Three-dimensional assessment of external apical root resorption after maxillary posterior teeth intrusion with miniscrews in anterior open bite patients

ABSTRACT Objective: The objective of this study was to assess the external apical root resorption (EARR) of the maxillary posterior teeth after intrusion with miniscrews. Methods: Fifteen patients (13 females and 2 males) with age ranging from 14.5 to 22 years (mean 18.1 ±2.03 years) were selected to participate in this study. All patients presented with anterior open bite of 3 mm or more. An intrusion force of 300 g was applied on each side to intrude the maxillary posterior teeth. Cone beam computed tomography (CBCT) scans were taken pretreatment and post-intrusion and were analyzed to evaluate the EARR. Results: The maxillary posterior teeth were intruded in average 2.79 ± 0.46 mm (p< 0.001) in 5.1 ± 1.3 months, and all examined roots showed statistically significant EARR (p< 0.05) with an average of 0.55 mm, except the distobuccal root of the left first permanent molars and both the palatal and buccal roots of left first premolars, which showed no statistically significant changes. Conclusions: The evaluated teeth presented statistically significant EARR, but clinically, due to the small magnitude, it was not considered significant. Moreover, the CBCT provided a good visualization of all roots in all three planes, and it was effective in detecting minimal degrees of EARR.

RESUMO Objetivo: o objetivo desse estudo foi verificar a existência de reabsorção radicular apical externa (RRAE) em dentes posterossuperiores após intrusão ancorada em mini-implantes. Métodos: quinze pacientes (13 mulheres e 2 homens) com a idade variando entre 14,5 e 22 anos (média de 18,1 ± 2,03 anos) foram selecionados para participar desse estudo. Todos os pacientes possuíam mordida aberta anterior de 3mm ou mais. Uma força de 300 gramas foi aplicada em cada lado para intruir os dentes posterossuperiores. Tomografias computadorizadas de feixe cônico (TCFC), adquiridas antes do tratamento e após a intrusão, foram comparadas para se avaliar a RRAE. Resultados: os dentes posterossuperiores foram intruídos em média 2,70 ± 0,46 mm (p< 0,001) em 5,1 ± 1,3 meses, e todas as raízes examinadas mostraram RRAE estatisticamente significativa (p< 0,05), com média de 0,55 mm, exceto pela raiz distovestibular dos primeiros molares permanentes esquerdos, e pelas raízes palatina e vestibular dos primeiros pré-molares esquerdos, que não apresentaram mudanças estatisticamente significativas. Conclusões: os dentes avaliados apresentaram RRAE estatisticamente significativa, a qual, porém, não foi considerada clinicamente significativa, devido à sua reduzida magnitude. Além disso, a TCFC possibilitou uma boa visualização de todas as raízes nos três planos espaciais, e foi eficaz para detecção de níveis mínimos de RRAE.

Orthodontic intrusion of the first and second mandibular molars with a vacuum-formed removable appliance: a case report / 华西口腔医学杂志

This case report focused on a patient with supraeruption of the first and second mandibular molars as a result of loss of the first and second maxillary molars for a long time. We adopted a combination of a vacuum-formed removable appliance and elastics to intrude the first and second mandibular molars by using a continuous, light force to acquire sufficient restoration space for maxillary molars. Thus, the dental-implant treatment was successful, and a good and stable occlusal relationship was established.

Intrusion of Overerupted Molars using Miniscrews and TMA Spring: A Case Report.

Over eruption of posterior tooth due to the loss of antagonist teeth causes occlusal and functional disturbances. To restore proper occlusion, intrusion of the overerupted tooth becomes essential before multidisciplinary reconstructive dental approaches can be initiated. Conventional orthodontic techniques do not intrude posterior teeth eff ectively, and almost all methods result in anterior extrusion rather than posterior intrusion. New absolute anchorages (miniscrews and miniplates) are said to make posterior tooth intrusion possible. Th is case report describes the treatment of a patient with supra-erupted maxillary right and left fi rst molars intruded with titanium molybdenum alloy spring and miniscrew anchorage. Th e results showed that the biological responses of the teeth and the surrounding bony structures to the intrusion appeared normal and acceptable. Periodontal health and vitality of the teeth were maintained throughout the treatment.

A study on the treatment of anterior open bite with midpalatal miniscrews / 대한치과교정학회지

Recently several techniques have been reported for the treatment of anterior open bite in adults characterized by molar intrusion with skeletal anchorage. In this study, five adult patients who had anterior open bite malocclusion were selected to undergo upper molar intrusion with midpalatal miniscrew to close the open bite. The aim of this study is (1) to validate true intrusion of molars in adults (2) to test the usefullness of midpalatal miniscrews as anchorage for intruding upper molars (3) to evaluate the skeletal and dental changes of open bite closure. The results are as follows. (1) All had true intrusion of the maxillary molars. Mean amount of molar intrusion was 3.4mm(range 1.5-5mm). (2) No movement of midpalatal miniscrew occurred during their use. (3) Open bite closure was achieved for all 5 patients. The mandible closed and B-point rotated anteriorly and upward. The mandibular plane angle and the occlusal plane angle decreased.