**Abstract**

Orthodontic miniscrews have had a considerable impact on modern orthodontic treatment, not only by providing a new source of anchors for anchorage-demanding cases, but also for force management and control. Whilst miniscrews need to be mechanically stable during treatment to provide sufficient anchorage and predictable force control, as temporary anchorage devices they need also be easy to remove after orthodontic treatment. These requirements differentiate orthodontic miniscrews from dental implants - which once placed, are not to be removed - and dictate the approach as to how their clinical performance can be optimized. Over the past decade, various titanium surface modifications and improvements in implant surface topography have shown to enhance osseointegration of endosseous dental implants. Some of these techniques have helped provide a similar enhancement of the biomechanical potential of orthodontic miniscrews as well. In this perspective, we present a brief discussion on all such reported techniques followed by a detailed account of the most recently proposed ultraviolet photofunctionalization technique - a novel chair-side surface modification method.

**Keywords:** anchorage, stability, surface modification, osseointegration, biomechanical potential, photofunctionalization, miniscrews

## **1. Introduction**

Anchorage control plays an important role in orthodontic treatment. Nevertheless, in clinical practice, this was a typically difficult and unpredictable challenge for many years. In the 1990s, temporary anchorage devices (TADs) called mini-implants were the first implants used to provide absolute and compliance-free intraoral anchorage [1]. Subsequently, these implants became smaller in size and are today used as 'orthodontic miniscrews' (**Figure 1**). They have the advantages of low cost, simple surgical placement, and ease of removal. Miniscrews have, therefore, found applications in the treatment of a variety of malocclusions. However, as with any other implanted material in the human body, the stability of orthodontic miniscrews is paramount to their clinical acceptability. The clinical stability of miniscrews has proven to be exceptionally high (**Table 1**). A few studies have reported success rates higher than 90% [2, 3], while others have reported slightly lower success rates [4, 5]. Notwithstanding such a high rate of clinical success, various surface modification techniques have been

#### **Figure 1.**

*Miniscrews used as temporary anchorage devices (TADs) in fixed orthodontic treatment of malocclusions (black arrows).*


#### **Table 1.**

*Clinical stability of orthodontic miniscrews.*

proposed to further enhance the stability of miniscrews, thereby allowing the orthodontist to optimize and expand its clinical use.
