Resolution of lower second molar impaction through miniscrew-supported biomechanics: A proposal for a simplified classification.

Two case reports are presented showing how the strategic use of skeletal anchorage via orthodontic miniscrews manages to solve the complex problems of orthodontic disimpaction of second mandibular molars with excellent anchorage control and reduction of the adverse effects common to the use of conventional methods. The temporary anchorage device (TAD)-mediated biomechanics used can be categorized as both "pulling from the distal side" and "pushing from the mesial side" techniques in which both direct and indirect anchorage mechanics were employed. Each of these mechanics has its advantages and disadvantages, which must be weighed and considered on a case-by-case basis. Based on the force application side and the type of anchorage, a simplified classification of TADs supported biomechanics for the recovery of fully or partially impacted second molars is proposed.

Mechanical Evaluation of the Stability of One or Two Miniscrews under Loading on Synthetic Bone.

The aim of the present study was to evaluate the primary stability of a two-miniscrew system inserted into a synthetic bone and to compare the system with the traditional one. Forty-five bi-layered polyurethane blocks were used to simulate maxillary cancellous and cortical bone densities. Samples were randomly assigned to three groups-one-miniscrew system (Group A, N = 23), two-miniscrew system (Group B, N = 22) and archwire-only (Group C, N = 10). A total of 67 new miniscrews were subdivided into Group A (23 singles) and Group B (22 couples). 30 mm of 19″ × 25″ archwires were tied to the miniscrew. The load was applied perpendicularly to the archwire. Maximum Load Value (MLV), Yield Load (YL) and Loosening Load (LL) were recorded for each group. The YL of Group B and C had a mean value respectively of 4.189 ± 0.390 N and 3.652 ± 0.064 N. The MLV of Group A, B and C had a mean value respectively of 1.871 ± 0.318N, of 4.843 ± 0.515 N and 4.150 ± 0.086 N. The LL of Group A and B had a mean value respectively of 1.871 ± 0.318 N and of 2.294 ± 0.333 N. A two- temporary anchorage device (TAD) system is on average stiffer than a one-TAD system under orthodontic loading.

Mandibular molar uprighting using mini-implants: different approaches for different clinical cases--two case reports.

AIM: To detail two different clinical protocols and case studies using mini-implant anchorage developed to respond to certain clinical conditions. METHODS: Two clinical protocols are described to upright mesially tilted mandibular molars. In the first protocol, a single mini-implant is inserted distally to the molar to be uprighted, and an elastic traction chain is applied to the tooth. In the second clinical approach, two mini-implants are inserted mesially. A screw-suspended TMA sectional archwire is applied (Derton-Perini technique). Two cases, descriptive of the two different treatment protocols, are described. In the first case, the mandibular right second premolar was missing and the adjacent first molar needed to be uprighted. A single screw was inserted distally to the first molar, and an elastic chain was applied. In the second case, the mandibular left second molar was missing and the third molar needed to be uprighted. Two mini-implants were inserted mesially and a fully screw-supported sectional archwire was used to upright and bodily mesialize the third molar. RESULTS: Both uprighting approaches uprighted the molar axis without loss of anchorage. CONCLUSION: The two approaches to mandibular molar uprighting, developed as rational responses to different clinical cases, were both found to be effective.

Orthodontic extrusion for a preprosthetic approach: a bracketless mini-implant-based mechanics.

AIM: To propose a new mini-implant-based mechanics for the orthodontic extrusion of fractured posterior teeth. METHODS: An innovative biomechanical bracketless system was used to gain vertical movement of fractured maxillary molars with three-dimensional control to meet preprosthetic objectives. Two slotted-head mini-implants were inserted between the roots of the canine and premolars. A sectional TMA wire was passively adapted to the mini-implant positions and connected to the first molar by a crossing crown hole. The extrusion movement was achieved in two phases. In the first phase, a vertical spring loop was formed in the sectional wire for initial pure vertical movement. Next, a horizontal spring loop was modeled to improve the proper spatial position of the molar. CONCLUSION: The extrusion movement and stabilization were achieved without patient compliance. The maxillary molar was extruded about 3 mm, allowing exposure of the most apical border of the fracture, giving the prosthodontist the proper clinical conditions for ideal restoration of the tooth.

Surgical and orthodontic treatment of skeletal Class III featuring severe transversal and sagittal discrepancy.

