Reasons for mini-implants failure: choosing installation site should be valued!

Abstract

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that:a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants.Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows:1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant.

The use of mini-anchorage screws in the surgical orthodontic treatment of stage-III periodontitis: a clinical case

“…This result is consistent with the study published by Khorsan et al (n = 8 aggressive periodontitis cases followed over 6 months) [11] and the clinical case (12-month follow-up) by Carnio et al (2015) [9]. In conclusion, the suitability of the screw mechanism has provided a definitive advantage to the use of the orthodontic mini-screw technique on a thinned periodontium such that the desired result has been achieved [13,14]. Other advantages include a reduction in the treatment duration [14] and an improved prognosis [7].…”

“…In conclusion, the suitability of the screw mechanism has provided a definitive advantage to the use of the orthodontic mini-screw technique on a thinned periodontium such that the desired result has been achieved [13,14]. Other advantages include a reduction in the treatment duration [14] and an improved prognosis [7]. Nevertheless, this technique requires perfect coordination between the orthodontist and the oral surgeon as well as the therapeutic compliance from the patient.…”

Buccally impacted maxillary canines increase the likelihood of root separation in adjacent first premolars

“…Knowledge about the prevalence of root separation in maxillary premolars and its associated factors is important for clinical dentistry, including canal preparation for endodontic treatment, orthodontic temporary anchorage device placement near the premolar roots, and design of surgical approach for their extraction when needed (Li et al , ; Consolaro and Romano, ; Agarwal et al , ). Among all four types of permanent premolars, the maxillary first premolar shows the most distinctive variation (Vertucci, ; Aoki, ; Chaparro et al , ; Atieh, ; Awawdeh et al , ; Tian et al , ).…”

RANK/RANKL/OPG gene polymorphisms and loss of orthodontic mini‐implants

“…In recent years, mini‐implants (MIs) have gained enormous popularity in the orthodontic environment and have become a reliable method to provide temporary orthodontic anchorage . The use of MIs allows the movement to be performed without side effect on the other teeth, being generally well accepted by the patients …”

“…The success rate of MIs depends on factors such as type, diameter and length of the MIs, orthodontic mechanics, dentist's ability, host bone thickness, oral hygiene, presence of soft tissue inflammation and genetic factors …”