Intrusion of posterior teeth using miniplates: intrusive mechanics is not the same as intrusion force

Craniomandibular transverse tomographic evaluation after anterior open bite orthodontic treatment with miniplates anchorage

BACKGROUND

Skeletal anterior open bite (SAOB) represents one of the most complex and challenging malocclusions in orthodontics. Orthodontic treatment supported by miniplates enable to reduce the need for orthognathic surgery. Transverse dimension may be affected by intrusion biomechanics. This study aims to assess transverse bone alterations in patients with SAOB who underwent orthodontic treatment with absolute anchorage using four miniplates.

METHODS

A total of 32 patients of both sexes, with an average age of 33.8 years, diagnosed with SAOB and treated orthodontically with four miniplates (one in each hemiarch), were selected for this study. Tomographic examinations were performed before (T1) and after (T2) orthodontic treatment. Linear measurements (width of the maxillary base, maxillary alveolar, maxillary root, maxillary dental cusp, mandibular alveolar) and angular measurements (maxillary intermolar angle) were assessed in these images. The Shapiro-Wilks normality tests were applied to verify data distribution, and the paired t-test was used to compare the initial and final measures obtained.

RESULTS

Among the evaluated parameters, the maxillary alveolar width, maxillary dental cusp width, mandibular alveolar cusp width, and intermolar angle showed statistically significant differences between T1 and T2 (p < 0.05). However, maxillary base and maxillary root widths showed no significant difference (p > 0.05).

CONCLUSIONS

Intrusion and distalization with miniplates in SAOB therapy may lead to significant expansive changes, due to molars cusps width and buccal inclination increase restricted at the alveolar level.

What changes in the biology of bone movement induced with mini-implants/miniplates is the synchronicity

Introduction:

Induced tooth-bone movement occurs by a synchronicity of dental and bone phenomena, thanks to the osteocytic network, which is a three-dimensional network that controls the bone shape or design.

Objective:

To describe the tooth-bone movement induced by enhanced anchorage, divided into three distinct moments: zero, start and stop.

Question:

From this description, the main question arises: with the use of mini-implants/miniplates, what changes in the biology of induced tooth-bone movement? The answer is: nothing changes, either biologically or microscopically.

Conclusion:

This technique optimizes the treatment time, and the range of therapeutic possibilities is broadened, thanks to the synchronicity of phenomena - which remain the same, in all teeth and bones, yet in a synchronized manner. Bone anchorage represents synchronicity in induced tooth-bone movement.