SEMINAR PRESENTATION ONPREPROSTHETIC SURGERY DR. SEENA SAM 2ND YEAR P.G. STUDENT DEPT. OF PROSTHODONTICS AND CROWN AND BRIDGE 29.01.2014 INTRODUCTION A significant number of patients can never be made to use dentures effectively because of : bone atrophy soft tissue hypertrophy localized soft and hard tissue problems all of them Various treatment methods to improve patient’s denture foundation and ridge relations are: Nonsurgical Surgical Combination of both Nonsurgical methods Rest for denture supporting tissues Occlusal correction of the old prosthesis Good nutrition Conditioning of the patient’s musculature . No bony or soft tissue undercut or prominences. No sharp ridges. No high muscle or frenal attachments. Adequate firm soft tissue coverage.Characteristic of ideal denture bearing area Adequate bone support. . No presence of peripheral fibrous tissue bands to prevent proper seating No soft tissue hypertrophies on the ridges or in the sulci No intraoral or extraoral pathology Proper alveolar ridge relationship in all three planes . DEFINITION – PREPROSTHETIC SURGERY Surgical procedures designed to facilitate the fabrication of a prosthesis or to improve the prognosis of prosthodontic care [GPT.8] . Preprosthetic surgery is carried out to reform/redesign soft / hard tissues by eliminating biological hinderness to receive comfortable & stable prosthesis. . Aims of preprosthetic surgery To provide adequate bony tissue support for the placement of prosthesis Provide adequate soft tissue support . Tori. genial tubercle Correction of mandibular and maxillary ridge relationship . promoinent mylohyoid ridge.optimum vestibular depth Elimination of the pre-existing bony deformities eg. flabby ridges. hyperplastic tissues Relocation of frenal or muscle attachments Relocation of mental nerve Establishment of correct vestibular depth . Elimination of preexisting deformities. eg. epulis. Specific indications for preprosthetic surgery include 1. anti post. 2. Complete or partial edentulism secondary to early tooth loss. transverse) d) Reduction of denture bearing area e) Muscle hypotonia f) Facial changes . a) Jaw atrophy b) Mucosal atrophy c) Interarch changes (vertical. Naturally occurring reduction of the residual bony ridge. ) c) Local recurrent ulceration d) Temporomandibular joint pain .3. Pain (not remedial by conventional prosthetic measures) due to: a) Mucositis (a burning discomfort of the mucous membrane) b) Neuropathy (alteration of sensation of the lips varying from objective/ subjective paraesthesia to anesthesia or pain arising from traumatized nerve trunks. Dysfunction (not remediable by conventional prosthetic means) of: a) Mastication b) Speech c) Deglutition d) Temporomandibular joint dysfunction due to deficient dental occlusion .4. b) Obturator which replaces the missing jaw or orbit. f) Phobia to normal prosthetic appliances. d) Enhanced gag reflex / excessive palatal sensitivity. e) Allergy to conventional prosthetic materials. c) Craniofacial prosthesis.5. Replacement of lost tissue following disease/trauma a) Orbital prosthesis. . metabolic/haematological 2. cardiovascular. Inadequate quality of bone (sclerotic/ osteoporotic) . e.g. Underlying systemic diseases.CONTRAINDICATIONS 1. Insufficient quantity of bone 3. horizontal. transverse) 5. Adverse skin conditions and congenital remnants . Adverse mucosal conditions (quality/quantity) 6. Unfavourable inter arch relations (vertical.4. floor of nose. Pre-existing pathology 8. Adjacent dentition 9. maxillary sinus. Local anatomy (inferior alveolar nerve.7. tongue size) . 10. Parafunctional habits 12. Opposing dentition/jaw 13. Psychological/ psychiatric disorders 11. Additional bone grafting . Poor patient co-operation/compliance 17.14. Poor oral hygiene 16. Previous radiotherapy 15. Heavy tobacco smoking . hypertrophic labial and lingual frenum.Common conditions that require surgical correction prior to CD construction Soft-tissue abnormalities: 1. 4. 5. 6. 2. hypermobile ridge tissue. 