How Does Orthodontic Mini-Implant Thread Minidesign Influence the Stability?—Systematic Review with Meta-Analysis

Abstract

Background: Clinical guidelines are lacking for the use of orthodontic mini-implants (OMIs) in terms of scientific evidence referring to the choice of proper mini-design. Thus, the present study aimed to investigate to what extent orthodontic mini-implant thread design influences its stability. Methods: Search was conducted in five search engines on 10 May. Quality assessment was performed using study type specific scales. Whenever possible, meta-analysis was performed. Results: The search strategy identified 118 potential articles. Twenty papers were subjected to qualitative analysis and data from 8 papers—to meta-analysis. Studies included were characterized by high or medium quality. Four studies were considered as low quality. No clinical studies considering the number of threads, threads depth, or TSF have been found in the literature. Conclusions: Minidesign of OMIs seems to influence their stability in the bone. Thread pitch seems to be of special importance for OMIs retention—the more dense thread—the better stability. Thread depth seems to be of low importance for OMIs stability. There is no clear scientific evidence for optimal thread shape factor. Studies present in the literature vary greatly in study design and results reporting. Research received no external funding. Study protocol number in PROSPERO database: CRD42022340970.

Correction of Midline Deviation and Unilateral Crossbite Treated with Fixed Appliance

“…Systematic reviews and meta-analysis demonstrated that the use of mini screws is strongly recommended in cases of maximum anchorage than other methods or combinations of treatments and it is associated with a shorter duration treatment time [ 17 – 19 ]. Whereas other reviews and meta-analysis showed that miniscrews have an acceptably low failure rate linked to insertion sites [ 20 ], to minidesign of screws [ 21 ], and to cortical bone thickness [ 22 ].…”

Effect of Surface Topography on the Primary Stability of Miniscrew Implants in Orthodontics—A Systematic Review and Meta-Analysis

“…[ 10 ] Additionally, it is understood that the geometry of the implant might affect the pattern of stress distribution along the bone interface. [ 11 12 13 14 ]…”

Tooth Complications after Orthodontic Miniscrews Insertion

“…In particular, the authors analyzed pitch, thread depth, and shape, concluding that only the first of these three factors is decisive. Implants with a denser thread show greater stability, while thread depth and thread shape are irrelevant [ 13 ].…”