Fonseca, R.J. Osseous Reconstruction of Edentulous Bone Loss. Chapter 6, pp 117-165.
Handout Section 18 - Pre-Prosthetic Surgery
The majority of patients who require prosthodontic treatment will not require surgical intervention prior to commencement of their prosthodontics. For many others, however, a thorough and comprehensive examination, diagnosis and treatment plan will reveal that surgical intervention can improve the prognosis for the case. Consideration of pre-prosthetic surgery is one of numerous methods by which a patient’s clinical presentation may be advantageously altered. As a general "rule of thumb" the best procedure to consider is the least invasive process that will produce clinical success. This may mean that it could be a disservice to the patient to perform surgery when a non-surgical method could be used. It is likewise a disservice to fail to consider and perform surgery when a non-surgical approach will produce a less than satisfactory result.
Types of pre-prosthetic surgery can be classified in a number of different ways. One method is to categorize the surgery as resective, recontouring or augmentation of bony or soft tissue. While many of these procedures are directed towards treatment of the patient who is completely edentulous, there are many indications for pre-prosthetic surgery for the patients who are either partially edentulous or completely dentate.
Treatment planning of pre-prosthetic surgery:
What two challenges must be faced in the prosthodontic rehabilitation of a patient? (Tucker Chapter 13, p 295) The restoration of the best masticatory function possible combined with restoration or improvement of dental and facial esthetics.
Before any surgical or prosthetic treatment, a thorough evaluation outlining problems to be solved and a detailed treatment plan should be developed. What factors should be considered in developing the treatment plan? (Tucker Chapter 13, p. 296). History, physical examination, patient’s chief complaint, expectations, esthetics, functional goals, psychological factors, patient’s surgical risk status, intraoral and extraoral examination.
What are the two objectives, goals or premises of pre-prosthetic surgery for the edentulous patient? (Zarb p1092) The provision of a comfortable tissue foundation to support the denture, and enlargement of the denture bearing area in attempt to provide stability for a denture.
Hypermobile tissue: Excessive tissue is usually the result of the resorption of the underlying bone. If adequate alveolar height will remain after reduction of hypermobile tissue, then excision may be indicated. If the ridge is atrophic and the bone is thin and sharp, excision may result in a greater deficiency.
What should be considered if the alveolar height is inadequate? (Tucker p 319, Chase/Laskin p349) Ridge augmentation or vestibuloplasty.
Papillary hyperplasia: When hyperplastic tissue forms on the hard palate, it usually takes a papillary form. The condition usually begins as a series of tiny papillary projections that gives the palate a velvety appearance. Later it assumes a more nodular form.
What are some potential causes of papillary hyperplasia? (Tucker p 322, Chase/Laskin p 356-7) Mechanical irritation, ill fitting dentures, poor oral hygiene, fungal infections, and the associated inflammation. Chase and Laskin point out that it has been reported in patients with maxillary partial dentures and even in patients with natural teeth and poor oral hygiene.
What are some of the options in the treatment of papillary hyperplasia? (Tucker p322,Chase/Laskin p 356-7) Non surgical treatment such as proper denture adjustment and tissue conditioning, surgical excision, electrosurgery, or abrasion of the superficial layer of palatal mucosa.
Inflammatory fibrous hyperplasia (epulis fissuratum) A continuous fold of hyperplastic tissue may form to fill the space between an ill fitting denture and the alveolus. It may appear as a lobulated localized mass which can be hidden under the denture, or may be bifid, extending both behind and in front of the flange. In long-standing cases, multiple folds may form.
What is the most common cause? (Laskin p 353) denture irritation from an ill fitting denture.
What are other possible causes? Allergic or chemical reactions to the denture material, or carcinoma. All excised tissue should be submitted for histological examination.
Treatment? (Tucker p 320) Correction of denture irritation, placement of a soft liner, electrosurgery(if small) or conventional surgery (if larger)
Frenectomy The labial frenum is usually not a problem in the dentate patient unless associated with a diastema. In the edentulous patient, it may be irritated by the flange of the denture. Movement of the soft tissue adjacent to the frenum may create discomfort and ulceration and may interfere with the peripheral seal and dislodge the denture. An abnormal lingual frenum may bind the tip of the tongue to the posterior surface of the mandibular alveolar ridge, and can affect speech and interfere with denture stability.
Treatment? (Laskin p 358, Tucker p 322) Simple excision, Z-plasty, or localized vestibuloplasty with secondary epithelialization, localized supraperiosteal dissection removing the fibrous attachment.
5. Maxillary tuberosity reduction of soft tissue. The amount of soft tissue available for reduction can often be determined radiographically, or with a sharp probe after local anesthesia. It may be necessary to remove both soft tissue and bone to achieve the desired result. (See below under Bony resective surgeries)
Ridge extension surgeries:
Vestibuloplasty: What is the goal of the vestibuloplasty? (Laskin p331) It attempts to expose and make available for denture construction that bone which is still present.