3. soft-tissue interferences. papillary hyperplasia. epulis fissuratum . prominent buccal frenum. Osseous abnormalities: 1. ridge undercuts, 2. prominent mylohyoid and internal oblique ridges, 3. bony tuberosity interference, 4. sharp spiny residual ridge, 5. tori and exostoses Retained dentition: 1. unerupted teeth, 2. retained roots Preprosthetic surgical procedures Alveolar ridge correction Alveolar ridge extension Alveolar ridge augmentation ALVEOLAR RIDGE CORRECTION Bone surgeries Labial alveolectomy Primary alveoplasty Secondary alveoloplasty Excision of tori Reduction of genial tubercle Reduction of mylohyoid ridges Maxillary tuberosity reduction . Soft tissue surgeries: •Removal of redundant crestal soft tissue •Frenectomy – labial & lingual •Excision of epulis fissuratum & palatal hyperplasia . ALVEOLECTOMY Surgical removal or trimming of the alveolar process Trimming done with roungeur or round bur and smoothened with bone file Use in the presence of sharp margins at interseptal or labiobuccal alveolar ridge Too much bone loss will result in poor denture base retention . Single tooth alveolectomy . Minimum amount of alveolar bone resorption occurs if after simple extraction . Primary alveoloplasty always done at the time of multiple extraction or single extraction.Simple Alveoloplasty Refers to surgical recontouring of the alveolar process.digital compression of the alveolar cortices done immediately. . maintaining stress bearing cortical bone intact Not require for raising mucoperiosteal flap .Intraseptal alveoloplasty – dean’s alveoloplasty with repositioning of labial cortical bone. Used in maxilla Used to reduce gross maxillary overjet To reduce the volume of cancellous bone . Carried following extraction of anterior teeth immediately. It will reduce buccal undercut or labial prominence without reducing the height of residual alveolar ridge. Maintain periosteal attachment to the labial plate of bone. in which the adequate bone height exists. Best long time result Indicated in cases . . . Multiple extraction 2.Indications 1. .Early initial post extraction period. repositioning of the labial cortical bone . Steps 1.removal of bone followed by 2. Interdental septal bone is cut from canine to canine region with the straight fissure bur attached to surgical handpiece or with rongeur. Technique Teeth should be extracted avoiding trauma to the labial cortex. . .vertical cuts are made only in the labial cortex at distal end of the canine extraction sockets bilaterally without perforation of the labial mucosa in the dean’s technique.With the same bur . . Digital pressure is used to compress the fractured labial cortex into the palatal direction.With periosteal elevator /osteotome placed in the base of the canine socket bilaterally. labial cortex is fractured. Labial and palatal plate will come into approximation with each other Interrupted continous suturing is carried out. Obwegesser’s modification for interseptal alveoloplasty Indication Gross max.overjet.( when compression of the labial cortex is not sufficient) After cutting the interseptal bone ,an inverted cone vulcanite bur is used to widen the socket. With small bur ,horizontal cuts are made at the base of the extraction socket in the labial and palatal cortices. Vertical cuts then made bilaterally in both the labial and palatal cortices in the area distal to the canine socket. With digital pressure,both the labial and palatal cortices are compressed together and sutures are given. Immediate denture delivery is planned ,used as a template to check for any pressure points. but the reflection Side ways separation with the periosteal elevator will help the smooth reflection Sharp areas or large undercuts should be trimmed with rongeur and suturing done.Alveoloplasty with post extraction healing Crestal incision is taken not to tear the mucoperiosteal flap. . due to resorption over the years.) Seen in patients wearing old dentures.Elimination of unfavourable undercut Usually done in the mandibular lingual aspect (genial tubercle . sharp mylohyoid ridge prominence. the denture become unstable . Reduction /resection of the genial tubercle Are bony attachments of genioglossus muscle. . Are seen on the crestal level on the lingual aspect. . Technique Crestal incision is made from the lower canine to canine region . after infilteration of the LA No reflection of flap done on the labial side Full thickness flap is reflected to expose the genial tubercle . Excision of tubercle is done by rotary instruments Smoothening can be done by a bone file Irrigation should be done before suturing . Reduction of mylohyoid ridges Done with IFAN block. . Mucoperiosteal flap reflected on the lingual side to expose the medial surface of the mandible at the mylohyoid ridge region. Crestal incision taken in the posterior ridge region. . Tissue from the floor of the mouth and lingual mucoperiostium are protected by inserting the flat blade of the tongue