The use of mucoperiosteal flap and osteotomy for the treatment of gummy smile: a case report

Tratamento do sorriso gengival com cirurgia a retalho total e osteotomia: relato de caso

ABSTRACT

Currently the search for aesthetic procedures has increased significantly in dentistry, with the aim of achieving a more harmonious and symmetrical smile. Among the most common aesthetic changes is the gummy smile, which can affect the individual’s self-esteem as it is outside the typical standards of a “perfect” smile. Excessive gingival display is primarily genetic, most frequently affecting women in the second decade of life and patients submitted to orthodontic treatment. Among the main ethiological factors is altered passive eruption, a phenomenon where there is a lack of apical migration of periodontal tissues during the end of tooth eruption, which gives the dental element the appearance of being shortened, affecting the aesthetics of the smile. The aim of this paper is to demonstrate, through a case report, the treatment of gummy smile caused by altered passive eruption using the technique of mucoperiosteal flap surgery with internal bevel incisions associated with ostectomy. After the procedure, we obtained a greater exposure of the anatomical crown elements, correcting the appearance of a gummy smile and promoting aesthetics. After a 90-days follow up, the results were stable, concluding that periodontal surgical procedures are a viable option for gummy smile correction, however, the clinician should be aware how to choose and perform the correct technique for each patient.

Indexing terms
Gingivoplasty; Osteotomy; Periodontics

RESUMO

Atualmente a busca por procedimentos estéticos vem aumentando significativamente dentro da odontologia, com o objetivo de alcançar um sorriso mais harmônico e simétrico. Dentro das alterações estéticas mais comuns está o sorriso gengival, que pode afetar a autoestima do indivíduo por estar fora dos padrões característicos de um sorriso “perfeito”. O excesso de exposição gengival tem caráter primordialmente genético, afetando mais frequentemente mulheres na segunda década de vida e usuários de aparelho ortodôntico. Dentre as principais etiologias está a erupção passiva alterada, fenômeno onde há falta de migração apical dos tecidos periodontais durante o final da erupção dentária, o que dá ao elemento dental a aparência de encurtado, afetando a estética do sorriso. Este trabalho tem como objetivo demonstrar através de um relato de caso, o tratamento do sorriso gengival causado por erupção passiva alterada utilizando a técnica de cirurgia a retalho total com incisões em bisel interno associado à osteotomia. Imediatamente após o procedimento, obteve-se maior exposição da coroa anatômica dos elementos, corrigindo o aspecto de sorriso gengival e promovendo a estética. Após acompanhamento de 90 dias os resultados foram mantidos, concluindo que os procedimentos cirúrgicos periodontais são uma opção viável para a correção do sorriso gengival, porém, é dever do clínico saber qual a técnica correta a ser realizada e quando indicá-la.

Termos de indexação
Gengivoplastia; Osteotomia; Periodontia

INTRODUCTION

Currently the search for esthetic dental procedures has significantly increased within contemporary dentistry, primarily driven by the desire for a more harmonious and symmetrical smile. Among the most prevalent esthetic concerns is the Gummy Smile (GS), a condition that can profoundly impact an individual’s self-esteem due to its perceived esthetic shortcomings and deviation from the characteristics of an “ideal” smile.

A smile can be broadly classified as high, medium, or low. A low smile line is characterized by the exposure of less than 75% of the maxillary teeth and no gingival display. A medium smile line involves slight gingival exposure and more than 75% of the maxillary teeth, and a high smile line is identified by the exposure of the entire clinical crown [¹]. Conventionally, a patient is diagnosed with GS when 4 mm or more of gingival tissue is exposed during smiling [²]. While the precise etiology of GS remains somewhat unclear, the primary contributing factors include Altered Passive Eruption (APE), hyperactivity of the elevator muscles of the lip, a short upper lip, vertical maxillary excess, and gingival hyperplasia [³].