Briefly describe the procedure (Zarb p 1096) The surgeon detaches the origin of muscles on either facial or lingual side of the edentulous ridge. Healing occurs by secondary epithelialization or by skin or mucosal graft. Vestibuloplasties with skin grafts do not seem to accelerate bony resorption. If healing occurs by secondary epithelialization, bone resorption changes of 4-20% may occur over a 2 year period.
What are some potential complications? (Davis p 92, Stoelinga p 1186)) Loss of sensation if the mental nerve is dissected, sagging of the chin if the mentalis muscle is completely dissected, and hypotonia of the circumoral muscles.
What are the indications for performing a transpositional flap vestibuloplasty (Lip switch) (Tucker p 1120): This procedure is indicated primarily for patients with sufficient mandibular bony height and an adequate vestibular sulcus on the lingual aspect of the mandible. It can be accomplished successfully without a splint or can be combined with immediate reinsertion of a modified relined denture or splint in order to maintain tissue adaptation in the depth of the vestibule.
What are the indications for lowering the floor of the mouth? (Tucker p 1122) As the alveolar bone is resorbed, the attachments of the mylohyoid and genioglossus muscles may interfere with the lingual aspect of the denture.
Bony related surgery
Alveoloplasty: Irregularities of the alveolar bone can be recontoured either at the time of tooth extraction, or after a period of initial healing before fabrication of the final prosthesis.
When might an intraseptal alveoloplasty be indicated? (Tucker p299) Where the ridge is of relatively regular contour and adequate height, but presents an undercut to the depth of the labial vestibule because of the configuration of the alveolar ridge.
Tori removal: A torus is a slowly growing osseous formation of unknown etiology. They can be variable in size, shape, location, and pattern. Usual locations are along the midline of the palate, and along the lingual aspect of the mandible.
What is the prevalence of maxillary tori (Tucker p 310) They are found in 20% of the female population, approximately twice the prevalence in males.
What are the indications for removal of tori (Scott p 67)?
1. Extremely large torus
2. Torus that extends beyond denture periphery
3. Torus with traumatized mucosal coverage
4. Torus with deep undercuts
5. Torus that interferes with speech or deglutition
6. Psychological reasons
Maxillary tuberosity reduction: As previously mentioned under soft tissue surgeries, either horizontal or vertical excess of the maxillary tuberosity may interfere with proper denture fabrication. This may be as a result of excess soft tissue, bone, or both.
What is the most common/typical problem created by enlarged maxillary tuberosities? Enlarged tuberosities encroach upon the available interarch distance for denture fabrication Recontouring and removal of bone and/or soft tissue may be necessary to remove irregularities or allow for adequate interarch distance.
What is the most frequent complication of tuberosity reduction surgery? (Laskin p304) Perforation of the maxillary sinus.
Ridge undercuts, irregularities, exostoses: Excessive bony protuberances and the resulting undercuts can interfere with fabrication of the prosthesis. The denture bearing area should be palpated as well as visually inspected for such potential problem areas.
Briefly describe the procedure for surgical correction. (Tucker p 305) After reflection of a flap, the areas of irregularity are recontoured with a bone file, rongeur, or rotary instrument. After completion of the bony recontouring, the soft tissue is readapted, and visually inspected and palpated to assure that no irregularities or bony undercuts exist.
How long should an area be allowed to heal prior to making impressions for denture fabrication? (Tucker p 305) Approximately 4 weeks.
What alternative should be considered if resective surgery would result in a narrowed crest of alveolar ridge and a less desirable area of support for the denture? (Tucker p305) Consider augmentation of the site with either autogenous, allogenic, or alloplastic material.
Genial tubercle reduction: As the mandible undergoes resorption, the area of attachment of the genioglossus muscle may become increasingly prominent. In some cases the tubercle may actually function as a shelf against which a denture can be made, and in other cases may interfere with proper denture fabrication.
What alternative to genial tubercle reduction should be considered? (Tucker p 309) Ridge augmentation.
Mylohyoid ridge reduction: Often the shelflike projection at the insertion of the mylohyoid muscle must be removed to lessen the amount of undercut present or to relieve irritation of the mucosa over a knifelike bony structure.
When should the denture be delivered following surgery? (Tucker p 309) Immediately, to help facilitated a more inferior relocation of the muscular attachment.
Augmentation with synthetic graft materials. Hydroxyapatite is a nonresorbable ceramic bone substitute, which comes in a granular form in a syringe, and may be placed alone, or combined with autogenous bone to augment the atrophic ridge.
Briefly describe the procedure (Laskin p328) Incisions are made down to the periosteum, and a subperiosteal tunnel developed on the crest of the alveolar ridge. The hydroxyapatite is injected, filling the tunnel. The incisions are then sutured closed. The hydroxyapatite is then molded with finger pressure to form an ideal ridge, and a stent placed.
What are some potential complications of the procedure? (Tucker p 346) Migration of the material, nerve dysesthesias, difficulty achieving height augmentation, inadequate increase in strength of mandible.
Maxillary autologous onlay bone graft (Rib). What are the treatment indications for a maxillary onlay bone graft: (Fonseca 118) Severe maxillary alveolar atrophy, flat palatal vault form, mild to moderate anteroposterior ridge relation discrepancy.