depressor The reduction of the mylohyoid ridge is carried with osteotome or round bur .after dissecting mylohyoid fibres away. . . After complete smoothening sutures are given. Bone is smoothened with bone file. Soft tissue flap is returned back and the complete lingual vestibule checked with digital pressure for any sharp areas. . Ulceration or traumatisation or hyperkeratinisation of the overlying mucosa. Large torus extending beyond the postdam area.filling the palatal vault.Excision of tori Indications Large torus . . Psychological consideration. Deep bony undercut. Interference with function. Food lodgement . . . Y’ shaped releasing incision at one or both the ends of the incision.Technique Under LA – ( bilateral grater palatine and incisive nerve block) A-P linear incision in the midline of the palate. . Retraction sutures placed on both the flaps to minimize the exposure. Division of the torus into the multiple segments should be done with the bur. Two mucoperiosteal flaps raised with periosteal elevator from the midline sideways. . Small pieces removed with chisel and mallet. Continous over and under type suturing using fine absorbable suture material. Prefabricated acrylic stent or splint or iodoform pack can be given to prevent heamatoma. . Mucoperiostial flap is raised .Mandibular tori removal Technique IFAN block is given. Incision over alveolar ridge in lower premolar region. Cleavage taken with a osteotome. Smoothen with round bur or bone file. . Make a purchase point or groove with bur on medial aspect of the torus. Irrigate band suture. Periostium is reflected and tissue present b/w the crestal incision removed with chisel mallet or bur.Maxillary tuberosity reduction and exostosis removal Technique Under infilteration or PSA nerve & GPN block Crestal elliptical incisions from tuberosity to premolar area. Flap is sutured and stent is placed. . . enlarged retromolar pad.eg . . To reduce this elliptical incision taken on either sides of the tissue . enlarged tuberosity.Soft tissue surgeries Removal of redundant crestal soft tissue . Denture granuloma or hyperplasia. Excision of epulis fissuratum. Sharp excision Electro-cauterisation Cryosurgery . Laser excision Palatal papillary hyperplasia. Supra-periosteal excision. . . Ulceration at the frenal attachment a due to overuse of the denture .Frenectomy Indications High attachment of frenum. . Surgical defect created by excision of fibrous bands. Base of the frenum at the alveolar crest is grasped with the hemostat and incision is taken below and above the hemostat.TECHNIQUE Crosss-diamond excision. . Z plasty procedure can be done. Dissection of genioglossus muscle and suture it. .Lingual frenectomy Indication: Tongue tie • • • Technique Bilateral lingual nerve block Submucosal dissection done on either side . . RIDGE EXTENSION PROCEDURE . labial vestibular procedure transpositional flap vestibuloplasty or lip switch procedure Indications Used when patient has a bone ht of 15mm or more in the ant region .Vestibuloplasty or sulcoplasty It is a deepening procedure of vestibule. .Techniques Kazanjian technique (1924) oldest technique use mucosal flap from the inner aspect of lower lip. Carried out in premolar to premolar region. Procedure submucosal dissection is done and directed inferiorly to remove muscle and connective tissue attachments Raised mucosal flap is adapted to the new vestibule and Suture is done . Stent is placed. .Godwin’ s modification (1947) Mucosal incision in inner aspect of lip is longer than the proposed vestibular depth Labial periosteal margin is sutured to the incised lip mucosa. Clarks technique . Supraperiosteal flap on the inner aspect of lip leaves a raw surface on the bone covering the inner lips surface Incision started labial to the crest Supraperiosteal dissection is done along the labial surface till the vestibular depth . Edge of the mobilized flap is pushed into the new vestibular area and held in position by sutures Alveolar bone is covered by periosteal layer . Obwegesser’s modification Similar to clarks method except the area of alveolar bone with its periosteal attachment covered with split thickness graft. . Advantages Covers the bone and ensures fast healing Less bone loss and scarring . .Lingual vestibuloplasty Indication In case where mylohyoid and genioglossus close to the alveolar ridge. Trauner’s technique Incision is done from 2nd molar to 2nd premolar region Supraperiosteal dissection is done Instrument passed