The excessive gingival display during smiling is primarily genetic driven, though it is more frequently observed in women during their second decade of life and in orthodontic patients [⁴]. Across the general population, approximately 7% of individuals exhibit a GS. The most prevalent causes are APE and hypermobility of the upper lip, followed by the presence of a short upper lip which is significantly less common, accounting for less than 10% of cases [⁵,⁶].

APE is a phenomenon characterized by the failure of apical migration of periodontal tissues at the culmination of tooth eruption, resulting in a clinically shortened tooth appearance and consequently affecting smile esthetics. To comprehend APE, an understanding of the tooth’s eruptive phases, conventionally divided into active and passive phases, is essential [⁷]:

Active Eruption Phase: This phase encompasses the tooth’s emergence into the oral cavity and its preceding formative periods. Its terminal stages are dictated by occlusal forces, the periodontal ligament, and the supracrestal fiber complex [⁸,⁹]. According to Steedle and Proffit [¹⁰], this phase can be subdivided into pre-functional (follicular growth, pre-emergence eruptive outbreak and post-emergent eruptive outbreak) and post-functional stages (juvenile occlusal equilibrium, puberal eruptive outbreak and adult occlusal equilibrium).

Passive Eruption Phase: According to Gottlieb and Orban [¹¹], this phase is characterized by the apical displacement of gingival tissue around the tooth, from the coronal aspect to just below the Cemento-Enamel Junction (CEJ). This occurs after the tooth has fully formed and established occlusal contact. The passive phase can be further subdivided into four stages based on the position of the dentogingival junction:

1. Located entirely on the enamel.

2. Located on both the enamel and cementum.

3. Located entirely on the cementum.

4. Located apically to the CEJ.

The first stage of passive eruption is considered physiological, whereas the subsequent stages are deemed pathological, resulting from periodontal destruction. Therefore, APE is understood to arise from a non-pathological alteration in the first stage of the passive eruptive phase.

Coslet et al. [¹²] classified APE into Type 1 and Type 2 based on the relationship between the Mucogingival Junction (MGJ) and the Alveolar Bone Crest (ABC). Each type is further subdivided into two subgroups (A and B), which are determined by the distance between the CEJ and the ABC, leading to a total of four possible classifications:

• Type 1A: The MGJ is located apically to the ABC or CEJ (Type 1), and there is an adequate physiological distance for periodontal ligament formation between the CEJ and the ABC (Subgroup A).

• Type 2A: The MGJ is located at the level of or coronally to the CEJ (Type 2), and there is an adequate physiological distance for periodontal ligament formation between the CEJ and the ABC (Subgroup A).

• Type 1B: The MGJ is located apically to the ABC or CEJ (Type 1), but there is an inadequate physiological distance for periodontal ligament formation between the CEJ and the ABC (Subgroup B).

• Type 2B: The MGJ is located at the level of or coronally to the CEJ (Type 2), and there is an inadequate physiological distance for periodontal ligament formation between the CEJ and the ABC (Subgroup B).

Typically, the alveolar crest is positioned 1 to 2 mm apically to the CEJ, facilitating proper fibrous insertion of the gingiva into the cementum, which is characteristic of Subgroup A. In contrast, Subgroup B exhibits a more coronal positioning of the alveolar bone crest relative to the CEJ, impeding correct fibrous insertion of the periodontal tissue. This relationship typically occurs during the active eruption phase.

According to some authors, APE Type 1 and Type 2 are attributed to an alteration in the passive phase of tooth eruption, leading to an excess of gingival tissue overlying the anatomical crown, even with a physiological distance between the alveolar bone crest and the CEJ. Conversely, APE Subgroup B is also thought to result from an alteration in the active phase of eruption, as the tooth appears to emerge insufficiently from the alveolar bone, leading to a non-physiological distance between the bone and the anatomical crown.