What are the advantages? (Fonseca p 118) Augments alveolus, improves vault form, improves anteroposterior relations, remodeling leaves good ridge form.
What are the disadvantages? (Tucker p. 347) Secondary donor site required, unpredictable resorption, secondary soft tissue surgeries necessary, delay in wearing dentures 6-8 months.
Mandibular superior border augmentation(Rib or iliac crest): (Tucker p 338, Fonseca p 145) What are the additional disadvantages of a mandibular superior border graft? Significant postoperative resorption, from one-half to two-thirds with rib, up to 70% with iliac crest bone.
Mandibular inferior border augmentation (Rib): In this procedure, a rib graft is used for augmentation of the inferior border of the mandible. What are the advantages? (Tucker p. 338) Prevention and management of fractures of the atrophic mandible.
Disadvantages? It does not address abnormalities of the denture bearing area.
3. Interpositional bone graft: This procedure can be used to augment the atrophic maxilla or mandible. It was developed in an attempt to overcome the main disadvantage of mandibular onlay grafting, i.e., rapid resorption. Briefly describe the procedure (Fonseca p 122-125, 145-147, Tucker p 340, 347-8) The maxilla or mandible is "split", elevated, positioned and supported by interposed grafts of autogenous bone or cartilage, freeze dried bone, alloplastic material, or combinations of these grafts.
Mandibular "visor" osteotomy: Used usually in combination with a graft, the osteotomy is a vertical one with an elevation of the lingual segment in a visor or sliding manner, with graft material placed along the lateral aspect to provide the proper contour of the ridge.
Segmental osteotomy in the partially edentulous patient: What are some indications for a segmental osteotomy in a partially edentulous patient? (Tucker p 362-3) Supraeruption of teeth and bony segments into an edentulous area, repositioning of abutments, loss of teeth in one arch producing esthetic and functional concerns.
Maxillary osteotomy with advancement: The natural tendency is for the maxilla to resorb to a smaller, more posterior position while the mandible becomes more prominent. If after thorough evaluation, the patient is determined to have a deficiency in the anteroposterior dimension, the maxilla can be positioned forward a predetermined distance and stabilized with transosseous wires and an interpositional grafts.
Nerve relocation: In the case of severe atrophy of mandibular alveolar bone, the mental neurovascular bundle may occupy a position at the superior aspect of the mandible. What complication does this present for the denture patient? (Tucker 358) Trauma from the denture on the superior portion of the alveolar ridge in this area can produce pain. When the discomfort is persistent, relocation of the mental neurovascular bundle may be required.
Sinus grafting: Placement of endosteal implants in the posterior edentulous maxilla often requires grafting of the floor of the maxillary sinus. Also commonly referred to as a sinus lift procedure, What materials may be used? (Tucker p 351) Alloplastic material, allogenic bone, autogenous bone, or a combination of these materials.
Tissue sclerosing: As an alternative to other procedures for treating the hypermobile alveolar ridge, injection of a sclerosing agent (sodium morrhuate) can produce fibrosis in soft hyperplastic tissue. (See Desjardins, R.P., J PROSTHET DENT 1974; 32:619-638)
18-001a. Peterson, L. J. Principles of Oral and Maxillofacial Surgery. Vol. II. J. B. Lippincott Co., Philadelphia, 1992. Zarb, G. Prosthodontic View of Traditional and Contemporary Preprosthetic Surgery. Chapter 42, pp. 1091-1102.
Purpose: The objective of the chapter was to review the then current relevance of traditional and newer preprosthetic surgical techniques and their impact on prosthetic treatment. It was stated that the role of preprosthetic surgery should be considered as adjunctive.
Discussion: It was stated that the traditional premise of preprosthetic surgery is based on two objectives: the provision of a comfortable tissue foundation to support the denture: and variations on a theme of enlargement of denture bearing areas (DBAs) in an attempt to provide denture stability. It was emphasized that surgical results may be unpredictable, that the adverse process leading to residual ridge reduction is not eliminated and that the results often turn out to be interim in nature. Several age-related changes of the denture supporting tissues were addressed; one of which was the increased dependence of the mandible on the subperiosteal plexus of vasculature due to collagenosis of the inferior alveolar artery. This change has implications for surgical procedures that involve reflection of the periosteum leading to some necrosis and resorption of bone.
Table 42-1 outlines "Conditions requiring preprosthetic intervention". It covers several tooth-related issues such as cysts, sequestra, unerupted teeth and retained roots. It also addresses several bone-related entities such as tori, exostoses, tuberosities, ridge undercuts, painful and pronounced mylohyoid ridges, and the sharp spiny ridge. Soft tissue related topics include hyperplastic, fibrous cord-like and hypermobile ridge conditions. The table outlines the associated features and proposed treatment of the above conditions. The section on bone related topics reflects a conservative approach to performing surgery and suggests the use of permanent soft liners and/or the modification of prosthetic design when possible.
The remainder of the chapter addresses two topics: enlargement of the DBAs using vestibuloplasty and ridge augmentation procedures, and the osseointegrated implant techniques that are replacing the need for much of traditional preprosthetic surgery.