below mylohyoid muscle and separate it from bony attachment Fixation of mylohyoid muscle to new desired vestibular depth by sutures. . Caldwell’s technique Here mylohyoid muscle superficial fibres of genioglossus muscle pushed inferiorly. Rubber tubing placed in the lingual vestibule and flap is held in position by sutures Obwegesser’s technique Lingual vestibuloplasty + buccal vestibuloplasty Edges of buccal and lingual flaps are raised and sutured below the inferior border of the mandible. Skin graft is placed over the entire alveolar ridge. Acrylic stent or denture placed and fixed to mandible with circum mandibular wiring. Submucosal vestibuloplasty technique Indication Shallow vestibular depth with good underlying bone height and contour. Technique Vertical midline incision is made in the labial vestibule. Supraperiosteal tunnel from one premolar to other . Intervening submucosal tissue excised or repositioned superiorly. mattress and pyriform aperture region helps in the denture extension into the pockets Intraoral incision is taken just above the attached gingiva from one maxillary buttress to the other buttress Supraperiosteal dissection is performed to create two pockets on either side of pyriform aperture . pocket inlay vestibuloplasty (obwegesser) Procedure involves surgically creating pockets in the max.Max. Dissection is extended superiorly to the level of attachment of the levator anguli oris Also continued in the midline upto the base of the pyriform aperture Impression is taken with the impression compound . . Labial flanges of the dentures then covered with split thickness skin graft Bilateral circumzygomatic wires and pyriform margin wires used to stabilize the denture. Complain of pain after wearing denture because of superior position of the mental neurovascular bundle .Mental nerve transposition Patients with severe mandibular atrophic ridges . .Repositioning of the mental nerve should be done. A crestal incision is taken with buccal releasing incision in the region of premolars Mucoperiosteal flap is reflected inferiorly to locate the nerve . . Nerve is positioned inferiorly and secured in place with the gelfoam and flaps is sutured. Dissection below the foramen till the inferior border of the mandible should be done and the nerve is freed lightly and held with hook upward. Bony groove is cut below the mental foramen.only in the buccal cortex. RIDGE AUGMENTATION PROCEDURES . Place the implants. . Two options are available Augmentation of alveolar bone.vestibuloplasty is not done. When alveolar ridge resorption is so extreme . Procedures Mandibular augmentation 1. Superior border augmentation Bone grafts cartilage graft alloplastic grafts . . 2.inferior border augmentation bone grafts cartilage grafts . interpositional or sand witch bone grafts Bone grafts Cartilage grafts hydroxyapatite blocks .3. visor osteotomy 5.onlay grafting autogenous allogenous alloplastic .4. Maxillary augmentation.B. Onlay grafting Onlay grafting of alloplastic material Interpositional or sandwitch grafts Sinus lift procedure . Augmentation in combination with orthognathic surgery mandibular osteotomy procedure maxillary osteotomy procedure Combination . Materials for augmentation of alveolar ridge autogenous grafts iliac crest rib graft allogenic bone freeze dried cadaver bone. Alloplastic material Hydroxyapatite . .Mandibular augmentation Superior border grafting or augmentation Use 15 cm rib graft Fixed to mandible with trans osseous wiring or circum mandibular wiring. Soft tissue dehiscence or limitation .Disadvantage Donor site morbidity Continued resorption of grafted sites. Procedure Supraclavicular incision followed by subplatysmal incision till the inferior border of the mandible. Freeze dried allogenic cadaver mandible is hollowed out and multiple perforations made into it and it is used as a tray.Inferior border grafting It is indicated when the arch less than 5. .8 mm in height. It is then filled with autogenous cancellous graft particles fixed to the inferior border with 2-0 vicryl sutures by circummandibular fixation . Interpositional bone grafting ( sandwitch bone grafting) Horizontal osteotomy is performed Splitting is done and bone graft is grafted into this gap . In mandible . . autogenic or allogenic bone or hydroxyapatite grafts can be used. Delivery of appliance is delayed for 3-5 months. .Onlay grafting Used in case of inadequate width but adequate height for the maxilla or mandible Oldest technique