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.

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

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.

Intrusion of maxillary incisors by mini-screw anchorage of Angle Class II division 2 malocclusion cases.

OBJECTIVES: to evaluate the effects of the upper incisor teeth intrusion by mini-screw on the amount of overbite and on the dental and skeletal parameters of the jaws. MATERIAL AND METHODS: Ten patients were selected from the outpatient clinic of the Department of Orthodontics, Faculty of Dentistry, Mansoura University with Angle's Class II division 2 malocclusions. Ages ranged from 13 to 19 years with deep overbite of 4mm or more requiring intrusion of the maxillary incisors. Alignment of the upper and lower dental arches was done with a pre-adjusted edgewise technique, then a mini-screw as anchorage for the intrusion of the upper incisor segment was inserted for every patient below the anterior nasal spine connected to a utility arch wire. RESULTS: The overbite was corrected from 6 mm to 1.8 mm (p<.001) by upper incisor intrusion and the gummy smile was improved. No extrusion of upper first permanent molars was observed. CONCLUSIONS: The maxillary incisors were effectively intruded by using mini-screws as orthodontic anchorage. Good occlusion and facial esthetics were achieved with no counteractive movements in the molars.