Selective piezocision-assisted orthodontic treatment combined with minimally invasive alveolar bone regeneration: A proof-of-concept

One-stage versus two-stage piezocision-assisted orthodontic tooth movement: A preclinical study based on Nano-CT and RT-PCR analyses

OBJECTIVE

To evaluate the effect of a second-stage piezocision on the biological response.

MATERIALS AND METHODS

60 rats were randomly allocated to 6 experimental groups of 10 rats. Rats undergoing a one-stage piezocision were sacrified on day 7, 28 and 42 (groups 1-3) while rats undergoing a two-satge piezocision were sacrified on day 42, 63 and 90 (groups 4-6), respectively. The biological response was investigated in 3D at the tissue level using Nano-computed tomography (Nano-CT) and, at the molecular level using the qRT-PCR technique. Bone Volume Fraction (BVF) loss was the primary endpoint.

RESULTS

Similar loss of BVF were observed both after the first and second piezocisions. The change in BVF loss between 7 and 28 days after each piezocision were 25.1 ± 13.0 (SE)% and 11.2 ± 11.6 (SE)% respectively and did not differ from each other (p = 0.43). Changes in BVF loss from 7 to 42 days were also comparable in one-stage and two-stage piezocision (4.9 ± 12.3 (SE) vs. -19.9 ± 13.4 (SE), p = 0.19). At the molecular level, all parameters except Translating Ribosome Affinity Purification (TRAP) protein had identical patterns.

CONCLUSION

Within the limits of the present study, a second piezocision allowed to re-induce the Regional Acceleratory Phenomenon (RAP) effect. Nevertheless, the relevance of the findings to the clinical effect has not been tested.

The Cone Beam Computed Tomography Evaluation of Cortical Bone Plate after Piezocision-Assisted Orthodontic Upper Arch Expansion: A Case Series

Background: The purpose of the study was to evaluate cone beam computed tomography (CBCT) after piezocision-assisted orthodontic maxillary arch expansion. Methods: Forty CBCT images of 20 patients taken before and after treatment were included in the study. The following radiographic parameters were measured: buccal/palatal bone plate thickness measured in three locations, 0.5 mm, 3.5 mm, and 5 mm from the margin of alveolar process; cemento-enamel junction-crest distance (CEJ-C) measured at buccal (CEJ-B) and palatal/lingual (CEJ-P) aspects. Results: After treatment there were insignificant changes in CEJ-C and thickness of buccal/palatal plates for all the dental groups except for incisors and premolars. CEJ-B increased by 1.43 mm on premolars and CEJ-P by 1.65 mm on incisors and by 0.31 mm on premolars. On the incisors, the buccal plate width increased significantly, by 0.2 mm and 0.44 mm at 3.5-mm and 5-mm measurement points. On premolars, the buccal plate width decreased in three measuring points by 0.27 mm, 0.37 mm, and 0.25 mm. Conclusions: Piezocision-assisted orthodontic maxillary arch expansion does not cause evident negative changes of cortical plates except for the premolar region. Therefore, premolars may be at greater risk of buccal plate loss than other teeth.

Effect of piezocision on molar intrusion in open-bite treatment using a modified MEAW technique

PURPOSE

The aim of this retrospective study was to investigate whether a piezocision technique influences molar intrusion in open-bite cases.

METHODS

In all, 30 patients with open-bite malocclusion were assigned to one of two groups: the piezocision group comprised 15 patients who were treated using curved arches and anterior elastics with the simultaneous combination of piezocision which was performed interdentally in the upper posterior region, while the control group comprised 15 patients who were treated with the same treatment mechanics without piezocision. In both groups, after leveling and aligning, upper 0.017 × 0.025 accentuated curve and lower 0.017 × 0.025 reversed curve of Spee NiTi archwires were placed. Anterior vertical elastics were applied between laterals and the canines on both sides. The effects of treatments were investigated on cone-beam computed tomography images acquired before use of elastics and after correction of open-bite.

RESULTS

Open-bite closure was achieved in 2.85 ± 0.85 and 4.1 ± 1.58 months in the piezocision and control groups, respectively, while total treatment lasted 1.4 ± 0.42 and 1.7 ± 0.43 years, respectively. Extrusion of lower posterior teeth (p < 0.05) was observed together with extrusion of incisors and canines (p < 0.001) in the piezocision group, while only incisors and canines were extruded in the control group (p < 0.001). There were no significant differences between the groups (p > 0.05) except significant lower incisor extrusion (p < 0.05) and counter-clockwise rotation of the lower occlusal plane in the piezocision group (p < 0.001).

CONCLUSION

The duration of open-bite correction was significantly shorter in the piezocision group. No molar intrusion was observed in either group. Open bite correction was achieved mainly by extrusion and retrusion of the incisors while maintaining upper molar positions.