Comprehensive approach to simultaneous molar intrusion and canine retraction in the treatment of Class II anterior open bite using miniscrew anchorage

Abstract

Introduction: Anterior open bite is one of the most difficult malocclusions to correct in orthodontic treatment. Molar intrusion using miniscrew anchorage has been developed as a new strategy for open bite correction; however, this procedure still has an important concern about prolonged treatment duration in the patient with anteroposterior discrepancy due to the separate step-by-step movement of anterior and posterior teeth. Objective: This article illustrates a comprehensive orthodontic approach for dentoalveolar open bite correction of an adult patient, by using miniscrew. Case report: A woman 19 years and 5 months of age had chief complaints of difficulty chewing with the anterior teeth and maxillary incisor protrusion. An open bite of -2.0 mm caused by slight elongation of the maxillary molars was found. The patient was diagnosed with Angle Class II malocclusion with anterior open bite due to the vertical elongation of maxillary molars. After extraction of the maxillary first premolars, concurrent movements of molar intrusion and canine retraction were initiated with the combined use of sectional archwires, elastic chains and miniscrews. Results: At 4 months after the procedure, positive overbite was achieved subsequent to the intrusion of maxillary molars by 1.5 mm and without undesirable side effects. Class I canine relation was also achieved at the same time. The total active treatment period was 21 months. The resultant occlusion and satisfactory facial profile were maintained after 54 months of retention. Conclusion: The presented treatment shows the potential to shorten the treatment duration and to contribute to the long-term stability for open bite correction.

Efectividad de la intrusión molar superior con mini implantes para corregir la mordida abierta anterior

“…La intrusión posterior con mini-implantes para corregir la mordida abierta anterior es detallada por varios autores (Akl, Abouelezz, El Sharaby, El-Beialy, 2020;Al-Falahi, Hafez, 2018;Malara, Bierbaum, 2021;Shirasaki, Ishihara, Komori, Yamashiro, 2020) quienes concluyeron que al usar un aditamento como una barra transpalatina juntamente con mini-implantes produce mayor intrusión de las raíces vestibulares que la raíz palatina y a su vez impide que se produzca la inclinación hacia vestibular de la corona (Akl, Abouelezz, El Sharaby, El-Beialy, 2020;Al-Falahi, Hafez, 2018;Shirasaki, Ishihara, Komori, Yamashiro, 2020). Scheffeler et al (Scheffler, Proffit, 2014) y Alsafadi et al 2016, señalan que al realizar el movimiento de intrusión a nivel de molares superiores se debe tener presente que los molares inferiores podrían experimentar una extrusión pasiva, que se puede evitar con el uso de mini-implantes para intruirlos o solamente como anclaje indirecto (Alsafadi et al 2014).…”

“…Para lograr una intrusión molar maxilar aproximada de 1,5mm la literatura menciona un tiempo de tratamiento activo de 8 -10 meses en promedio dependiendo de la fuerza (Akl, Abouelezz, El Sharaby, El-Beialy, 2020;Al-Falahi, Hafez, 2018;Manea, Dinu, Baciut, Buduru, 2022;Shirasaki, Ishihara, Komori, Yamashiro, 2020) el ángulo de inserción del mini implante en el área maxilar a nivel interradicular debe considerarse entre 30 y 40° para lograr intrusión pura y así evitar tener contacto con las raíces y con las demás estructuras anatómicas (Miranda, Valencia, Ramírez, 2020;Otazú, Janson, Coelho, Gamba, 2018).…”