Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile

original article Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile Érica Miranda de Torres1, José Valladares-Neto2, Karina de Oliveira Bernades3, Luis Fernando Naldi4, Hianne Miranda de Torres3, Alexandre Leite Carvalho3, Carlos Estrela5 DOI: https://doi.org/10.1590/2177-6709.25.2.044-051.oar Objective: To evaluate facial profile changes promoted by polymethyl methacrylate (PMMA) cement graft to reduce excessive gingival display due to hyperactivity of the elevator muscles of the upper lip during smiling. Methods: Eleven patients (all females, age range: 20 to 43 years) presenting gingival smile that were treated with PMMA cement grafts in a private clinic were selected for this retrospective study. Three angular and ten linear cephalometric facial profile measurements were performed preoperatively (baseline, T1) and at least 6 months postoperatively (T2). Differences between T1 and T2 were verified by Wilcoxon test, and the correlation between the thickness of the graft and facial profile changes was statistically evaluated by Spearman’s Coefficient test. The significance level was set at p < 0.05. Results: The nasolabial angle (p = 0.03) and the labial component of the nasolabial angle showed statistically significant differences (p = 0.04), with higher values in T2. No correlations were found between the graft thickness and the statistically significant facial profile changes (p > 0.05). Conclusions: The PMMA bone cement graft projected the upper lip forward, thereby increasing the nasolabial angle without affecting the nasal component. No correlations between the graft thickness and the facial profile changes were detected. Keywords: Gingival smile. Bone cement. Polymethyl methacrylate. Facial profile. Objetivo: Avaliar as alterações do perfil facial promovidas pelo enxerto de cimento de polimetilmetacrilato (PMMA) para redução da exposição gengival excessiva devida à hiperatividade dos músculos elevadores do lábio superior durante o sorriso. Métodos: Onze pacientes (todos do sexo feminino, faixa etária de 20 a 43 anos) com sorriso gengival, tratados com enxerto de cimento de PMMA em clínica privada, foram selecionados para este estudo retrospectivo. Três medidas cefalométricas angulares e dez lineares do perfil facial foram realizadas no pré-operatório (T1) e com pelo menos seis meses de pós-operatório (T2). As diferenças entre T1 e T2 foram verificadas pelo teste de Wilcoxon, e a correlação entre a espessura do enxerto e as alterações do perfil facial foi avaliada estatisticamente pelo Coeficiente de Spearman. O nível de significância foi estabelecido em p < 0,05. Resultados: o ângulo nasolabial (p = 0,03) e o componente labial do ângulo nasolabial apresentaram diferenças estatisticamente significativas (p = 0,04), com maiores valores em T2. Não foram encontradas correlações estatisticamente significativas (p > 0,05) entre a espessura do enxerto e as alterações do perfil facial. Conclusões: O enxerto de cimento ósseo de PMMA projetou discretamente o lábio superior, aumentando o ângulo nasolabial sem afetar o componente nasal. Não foram detectadas correlações entre a espessura do enxerto e as alterações do perfil facial. Palavras-chave: Sorriso gengival. Cimento ósseo. Polimetilmetacrilato. Perfil facial. Universidade Federal de Goiás, Faculdade de Odontologia, Divisão de Reabilitação Oral (Goiânia/GO, Brazil). 2 Universidade Federal de Goiás, Faculdade de Odontologia, Divisão de Ortodontia (Goiânia/GO, Brazil). 3 Universidade Federal de Goiás, Programa de Pós-graduação em Odontologia, Faculdade de Odontologia (Goiânia/GO, Brazil) 4 Universidade Federal de Goiás, Faculdade de Odontologia, Divisão de Periodontia (Goiânia/GO, Brazil). 5 Universidade Federal de Goiás, Faculdade de Odontologia, Divisão de Endodontia (Goiânia/GO, Brazil). How to cite: Torres EM, Valladares-Neto J, Bernades KO, Naldi LF, Torres HM, Carvalho AL, Estrela C. Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile. Dental Press J Orthod. 2020 Mar-Apr;25(2):44-51. DOI: https://doi.org/10.1590/2177-6709.25.2.044-051.oar 1 » Patients displayed in this article previously approved the use of their facial and intraoral photographs. The authors report no commercial, proprietary or financial interest in the products or companies described in this article. Contact address: Érica Miranda de Torres Av. Universitária, esquina com 1ª Avenida, s/ número CEP: 74.605-220, Goiânia/GO – Brasil E-mail: Submitted: December 04, 2018 - Revised and accepted: February 20, 2019. © 2020 Dental Press Journal of Orthodontics 44 Dental Press J Orthod. 2020 Mar-Apr;25(2):44-51 original article Torres EM, Valladares-Neto J, Bernades KO, Naldi LF, Torres HM, Carvalho AL, Estrela C Recently, a new surgical technique for the management of the gingival smile was proposed by Naldi et al.23-25 The technique consists in implanting a bone cement graft based on polymethyl methacrylate (PMMA) in the anterior maxilla below the pyriform aperture. According to the authors, some patients with a gingival smile have a major subnasal depression that allows the upper lip to be lodged during spontaneous smile. The PMMA bone cement graft fills this depression, preventing excessive displacement of the upper lip during contraction. The graft, associated with esthetic crown lengthening, has been shown to be effective in reducing gingival display.23-25 An internal bevel incision followed by a reflected full-thickness flap is performed until exposure of the subnasal depression. The PMMA bone cement is indicated by the manufacturer for use in fixing orthopedic prostheses to bone tissue. It is manipulated (powder and liquid) and adapted to the region of interest. After polymerization, the PMMA graft is fitted with drills, for better volume and conformation. Two screw fixations are used to immobilize the PMMA graft in the subnasal depression. Sutures are inserted and removed 10 days later.23-25 Figure 1 illustrates this surgical technique and the outcomes. INTRODUCTION The smile is the spontaneous expression linked to joy, pleasure and receptivity.1 Tarantili et al.2 defined a pleasant smile as one in which there is complete exposure of the anterior maxillary teeth and a mild gingival display of 1 to 3 mm. An excessive gingival display greater than 3 mm is considered unpleasant or unattractive, and is popularly called “gummy smile”.1,3,4 Several etiological factors have been associated to gingival smile, and it is important for the clinician to properly identify its etiology, for an adequate treatment. These factors occur separately or in combination,4-8 and according to the origin, they can be grouped into: dental (excessive dentoalveolar extrusion9), gingival (altered passive eruption10,11 or gingival enlargement12), skeletal (excessive maxillary vertical growth8) or muscular (short upper lip or hyperactivity of the elevator mus (...truncated)