Tooth rotation remains one of the most challenging tooth movements in clear aligner treatment.
A recent study evaluated the predictability of rotational movement with and without attachments and analyzed the impact of trimline design.
Existing evidence suggests that even without attachments, most teeth can achieve a wide range of rotation, but certain teeth, such as lateral incisors, remain challenging to move.
In contrast, aligners with straight trimline designs are more reliable in controlling tooth rotation than traditional scalloped designs.
Digital tools such as CandidPro’s Pro-Check and CandidConsult can further enhance treatment outcomes through material selection, movement staging, and strategic case planning.
Clear aligners are transforming orthodontic treatment with their aesthetic, removable, and comfortable features, but rotational movement—particularly of rounded or tapered teeth—remains challenging. The use of attachments, trimline type, and material properties significantly impact the predictability of rotation.
Several studies have shown that effective rotation can be achieved without attachments in certain situations. For example, a retrospective analysis of the rotation of 200 incisors, canines, and premolars showed that orthodontic appliances can still achieve acceptable rotational results without attachments, although responses vary among teeth.
Tooth morphology is a key factor influencing the success rate of rotation: lateral incisors, due to their short, conical crowns, are among the most difficult teeth to rotate; premolars and central incisors, on the other hand, respond more positively to rotational forces.
Attachments increase tooth surface area and create grooves, helping orthodontic appliances apply targeted forces, thereby improving rotational accuracy. Systematic reviews have shown that attachments are particularly effective for rotating canines and premolars when specific force vectors are optimized.
“With traditional scalloped braces, attachments help enhance retention and achieve targeted rotational movement,” said Perry Stevenson, DDS, MSD.
However, with straight trimming wires, the braces can grip the teeth directly, reducing reliance on attachments. This improves movement predictability and reduces human error.”
The properties of brace material are crucial for consistent and predictable force transmission. Bay Materials’ Zendura FLX is a three-layer composite: a flexible inner layer provides resilience, while a rigid outer layer ensures the braces securely grip the teeth while maintaining sustained force transmission.
Studies have shown that Zendura FLX applies less initial force, increasing patient comfort and maintaining consistent force levels throughout treatment.
This material improves brace fit and grip, and in some cases, can even reduce the need for attachments.