AIMS: Anterior cross-bite is a difficult malocclusion to treat in adult patients, especially if compounded by skeletal discrepancy. The present study describes a dentoskeletal Class III case and aims to provide the clinician with rational guidelines for presurgical orthodontic preparation and postsurgical finishing. PATIENT AND METHODS: In this case, a 20-year-old male patient, R.M, was treated for severe dental and skeletal Class III malocclusion on both the transversal and anteroposterior planes via combined orthodontics and surgery. Initially, the treatment involved surgically-assisted expansion of the upper jaw (total 1 month), followed by a fixed-orthodontics phase to decompensate for the malocclusion in preparation for movement of the osseous bases with the aim of achieving maximum coordination of the dental arches. After 19 months of orthodontic preparation, the patient underwent combined orthognathic surgery (upper and lower jaws). In the subsequent 4 months, orthodontic stabilization and finishing were performed, and debonding was carried out 24 months after the start of active treatment. RESULTS: The combined orthodontic and surgical treatment adequately corrected the severe Class III over a period of 2 years, leading to a satisfactory occlusal, functional and aesthetic result. CONCLUSIONS: Thorough diagnosis and close communication between the orthodontist and maxillofacial surgeon, operating as an interdisciplinary team, ensures good outcomes, even in complex orthodontic and surgical cases.

Forced eruption with miniscrews; inter-arch [corrected] method with vertical elastics versus intra-arch method using the Derton-Perini technique: two case reports.

INTRODUCTION: Orthodontic preprosthetic treatment is an important feature of interdisciplinary dental therapy in the adult patient. Extrusion can be very useful to obtain successful prosthodontic results. The literature describes different ways to obtain forced dental eruption. Miniscrews represent a step towards resolving the problem of anchorage in orthodontics, including in forced eruption cases. The aim of this study is to report two cases of orthodontic preprosthetic extrusion by means of miniscrews and bone anchorage. We will describe and discuss the indications, orthodontic and surgical technique and the clinical advantages. MATERIALS AND METHODS: In the first reported case, a decayed upper molar was extruded using miniscrews and an inter-arch technique (direct skeletal anchorage), which needs patient compliance to properly position the inter-arch elastics. In the second case, an upper premolar with an oblique corono-radicular fracture underwent forced eruption by means of intra-arch miniscrews (indirect bone anchorage with the "Derton-Perini" technique). Patient compliance was not required. RESULTS: Adequate extrusion of the treated teeth was obtained, with no undesired movement of the neighbouring teeth. Using the "Derton-Perini" technique, we reached our objectives without patient compliance. CONCLUSIONS: Miniscrews for skeletal anchorage proved to be an effective device to obtain extrusion for prosthetic purposes without undesired movements on other teeth and with no need for patient compliance when used in the same arch.

Orthodontic treatment in periodontal patients: a case report with 7 years follow-up.

INTRODUCTION: Tooth flaring of the anterior segment is often unesthetic and therefore a primary reason for combined orthodontic and periodontal treatment in adult patients with periodontal disease. Thus, a multidisciplinary approach is frequently chosen for these patients by a qualified dental team. MATERIALS AND METHODS: A clinical case of an adult patient suffering from chronic periodontitis with horizontal bone loss in the anterior segment and consequent flaring of the anterior teeth is described. A combined approach was chosen, initially to improve and stabilize the periodontal situation via multiple scaling and root planning sessions with additional pharmacological therapy and, finally by orthodontic treatment, to resolve the malocclusion. RESULTS: At the end of treatment, bone resorbtion was stabilized, the vertical bone defect was improved and incisor flaring was absent. Follow-up at 7 years post-treatment confirmed the stability of the orthodontic and esthetic results. CONCLUSIONS: The correct combination of orthodontic and periodontal treatment may contribute efficaciously to eliminate the effects of chronic periodontitis in adult patients, as well as improving esthetic parameters.

[Orthodontic partial disimpaction of mandibular third molars prior to surgical extraction]. / Désinclusion orthodontique partielle des dents de sagesse mandibulaires avant leur extraction chirurgicale.

Odontodysplasia of the third molars is a relatively common anomaly. The frequent complications associated with this disorder very often constitute an indication for extraction of the third molar. This surgical treatment can damage the lower alveolar nerve and/or trigger distal bone loss of the second molar, thus jeopardizing the future status of the periodontium. The author presents two case studies treated exclusively with miniscrews with no dental anchorage in order to achieve partial eruption of the third molar moving it away from the lower alveolar nerve and to avoid unwanted impact on other teeth. Following this procedure, the third molar was extracted without complications. In conclusion, this approach can offer an alternative to surgical treatment alone in cases where the proximity of tooth and nerve poses a significant risk.