A clinical observation usually encountered after vestibuloplasty or interventions aiming at deepening the vestibule with or without simultaneous free epithelialized grafts in the posterior ridges is that they are subjected to major dimensional changes attributed to the buccinator fibers attachment. Hence, this study aimed at assessing the attachment of the buccinator muscles in relation to other anatomical landmarks. An ex-vivo study was performed in cadaver heads to explore the association of fibers attachment in relation to the distance from the crestal aspect of edentulous alveolar process (CAP) and the vestibular depth (VD), crestal band of keratinized mucosa (KM), and ridge height (RH). Interestingly, VD and KM were found to be strongly correlated. Likewise, VD/KM and CAP-BUC were further noted being correlated. CAP-BUC was negatively correlated with RH. Accordingly, the more atrophic the alveolar ridge (being more noticeable in the mandible) is, the shallower the vestibule, the lesser the crestal band of KM and the more crestal attachment of the buccinator muscular fibers. That might be the reason why whenever performing free epithelized graft in the posterior ridges to enhance the peri-implant soft tissue phenotype and deepening the vestibule, the graft is subjected to major dimensional changes.