The final section concerned the peri-implant mucosa. The opinion of the author was that the presence of attached tissue is beneficial but not required. Consequently the deepening of labial or buccal vestibules around the implants and the grafting of attached tissues is not always prescribes and can cause the sulci to gape and entrap food particles leading to inflammation and discomfort.
18-001b. Peterson, L. J. Principles of Oral and Maxillofacial Surgery. Vol. II. J. B. Lippincott Co., Philadelphia, 1992. Zarb, G. Ambulatory Preprosthetic Reconstructive Surgery. Chapter 43, pp. 1103-1132.
Factors Affecting Bony and Soft Tissue Changes
General factors- systemic bone disease, nutritional abnormalities,
Local factors-size, shape of alveolus before and after extraction, effects of ill fitting prosthesis
Goals of Preprosthetic surgery: Create broad ridge form, adequate fixed tissue over denture bearing area, adequate vestibular depth for prosthesis extension, proper interarch relations, adequate integrity (to prevent mandible fracture), Protection of the neurovascular bundle, adequate palatal vault form, proper posterior tuberosity notching, to facilitate implant placement where desired
Patient Evaluation: Detailed intraoral exam, review medical history, physical evaluation when appropriate, discussion of patients goals and expectations for long term function and esthetics
Bony Evaluation: Evaluate height, width and general shape of alveolar ridge and underlying basal bone, locate undercuts, neurovascular bundle and concavities
Combining Soft tissue modification with augmentation techniques
Mandible-advantages: single surgical procedure (therefore one sedation), improved access for placement of the graft material, decreased postsurgical displacement of the material, maintenance or increase in the existing sulcular depth, no splint needed, less mental nerve damage.
Maxilla-advantages are the same.
18-001c. Peterson, L. J. Principles of Oral and Maxillofacial Surgery. Vol. II. J. B. Lippincott Co., Philadelphia, 1992.Stoelinga, P.J.W. Preprosthetic Reconstructive Surgery. Ch. 43, pp. 1169-1207.
18-002a. Chase, D.C. and Laskin, D.M. Procedure to Improve the Alveolar Soft Tissue. Basic Preprosthetic Surgery, Vol. II, Oral Surgery, Chapter 9, C.V. Mosby Co., St. Louis, 1985, pp. 293–347.
Purpose: The purpose of this chapter is to discuss the procedures involved in improving the bony alveolar ridge.
Methods & Materials: Methods are general prosthetic and surgical guidelines in order to improve the alveolar architecture.
Discussion: Surgical planning prior to denture construction is essential. Proper assessment, history taking and radiographs are the key for future success. Various techniques will be covered in order to maximize the prosthetic success.
Excess Alveolar Bone.
Alveoloplasty – Shaping of the alveolar process
Alveolectomy – removal of the alveolar process
Single Tooth Extraction
If a single tooth is extracted, a conservative alveoloplasty should be completed in order to improve future denture fabrication. The site should be smooth and rounded for either RPD or FPD treatment in the future.
Extraction of Entire Arch
Conservative removal of the teeth and the bone has shown better long-term success. Both Schlosser and Liskowski showed this in their studies from the 1940’s. They showed that excessive soft tissue and bone removal should be avoided. In this case a smooth alveolar surface devoid of undercuts and prominences should be achieved. The more bone that remains post extraction is important for the long-term resorption patterns of the patient.
All unsalvageable teeth should be extracted prior to radiation therapy. In may of these cases an alveoloectomy procedure is completed in order to prevent any osteoradionecrosis during radiotherapy. Long term planning is paramount in these cases.
The removal of interseptal bone allows for the removal of undercuts but preserves all stress-bearing cotices. This is an ideal procedure for immediate dentures. It is more successful in the anterior region bur can be utilized successfully in the posterior region.
When alveolar bone is over basal bone, there is better retention and stability of the denture. In these cases alveolar repositioning is achieved either via an Osteotomy or LeFort technique.
Removal of both soft tissue and alveolar bone will allow for an increase in posterior vertical clearance.
Mylohyoid Ridge Reduction
Reduction of the mylohyoid ridge is necessary when a knife-edge exists, a prominent undercut exists or chronic irratation is occurring. Great care must be taken in this area because of thin mucosa and the mylohyoid muscle attachment. If the mylohyoid muscle is to be repositioned proper tonicity must be maintained in order to maximize denture retention.
Removal of Exostoses
Removal of all tori is indicated when the tori will interfere with the construction of the prosthesis. Proper surgical technique is important to minimize trauma to the soft tissue and remaining bone.
Excessive Alveolar Resorption
Excessive ridge resorption is a perplexing and its causes are not completely known. In many cases a graft taken either from a rib, illac or femur augments the severely resorbed ridge. Additional surgeries are also necessary to ensure proper vestibule depth for denture construction. Davis did show that a 67% resorption rate occurred at 3 years. Sliding osteotomies also allow for alveolar bone increase. Either a vertical technique or horizontal technique can be utilized in order to gain the necessary height. One disadvantage to using this technique is the increased possibility of future iatrogenic fracture. Synthetic graft materials have been proposed and were used in the past, the long-term studies have shown the material either resorbed or was displaced.
