Lip repositioning surgery for gummy smile: 6-month clinical and radiographic lip dimensional changes

Effectiveness and Personalized Approaches in the Correction of Gummy Smile: A Systematic Review of Orthodontic and Surgical Treatments

Background/Objectives: This systematic review seeks to assess the effectiveness of different orthodontic and combined orthodontic-surgical approaches for correcting gummy smile, with a focus on treatment efficacy, duration, and the potential for integrating various techniques. The objective is to offer evidence-based recommendations for the optimal management of gummy smile. Methods: A thorough search of the literature was conducted in the PubMed, Cochrane Library, Scopus, and Web of Science databases, covering publications from 1 January 1982 to 4 November 2024. Only randomized controlled trials involving adult human subjects with available full-text articles were included, while systematic reviews, editorials, case reports, and studies involving animals or in vitro experiments were excluded. Studies were selected based on their relevance to orthodontic or combined orthodontic-surgical treatments for correcting excessive gingival display (gummy smile), particularly in cases where residual growth does not impact treatment outcomes. The primary focus was on evaluating the efficacy of these interventions in improving smile aesthetics. Follow-up data were considered when available, though not required for inclusion. Results: The findings revealed that both orthodontic and surgical methods are effective in reducing gingival display. Orthognathic surgery offers lasting outcomes, particularly for patients with vertical maxillary excess, whereas orthodontic treatments, including the use of skeletal anchorage devices, are particularly effective for less severe cases. Minimally invasive approaches, such as botulinum toxin injections, provided temporary but promising results for patients reluctant to undergo surgery. Conclusions: Orthodontic and surgical techniques are viable options for treating gummy smile, with treatment choices depending on the condition's severity. Future research, particularly long-term randomized studies, is required to further refine treatment protocols and improve patient outcomes.

Effects of polymethyl methacrylate-based bone cement graft for treating excessive gingival display and its dimensional facial changes: 12-Month clinical study

Objective

to present a 12-month follow-up with photographic and tomographic analyses of the effect of polymethyl methacrylate-based bone cement graft (PMMA) in gingival exposure (GE) in patients with excessive gingival display (EGD).

Methods

Twelve patients with EGD were included. The PMMA was surgically placed. A frontal and lateral photograph protocol was performed at baseline (T0), 3 (T3), 6 (T6), and 12 months (T12) post-operatively. Soft tissue cone-beam computed tomography (ST-CBCT) was performed at T0 and T12. Measures included GE, length of the lip vermilion (LLV), lip shape (LS), nose width (NW), filter width (FW), nasolabial angle (NAS) while smiling, and nasolabial angle at rest (NAR). The height, thickness, and volume of the cement graft were also measured in the ST-CBCT. The comparisons were performed by Kruskal-Wallis test at 5 % of significance (p < 0.05).

Results

The height, thickness, and volume of the PMMA were respectively 12.84 ± 1.59 mm, 3.83 ± 0.53, and 1532.02 ± 532.52 mm3. PMMA significantly decreased GE from 8.33 ± 1.25 mm (T0) to 6.60 ± 0.93 mm (T12) (p < 0.01). NAR was 98.34 ± 9.28° at T0 and increased to 105.13 ± 7.33° at T12; however, the angle value was not statistically different (p = 0.08). LLV, LS, NW, FW, and NAS did not exhibit statistical differences between the baseline and follow-up periods.

Conclusions

PMMA significantly decreased GE in a 12-month follow-up without influencing adjacent soft tissue anatomical structures.

Dental and periodontal dimensions stability after esthetic clinical crown lengthening surgery: a 12-month clinical study

OBJECTIVES

To evaluate the stability of periodontal tissues 3 (T3), 6 (T6), and 12 (T12) months after esthetic crown lengthening (ACL) and the possible correlations between changes in those structures.

MATERIALS AND METHODS

Twenty individuals were evaluated through clinical assessment, photography, and tomography. Measurements included gingival margin (GM), clinical crown length (CCL), interdental papilla height (PH) and width (PW), gingival thickness (GT), bone thickness (BT), probing depth (PD), distance between alveolar crest and GM, distance between alveolar crest and cementoenamel junction. Nonparametric and correlation statistics were performed (p < 0.05).

RESULTS

CCL at T0 was 7.42 ± 0.70 mm and increased to 9.48 ± 0.49 mm immediately after ACL, but it decreased to 8.93 ± 0.65 mm at T12. PD decreased 0.60 mm from T0 to T6, and it increased 0.39 mm from T6 to T12. BT decreased 0.20 mm, while GT increased 0.29 mm from T0 to T12. Both PW and PH showed enlargement in T12. A positive moderate correlation was found between CCL/T0 and CCL/T12, GT/T0 and AC-GM/T12, BT/T0 and GT/T12. A few negative moderate correlations were PD/T0 and CCL/T12, PD/T0 and PH/T0, PD/T0 and BT/T12.

