Cephalometric changes in Class II division 1 patients treated with two maxillary premolars extraction

Abstract

Objective: The purpose of this study was to evaluate the cephalometric alterations in patients with Angle Class II division 1 malocclusion, orthodontically treated with extraction of two maxillary premolars. Methods: The sample comprised 68 initial and final lateral cephalograms of 34 patients of both gender (mean initial age of 14.03 years and mean final age of 17.25 years), treated with full fixed appliances and extraction of the first maxillary premolars. In order to evaluate the alterations due the treatment between initial and final phases, the dependent t test was applied to the studied cephalometric variables. Results: The dentoskeletal alterations due to extraction of two maxillary premolars in the Class II division 1 malocclusion were: maxillary retrusion, improvement of the maxillomandibular relation, increase of lower anterior face height, retrusion of the maxillary incisors, buccal inclination, protrusion and extrusion of the mandibular incisors, besides the reduction of overjet and overbite. The tissue alterations showed decrease of the facial convexity and retrusion of the upper lip. Conclusions: The extraction of two maxillary premolars in Class II division 1 malocclusion promotes dentoskeletal and tissue alterations that contribute to an improvement of the relation between the bone bases and the soft tissue profile. Objetivo: avaliar as alterações cefalométricas em pacientes com má oclusão Classe II, divisão 1, de Angle, tratados ortodonticamente com extrações de dois pré-molares superiores. Métodos: a amostra consistiu de 68 telerradiografias iniciais e finais de 34 pacientes de ambos os sexos (idade inicial média de 14,03 anos e idade final média de 17,25 anos), tratados com aparelho fixo completo e extrações de primeiros pré-molares superiores. Para avaliar as alterações decorrentes do tratamento entre as fases inicial e final, foi realizado o teste t dependente aplicado às variáveis cefalométricas estudadas. Resultados: as alterações dentoesqueléticas decorrentes da extração de dois pré-molares superiores na má oclusão de Classe II, divisão 1, foram retrusão da maxila, melhora da relação maxilomandibular, aumento da altura facial anteroinferior, retrusão dos incisivos superiores, vestibularização, protrusão e extrusão dos incisivos inferiores, além da diminuição dos trespasses horizontal e vertical. As alterações tegumentares mostraram diminuição da convexidade facial e retrusão do lábio superior. Conclusões: a extração de dois pré-molares superiores na má oclusão de Classe II, divisão 1, propicia alterações dentoesqueléticas e tegumentares que contribuem para uma melhora da relação entre as bases ósseas e do perfil mole.Palavras-chave: Ortodontia corretiva. Circunferência craniana. Estudos retrospectivos. Extração dentária.

Esthetic perception of facial profile changes after extraction and nonextraction Class II treatment

“…Studies analyzing the long-term influence of treatment by extraction on facial esthetics concluded that this treatment does not negatively influence facial attractiveness in Class II malocclusions. 23,24,26,28 Just like the extraction group, treatment with the Forsus appliance also produced positive changes in the facial profile; however, both groups of evaluators assigned greater scores to the Forsus appliance at posttreatment (Table 3), thus corroborating other studies that used fixed functional appliances to achieve an improvement in the facial profile. 4,21,29 Even though the protocols for both extraction and Forsus achieved favorable results, the observation between lay individuals and orthodontists was different concerning the facial impact, in that the impact was more perceptible to orthodontists.…”

“…In this respect, over the years, orthodontists have been investigating the relationship between facial profile esthetics and orthodontic treatment by tooth extraction. 2,10,23,24,25 The results of the present study revealed no significant difference between the protocols using extraction versus a mandibular advancement appliance (Table 2), i.e., both treatment protocols provided positive changes to the patients' faces ( Table 3).…”

“…Similar results were found in studies analyzing the soft tissue profile after orthodontic treatment with extraction. 11,20,23,24 Conversely, it has been reported that the greatest benefit of treatment by extraction is achieved in cases with greater dental protrusion, marked crowding, and thick and protruded lips. 10,11,26 However, in individuals presenting a thin upper lip and an increased nasolabial angle at pretreatment, extraction may affect the upper lip positioning negatively and increase the nasolabial angle.…”

Comparison of Soft Tissue Changes Between Two Class II Malocclusion Treatment Protocols: with and without Extractions Associated to Intermaxillary Elastics

“…2 Class II malocclusions may be treated with corrective orthodontics combined or not with surgical approaches, 3 intraoral distalizers, 4 intermaxillary elastics, 5,6 and dental extractions. 3,[7][8][9] The orthodontist must be aware of differences between the treatment protocols and their applications in order to reach optimal clinical outcomes. 3 Treatment with two maxillary premolars extraction is an approach indicated when the molar relationship is in full-step Class II, with no crowding and no cephalometric discrepancies in the mandibular arch.…”

“…4,7 However, its indication depends on the patient's lip thickness and tonus, the malocclusion severity, and lower anterior facial height. 11 Increase in the nasolabial angle, 12,13 upper lip retraction, 4,8,12 and facial convexity reduction 8,12 are the cephalometric alterations related to the treatment protocol with dental extractions. Furthermore, the scientific literature ranks many other favorable outcomes from the upper premolars extraction, such as satisfactory occlusal relationships, long-term stability, and non-interference with the patient's facial profile.…”