Downloaded 1,334 times
Uploaded byKrupa Mayekar
Pre prosthetic surgery
This document discusses various pre-prosthetic hard tissue procedures including: recontouring alveolar ridges through alveoloplasty and Dean's alveoloplasty; reducing maxillary tuberosities, palatal exostoses, mylohyoid ridges, and genial tubercles; removing tori and bone augmentation of atrophic maxillary and mandibular ridges through onlay grafts, sinus lifts, and hydroxyapatite grafts. The goal is to modify oral anatomy and eliminate undercuts/protuberances to facilitate dental prosthesis placement through reshaping bony areas.
More Related Content
Similar to Pre prosthetic surgery
Pre prosthetic surgery
- 1. PRE PROSTHETIC SURGERY- HARDTISSUES
- 2. Contents Introduction Objectives Patient evaluation and Treatment planning Evaluation of the supporting bony tissues Recontouring of alveolar ridges Maxillary tuberiosity reduction Buccal exostosis and excessive undercuts Lateral palatal exostosis Mylohyoid ridge reduction Tori removal Bone augmentation
- 3. Introduction Preprosthetic surgeryrefers to the surgical procedures that can modify the oral anatomy to facilitate the retention of conventional dentures. The ultimate goal of preprosthetic surgery is to prepare the mouth to receive dental prosthesis by redesigning and smoothing bony edges or areas and removing excess of flabby soft tissues
- 4. Objectives No evidence ofintraoral and extraoral pathological conditions. Proper inter arch jaw relationship Alveolar processes that are as large as possible and of the proper configuration. No bony or soft tissue protuberances or undercuts Adequate palatal vault form Proper posterior tuberosity notching Adequate attached keratinized mucosa and adequate vestibular depth. Protection of the neurovascular bundle
- 5. Preprosthetic procedures Ridgecorrection Alveoloplasty Maxillary tuberosity reduction Removal of exostosis Removal of undercuts Lateral palatal exostosis Mylohyoid reduction Genial tubercles reduction Removal of tori Ridge augmentation Maxillary Mandibular
- 6. Patient evaluation andtreatment planning Preprosthetic surgical treatment must begin with a proper case history and physical examination Special attention should be given to systemic diseases that may be responsible for the severe degree of bone resorption. Esthetic and functional goals of the patient must be assessed carefully. Long term maintenance of the underlying tissues as well as prosthetic appliances should be kept in mind.
- 7. Recontouring of alveolarbone Simple alveoloplasty Intraseptal or Dean’s alveoloplasty
- 8. ALVEOLOPLASTY Defined assurgical recontouring of alveolar process Indications Patients with prominent and dense alveolar bone undergoing extraction Prior to construction of an immediate denture The simplest form of alveoloplasty consists of compression of the lateral walls of the extraction socket after simple tooth removal
- 9. Bony areasrequiring recontouring should be exposed using an envelop type of flap. A mucoperiosteal incision along the crest of the ridge with adequate A-P extension is given Adequate visualization and access to the alveolar ridge obtained Vertical incisions given if necessary Excessive flap reflection may result in devitalized areas of bone which may resorb rapidly after surgery Recontouring can be accomplished with Rongeur Bone file Bone bur in handpiece
- 10. Copious salineirrigation should be done throughout the recontouring procedure to avoid overheating and bone necrosis After this the edges of the flap are trimmed and then sutured with continuous or noncontinuous sutures.
- 11.