Among potential etiologies, Zucchelli [¹³] observed that the presence of a thick buccal bone is frequently associated with APE cases, irrespective of the subtype. Other causal factors reported in the literature include the presence of soft tissue occlusal interferences during the eruptive phase, a thick periodontium, orthodontic tooth movement, and endocrine conditions [¹⁴].

Therefore, a proficient clinician must be cognizant of the various potential causes of gummy smile and be capable of formulating an appropriate treatment plan for each case. Given that each diagnosis necessitates a specific treatment, encompassing diverse areas of dentistry, and may involve a combination of multiple etiological factors, a comprehensive understanding is paramount [¹⁵].

CASE REPORT

Patient I.R.C., a 20-year-old caucasian female, presented to the Periodontology Clinic at the State University of Ponta Grossa with the chief complaint of “short teeth and excessive gum display.” During anamnesis, the patient reported no frequent medication use and no systemic alterations.

Extraoral physical examination and vital sign assessment revealed no noteworthy changes. Intraoral clinical examination showed that the patient had a mild gummy smile, with approximately 2 to 3 mm of gingival exposure when smiling (figure 1). Additionally, shallow gingival sulci were observed on the buccal surfaces, and the clinical crowns of teeth #13 to #23 appeared short (figure 2). Measurements were performed with a Chu’s proportion gauge (Hu-Friedy, North Carolina, USA) to aid in surgical planning. Based on the clinical analysis, a periodontal flap surgery with an internal bevel incision, associated with ostectomy of teeth #13 to #23, was chosen to achieve longer clinical crowns for these elements and correct the patient’s gummy smile.

Figure 1
Initial aspect of the smile.

Figure 2
Initial intraoral front view.

Immediately before the surgical procedure, extraoral antisepsis was performed with 10% PVP-I, and intraoral antisepsis was achieved with a 0.12% chlorhexidine gluconate rinse. Topical anesthesia was administered with 200 mg/g Benzocaine (Benzotop, DFL, São Paulo, Brazil), followed by infiltrative anesthesia of the right and left anterior superior alveolar nerves with 4% Articaine + 1:100,000 Epinephrine (Articaine 100, DFL, São Paulo, Brazil). After local anesthesia, the new gingival margin was delineated using bleeding points, created with the aid of the Chu’s proportion gauge, which served as a reference for the internal bevel incision. Following the initial incision with a 15C blade (Solidor, Lamedid, São Paulo, Brazil) and #5 scalpel handle, the excess gingival tissue was removed with a McCall 13-14 universal curette (Golgran, São Paulo, Brazil).

To obtain an adequate operative field and flap mobility, intrasulcular incisions were extended to the first premolars, and a buccal mucoperiosteal flap was elevated using Molt and Freer periosteal elevators (Golgran, São Paulo, Brazil) until the alveolar bone crest of the teeth of interest was visualized. After flap reflection, ostectomy of teeth #13 to #23 was performed using a 1014 diamond bur (KG Sorensen, São Paulo, Brazil) with a high-speed handpiece, abundantly irrigated with sterile 0.9% physiological saline for cooling, as well as manual instruments including Rhodes 36/37 and Ochsenbein 1 chisels (Golgran, São Paulo, Brazil). Bone removal was carried out to achieve a distance of 2 to 3 mm between the alveolar bone crest and the cementoenamel junction (figure 3).

Figure 3
Clinical aspect after ostectomy.

Upon completion of the ostectomy, suspensory-type sutures were placed, anchored in the papillae of the buccal flap, using 5-0 nylon suture thread (Bioline Fios Cirúrgicos Ltda, Goiás, Brazil) (figure 4). The patient was instructed on postoperative care and chemical biofilm control through rinsing with 0.12% chlorhexidine gluconate twice daily for seven days. For postoperative pain control, Ibuprofen 600 mg was prescribed every twelve hours for three days. Sutures were removed seven days after the procedure.

Figure 4
Clinical aspect after ostectomy.

During the 90-day postoperative follow-up, it was observed that the gingival architecture was maintained in the desired position, eliminating the gummy smile appearance and improving both the proportion and symmetry of the teeth (figures 5 and 6).

