Failure rates of 958 interradicular mini-screws for maxillary total arch distalization following a well-established insertion protocol.

OBJECTIVES

Maxillary Total Arch Distalization (MTAD) with interradicular mini-screws (MSs) in combination with Completely Customized Lingual Appliances (CCLAs) is an effective concept for Class II correction in adolescents and adults which does not require any additional supraconstructions. The aim of this study was to investigate the failure rates of MSs after strictly following a defined insertion protocol.

PATIENTS AND

METHODS

From November 2015 to August 2025, a total of 958 interradicular MSs were inserted in the maxilla for MTAD in combination with a CCLA in one orthodontic specialist practice. The surgical procedures were performed by 8 different clinicians (6 orthodontist specialists/2 postgraduate students in orthodontics) on 283 patients (female: 199/male: 84) with an average age of 27.6 years, ±13.3. Premature loss was defined as any instance in which a MS required removal due to mobility or was lost spontaneously on a yes/no basis.

RESULTS

Of the 958 interradicular mini-screws, 14 (1.5%) failed before schedule (palatal 13/buccal 1). No significant influence of the experience level of the clinicians (P = 0.394) on the mini-screw loss rate was observed. The highest loss rate was observed in the patients > 45 age group.

LIMITATIONS: One limitation is the retrospective study design, but no patient meeting the inclusion criteria was excluded for any reason.

CONCLUSIONS

Interradicular mini-screws used as temporary anchorage devices for maxillary total arch distalization can exhibit comparably low failure rates (1.5%) to those placed in the anterior palate, provided that a well-established clinical protocol is strictly followed.