Onlay augmentation with hydroxyapatite is advocated by obwegessor via submucosal vestibuloplasty technique. . Split thickness ribgraft or iliac crest can be used. After creating a tunnel via a midline a putty is formed of hydroxyapatite crystals mixed with saline or blood and is injected via syringe into the submucosal tunnel. Solid or porous blocks of hydroxyl apatite is used. . mucoperiostial flap is reflected to expose the defect. Grafting material is placed or mounted over the external cortex. Small perforations made in this external cortex by using small round bur.Technique High vestibular incision is taken . .Visor osteotomy To increase the height of mandibular ridge for denture support. Consists of central splitting of the mandible in buccolingual dimension and the superior positioning of the lingual section of mandible wired in position Cancellous bone grafting material placed at the outer cortex over the superior labial junction for improving the contour. Modified visor osteotomy Consists of splitting of the mandible buccolingually by vertical osteotomy only in the posterior region and a horizontal osteotomy in the anterior region. . Posterior lingual segments are then pushed superiorly on both sides. inferior and anterior segments. . Cortico-cancellous bone graft particles with hydroxyapatite granules placed in the gap between the superior . Anterior fragment is also pushed superiorly and fixed with wires. . Totum was the first surgeon who used this method.Sinus lift procedure or sinus grafting Sinus lining at the floor of the mouth is lifted up surgically and the bone graft is placed between the sinus lining and the inner aspect of the alveolar crest or floor of the maxillary sinus in the posterior maxilla. . .Materials used are autogenous bone allogenic bone. tricalcium phosphate’ hydroxyapatite. ceramics calcium deficient carbonate apatite from bovine bone. calcium phosphate. Technique Intraoral incision is taken on maxillary crest or slightly on the palatal aspect with vertical incision from canine to tuberosity area Antrolateral wall of maxilla is exposed by reflecting the mucoperiosteal flap Bony windows made with trap door type osteotomy . . lateral and posterior to the canine fossa. Vertical cuts are joined superiorly by placing the small bur holes placed at small intervals without completing the . Posterior vertical cut is at the maxillary tuberosity. 15 – 20 mm long inferior osteotomy cut placed 3mm above the sinus floor Anterior vertical cut parallel to the lateral nasal wall and perpendicular to the horizontal osteotomy. Gap between lifted sinus membrane and the floor is filled with graft material. Trap door type of bony window is lifted up superiorly to expose the schineiderian membrane. One stage implant . Coticocancellous iliac crest bone block Otherwise 6-9 months before implant placement . total lefort osteotomy used along with interpositioning of grafts.Augmentation in combination with orthognathic surgery 1.anterior maxillary osteotomy. . 2. dehiscence of overlying mucosa.resorption of graft.inadequate soft tissue coverage. 2.rejection of autografts.Limitation of augmentation technique 1.migration of graft material. 4. 3. . 5. [The optimal vestibuloplasty in preprosthetic surgery of the mandible. Issue 2. Fröschl. Pages 85–90] . and 1989–1993 prospective) were performed to determine the optimal methods in preprosthetic surgery.Review of the literature Two studies (1981–1990 retrospective. April 1997. Journal of CranioMaxillofacial Surgery Volume 25. T. Kerscher. A. The first study deals with four different types of grafts (split thickness skin. . mucosal. palatal) in combination with vestibuloplasties and lowering of the floor of the mouth. mesh mucosal. . prefer a split-thickness skin graft. Keratinized grafts (split-thickness skin and palatal) showed advantages. On the basis of a high rate of complications at the site of harvesting of palatal mucosa and the limited amount of palatal mucosa available for grafting. and Kazanjianplasty showed the disadvantages of both methods. A second prospective study to compare the Edlan. in combination with implants. the Kazanjian-plasty showed a significant loss of attached mucosa. showed a small amount of bone resorption. The Edlan-plasty. . If there is a deep palatal vault and the need for a large amount of graft material. the graft can be harvested from the palate. For cases with insufficient width of attached mucosa. a split-thickness skin graft