This technique has become popular and makes no attempt to cure the ridge but it attempts to expose more of the ridge. The assumption is made, when using this technique, that bony resorption will have an end and better support of the denture will distribute the forces of mastication more evenly and slow the resorptive process.
Ultimately, implants have been used to compensate for deficient alveolar bone and have now become the best choice. Refer to Chapter 11 or the abstract of the above text for the implant methods and techniques to compensate for deficient bone height.
18-002b. Chase, D.C. and Laskin, D.M. Procedure to Improve the Alveolar Soft Tissue. Basic Preprosthetic Surgery, Vol. II, Oral Surgery, Chapter 10, p.349-361. C.V. Mosby Co., St. Louis, 1985.
The following preprosthetic tissue conditions may exist :
Hypermobile tissue: This problem can occur after extraction from alveolar bone resorption under an ill-fitting denture, from excessive force placed on the alveolar process when natural teeth in one arch occlude against a denture or from excessive submucosa that developed during an extended period of periodontitis and accompanying bone resorption.
Treatment: Excision of the excessive tissue and injection of 2-4ml of a sclerosing solution ( 5% sodium morrhuate) to produce fibrosis in the soft hyperplastic tissue. No attempt to limit swelling is made as swelling is an indication of inflammation and fibrosis is related to the degree of inflammation. The patient should not wear his/her dentures for 4-6 weeks following the injection of a sclerosing agent. If a second injection is required it may be done.
Epulis fissuratum: This is the most common soft tissue abnormality and is caused by denture irritation resulting from ill fitting dentures, faulty denture construction or allergic reaction to the denture material.
Treatment: If a single fold is present simple excision will suffice. If multiple folds exist each fold should be individually excised.
Fibrous hyperplasia of the maxillary tuberosity : This entity is often due to the presence of a relatively dense avascular connective tissue. Use of radiograph will aid in distinguishing this entity from bony enlargement.
Treatment: Surgical incision with removal of excessive fibrous connective tissue and reduce thickness of the flaps.
Fibrous hyperplasia of the mandibular retromolar pad: This is a result of the retromolar pad being in contact with the maxillary tuberosity or molar teeth during jaw closure.
Treatment: same as for fibrous hyperplasia of the maxillary tuberosity.
Hyperplastic palatal mucosa: Fibrous enlargement of the mucosa in the maxilla in the region of the first, second and third molars.
Treatment: Submucosal dissection is one way to treat this but it is a difficult procedure and may lead to sloughing due to interference of the palatal blood supply.
Papillary palatal hyperplasia: Caused by poor oral hygiene and ill fitting dentures worn day and night. Candida albicans has been implicated as an etiologic agent.
Treatment: Electrosurgery with a large wire loop. Reline the denture with a tissue conditioner or soft cold curing acrylic and then reline denture at weekly intervals until healing occurs.
Hypertrophic labial frenum: Ideally a hypertrophic frenum should be corrected at time of extraction.
Treatment: A frenectomy( either a Z-plasty or V-Y plasty) is the treatment of choice.
High buccal frenum attachments: On occasion frenal attachments are found in the premolar region. They should only be treated if they interfere with adequate extension of the denture flange.
Treatment: Transplantation by a u shaped incision or a diamond shaped incision.
Abnormal lingual frenum: Ankyloglossia.
Treatment: Frenectomy; edema is controlled with parenteral steroids. Hematoma formation is prevented by not suturing the wound too prevent.
Scar contractures: The result of multiple frena or contracted scars from previous surgeries. Sometimes wide scar bands can result in deficient denture-bearing mucosa over the ridge or at the depth of the sulcus.
Treatment: Incise the frenum and excise the scar tissue followed by supraperiosteal dissection of the mucosa and connective tissue from the alveolar process in the same manner as used for vestibuloplasty. Palatal mucosa or a partial thickness skin graft can be used to cover the periosteum. Allow 6 weeks before final denture fabrication.
18-003a. Peterson, L.J. Contemporary Oral and Maxillofacial Surgery. 2nd ed., Mosby Year-book Inc., St. Louis, 1993. Tucker, M.R. Basic Preprosthetic Surgery. Chapter 13, pp. 395-334.
Purpose: the objective of preprosthetic surgery is to create proper supporting structures for subsequent placement of prosthetic appliances.
Discussion: The best denture support has the following characteristics:
No evidence of intraoral or extraoral pathologic conditions.
Proper jaw relationship in the anteroposterior, transverse, and vertical dimensions.
Alveolar processes as large as possible and proper configuration. The ideal shape of the alveolar process is a broad U-shape ridge with the vertical components as parallel as possible.
No bony or soft tissue protuberances or undercuts.
Adequate vestibular depth.
Adequate attached keratinized mucosa in the primary denture-bearing areas.
Adequate form and tissue coverage for possible implant placement.
