Feasibility of Transnasal dental Implant Placement Determined by PLACATE Guidelines

Author(s): Dan Holtzclaw, David Zelig, David Bulot, Steven Nelson, Alex Nguyen

Introduction: Transnasal dental implant treatment is a relatively new manner of addressing severely atrophic maxillae. These implants involve anatomic features which are not common to traditional implant dentistry such as inferior conchae, prelacrimal bone, and nasolacrimal ducts. To date, there is no systematic manner for presurgical anatomic evaluation of transnasal dental implant feasibility. This paper remedies this deficiency with the PLACATE guidelines.

Methods: A sequential review of 300 CBCT scans of patients referred for advanced full arch implant treatment was performed to determine feasibility for transnasal dental implant placement according to PLACATE guidelines. The following parameters were measured: 1) Simmen classification; 2) Prelacrimal bone width; 3) Subnasal bone height; 4) Distance from subnasal bone to prelacrimal bone engagement point. Additionally, the following anatomic data pertinent to transnasal dental implants was collected: 1) Diameter of nasolacrimal canals; 2) Distance from nasal aperture to nasolacrimal canal; 3) Angle of nasolacrimal canal relative to maxilla; 4) Patency of nasolacrimal canals.

Results: A total of 300 CBCT scans were evaluated for 117 men and 183 women with an average age of 62.1 years (range 31-87). Using PLACATE Guidelines, 30.54% of scans were found to be appropriate for transnasal dental implant treatment. The most common reason for patient disqualification from transnasal dental implant treatment was insufficient prelacrimal bone width.

Conclusion: Using PLACATE guidelines as a systematic method for evaluating full arch patients for transnasal dental implant feasibility, patient safety may be improved by treating only those patients who anatomically qualify.