- 13. DEAN’S INTRASEPTAL ALVEOLOPLASTY This technique is best used in an area where the ridge is of relative regular contour and adequate height but presents an undercut to the depth of the labial vestibule. Performed during the time of extraction Advantages : 1. Labial prominence is reduced without reducing the height of the ridge 2. The periosteal attachment to the bone can be maintained hereby reducing bone resorption 3. Muscle attachments are left undisturbed Disadvantage : 1. Decrease in ridge thickness
- 15. MAXILLARY TUBEROSITY REDUCTION Excess tissue in the region of the maxillary tuberosity may become so large that it: Impinge upon the mandible during mastication. Interfere with denture construction, insertion and seating Complication of tuberosity reduction -expanded tuberosity in proximity to sinus
- 17. Lateral palatal exostosis Presents problems in denture construction because of the undercut created by the exostosis and narrowing of the palatal vault Technique : Local anesthetic solution in the area of the greater palatine foramen Crestal incision made from the posterior aspect of the tuberosity extending to the exostosis Reflection of the mucoperiostium Removal of excess bony projection by a bone file Saline irrigation Suturing
- 19. Mylohyoid ridge reduction Linear incision is made over the crest of the ridge in the posterior aspect of the mandible Full thickness mucoperiosteal flap is elevated to expose the muscles Bone file is used to remove the sharp prominance of the mylohyoid ridge
- 21. Genial tubercle reduction Reduction required to construct the prosthesis properly If augmentation is to be carried out, tubercle left to add support to the graft
- 22. Tori removal Inthe patient requiring complete or partial conventional prosthetic restoration, tori maybe a significant obstruction to insertion or interfere with the overall comfort, fit, and function of the planned prosthesis. In the maxilla,bilateral greater palatine and incisive blocks are given.
- 23. A linearmidline incision with posterior and anterior vertical releases or a U-shaped incision in the palate followed by a subperiosteal dissection is used to expose the defect. Rotary instrumentation with a round acrylic bur may be used for small areas; however, for large tori, the treatment of choice is sectioning with a cross-cut fissure bur. Once sectioned into several pieces, the torus is easily removed with an osteotome
- 24. Closure isperformed with a resorbable suture. Presurgical fabrication of a thermoplastic stent, made from dental models with the defect removed, in combination with a tissue conditioner helps to eliminate resulting dead space, increase patient comfort. Complications :- Postoperative hematoma, Perforation of the floor of the nose Necrosis of the flap
- 26. MANDIBULAR TORI • Bilaterallingual and inferior alveolar anesthesia is given • Incision extending from 1 to 1.5cms beyond each tori is given • Always leave behind a band of tissue attached to the midline between the anterior extent of the 2 incisions. • When the torus has a small pedunculated base, a mallet and an osteotome is used to cleave the tori from the medial aspect of the mandible • The direction of the initial bur is parallel to the medial aspect of the mandible to prevent fracture of the lingual or inferior cortex
- 27. • A bonefile is then used to smoothen the lingual cortex • Palpation is done to check for proper contour and presence of any undercuts • Continuous suturing is done and gauze packs are placed and retained for the next 12 hrs • The direction of the initial bur is parallel to the medial aspect of the mandible to prevent fracture of the lingual or inferior cortex • A bone file is then used to smoothen the lingual cortex • Palpation is done to check for proper contour and presence of any undercuts • Continuous suturing is done and gauze packs are placed and retained for the next 12 hrs
- 28. Mandibular augmentation Augmentationgrafting adds strength to an extremely deficient mandible and improves the height of contour of the available bone for implant placement on the denture bearing areas. The sources of graft material include autogenous or alloplastic bone and alloplastic materials
- 29.
- 30. Superior border augmentation Thoma& Holland technique: Corticocalcellous iliac crest blocks are contoured to adapt to the configuration of the mandible. Then fixated with screws and miniplates
- 31.
- 32. Osteopromotion A membraneis used to cover an area where bone regeneration is necessary By placing a membrane over the bone graft, faster growing fibroblasts and epithelial cells are walled off allowing the bone to grow in a relatively protected environment. Currently, expanded polytetrafluoroethylene is used as a membrane.
- 33. Maxillary augmentation Onlay bone grafting Hydroxyapatite augmentation Sinuslifts Interpositional bone grafts
- 34.
- 35. Sinus lift Extensionof the maxillary sinus into the alveolar ridge may prevent placement of implants in the posterior maxillary area because of insufficient bony support. A sinus lift procedure is a bony augmentation procedure that places graft material inside the sinus and augments the bony support in the alveolar ridge area. The graft is allowed to heal for 3 to 6 months after which the first stage of implant placement can begin.