## 4 Discussion  
Implants immediately placed and provisionalized in fresh extraction sockets in the esthetic zone are well documented with survival rates similar to traditional delayed protocols [27]. However, the lack of long-term tissue stability resulting in less predictability of esthetic results, has limited the utilization of this protocol to ideal Type I extraction sites [11]. Even in Type I sites, the inclusion of bone and/or soft tissue grafting techniques are often necessary to minimize less than optimal outcomes. The MMC protocol utilizes biologically sound steps in order to further enhance the predictability of the treatment outcomes for both type I sockets as well as type II sites, comprising a thick or thin tissue biotype (Sketch 1 and 2) (Schemes 1 and 2) [18]. In this article, the authors utilized a socket classification proposed in by [PERSON] and [PERSON] 1993, as we considered it to be the most suitable one [18]. According to more recent classifications, the MMC can be utilized also in Class III sockets that do not present interproximal bone loss and, or class II or III Miller soft tissue recession [19; 41]. The MMC protocol does not utilize any vertical incisions. Instead, the surgical design utilizes a partial thickness, supra-periosteal, to create an envelope pouch on the labial aspect of the socket. It is believed that a partial thickness flap is more advantageous relative to a full thickness flap for the MMC technique as it minimizes any compromise to the blood supply originating with the supra-periosteal vascular complex. In addition, a partial thickness flap allows for greater tension-free mobilization of the labial soft tissue. Unlike other techniques which utilize similar partial-thickness labial pouches as receptors of soft tissue grafts, however, the novel aspect of the MMC protocol is this envelope pouch is designed to initiate a control trauma to the periosteum that will lead in the formation of a blood clot, and potentially stimulate osteoprogenitor cells coming from the periosteum to occupy the area [42; 43; 44]. In combination with the proposed vertical mattress suturing technique, the protocol's design allows the application of a vertical pull-force at the line angles instead of a horizontal pressure-force to the mid buccal side of the treatment site. Moreover, the location of the vertical mattress sutures constrains the blood clot in a mesio-distal direction between the lateral line angles, allowing it to form and expand in an apico-coronal direction just on the buccal portion of the site without expanding towards the areas of the adjacent teeth [45]. The mobilized buccal tissue with the support of the blood clot is guided by the pull-force to migrate coronally, improving at the same time its vertical location and thickness [45; 46]. As the healing process progresses and the inflammation moderates, the coronally migrated soft tissue remains supported, supra-crestally, by portions of the low turnover BRG and resorbable membrane that are purposefully located supra-crestally to provide for a scaffold at the supra-crestal zone of the healing socket [42; 47]. Specifically, the membrane is critical to maintaining the graft particles in place and minimizing the popcorn effect often seen in bone grafted cases with thin soft tissue biotype. Moreover, due to the modification and adaptation of its supra-socket portion, the membrane is placed tension free and does not apply any lateral force to the BRG. Similar approaches that tag and/or suture the membrane at the lingual aspect of the socket, can apply pressure on the BRG during the steps of adaptation, moving part of the BRG away from the buccal side, where most of the socket remodeling will take place and thus the BRG is mostly needed [48]. There are several studies that support the utilization of a connective tissue graft within a partial thickness pouch on the buccal aspect of the socket [49; 50].