units per side. In the quantitative analysis, the difference in mean reduction between both groups was -2.51 mm at two weeks and -2.24 mm at three months. The benefit of BTX-A in terms of improvement of gummy smile is demonstrated, as a significant reduction in gummy smile is estimated by BTX-A therapy two weeks after its application. Its results gradually decrease over time, however, they stay satisfactory without returning to their initial values after 12 weeks.

Botulinum toxin to improve facial expression in a patient with Urofacial (Ochoa) Syndrome

The Urofacial or Ochoa Syndrome is a very rare congenital disorder that includes vesical bladder dysfunction and a peculiar inverse facial expression, which brings patients to express a sad-crying face while they intend to laugh. Up-to-date treatments have addressed only the urological side of this disease. However, also the impaired facial mimicry has a strong impact on patients' quality of life. We treated a young patient with Botulinum toxin to address this impairment and obtained pleasing results, including a harmonic smile and a very satisfied patient. To the best of our knowledge, this is the first time that the use of Botulinum toxin is reported in literature to address the facial expression component of this disease.

An Approach for Gummy Smile Treatment Using Botulinum Toxin A: A Narrative Review of the Literature

Excessive gingival exposure (gummy smile) is a non-aesthetic condition characterized by excessive exposure of the gingiva during smiling. The most common cause of gummy smiles was reported to be the hyperfunction of the muscles of the upper lip. Previous reports showed that botulinum toxin (Botox) is effective in the treatment of gummy smiles with a reversible effect, rapid initial action, safe application, low risk, and satisfactory outcome. The effect of Botox is usually observed between one and two weeks. This study aims to review the recent updates and guidelines for gummy smile treatment using botulinum toxin. A literature review was conducted involving relevant studies discussing gummy smile treatment using botulinum toxin with no time restriction. The PubMed and Google Scholar databases were used to gather the most relevant studies. The initial screening revealed 62 studies, and after removing the out-of-scope studies, the final review included 28 studies. Botulinum toxin can be used effectively for the treatment of gummy smile caused by lip dynamics with rarely reported complications. However, the most observed limitation was the temporary duration, which was reported to range from four to six months, and the re-injection of botulinum toxin is usually needed.

Effects of Dose and Injection Site on Gingival Smile Treatment with Botulinum Toxin Type A: A Prospective Study

BACKGROUND

Botulinum toxin type A is an easy and efficacious treatment for gingival smile. However, the optimal dose and injection site are controversial. The authors compared the reduction in gingival exposure using two methods with different doses and injection sites.

METHODS

In this prospective self-controlled study, healthy participants with gingival smile (anterior gingival exposure of >3 mm) underwent two treatment methods. First, participants received a single-point injection of 2 U of botulinum toxin type A per side (simplified method). After 8 months, the individualized method was performed with 2 to 5 U of botulinum toxin type A (total, 4 to 10 U), which was injected at one or two sites according to pretreatment severity. Data were collected at baseline and at 4, 12, and 32 weeks of follow-up.

RESULTS

Fifty-five participants were enrolled. Anterior gingival exposure and bilateral posterior gingival exposure were significantly reduced 4 and 12 weeks after botulinum toxin type A injection ( P ≤ 0.05) with both methods. These parameters returned to baseline by 32 weeks ( P > 0.05). Posttreatment anterior gingival exposure at 4 weeks and 12 weeks with the individualized method was significantly lower compared with the simplified method (both P ≤ 0.05). Patient satisfaction with the individualized method was preferred compared with the simplified method ( P ≤ 0.05). Few adverse events were observed with both methods without statistical significance.

CONCLUSION

It is necessary to increase the injection dose and tailor the injection site according to the pretreatment severity of anterior gingival smile.

Botulinum Toxin Type A: Adverse Events and Management

Aesthetic medicine is witnessing an increasing exploitation of all the procedures. The demand has never been higher than it is today. The number of practitioners is also increasing year by year. Consequently complications and other kinds of related troubles and procedures are also rising. Never like today is fundamental, in case of troubles, how to properly manage with the most frequent issues. In aesthetic medicine field, botulinum toxin procedures are the safest. Lot of patients are worried about botulinum toxin despite the available scientific literature. Rare short-term complications are observed. In the most of cases, nothing severe occurs if the international recommendations and the most recent guidelines are closely followed, the majority of them are injection related. This study is a review of rare or common problems that can occur and how to manage or solve the situations.