A Retrospective Multicentric Study of 52 Nasal and Transnasal Implants in 31 Severely Atrophic Patients to Reduce Anterior Cantilever Bending in Full-Arch Implant-Supported Fixed Rehabilitations.

Abstract

Purpose: To assess the feasibility and success rate of nasal or transnasal implants placed in patients who were affected by severe maxillary anterior atrophy with residual anatomical features that indicate this surgery.

Materials and methods: In this retrospective multicentric study, 52 nasal or transnasal dental implants were placed in 31 maxillary atrophic anterior sites (Cawood and Howell's class V/VI). All implants were successful after the healing period; 27 nasal implants reached an insertional torque ≥ 50 Ncm2, and the threshold value was estimated to be able to support an immediate load.

Results: All 52 implants were successful, so the proportion of success was 100%, with a 97.5% one-sided CI of 88.8% to 100%. The success rate was achieved only when at least two of the following criteria were met: (1) a torque > 50 Ncm as a minimum sufficient condition to plan immediate loading; (2) after a healing period of 16 weeks, no coronal bone resorption (this condition allows for successive prosthetic finalization) observed clinically or radiographically; and (3) a possibility of carrying out a full-arch rehabilitation with minimal anterior spread. Insertion torque was < 50 Ncm in 14 patients (45%) and 50 Ncm in 17 patients (55%). Mechanical loading was delayed in the former group of patients and immediate in the latter group of patients. The proportion of torque that was < 50 Ncm was greater in men (69%) than in women (28%; P = .033). Immediate torque was not significantly affected by age.

Conclusions: Although the present sample was not extremely numerically significant, it conveyed a clear and significant clinical and surgical meaning that has never been seen before in the literature: nasal or transnasal implants can be very useful in reducing the anterior cantilever and overcoming the anatomical limitations affecting conventional quad zygoma implants.