Objective: As a guide to the clinical practice of infiltration of local anesthesia into the pterygopalatine fossa via the greater palatine canal, this study sought to determine and record the mean CT scan measurements of the following: 1) palatal mucosal thickness, 2) length and width of greater palatine canal, and 3) length and width of pterygopalatine fossa among adult patients in a private tertiary hospital in Quezon City.
Design: Retrospective, Descriptive Study
Setting: Tertiary Private Hospital
Subjects: Paranasal Sinus (PNS) CT Scans of 113 adult patients from January 2014 to May 2014 were reviewed and evaluated. Excluded were images with pathology that distorted the anatomy of the sinuses and surrounding structures.
Results: Our study showed average CT scan measurements of 5.98 mm palatal mucosal thickness, 16.99 mm greater palatine canal length, 18.75 mm pterygopalatine fossa length, 2.37 mm greater palatine canal width and 2.58 mm pterygopalatine fossa width. Comparison of average measurements by sex was not statistically significant. There was statistical significance when comparing the right palatal mucosal thickness of 5.86 mm with the left which was 6.11 mm with p-value of 0.001. Comparison between the length of the right pterygopalatine fossa of 18.48 mm with the left side at 19.01 mm showed statistical significance with p-value of 0.01.
Conclusion: As the average measurement of the mucosal palatal thickness combined with the length of the greater palatine canal was 22.97 mm, we recommend bending the needle 23 mm from the tip in a 45 degree angle for adult patients who will undergo sinus surgery, control of posterior epistaxis, trigeminal nerve block and minor oral cavity surgeries.