should be harvested. In cases of limited need and flat palatal vault. . with keratinized grafts. recommend a vestibuloplasty secondarily. M. [The carbon dioxide laser in soft tissue preprosthetic surgery. The surgical carbon dioxide laser has the ability to vaporize soft tissues with little bleeding.61:203-8. evaluation.)] . or wound contraction. pain. swelling. A. (J PROSTHET DENT 1989. Pogrel. tuberosity reduction. hyperplasia removal. including frenectomies. . The laser was evaluated on 27 patients requiring soft tissue preprosthetic surgery. and sulcus deepening. as measured on a linear pain scale. . One third of the patients required no analgesics. Swelling was minimal and pain. Surgery was performed on an ambulatory basis with no bleeding or infection. was moderate. The carbon dioxide laser would appear to have advantages for soft tissue preprosthetic surgery that warrant further . Wound contraction did occur but was less than is historically quoted for scalpel wounds. Well-defined prosthodontic needs of ridge improvement may be satisfied in a simple and cost-effective manner with the aid of preprosthetic surgery.Hillerup concluded in his article: Preprothetic surgery is still a relevant treatment option for elderly patients. . [Preprosthetic surgery in the elderly. Interdisciplinary cooperation is a prerequisite for optimal service. J PROSTHET DENT 1994. Soren Hillerup. 72 : 551-8] . The combination of preprosthetic surgery and implants may solve problems that neither of the two can alone do. Patient satisfaction and chewing ability with implant-retained mandibular overdentures: A comparison with new complete dentures with or without preprosthetic surgery . [E.M Boerrigter. Pages 1167–1173] . The objective of the study was to compare denture satisfaction and chewing ability of edentulous patients treated with dental implant-retained overdentures or with full dentures with or without previous preprosthetic surgery. Journal of Oral and Maxillofacial Surgery Volume 53. Issue 10. October 1995. Two factors did not vary following treatment and were excluded from the outcome analysis.Based on the baseline data from the “denture complaints” and “chewing ability” questionnaires. nine interpretable factors could be extracted. . At the 1-year evaluation five of seven factors showed significantly better scores for the two surgical groups than for the control group. The same was found for the overall denture satisfaction rate. . . Overdentures retained by dental implants or complete dentures made after a vestibuloplasty and deepening of the floor of the mouth provide a more satisfactory solution for denture-related problems than complete dentures alone. .soft tissue hypertrophy or localized soft and hard tissue problems or all of them.Conclusion Preprosthetic surgery offers a sigificant contribution in patients with bone atrophy. Pre existing structures like frenal attachments. exostosis.tori are insignificant while teeth are present in the oral cavity. . But these non significant structures cause hindrances for denture stability and resultant reduced masticatory function after tooth loss. .Preprosthetic surgery plays an important role in providing a better anatomic environment and to create proper supporting structures for denture construction. St. 4. Philadelphia. 1987. Winkler S. 2005. 3. Essentials of complete denture prosthodontics. Lea and Febiger. Color atlas of preprosthetic surgery. Lea and Febiger.REFERENCES 1. 2000. Delhi: AITBS Publishers. Sharry J J. The Academy of Prosthodontics Foundation. 8th ed. Textbook of complete dentures. 2nd ed. Complete denture prosthodontics. 2. 142-182. 5th ed. Rahn AO. . 5. Heartwell CM. The Glossary of Prosthodontics Terms. GPT-8. 3rd ed. 1993. Hopkins R. 15-27. 59-110. Philadelphia. London: McGraw – Hill Book Company. Louis: CV Mosby . Ellis E. Comparing ridge resorption with various surgical techniques on immediate dentures. 34-50. Barsoum WM. Davis W. Tucker MR. Zarb GA. Mosby publication. Michael CG. 2004. Bolender CL. Hupp JR. St. Reconstructive prepeostrhetic oral and maxillofacial surgery. Louis. 1985. 7. 35: 142-145.. Fonseca RJ. Louis: CV Mosby. Prosthodontic treatment for edentulous patients: Complete dentures and implant-supported prostheses. Philadephia. Contemporary oral and maxillofacial surgery. 8. 9. WB Saunders. J Prosthet Dent 1976. 1993. . 2nd ed.6. St. 12th ed. Peterson LJ. THANK YOU . FORTHCOMING SEMINAR ON 31ST JANUARY. 2014 DR. FATHIMA SEETHI DR. PARVATHY RAJ .