Anatomical Variations of the Greater Palatine Foramen in Different Facial Skeletal Relationships and its Implications on LeFort 1 Osteotomy (Trimble's Modification).

Purpose: To determine the positional variations of the greater palatine foramen in different facial skeletal relationships and discuss its surgical implications on the Trimble's modification of Lefort I osteotomy. Materials and Methods: This retrospective study examined 50 computed tomography scans of patients a total of 100 sides. The sample was divided into four groups: Class 1, Class 2, Class 3 malocclusion and Unilateral cleft lip and palate). The outcome variables included the distance between anterior, middle and posterior points of the GPF to the distal of second molar and variables to assess relative position of the GPF to the posterior maxilla. Outcome measures were to demonstrate intra- and intergroup variability. Results: Fifty patients (100 sides) were divided into four groups. This included 23 males and 27 females with a mean age of 24.1 years. Significant intergroup variability was observed between all the parameters that demonstrate the relative position of the GPF to (i) the maxillary second molar and (ii) the posterior maxilla. The analysis revealed that the GPF was positioned significantly anterior in Class 2 patients when compared with Class 3 patients. Conclusion: The GPF exhibits significant positional variability in different facial skeletal relationships which should be borne in mind while designing and performing the Trimble's modification of the Lefort 1 osteotomy.