Changes in canine inclination after rapid and slow maxillary expansion compared to untreated controls

Abstract

Palatal canine displacement is genetic and anatomical disorder that afflicts 0.2%-2.3% of the orthodontic population. 1 Multiple etiological factors leading to canine impaction were suggested comprising genetics, absence or anomalies referred to lateral incisors, lack of guidance during eruption, presence of obstacles to eruption such as follicular cysts or odontomas or ectopic position of the tooth germ. Palatally displaced canines (PDC) might represent condition causing several clinical problems, such as roots resorption and malocclusion, and can develop with palatal canine impaction. The correct eruption and position of canine is not only related to functional implications but also involved in harmony and symmetry of occlusal relationships, leading strategic role in aesthetics and in determining the contours of the mouth as a whole. 2 An early diagnosis of eruption problems with a timely treatment could reduce duration, cost and complexity of entire treatment. 3 In fact, treatment of canine impaction is complex and of uncertain outcome. According to this, interceptive treatment might be considered the recommended choice to prevent impaction of displaced canines. Ericson and Kurol suggested methods to perform diagnosis of canine displacement using panoramic films 4 indicating as α-angle the angle

Tratamiento interceptivo de los caninos impactados. Revisión de literatura.

“…La falta de diámetro transversal es un hallazgo frecuente en pacientes pediátricos, Ghaffar et al, mencionan que se puede calcular la discrepancia transversal del maxilar, con la medida del ancho intermolar mandibular que se resta del ancho intermolar maxilar, los valores negativos refieren una discrepancia transversa maxilar (Ghaffar et al, 2019) , 2018). La literatura sugiere que dentro de los procedimientos interceptivos que mejoran la tasa de éxito de erupción espontánea hasta en 66% de los pacientes, se encuentra la ERM, ya que este proceso disminuye la angulación de los caninos y aumenta el diámetro transversal del maxilar (Caprioglio et al, 2020). Wolff en su estudio sugirió la ERM mediante la utilización de un aparato disyuntor intraoral cementado a nivel de los molares, activándolo dos cuartos de vuelta al día manteniendo el aparato como contención durante 6 meses (Wolff et al, 2017), Barros et al justifican este procedimiento en casos de pacientes con caninos ectópicos o impactados, ya que en su ensayo clínico menciona que luego de la ERM, el 70% de caninos ectópicos mejoraron su angulación (Barros et al, 2018).…”

CBCT Analysis of Dento-Skeletal Changes after Rapid versus Slow Maxillary Expansion on Deciduous Teeth: A Randomized Clinical Trial

“…Rapid Maxillary Expansion (RME) increases molar and canine diameters [ 1 ] and enlarges the upper arch through orthodontic and orthopedic effects [ 2 ]. RME can also be useful in class II malocclusion characterized by mandibular retroposition caused by maxillary transverse discrepancy not immediately evident due to occlusion of maxillary posterior teeth on narrower sectors of the mandible [ 3 ].…”

Condylar Changes in Children with Posterior Crossbite after Maxillary Expansion: Tridimensional Evaluation

“…After maxillary expansion, transverse, vertical and anteroposterior changes of maxilla and mandible were reported, such as clockwise rotation of the mandibular plane, resulting from a lower and posterior position of the mandible in unilateral crossbites and sagittal changes in bilateral crossbites [ 7 , 8 ]. The protocol foresees the possibility to apply the maxillary expander both on the first permanent molars or the second deciduous molars, but the maxillary expansion on the deciduous molars showed some advantages, such as a spontaneous rotation of the first molars and a spontaneous retraction and alignment of the upper central and lateral incisors compared to the expansion on the first molars [ 9 ] and positive effects of treatment on canine inclination such as a reduction of α-angle [ 10 ]. Moreover, the expansion of permanent molars could affect their periodontal ligament and endodontic status [ 11 , 12 ].…”

“…On the other hand, other studies reported a symmetrical condyle position before and after treatment with RME [ 20 , 21 , 22 ]. Most of the studies performed over the past years were based on 2D analysis [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ] or magnetic resonance [ 24 , 25 ], while 3D analysis is of more recent use [ 20 , 21 , 22 ], which could partly be the reason of the discordance between the results of the different studies.…”