## 1 Introduction  
After the extraction of one or more teeth, volume reduction occurs both horizontally and vertically in the extraction socket during the tissue remodeling process. According to a systematic review of the literature, when assessing the magnitude of dimensional changes of both the hard and soft tissues of the alveolar ridge up to 12 months following tooth extraction in humans, the results showed an average reduction in the width of the alveolar ridge of 29 to 63% in 6 months, while for the height of the alveolar ridge the average reduction was 11 to 22% in 6 months [1]. For well-informed decision-making and thorough treatment planning that includes provisions for possible solutions, the extent of these dimensions alterations is crucial to anticipated issues during the rehabilitation of prosthetics. Furthermore, given the increased focus on aesthetics recently, a comprehensive understanding of the resorption pattern and changes in the bony and mucosal contours following extraction would significantly improve our capacity to reconstruct our patients to a level of optimal function and acceptable aesthetics [1]. [PERSON] and [PERSON] classified the defects of the resorbed alveolar ridge based on horizontal and vertical absorption. In 1983, [PERSON] classified different types of alveolar ridge defects: Class I defects have a bucco-lingual loss of ridge contour with normal ridge height, Class II defects have a apico-coronal loss of ridge contour with normal ridge height, and Class III defects have a combined loss of the ridge contour [2]. In 1985, [PERSON] classified apico-coronal loss of tissue as type A, buccolingual loss of tissue as type B, and combination loss of tissue as type C. Also, [PERSON] classified the ridge defect according to the depth of the defect, mild as a depth of less than 3 mm, moderate as 3 to 6 mm, and severe as more than 6 mm [3]. Various soft tissue graft techniques have been proposed to increase the volume of the resorbed edentulous alveolar ridge, which include the roll technique, pouch procedure, onlay graft, and inlay graft [4; 5; 6; 7; 8; 9]. The roll technique utilizes a pedicle flap graft and is indicated for Class I defects, according to [PERSON]'s classification [4; 5; 6]. The Pouch procedure employs a subepithelial connective tissue graft and is suitable for Class I and mild Class II defects [7; 8]. The Onlay graft involves the use of either a free gingival graft or a connective tissue graft. It is recommended for severe Class II and Class III defects [9]. The Inlay graft also utilizes either a free gingival graft or a connective tissue graft and is applicable to Class I, mild Class II, and Class III defects [9]. Among them, the roll technique is effective for Seibert Class I defects. The roll technique can be divided into three methods, which is conventional roll technique, modified roll technique, and roll-in envelope technique. The conventional roll technique was designed to increase soft tissue volume around the pontic. The conventional roll technique includes a palatal de-epithelialization procedure and the exposure of palatal bone, which leads to unfavorable healing on the palatal side. The pedicle is then rolled beneath the buccal mucosa to augment the soft tissue volume [5]. To avoid the unfavorable healing on the palatal side, the roll technique was modified using the trap-door technique. The epithelium over the palatal connective tissue is raised and preserved to cover the palatal bone in this technique. This modified roll technique induces primary healing on the palatal side [6]. The minimally invasive roll-in envelope technique was introduced. In the roll-in envelope technique, the palatal flap is not elevated, the crestal epithelium is de-epithelialized, and a minimally invasive incision is made, followed by the insertion of the pedicle flap into the buccal pouch. This technique promotes better blood supply with less soft tissue manipulation [10]. Recently, the intraoral scan has emerged as a convenient imaging method that offers comprehensive 3D information.