Introduction: The main objective of our study is to assess the importance, direction, and predictability of dentofacial changes following LeFort I maxillary advancement while focusing on the extent of improvement of the soft and hard tissue profile of the face after surgery. Material and Method: This is a retrospective study carried out on patients treated in the dentofacial orthopedics unit at the Farhat Hached University Hospital of Soussa. The data of the study were obtained from a sample of 20 participants aged at least 18 years. Cephalometric measurements were performed on each patient and the collected data were analyzed with SPSS 22.0. Spearman's correlation test and simple linear regression test were used. The normality of the sample distribution was studied with the Shapiro-Wilk and Kolmogorov-Smirnov tests. The statistical significance level was set at 5%. Results: A negative and statistically insignificant correlation was found between patient age and the amount of maxillary advancement. The SNA and ANB angles were significantly and positively correlated with the amount of maxillary advancement. There was also a positive, statistically significant correlation between the amount of advancement and the thickness of the postoperative upper lip, which was confirmed by simple linear regression analysis, whereas the Z and nasolabial angles were negatively and significantly correlated with the amount of advancement. Also, a positive and statistically significant correlation was found between upper incisor exposure and upper lip thickness and length. Discussion: The results found in the literature have commonalities and differences with those found in our study, these comparisons will be discussed in our article. Conclusion: These variations should be taken into consideration and anticipated in our daily practice.