pre-prosthetic surgery

Preprosthetic Surgery : 

Preprosthetic Surgery Mouth Preparation / Mouth Rehabilitation: Restoration of the form & function of the masticatory apparatus to as nearly as possible Praveen V Badwaik

Preprosthetic Surgery : 

Preprosthetic Surgery Maintenance of healthy condition before fabrication of new dentures Often patients are not aware of tissues been damaged due to old dentures Logical explanation & radiographs, casts are required Methods are Surgical / Nonsurgical

Nonsurgical methods : 

Nonsurgical methods Rest for denture supporting tissues Occlusal & Vertical dimension correction of Old prostheses Good nutrition Conditioning of patients musculature

Rest for denture supporting tissues : 

Rest for denture supporting tissues Removal of dentures Use of liners – recovery of tissues Regular massage of denture bearing mucosa Tissue abuse – improper occlusion With-holding of faulty dentures from patient Correcting occlusion Refitting denture by liners Substituting properly made dentures Recovery – removing dentures for 48-72 hrs before impressions

Occlusal & Vertical dimension correction of Old prostheses : 

Occlusal & Vertical dimension correction of Old prostheses Restore vertical dimension – liner Determines the facial support the patient can tolerate Also permits movement of denture base with the existing occlusion – recovers to original form Ridge relations are improved

Conditioning of patients musculature : 

Conditioning of patients musculature Jaw exercises can permit relaxation of muscles, strengthen their coordination & help patient psychologically At 1st appointment, if patient shows difficulty to instructions for relaxation & coordinated mandibular movements - exercises may be prescribed to them

Objectives of preprosthetic surgical prescriptions : 

Objectives of preprosthetic surgical prescriptions 1) Correcting conditions that preclude optimal prosthetic function Hyperplastic ridge Epulis fissuratum Papillomatosis High frenal attachments Pendulous maxillary tuberosities Bony prominences, undercuts Discrepancies in jaw size relationships Pressure on mental foramen

Objectives of preprosthetic surgical prescriptions : 

2) Enlargement of denture bearing areas Vestibuloplasty Ridge augmentation 3) Provision for placing tooth root Analogues by means of osseointegrated dental implants Objectives of preprosthetic surgical prescriptions

Hyperplastic ridge, Epulis fissuratum, Papillomatosis : 

Hyperplastic ridge, Epulis fissuratum, Papillomatosis Tissues interfere with optimal seating of dentures Tissues harbor microorganisms So, these tissues should be rested, massaged &/or treated with antifungal agent prior to their surgical excision Injection of a sclerosing agent (sodium morrhuate) can produce fibrosis in soft hyperplastic tissue. Electrosurgery, or abrasion of the superficial layer of palatal mucosa

frenular attachments : 

frenular attachments Frena / fibrous bands, if are close to crest - difficult to obtain proper extensions They often become prominent because of residual ridge resoption (RRR) Frenectomy can be done before prosthetic t/t or at the time of denture insertion Simple excision, Z-plasty, or localized vestibuloplasty with secondary epithelialization, Localized supraperiosteal dissection removing the fibrous attachment

Pendulous maxillary tuberosities : 

Pendulous maxillary tuberosities Unilateral / Bilateral – may interfere with interarch space Recontouring and removal of bone and/or soft tissue OPG – maxillary sinus dipping down- Avoid Perforation

Bony prominences : 

Bony prominences Indications for removal of Maxillary tori – Extremely large torus interferes with speech or deglutition Undercut torus – traps food debris – chronic inflammation Torus that extends to PPS One that causes cancerphobia 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.

Genial tubercles : 

Genial tubercles As the mandible undergoes resorption, genioglossus muscle attachment becomes prominent. Sometimes tubercle - functions as a shelf against which a denture can be made, and in other cases may interfere with proper denture fabrication Genial tubercle reduction Genioglossus muscle can be sutured to geniohyoid muscle below it

undercuts : 

undercuts Gives extra Stability Survey diagnostic cast Remove undercut that occurs opposite the lingual side of mandibular 2nd & 3rd molar & is tender on palpation Path of insertion – distal placement of lingual flanges with downward & forward final seating movt.

