An Updated Digital Approach to Regional Anesthesia: A Pilot Study on Computer-Guided Maxillary Nerve Block via the Greater Palatine Canal

TL;DR

A new computer-guided method for maxillary nerve blocks shows high success rates in achieving regional dental anesthesia, especially in the posterior teeth.

Contribution

This study introduces a computer-guided approach using CBCT-based surgical guides for maxillary nerve blocks, demonstrating clinical feasibility and effectiveness.

Findings

Computer-guided needle placement achieved success in 96.7% of patients.

Complete soft tissue anesthesia was achieved in all subjects tested.

Anesthetic success was highest in posterior teeth but lower in central incisors.

Abstract

Objectives: Maxillary nerve block via the greater palatine canal (GPC) offers the potential for profound regional anesthesia of the maxilla but remains underutilized due to anatomical variability and technical complexity. The aim of this study was to explore the clinical feasibility, accuracy, and anesthetic effectiveness of a computer-guided approach by using CBCT-based surgical guides to access the pterygopalatine fossa via the GPC. Methods: Thirty-one patients underwent the procedure with patient-specific guides designed from cone-beam computerized tomography (CBCT) and intraoral scans. A 27G needle was directed through the guide to deliver 1.8 mL of 2% lidocaine with epinephrine 1:80.000. Pulpal anesthesia was assessed via electric pulp testing (EPT), and soft tissue anesthesia via pressure algometry at predefined oral and facial sites. Success was defined as absence of EPT response at maximum output and pressure pain threshold ≥ 700 g. To assess variations in anesthetic efficacy among multiple related groups, Cochran’s Q test and McNemar’s test were employed. Results: Successful needle placement was achieved in 30 out of 31 patients (96.7%) using the computer-guided approach, with a mean of 1.45 insertion attempts per case. Complete palatal soft tissue anesthesia was achieved in all subjects across the tested sites (100%). Pulpal anesthesia was most effective in posterior teeth, with success rates of 96.7% for first molars and 93.3% for first premolars, while the central incisor showed a reduced success rate of 50%. Transient visual disturbances occurred in three patients (10%), with no other adverse effects reported. Conclusions: These findings support the use of computer-guided GPC block as a method for achieving maxillary nerve anesthesia. Although anesthetic spread to anterior and buccal regions was limited, the technique demonstrated consistent effectiveness in the posterior maxilla, highlighting its potential utility in complex dental and surgical interventions requiring deep and long-lasting regional anesthesia.

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