Figure 5
Intra-oral frontal view 90 days post-operative.

Figure 6
Final aspect of the smile 90 days post-operative.

DISCUSSION

Even though APE is considered a non-pathological condition, it’s frequently associated with GS and can only be corrected through surgical treatment. In most cases, this involves full-thickness flap surgery with internal bevel incisions or a repositioned flap, with or without an associated ostectomy. When an adequate amount of keratinized tissue is clinically observed in the area of interest internal bevel incisions are chosen, otherwise, the apically positioned flap technique is used to preserve keratinized tissue. In both scenarios, a mucoperiosteal flap is elevated to visualize the alveolar bone crest and its distance to the cementoenamel junction. In cases where the biologic width is not preserved (distance between ABC and CEJ <2 mm) ostectomy becomes necessary during the transoperative phase to prevent recurrence, varying according to the gingival phenotype and the thickness of the buccal bone [¹⁶,¹⁷]. Similarly, the need for osteoplasty should be assessed after flap reflection, correcting any bone exostoses that may be present and promoting proper bone contour [¹⁸].

According to Garber and Salama [¹⁹], another treatment option for altered passive eruption is gingivectomy in Type 1A cases, where the biologic width is preserved, and only soft tissue removal is required.

When delineating the incisions, we must consider the golden proportion for tooth dimensions, where the width of the maxillary central incisors should be 80% of their length, and the maxillary lateral incisor around 70%, always respecting the alignment of the gingival zeniths [²⁰]. To facilitate this clinical analysis, the Chu’s proportion gauge is a reliable tool that can be utilized [²¹].

Ribeiro et al. [²²] analyzed the efficacy of the “flapless” technique for clinical crown lengthening surgery, where the procedure is performed without flap reflection, and ostectomy is carried out by inserting chisels through the incisions. The authors found that the flapless technique showed stability after 12 months of follow-up and yielded similar results to the conventional technique, thus proving to be a viable treatment option for certain cases.

It’s important to note that although gummy smile is very common, it’s not always due to APE. It can be associated with other factors, either in isolation or concomitantly, such as hyperactivity of the lip elevator muscles, a short upper lip, vertical maxillary excess, and gingival hyperplasia [²³].

In cases where the patient presents with moderate vertical maxillary excess or a hypermobile lip, lip repositioning surgery may be chosen [²⁴]. If there is also periodontal involvement, it can be combined with a full-thickness flap procedure or gingivectomy [²⁵]. Contraindications include patients with limited labial attachment area or severe vertical maxillary excess; in these instances, orthognathic surgery may be necessary [²⁶].

Botulinum toxin application is also used for gummy smile correction in cases of lip hyperactivity, as it causes paralysis of the lip elevator muscles [²⁷]. Its main advantage is being a non-invasive procedure, but it requires applications every 6 months for results maintenance and can also be associated with orthognathic surgery [²⁸].

CONCLUSION

Gummy smile and short clinical crowns are very common complaints today, especially with the growing aesthetic concern within dentistry. Excessive gingival exposure has various etiologies, with APE being the primary one.

Among the possible treatments for APE, the most utilized procedure is full-thickness flap surgery with an internal bevel in the aesthetically affected region, which may be associated with ostectomy according to transoperative analysis. This was proven by the presented clinical case, which showed a stable result after 90 days.

• How to cite this article
  Laudelino LT, Pilatti GL. The use of mucoperiosteal flap and osteotomy for the treatment of gummy smile: a case report. Rev Gaúch Odontol. 2025;73:e20250023. http://dx.doi.org/10.1590/1981-86372025002320250011

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Edited by

• Assistant editor:
  Luciana Butini Oliveira

Publication Dates

• Publication in this collection
  19 Sept 2025
• Date of issue
  2025

History

• Received
  06 Apr 2025
• Accepted
  06 June 2025