CONCLUSIONS

ACL procedure was effective. Although some rebound occurred, that was not clinically important. PD tended to reestablish its original length, partially due to a migration of GM during the healing period. Besides, a thickening of supracrestal soft tissues was observed.

CLINICAL RELEVANCE

The present study centers on the factors influencing the stability of periodontal tissues after esthetic crown lengthening, underscoring the procedure's influence on esthetics and biology and the need for careful treatment planning.

Upper lip characteristics and associated excessive gingival display etiologies in adults: Race and sex differences

BACKGROUND

This cross-sectional study aimed to examine upper lip (UL) and smile characteristics and soft tissue excessive gingival display (EGD) etiologies (hypermobile upper lip [HUL], altered passive eruption [APE], and short upper lip [SUL]) in a nondental adult population and to analyze interracial (Black and White) and intersex differences.

METHODS

Community participants, non-Hispanic Blacks (NHB) and non-Hispanic Whites (NHW), were recruited and examined for UL vertical dimensions at rest and maximum smile and for HUL, APE, and SUL. Associations between gingival display (GD) or EGD and UL anatomical characteristics, HUL, APE, and SUL were analyzed.

RESULTS

Participants included 66 NHB and 65 NHW adults. Ergotrid height (greater among NHW; p = 0.019) averaged 14.0 mm. Upper lip vermilion length (ULVL), total UL length, internal lip length, total UL length during smile, and UL mobility averaged 8.6, 22.5, 23.1, 16.6, and 5.9 mm, respectively (all significantly greater in NHB; p ≤ 0.012). SUL prevalence was 4.6%, found only among NHW. Lip length change from rest to smile (LLC) averaged 26.2% (significantly greater in females; p = 0.003). HUL prevalence was 10.7% (NHB 13.1%, NHW 3.5%; p = 0.024). NHB had significantly greater GD (p ≤ 0.017). EGD and APE prevalence (6.9% for both) showed significant interracial and intersex differences (p ≤ 0.014). Multivariate logistic regression analyses indicated that LLC and HUL were the most consistently significant EGD determinants.

CONCLUSIONS

UL anatomical and functional characteristics and soft tissue-related EGD etiologies exhibit significant interracial and intersex differences, with UL mobility/hypermobility being the most consistently significant determinant of GD.

Contemporary treatment techniques for excessive gingival display caused by altered passive eruption or lip hypermobility

OBJECTIVES

Excessive gingival display (EGD), also known as gummy smile, has various causes, including altered passive eruption (APE) and hypermobile upper lip (HUL). This state-of-the art narrative review explores current concepts regarding soft tissue EGD etiologies and the contemporary modalities available for APE or HUL treatment.

DATA, SOURCES, STUDY SELECTION

Literature search was conducted for a narrative review on the etiology, diagnosis, and treatment of EGD caused by APE and HUL. Searching for articles was carried out in PubMed and Google Scholar. Published articles, including case reports, case series, observational and interventional clinical trials, and critical appraisals of the literature (e.g., systematic reviews) on the etiology, diagnosis, and treatment of EGD caused by APE and HUL were retrieved and reviewed. Particular focus was placed on novel treatment modalities introduced in the last five years.

CONCLUSIONS

Recent research evidence indicates that APE and HUL are the two major soft tissue-based EGD etiologies. Aesthetic crown lengthening (ACL) and lip repositioning surgery (LRS) are the established surgical treatment modalities for APE and HUL, respectively. The last few years have seen the introduction of new techniques for APE and HUL management, an expansion of the available ACL and LRS technique variations, and additional evidence further supporting the effectiveness of these two procedures. Several of the recently introduced approaches offer unique, innovative, and potentially impactful concepts. However, for many of these newly described treatments the available evidence is limited to case reports and the exact indications remain to be adequately defined.

CLINICAL SIGNIFICANCE

Altered passive eruption and hypermobile upper lip are the common soft tissue causes of gummy smile and can be successfully managed through aesthetic crown lengthening and lip repositioning surgery, respectively. A wide range of newly introduced approaches promises to further facilitate gummy smile treatment and improve outcomes.

Lip Repositioning Techniques and Modifications

A common etiology of excessive gingival display is hypermobile upper lip, which can be managed by non-surgical and surgical approaches. Among the surgical options, lip repositioning surgery is a relatively simple procedure with minimal complications. Since the original description of the technique almost 50 years ago, several minor and major modifications have been introduced. The available evidence indicates that, when applied to properly diagnosed cases, the technique is effective in reducing gingival display and results in improved smile esthetics and high patient satisfaction. This article reviews the various techniques and modifications and summarizes the reported outcomes of the procedure.