This document summarizes reconstructive preprosthetic surgery techniques used to enhance tissues for denture support and retention. It discusses vestibuloplasty procedures like skin grafting to increase the vestibule depth and amount of keratinized tissue. Ridge augmentation techniques are described including bone grafts, rib grafts, and visor osteotomies which aim to widen denture foundations but often result in resorption or nerve damage. Hydroxyapatite injections and different types of dental implants are also summarized as alternative ridge augmentation options.

7. Vestibuloplasty with Buccal Mucosa Grafts This technique lengthens the labial and buccal vestibule but does not improve the quality of the tissues in the primary support areas. We do not recommend this procedure.

10. Retrieval and Placement of the Skin Graft The graft is retrieved with a dermatone and is removed at the level of the rete pegs. Small islands of epithelium left at the donor site, expand and eventually coalesce upon healing. The graft is secured to a surgical stent, that was previously adapted to the surgical site with a temporary denture reliner, with a biodegradable adhesive. The stent is retained with circumandibular sutures and is left in place about 10 days Donor site Skin Graft Surgical stent Stent sutured in position Retrieving graft with dermatome

12. Skin Graft Vestibuloplasty - Results Note the changes. The unattached poorly keratinized mucosa has been replaced with skin that is firmly attached to the underlying periosteum and the muscle attachments in the floor of the mouth have been lowered. The skin lined areas improve the support for the denture and the change in floor of posture permits a longer lingual extension enhancing stability of the denture. Mandibular Arch (Obwegeser Method)

15. Skin Graft Vestibuloplasty- Other Problems Granulation tissue formation Fungal infestation Callous formation Scar tissue at the mucosa-skin graft-mucosa junction Perforation of the periosteum during the dissection leading to exposure of bone Mandible

19. Palatal Graft Vestibuloplasty – Maxillary Arch Palatal grafts are used when only limited amounts of graft material are needed The donor sites need about one month for complete healing

22. Prong Denture - Maxilla Preop condition After supraperiosteal dissection Prefabricated prongs attached to border molded denture. Note the skin graft adapted to the denture. Postoperative view. Note the two skin lined channels. These channels extend all the way to the floor of the nose

25. Inferior Border Rib Grafts Prosthodontic Advantages a)Widens the bearing surface b) Occlusal plane and interocclusal space undisturbed

27. Visor Osteotomy preop 3 mths 2 yrs 5 yrs preop 3 mths 2 yrs This technique uses a pedicled bone flap combined with cancellous bone grafts obtained from the iliac crest.

31. Augmentation with Hydroxyl Apatite Hydoxyl apatite particles are injected under the periosteum via a small tunneling incision made on the crest of the ridge anteriorly. The intent is to rebuild the alveolar process

33. Hydroxyl Apatite - Migration In this patient the material is beginning to extrude through the mucosa. In this patient the material has migrated onto the buccal shelf making this structure less effective as a primary support area.

37. Subperiosteal Implants-Biologic Limitations Upon healing the metal struts of these chrome cobalt implants became surrounded by fibrous connective tissue. Upon occlusal loading the collagen fibers became oriented to resist these forces and formed a suspensory ligament (arrows). If the surface area of this “ligament” was insufficient to support the occlusal loads the implant was driven into the bone resulting in bone loss and sometimes leading to fracture of the mandible. Implant Strut Occlusal Load

38. Subperiosteal Implants-Biologic Limitations The design was improved by the addition of implant struts parallel to the occlusal plane. These designs provided more support for the occlusal forces and prevented the implant from being impacted into the bone. However, this design change did not prevent the migration of epithelium along the interface of the implant strut and the fibous connective tissue capsule.

39. Subperiosteal Implants-Biologic Limitations The epithelial migration led to the formation of extended peri-implant pockets and eventually local infections around the implant posts and struts and ultimately, in many patients, resulting in the loss of the implant. Coating the implant with hydroxyl apatite was ineffective in preventing this migration and the material eventually was resorbed.

41. Subperiosteal Implants-Maxilla Most fail within 5 years because of fibrous encapsulation of the implant,and epthilelial migration. The chronic infections resulting from the extended pockets lead to rapid and extensive bone resorption.

42. Subperiosteal Implants-Maxilla The bone loss secondary to infections associated with subperiosteal implants in the maxilla can be quite extensive. The patient on the left has lost almost all the hard palate and the patient on the right has lost the premaxillary segment.

43. Subperiosteal Implants-Maxilla As was the case in the mandible, coating the implant with hydroxyl apatite did nothing to prevent epithelial migration and development of deep peri-implant pockets, and with these pockets, recurrent and chronic infections.

44. Implants - Blades These were used quite often in the 70’s and 80’s but fell out of favor because of failures associated with epithelial migration, infection and bone loss around the implants. They were used to support overlay dentures and also served as abutments for fixed partial dentures. Patient acceptance was very high in spite of the relatively high failure rates.

45. Implants-Ramus Frame A variation of the subperiosteal design Success rate was low because of epithelial migration and the lack of implant struts parallel to the occlusal plane

46. Implants – Mucosal Inserts The female portion of the metal mucosal inserts were surgically implanted into the mucosa and the male portion imbedded within the denture. However the mucosa inserts soon fail. This procedure is not recommended.

47. Transmandibular (Staple) Implants This implant is made of titanium alloy and becomes osseointegrated if the surgical site is prepared in a precise and atraumatic manner. It is designed to retain and stabilize an overlay denture. Implant success rates have been in excess of 90% at 10 year followup.

48. Osseointegrated Implants A radically new concept in implant dentistry Following placement the adjacent bone grows against the surface of these titanium implants firmly anchoring the implant in bone. When examined at the light microscopic level there is no fibrous connective tissue interface between the surface of the implant and the surface of the bone. As a result epithelial migration is prevented and the risk of chronic infection secondary to the formation of deep peri-implant pockets is almost eliminated.