Morphometric Assessment of Pterygomaxillary Fissure and Pterygopalatine Fossa using Cone-Beam Computed Tomography: A Retrospective study

BACKGROUND: The Pterygopalatine fossa (PPF) is a small pyramidal space below the apex of the orbit on the lateral side of the skull. This space is an inverted pyramid-shaped space surrounded by the junction of the maxilla, palatine, and sphenoid bones. Pterygomaxillary fissure (PMF) is located in the medial aspect of infra temporal fossa and it is formed by divergence of maxilla from the pterygoid process of sphenoid bone. Detailed evaluation of variations in the Pterygopalatine fossa (PPF) and Pterygomaxillary fissure (PMF) is needed to avoid complication such as headaches, lacrimation, nasal congestion, rhinohorrea and ptosis during fracture management and implant placement. AIMS AND OBJECTIVES: To investigate the detailed anatomy of the Pterygomaxillary fissure (PMF) and Pterygopalatine fossa (PPF) using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: • CBCT scan records will be retrieved from our institution’s Digital imaging and communications in medicine (DICOM) archive folder. • The CBCT scans of 100 patients were selected in the study based on the inclusion and exclusion criteria. • Anatomical variations in Pterygomaxillary fissure and Pterygopalatine fossa for the purpose of implant placement and management of Le fort - 1 osteotomy. • All CBCT exposures were performed using PlanmecaPromax 3D classic CBCT machine with PLANMECA ROMEXIS SOFTWARE version 6. operating at 90 kVp and 14 mA, 406 × 406 matrix, 14 bits grayscale and no added filtration. RESULTS: Out of 100 samples the subjects were divided into 3 age groups as (19 – 34), (35-50) and (51-66) respectively. On comparing the mean PMF area in sagittal plane between right and left sides for all the 3 age groups by one-way ANOVA test shows “P” value of 0.040 in right side which was less than P < 0.05 considered to be statistically significant. • Out of 100 samples subjects were divided according to gender as male and female. on comparing the mean PMF area in the axial plane between right and left sides for male and female by INDEPENDENT “T” test shows “P” value of 0.023 in female groups, 0.000 in right side and 0.040 in left side which was less than P< 0.05 considered to be statistically significant. • Out of 100 samples subjects were divided according to gender as male and female. On comparing the mean PMF area in coronal plane between right and left sides for male and female by INDEPENDENT “T” test shows “P” value of 0.004 in female groups and 0.011 “P” value in right side which was less than P< 0.05 considered to be statistically significant. • Out of 100 samples subjects were divided according to gender as male and female. on comparing the mean PMF area in sagittal plane between right and left sides for male and female by INDEPENDENT “T” test shows “P” value of 0.007 in right side and 0.011 “P” value in left side which was less than P < 0.05 considered to be statistically significant. • Out of 100 samples subjects were divided according to gender as male and female. On comparing the mean PPF volume in sagittal plane between right and left side for male and female by INDEPENDENT “T” test gives “P” value of 0.040 for female group and 0.002 “P” value in right side respectively which was lesser than P< 0.05 considered to be statistically significant. CONCLUSION: In our study comparison of PMF area and PPF volume for right and left side among age group between 19-66 showed no statistical significance. This may be due to the smaller sample size in our study groups. On comparing the PMF area and PPF volume among the genders showed statistical significance. According to gender male shows greater area and volumes than female. According to location in male, the area and volume were greater on the right side and in female the area and volume were greater on left side. So further studies conducted with a larger sample size may show significant differences for PMF area and PPF volume among different age groups