Three‐dimensional comparison of bone‐borne and tooth‐bone‐borne maxillary expansion in young adults with maxillary skeletal deficiency

Abstract

Objective To compare the transverse dental and skeletal changes in patients treated with bone‐anchored palatal expander (bone‐borne, BB) compared to patients treated with tooth and bone‐anchored palatal expanders (tooth‐bone‐borne, TBB) using cone‐beam computer tomography (CBCT) and 3D image analysis. Methods The sample comprised 30 patients with transverse maxillary discrepancy treated with two different types of appliances: bone‐borne (Group BB) and tooth‐bone‐borne (Group TBB) expanders. CBCT scans were acquired before (T1) and after completion of maxillary expansion (T2); the interval was 5.4 ± 3.4 and 6.2 ± 2.1 months between the T1 and the T2 scans of Group TBB (tooth‐bone‐borne) and Group BB (bone‐borne), respectively. Transverse, anteroposterior and vertical linear and angular three‐dimensional dentoskeletal changes were assessed after cranial base superimposition. Results Both groups displayed marked transverse skeletal expansion with a greater ratio of skeletal to dental changes. Greater changes at the nasal cavity, zygoma and orbital levels were found in Group BB. A relatively parallel sutural opening in an anterior–posterior direction was observed in Group TBB; however, the Group BB presented a somewhat triangular (V‐shaped) opening of the suture that was wider anteriorly. Small downward‐forward displacements were observed in both groups. Asymmetric expansion occurred in approximately 50% of the patients in both groups. Conclusion Greater skeletal vs dental expansion ratio and expansion of the circummaxillary regions were found in Group BB, the group in which a bone‐borne expander was used. Both groups presented skeletal and dental changes, with a similar amount of posterior palate expansion. Asymmetric expansion was observed in both groups.

Changes in digital cast measurements related with two types of rapid maxillary expanders, tooth-borne versus hybrid one

“…According to this study's findings, an increase in IDDM1 in CH as compared to HH due to increase the tipping effect in CH, this was in agreement with Gunyuz et al 3 , Bazzani et al 24 and Martina et al 27 . On the other side this was in disagreement with Pasqua et al 38 since maxillary width showed significant difference between groups, increasing more in HHG than conventional one, this might attributed to different design of the appliance with different age group.…”

“…1,2 In a growing patient, RPE successfully opens the midpalatal suture using a conventional hyrax(CH). 3 Because RPE is frequently coupled with high force 4 , there is a danger of root resorption 5 and bone dehiscence of the anchored teeth. 6 Some authors believe that with the introduction of bone-borne maxillary expansion, a few risks to anchored teeth have been avoided 7,8 , while other studies found no change.…”

Three-dimensional analysis of miniscrew position changes during bone-borne expansion in young and late adolescent patients

“…Moreover, asymmetry of miniscrew position changes was observed: both left screws showed a greater amount of displacement and angular variation when compared to the opposite side; this observation suggests a greater stability loosening on the left side in respect to the right side. These results can be related to the asymmetrical skeletal expansion results observed in a previous study, where the right side showed more displacement when compared to the left side [ 19 ].…”

“…This pyramidal pattern suggests a reason why the expansion screw opening, which occurs at a lower height with respect to the pyramid vertex, is greater than the suture opening measure. However, in a more recent study it was observed that bone-borne expansion of the maxilla did not follow the pyramidal pattern reported in previous studies, with similar amounts of skeletal expansion observed at orbitale, zygoma and nasal cavity [ 19 ].…”

“…Finally, according to the present study the amount of expansion screw opening converted to sutural opening is estimated between 52.4% and 61.5% of the value in the anterior area and 29.9% and 31.9% of the value in the posterior area, being the anteroposterior difference due to the already known triangular (V-shaped) opening of the suture that was wider anteriorly [ 19 ].…”