Miniplates and mini-implants: bone remodeling as their biological foundation

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.

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

Objective:

Biologically explain some of the bone mechanisms involved in the intrusion, or intrusive effect, of teeth submitted to skeletal open bite correction using four miniplates.

Methods:

The results of dental intrusion were measured and compared in 3D reconstructions of cone beam computed tomography scans taken before and after treatment of 20 patients with skeletal open bite, aged between 18 and 59 years.

Results:

The results allow deducing that the compression and traction forces biologically promoted deformation or deflection of the osteocyte network that controls bone design, and these effects involved the external and internal surfaces of the bone, with the formation of new layers, including the cervical portion of the alveolar bone crest. This helps understanding how dental intrusion occurs in intrusive mechanics, whose forces are of inclination rather than intrusion. The root resorptions caused by the use of miniplates were insignificant, due to the more homogeneous distribution of forces in the several teeth simultaneously involved.

Conclusion:

Imaging studies in CT scans tend to capture in details the subperiosteal and endosteal phenomena of dental intrusion - before and after the application of intrusive mechanics -, in the form of a set of modifications called dental intrusion or intrusive effect .

Dehiscences and fenestrations: methodological care necessary to avoid errors in diagnosis and measurement

The low prevalence of gingival recessions observed in orthodontic clinical practice may be assigned to the fact that in studies in which dehiscences and bone fenestrations are described as frequent, they were diagnosed based on: 1) dry skull studies; 2) areas with periosteal reflection together with flap; and 3) imaging techniques with low sensitivity to detect these defects, which have a delicate structure and function. In areas of pseudo-dehiscences and fenestrations, the periosteum and the alveolar cortical bone are very thin; also, they either have been removed during preparation of the dry specimens in the areas for analysis, or, alternatively, have not been investigated using an ideal imaging method.

Third molars and premolars extraction in conventional orthodontics and in treatments based on maxillary bone remodeling with temporary anchorage: indications and care

A bone is an anatomic structure in constant remodeling, with different, mutant and wonderfully inconstant designs. With every new and immediate functional demand, there are changes in cortical thickness, trabecular bone density and also in direction and size of trabeculae. Bones' non-stopping search is for adjusting to the functions induced by forces and movements required by a certain life style. Conventional orthodontic planning or with temporary anchorage based on bone remodeling takes into consideration the spaces that are - or may be - occupied by the teeth, in the formation of a functional and esthetic dental arch for the patient. In case it is necessary to extract a tooth and the options are the third molars, partially or totally unerupted, and teeth that belong to other dental groups, obviousness recommends - due to mouth anatomy and physiology, as well as pathologic reasons - extracting the third molars, due to of the several reasons described in the present study.