Irregularities of the alveolar ridges either at the time of tooth extraction or after a period of initial healing require contouring before final prosthesis is fabricated. Digital compression in many cases after ext. can provide adequate contours of the underlying bone. The simplest form of alveoloplasty is the compression of the lateral walls of the ext. socket. An alternative is an intraseptal alveoloplasty or Dean’s technique.
Hard tissue recontouring: Maxillary tuberosity reduction is best performed with a full thickness flap to allow adequate access. A surgical template may be used as a reduction guide and blanching indicates inadequate reduction. If sinus perforation has occurred, antibiotics (PCN) 7-10 days with a decongestant is recommended. Buccal exostosis and excessive undercuts are more common in the maxilla and a vertical releasing incisions are indicated. Lateral and midline palatal exostosis should be removed if large and interfere with speech or become ulcerated from frequent palatal trauma. The origin of maxillary tori are unclear. They are found in 20% of females and twice the prevalence in males. Removal of tori once exposed is performed with fissure bur and handpiece. On the mandibular a trough is created between the ridge and the tori, and the use of a small osteotome is utilized in the final removal. A more common area interfering with the mandibular denture is the mylohyoid ridge area. When the ridge is sharp it may produce pain from the denture. A full thickness flap is indicated and use of a rotary instrument or bone file can be used to remove the sharp prominence of the mylohyoid ridge.
As the mandible begins to resorp, the area of the attachment of the genioglossus muscle becomes prominent and the tubercle may act as a shelf for the denture, but usually requires reduction.
Soft tissue abnormalities include soft tissue maxillary tuberosity reduction, retromolar pad reduction or recontour (rare), unsupported hypermobile tissue, inflammatory fibrous hyperplasia and papillary hyperplasia. Labial frenectomy may be indicated due to discomfort, ulceration and lack of peripheral seal that will dislodge the denture. Z-plasty for a narrow band, localized vestibuloplasty for a wide band and localized vestibuloplasty with secondary epithelialization.
Immediate dentures involves the most conservative tech as possible. A clear acrylic guide will indicate any gross irregularities. Overdenture abutments should be evaluated as to the pocket depth and should not exceed 3mm. If excessive, a gingivectomy may be performed, or an apically positioned flap. A split thickness flap may be used when less than 3mm of attached gingiva would be left if a gingivectomy were performed or when there is less than 3mm of attached gingiva before surgery.
Purpose: Textbook chapter to discuss procedures for advanced preprosthetic surgery.
Discussion: Covered are the following procedures:
Factors affecting bone resorption- General and systemic factors
Goals of advanced preprosthetic surgery- when basic preprosthetic surgery may not be adequate, advanced procedures may be required to satisfy the functional, esthetic, and comfort requirements of the patient.
Patient evaluation: should include- bony evaluation, soft tissue evaluation and treatment planning
Superior border augmentation
Inferior border augmentation
Pedicle or interpositional grafts
Hydroxyapatite augmentation of the mandible
Onlay bone grafting
Interpositional bone grafts
Maxillary hydroxyapatite augmentation
Soft tissue surgery for ridge extension of the mandible
Transpositional flap vestibuloplasty (lip switch)
Vestibule and floor of the mouth extension procedures
Relocation of the mental nerve
Soft tissue surgery for maxillary vestibule extension
Correction of skeletal abnormalities in the totally edentulous patient
Conclusion: When severe bony atrophy exists, treatment must be directed at correction of the bony deficiency and alteration of the associated soft tissue. When adequate bony tissue remains, improvement of the denture-bearing area may be accomplished either by directly treating the bony deficiency or by compensating for it with soft tissue surgery. The patient's health status must be carefully evaluated, along with the ability and willingness to undergo these procedures including possible long periods without dentures during healing phases.
18-004a. Fonseca, R.J. and Davis, W.H. Reconstructive Preprosthetic Oral and Maxillofacial Surgery. W.B. Saunders Co., Philadelphia, 1986. Scott, R.F. and Olson, R.A. Minor Preprosthetic Procedures. Ch 4, pp. 61-68.
I. Alveoloplasty along with tooth removal.
Crestal bone should be spared.
Alloplastic materials into extraction sites are being evaluated, but no long term studies are available. (1986)
Today (2000) no material stops bone loss due to socket healing.
II. Secondary alveolar recontouring.
The ridge does not need to be perfectly smooth.
III. Redundant crestal tissue removal.
An elliptical incision is made to allow access to the mass of mobile tissue. The incision is V shaped with the opening of the V at the mucosal surface.
IV. Maxillary tuberosity reduction.
When the tuberosity impinges on the intermaxillary space. One centimeter is needed between arches. Impingement on the space may be produced by soft tissue and osseous hypertrophy in the mandibular retromolar area.
Pendulous tissue inhibits denture stability.
Excess tissue is removed by a wedge resection. Both lateral and vertical dimensions are removed by this procedure. Bone removal can be done at this time. No problem should occur when the maxillary sinus is entered if the soft tissue is closed and no antral infection is present.
At least 2-3 mm of vertical sulcus height should remain distal to the tuberosity to produce denture stability.
