A clinical observation usually encountered after vestibuloplasty, or after interventions aiming to deepen the vestibule with or without simultaneous free epithelialized grafts in the posterior ridges, is that the vestibule can be subjected to major dimensional changes attributed to the buccinator fiber attachment. Therefore, this study aimed to assess 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 fiber attachment in relation to the distance from the crestal aspect of the 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 (CAP to the most coronal insertion of the buccinator muscle) were also correlated. CAP–BUC was negatively correlated with RH. Accordingly, the more atrophic the alveolar ridge (ie, more noticeable in the mandible), the shallower the vestibule, the smaller the crestal band of KM, and the greater crestal attachment of the buccinator muscular fibers. This may be the reason why the graft is subjected to major dimensional changes whenever a free epithelialized graft is performed in the posterior ridges to enhance the peri-implant soft tissue phenotype and deepen the vestibule.