Discrepancies in jaw size : 

Discrepancies in jaw size Prognathic mandible – osteotomy Causes arch alignment & improves cosmetics Face-lifting procedures

Pressure on mental foramen : 

Pressure on mental foramen Nerve relocation : When the discomfort is persistent RRR in mandibular alveolar bone, the mental neurovascular bundle may occupy a position at the superior aspect of the mandible. Trauma from the denture on the superior portion of the alveolar ridge in this area can produce pain.

Enlargement of denture bearing areas : 

Enlargement of denture bearing areas RRR – labial sulcus obliterated by mentalis – Myoplasty Vestibuloplasty: exposes and makes space available for denture construction (The surgeon detaches the origin of muscles on either facial or lingual side of the edentulous ridge) Healing occurs by secondary epithelialization (bone resorption changes of 4-20% may occur over a 2 year period) or by mucosal graft or skin graft (do not accelerate bony resorption). Complications: 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. Transpositional flap vestibuloplasty (Lip switch)

Ridge augmentation : 

Ridge augmentation Augmentation with synthetic graft materials. Hydroxyapatite Onlay bone grafting: Maxillary autologous onlay bone graft (Rib). Severe maxillary alveolar atrophy, flat palatal vault form, mild to moderate anteroposterior ridge relation discrepancy. Advantages: Augments alveolus, improves vault form, improves anteroposterior relations, remodeling leaves good ridge form.  Disadvantages: Secondary donor site required, unpredictable resorption, secondary soft tissue surgeries necessary, delay in wearing dentures 6-8 months.

Ridge augmentation : 

Mandibular superior border augmentation(Rib or iliac crest): Significant postoperative resorption, from one-half to two-thirds with rib, up to 70% with iliac crest bone. Mandibular inferior border augmentation (Rib): Prevention and management of fractures of the atrophic mandible. Disadvantages? It does not address abnormalities of the denture bearing area. Ridge augmentation

Interpositional bone graft : 

Interpositional bone graft Can be used to augment the atrophic maxilla or mandible To overcome the main disadvantage of mandibular onlay grafting, i.e., rapid resorption. 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.

Osteotomies: : 

Osteotomies: Mandibular "visor" osteotomy: Used usually in combination with a graft, It 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: Supraeruption of teeth and bony segments into an edentulous area, repositioning of abutments, loss of teeth in one arch producing esthetic and functional concerns.

Osteotomies: : 

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      Maxillary osteotomy with advancement: maxilla becomes smaller, mandible becomes more prominent - deficiency in the anteroposterior dimension, the maxilla can be positioned forward and stabilized with transosseous wires and an interpositional grafts. Osteotomies:

Osseointegrated implants : 

Osseointegrated implants Titanium : Screws of specific design – placed in ridge for 4-6 months 2nd surgery – bridge is attached – Overdentures Recently recommended technique

Objectives of preprosthetic surgical prescriptions : 

Objectives of preprosthetic surgical prescriptions 1) Correcting conditions that preclude optimal prosthetic function Hyperplastic ridge Epulis fissuratum Papillomatosis High frenal attachments Pendulous maxillary tuberosities Bony prominences, undercuts Discrepancies in jaw size relationships Pressure on mental foramen

Objectives of preprosthetic surgical prescriptions : 

2) Enlargement of denture bearing areas Vestibuloplasty Ridge augmentation 3) Provision for placing tooth root Analogues by means of osseointegrated dental implants Objectives of preprosthetic surgical prescriptions

Nonsurgical methods : 

Nonsurgical methods Rest for denture supporting tissues Occlusal & Vertical dimension correction of Old prostheses Good nutrition Conditioning of patients musculature