V. Hamular notch deepening (Tuberoplasty)
The notch may be very shallow in patients with decreased vertical height of the tuberosity. Poor retention due to loss of seal and resistance to displacement can result.
An incision 5 mm posterior to the notch extending the depth of the vestibule and medially 2 cm lateral to the midline is made.
A curved ostoetome in the notch is maleted until the pterygoid plates fracture free and are displaced posteriorly.
Healing by secondary epithelialization.
VI. Abnormal labial or buccal frenum correction.
Diamond incision - two hemostats, one superior, one inferior, blade follows the hemostats, suture from the superior.
Z plasty - cut superior to inferior in the middle of the frenum, two triangles are transposed.
Localized vestibuloplasty - semilunar incision at the junction of the free and attached mucosa. Heal by secondary epithelialization.
VII. Abnormal lingual frenum (tongue tie, ankylglossia) correction.
Prevents stability and retention of a denture.
Cut frenum close to the tongue to prevent cutting the submandibular gland orifice.
Cut posteriorly until tongue tip reaches the palate with the mouth open.
VIII. Epulis fissuratum removal.
Benefit from some treatment before surgery - tissue conditioner, leave denture out. Spontaneous resorption may require many weeks then the remaining is removed. Cryosurgery is more conducive to nerve regeneration than excision.
IX. Mandibular (lingual) torus removal.
Edentulous - incision on crest.
Dentate - envelope-type incision including the gingival margin avoid vertical incisions as they may interfere with blood supply to the thin mucosa.
Cut a groove 1-2 mm deep and maleting will free the torus.
X. Palatal torus removal.
Incision over the middle with releasing incisions at the anterior and posterior that from a "Y" at each end.
Curette leaving periosteum, electrocauterization, mucoabrasion with an acrylic burr, cryosurgery.
18-004b. Fonseca, R.J. and Davis, W.H. Reconstructive Preprosthetic Oral and Maxillofacial Surgery. W.B. Saunders Co., Philadelphia, 1986. Davis, W.H. Surgical Management of Soft Tissue Problems. Ch 5, pp 69-116.
The chapter discusses procedures to optimize the soft tissues of edentulous area.
Vestibuloplasty with skin grafting and lowering of the floor of the mouth. The technique describes placing a skin graft over the edentulous ridge and securing it with either sutures or a surgical stent. The stent is preferred as it is easier to adapt the tissue to the contours. In suturing to lower the floor of the mouth the sutures may circumnavigate the mandible and use the bone as a sling to hold down the vestibule.
Lowering the floor of the mouth. The vestibule after reflection may be sutured down and ligated to a button extraorally.
Mandibular anterior vestibuloplasty with free mucosal graft. A thin mucosal graft is elevated and the periosteum is incised at the base of the pedicle beyond the projected depth of the vestibule. The reflected periosteum is again incised just above the depth of the dissection of the perostieum. This provides a purchase layer to which mucosa can be sutured. The mucosa is then sutured to the inferior periosteal margin. The superior periosteal margin, now on the lip surface, is sutured as closely as possible of the mucosa to the lip.
Mylohyoid area vestibuloplasty. Incise on the top of the ridge and reflect the flap to the lingual beneath the periosteum, thus exposing the fibers of the mylohyoid. Detach the muscle from the ridge and reduce the ridge with a bur. Extend the length of the denture with compound to adapt the tissue to the periosteum. After 7 days the stent may be removed.
Maxillary vestibuloplasty with skin grafting. Fabricate a stent to be retained by either a screw, circumnasal floor wiring, alveolar pins, or a perialveolar wire. Balloon the vestibular mucosa with local anesthetic and begin incision at the hamular notch. At the junction of the free and attached mucosa. Disect the soft tissue leaving the periosteum intact and suture the mucosa to the periosteum as far superiorly as possible.Support with the stent.
Submucous vestibuloplasty. Incise at the midline and disect a layer above the periosteum and below the mucosa. Separate the soft tissue lateral to the periosteum and move it superior in the vestibule and secure it to the periosteum.
Secondary epithelialization. The is effective in dealing with the epulis fissuratum. If ridge augmentation is done it is to be done prior to this procedure. An incision is made at the crest of the ridge and the junction of the free and attached mucosa. The incision is begun posteriorly where the vestibuloplasty is indicated and proceeds anteriorly. The mucosal-submucosal flap is elevated, leaving only the periosteum remaining on the bone. The edge of the mucosa is sutured as far superiorly as possible and the denture should not contact the wound until some epithelialization has taken place. If a stent was used it should remain for 1 week.
Palatal mucosal grafts. Palatal mucosa grafts can be used as an alternative to skin grafts. The graft is harvested from the palate and the fat and salivary glands removed and placed with a stent as previously described. He disadvantages are limited tissue and prolonged donor site morbidity.
Skin lined pockets. A system of denture retention was described by Wallenius and Owall in 1966. To improve retention of the mandibular denture, skin lined pouches project beneath the anterior portion of the mandible and accept prongs that project from the denture. Similarly, skin lined tubes are created in the maxilla. These procedures are rarely used.
