BBO’s Selected Article Importance of orthodontic intervention of the Class III malocclusion in mixed dentition Dennyson Brito Holder da Silva1, Ariane Salgado Gonzaga2 DOI: https://doi.org/10.1590/2177-6709.25.5.057-065.bbo Introduction: Supervising the development of occlusion, managing problems during the transition from mixed to permanent dentition, as well as controlling environmental factors that contribute to establishing malocclusion, are important actions to achieve a Class I occlusion with facial balance. Among these problems, the malocclusions associated with dysfunctions such as mouth breathing or obstructive sleep apnea syndrome (OSAS), atypical swallowing and abnormal tongue position, open bites, crossbites and maxillomandibular discrepancies, and especially the Class III malocclusion can be listed. Objective: The purpose of this article is to present and discuss the main aspects relevant to the benefits of performing the treatment of Class III malocclusion in patients with growth. Keywords: Interceptive orthodontics. Corrective orthodontics. Malocclusion. Introdução: A supervisão do desenvolvimento da oclusão e o gerenciamento de problemas durante a transição da dentição mista para a perma- nente, bem como o controle de fatores ambientais que contribuem para estabelecer a má oclusão, são importantes ações para se obter uma oclusão de Classe I com equilíbrio facial. Entre esses problemas, pode-se considerar más oclusões associadas às disfunções como respiração bucal ou sín- drome da apneia obstrutiva do sono (SAOS), deglutição atípica, posição anormal da língua, mordidas abertas e mordidas cruzadas e discrepâncias maxilomandibulares, especialmente, a má oclusão de Classe III. Objetivo: O objetivo do presente artigo é apresentar e discutir os principais aspectos pertinentes aos benefícios de se realizar o tratamento da má oclusão de Classe III em pacientes com crescimento. Palavras-chave: Ortodontia interceptora. Ortodontia corretiva. Má oclusão. INTRODUCTION change;1 or a dentition whose normal development Supervising the development of occlusion, man- can be interrupted by some local etiological factor, aging problems during the transition from mixed to which requires treatment to maintain or restore the permanent dentition, as well as controlling environ- appropriate development.2 mental factors that contribute to establishing mal- Some of the most relevant objectives of super- occlusion, are important actions to achieve Class I vising the development of occlusion are to properly occlusion with facial balance, which often does not manage the growth potential in order to intercept occur naturally without interceptive orthodontic skeletal imbalances, eliminate functional deviations, treatment. Orthodontic approaches may be related to improve self-esteem, minimize trauma and prevent different categories of problems, such as a malocclu- periodontal problems.3 The possible advantages of sion in development, in which it may be necessary the early intervention are the emotional satisfaction of to intervene to reduce or interrupt the unfavorable the child, the growth potential available at this stage 1 Academia Norte-Rio-Grandense de Odontologia (Natal/RN, Brasil). How to cite: Silva DBH, Gonzaga AS. Importance of orthodontic intervention 2 Universidade Federal do Rio Grande do Norte, Departamento de Odontologia of the Class III malocclusion in mixed dentition. Dental Press J Orthod. 2020 (Natal/RN, Brasil). Sept-Oct;25(5):57-65. DOI: https://doi.org/10.1590/2177-6709.25.5.057-065.bbo » The authors report no commercial, proprietary or financial interest in the prod- ucts or companies described in this article. Submitted: July 20, 2020 - Revised and accepted: July 30, 2020 » Patients displayed in this article previously approved the use of their facial and Contact address: Dennyson Brito Holder da Silva intraoral photographs. E-mail: [email protected] © 2020 Dental Press Journal of Orthodontics 57 Dental Press J Orthod. 2020 Sept-Oct;25(5):57-65 BBO’s Selected Article Importance of orthodontic intervention of the Class III malocclusion in mixed dentition of development, greater collaboration with treatment, In addition to the anteroposterior skeletal dis- the possibility of a more simplified second phase and crepancy, it is common to find other malocclusions the possible reduction of extractions in the correc- associated with Class III due to maxillary hypopla- tive phase of treatment. Disadvantages also exist, such sia, such as posterior crossbite and anterior open as inefficiency, longer treatment time, immaturity of bite. Once the muscular balance is compromised by the patient, inefficient oral hygiene, inability to care the negative overjet, habits such as the anterioriza- for the devices and