Dentoalveolar comparative study between removable and fixed cribs, associated to chincup, in anterior open bite treatment

OBJECTIVE: The aim of this prospective study was to compare the dentoalveolar effects produced by two types of palatal crib, removable (Rpc+C) and fixed (Fpc+C), combined with chincup in growing patients with anterior open bite. MATERIAL AND METHODS: each group comprised 30 patients, in the mixed dentition phase, with similar cephalometric characteristics and skeletal ages. Group 1 (Rpc+C) presented initial mean age of 8.3 years and mean anterior open bite of 4.0 mm. Group 2 (Fpc+C) presented initial mean age of 8.54 years and mean anterior open bite of 4.3 mm. The evaluation period comprised 12 months between initial (T1) and second lateral radiograph (T2). The T2-T1 changes were compared cephalometrically in the 2 groups using the non-paired t-test. RESULTS: Vertical changes in the posterior dentoalveolar region were similar between the groups (about 1 mm) and no significant differences were found in molar mesialization. The Fpc+C group had in average 1.6 mm more improvement of the overbite as a result of greater maxillary incisor extrusion (1.3 mm). Patients in this group also presented less lingual tipping of maxillary incisors and more mandibular incisors uprighting. CONCLUSIONS: The Fpc+C combination was more efficient in the correction of the negative overbite mainly due to greater extrusion of the maxillary incisors. However, the Rpc+C appliance promoted better upper and lower incisor inclination, resulting in a more adequate overjet.

A utilização dos mini-implantes como alternativa na correção da classe II, subdivisão / The use of mini-implants as an alternative for class II, subdivision correction

Os casos de assimetrias dentoalveolares representam um desafio na práticaortodôntica. Os tratamentos mais comuns são extrações dentárias assimétricas, utilização de aparelhos ortopédicos funcionais, realização de desgastes interproximais e uso de elásticos intermaxilares, dependendo da etiologia da assimetria, do desvio da linha média, da quantidadede apinhamento e do perfil do paciente. Na correção das assimetrias, muitas vezes, há dificuldades mecânicas no controle de ancoragem, sendo necessário um planejamento para que se evitem efeitos colaterais como desvios indesejados de linha média durante acorreção da má-oclusão. O presente artigo demonstra uma maneira de correção de uma Classe II, subdivisão, Tipo 1, utilizando-se um sistema de cursar associado à ancoragemcom mini-implantes.

The asymmetric cases represent a challenge for the orthodontic practice. The most common treatments are asymmetric extractions, use of functional appliances, performance of interproximal stripping and use of intermaxillary elastics. It depends of the etiology ofasymmetry, midline deviation, amount of crowding and patient profile. Tothe correction of such imbalances, often there are difficulties in mechanical anchorage control. It requires planningto avoid side effects, such as unwanted deviations from the midline during the correction of malocclusion. This article demonstrates a way of correcting a Class II, subdivision, type 1, using a system composed by a cursor associated with mini-implants anchorage.