Maxillary buccal inlay vestibuloplasty. Is the most controversial of maxillary vestibuloplasty procedures. After flap reflection an impression is made in compound with a surgical stent. This is duplicated with alginate by the prosthodontist. A new surgical stent is made with autopolymerizing resin and placed at surgery and left for 1 week. Denture construction can begin 6 to 8 weeks after surgery. The patient is to wear a stent or denture constantly for 12 to 18 months.
18-004c. Fonseca, R.J. and Davis, W.H. Reconstructive Preprosthetic Oral and Maxillofacial Surgery. W.B. Saunders Co., Philadelphia 1986. Fonseca, R.J. Osseous Reconstruction of Edentulous Bone Loss. Chapter 6, pp 117-165.
Purpose: To discuss osseous management of physiologic edentulous bone loss (EBL), using onlay bone grafting and interpositional bone grafting techniques in the maxilla and the mandible.
Discussion: When the EBL is severe enough to make conventional prosthetics impossible, surgical intervention with various methods of osseous bone grafting may be indicated. A thorough preoperative evaluation includes: detailed medical history, a history for possible contributing reasons for EBL, radiographs (panorex, lateral ceph, and occlusal radiograph for the mandible), articulated study casts, and clinical exam of the hard and soft tissues. The patient should also be informed that the majority of treatment plans involve two major surgical procedures with two general anesthetics.
Maxillary: Indications for theonlay bone grafting technique include: severe maxillary alveolar atrophy, flat palatal vault form, and mild to moderate anteroposterior ridge discrepancy that does not include the tuberosities. The autologous onlay rib grafts are more successful than allogenic bone grafts. The surgical procedure generally involves despining of a rib (by a thoracic surgeon), notching it to 270 degrees for contouring to a cast of the maxilla (made of acrylic and gas sterilized). A second rib is also split with the marrow removed with a curette, and the cortical bone layers are particulated stored in normal saline or D5W. Ideally the preparation of the recipient site and donor bone will be done simultaneously. Once the rib strut is tried and fitted intraorally, then stainless steel wires are used to secure the bone graft followed by particulate bone and marrow.
Indications for interpositional bone grafting include an edentulous, bony deficient maxilla with adequate palatal vault, and also Class III relationships usually secondary to EBL of the maxilla and mandible. There is less rapid resorption than an onlay bone graft. The surgical procedure generally involves downfracturing of the maxilla (LeFort I) osteotomy, then either using allogenic or autologous bone graft (or a composite of both), shaped to form a "dumbbell" for stability of the segment, without danger of slipping.
This graft is held into place with transosseous wires. Three maxillary osteotomy cases were also presented.
Mandibular:A common pattern of mandibular EBL involves a generalized loss of alveolar bone, fairly uniform around the arch. The genial tubercles and mylohyoid ridges may remain elevated, with the rest of the ridge flat. There may be a "negative ridge" if the muscle attachments are more elevated than the denture bearing region.
Indications for the total onlay grafts include a mandible with generalized atrophy that measures 5 to 6 mm at the mental foramen region. The rib is despined similar to the maxillary onlay rib grafting technique mentioned above, and shaped to fit an acrylic cast of the mandible. When placed in the mouth, the rib should be placed slightly lingual to reproduce the position of the resorbed alveolar bone, and wired either transosseous or circummandibular. An alternate method is also described by splitting two ribs and placing four sections of the ribs with each inner surface next to an outer surface.
This total onlay graft technique shows rapid vertical resorption, studies show that after two years, one half to two thirds of the augmentation may be involved. This is true for both rib and iliac bone grafts. Clinically, the healed ridge has a broader base and better contour for denture stability. The procedure requires a vestibuloplasty after healing of the bone graft.
An interposed bone graft augmentation, maybe done to overcome the main disadvantage of the subperiosteal onlay bone grafting, ie. rapid resorption.
There are basic three techniques involved with the interposed graft augmentation:
The sliding"visor" osteotomy where a sagittal osteotomy is performed and moved vertically. The main drawback is potential damage to the nerve
The "sandwich technique" where a horizontal osteotomy is performed between the two mental foramina, and thus only the anterior fragment is lifted. This technique is limited by the anatomy of severe atrophic mandibles.
A combination of the "visor and sandwich techniques", this is called a modified "visor" osteotomy. Here the osteotomy posterior to the mental foramina is in a vertical plane, changing to 45 degrees in the anterior region.
There needs to be at least 8 mm of bone height as measured in the mental nerve region.
The main drawbacks of these procedures is the relatively high incidence of sensory disturbances of the chin and lower lip.
Another variation of mandibular osteotomy is called "three piece augmentation", in which the osteotomy is done in three fragments, this greatly reduces the chances of damaging the neurovascular bundle.
The article also mentions another procedure with the same indications as the modified "visor" technique, this is called an anterior osteotomy with posterior onlay graft.
Three mandibular osteotomy cases were also presented.
Donor Site Surgery: Surgical technique was described for harvesting bone from both anterior and medial iliac crest, as well as resection of the rib in the region of ribs 5-7.