cost. tion of the tongue on swallowing and phonation are The ideal age to treat malocclusions in growing perpetuated during the child's development, chang- patients has been a widely discussed and controversial ing the muscle tone, the posture at rest, and conse- topic. One of the most important debates is to stop the quently establishing the anterior open bite.4,6,8,9 It is development of problems with early treatment or to for this reason that the interception of oral habits delay therapy. Among these problems, the malocclu- and multiprofessional treatment is essential for the sions associated with disorders such as mouth breathing stability of the results obtained with orthopedic and or obstructive sleep apnea syndrome (OSAS), atypical orthodontic therapy.4,8,9 swallowing and abnormal tongue position, open bites Therefore, the objective of this article is to pres- and crossbites, and maxillomandibular discrepancies, ent and discuss the main relevant aspects of the ben- and especially the Class III malocclusion can be listed. efits of carrying out the supervision of the develop- Class III malocclusion is a condition that can be ment of the occlusion, in addition to describing the classified as dentoalveolar, skeletal or functional, and interceptor and corrective orthopedic and corrective its etiology will determine the diagnosis and prognosis treatment of a patient with growing Class III maloc- of treatment.4 This malocclusion must be intercept- clusion (case report presented to the Brazilian Board ed early, preferably during the deciduous dentition of Orthodontics and Facial Orthopedics). phase, since Class III tends to exacerbate itself during growth, especially during adolescence.4-6 The sooner CASE REPORT treatment is started, the greater the compensatory Male patient, at the end of the first transitional pe- orthopedic effects of the inevitable orthodontic dis- riod of mixed dentition, aged 8 years and 4 months, crepancies, which can often prevent need for orthog- with good general health and without carious lesions nathic surgery at the end of growth. In addition, the or periodontal problems. During the initial consul- early treatment of Class III brings psychological ben- tation, the patient reported as the main complaint efits, due to the improvement of facial aesthetics that “the lower part is crossed and developed”, in addition to also implies in the improvement of self-esteem.5,6 the practice of parafunctional habits. Long-term studies of early treated Class III mal- Upon extraoral examination, the patient's face occlusions reveal that the results of the treatment are revealed typical characteristics of Class III maloc- stable, with visible improvement in facial profile, oc- clusion, with a deficiency of the middle third of the clusion and masticatory functions.4,6 Maxillary pro- face, without zygomatic projection, showing the traction therapy with a facemask is the most common sclera in the lower part of the iris and active lip seal- treatment for patients with skeletal Class III due to ing. In frontal view, there was a slight facial asym- maxillary retrusion, as it stimulates maxillary advance- metry with mandibular deviation to the right, while ment and assists in the control of mandibular develop- in lateral view it showed a concave profile, with a ment.7 As this type of treatment must be started early, chin-neck line apparently adequate to the face size the anchorage is performed on permanent and/or de- (Fig 1). During the anamnesis and initial examina- ciduous teeth, stimulating the movement of the maxil- tion, the parafunctional habits of lingual interposition la forward, rotating the mandible down and back, and in phonation, adapted swallowing and tongue hypo- decreasing the rotation of the palatal plane. There is tonia were found. also the projection of the upper incisors, mesialization The intraoral analysis showed an Angle Class I and extrusion of the upper molars and the retroinclina- dental relationship, maxillary hypoplasia, bilateral tion of the lower incisors.4-7 posterior crossbite, anterior crossbite with a - 6 mm © 2020 Dental Press Journal of Orthodontics 58 Dental Press J Orthod. 2020 Sept-Oct;25(5):57-65 Silva DBH, Gonzaga AS BBO’s Selected Article overjet, anterior open bite of 7 mm and inverted low- Steiner's cephalometric analysis revealed a growth ten- er Spee curve. In addition, there was a severe lack of dency of Class III (SNA = 80°, SNB = 80° and ANB = 0°), space of -8 mm in the upper arch to the lateral inci- while Wits10 analysis (- 4 mm) showed a real Class III. sors irruption, biprotrusion and diastema between the The patient had a horizontal growth pattern (Y axis = 54°, upper central incisors. Despite the slight mandibular FMA = 22° and SN.GoGn = 31°) and dental