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Preprosthetic Surgery. Part 1. Epidemiology of Aging. By 2030, one in five Americans will be elderly Considered on of the fastest growing age groups in the United States. Edentulous US population 10% entire US population 35% of the 65 and older population. Objective.
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Preprosthetic Surgery Part 1
Epidemiology of Aging • By 2030, one in five Americans will be elderly • Considered on of the fastest growing age groups in the United States. • Edentulous US population • 10% entire US population • 35% of the 65 and older population
Objective • To create supporting oral structures for placement of partial or complete dentures
Introduction • Tooth loss • No stimulus • Resorption • Patterns of resorption may vary • >mandible than in maxilla (decreased surface area less favorable distribution of the occlusal forces)
Pattern of alveolar bone loss • General Systemic factors • Nutritional • Bone disease • Endocrine dysfunction • Local factors • Alveloplasty technique • Localized trauma
Resorption patterns • Facial Structure • Volume of bone • Low mandibular plane • Acute gonial angle –Generate higher bite force
Characteristics of best denture support • Absence of any Pathologic conditions • Proper interarch jaw relationship • Appropriate size alveolar arches • No soft or bony protruberences or undercuts • Adequate palatal vault • Proper posterior tuberosity notching • Adequate attached keratinized mucosa for the denture bearing area • Adequate vestibular depth • Protection of vital anatomic structures • Adequate bony support and soft tissue covering for implant placement
Ideal support mandible Broad Alveolar ridge Adequate FOM Deep Vestibular depth Mylohyoid muscle
Ideal vs atrophic(mandible) • Lack of • FOM • Vestibular depth • Resorption
Resorption Pattern of Maxilla • Upward and Inwards
Resorption Pattern -Mandible • Down and Outward
Patient evaluation and treatment planning • History , physical examination, patients expectations • Final outcome of the prosthesis vs. patient expectations • Thorough Intraoral and extra oral evaluation
Evaluation of Supporting Bone • Visual • Palpation • Radiographic examination
Evaluation of Supporting Soft tissue • Quality • Amount of keratinized soft tissue over the denture overlying areas Vs poorly keratinized tissue • Hypermobile keratinized tissue • Vestibule • Ulcerations • Scarring • Inflammed areas • Frenal attachments • Type
Evaluation of Supporting Soft tissue • Tissue should be • Supple • Without irregularities Mylohyoid Muscle • level of attachment in relation to the crest of the alveolar ridge • Genioglossus attachment
Treatment Planning • Think of long term consequences • Do not burn the bridges behind you • Outcomes /responsibility
Recontouring of Alveolar Ridges • Simple Alveloplasty associated with Removal of Multiple teeth • Interseptal alveloplasty (Dean’s Technique) • Maxillary tuberosity reduction (hard Tissue) • Buccal Exostosis and Excessive undercuts • Lateral Palatal Exostosis • Mylohyoid ridge reduction • Genial Tubercle reduction
Simple Alveloplasty associated with Removal of Multiple teeth • Simplest Alveloplasty- Compression of alveolar socket • Simple Alveloplasty- Immediate/Delayed
Alveoloplasty Anesthesia (local infiltration) Incision & Mucoperiosteal flap reflection (scalpel & periosteal elevator) • Take home points • exposure & visualization • blood supply • rest on intact bone • full-thinckness • avoid injury to vital structures
Bone removal (bur/chisel&mallet / rongeur) unibevel side-cutting Bone smoothening • Take home points • side-cutting for rongeur • unibevel chisel • preserve bone AMAP • “pull” for smoothening (bone file)
(Interrupted/continuous/continuous locking) Suturing Post-op care • Mouth rinses • Suture removing • (1w post-op) • Prosthetic restoration • (2w post-op)
Immediate/Delayed Technique Mucoperiosteal flap Crest of Alveolar ridge Envelop flap Visualization Access Simple Alveloplasty
Assess the irregularity Recontour Rongeur/bone file Bone bur/Handpiece Ensure all Irregularities are removed Irrigation with copious saline Suture Interrupted Continuous
Soft tissue redundancy created with reduction of the bony irregularities often shrinks and readapts over the alveolus • Allows preservation of attached gingiva
Dean’s technique Indications Regular ridge Adequate height Undercut to depth of labial vestibule Advantages Reduced prominence without height loss Reduced bone resorption Muscle attachment to the area is undisturbed Interseptal alveloplasty
Small rongeur’s Remove the interseptal bone Technique
Maxillary Tuberosity reduction • Indications: • Horizontal/vertical excess • Create adequate interarch space • Contour overlying soft tissue
Crestal incision Reflect mucoperiosteal flap Side cutting rongeurs Avoid floor of the maxillary sinus Debridment Suture Technique
Excessive Undercuts • Excessive bony protuberances >Maxilla • Technique: (large protuberances) • Crestal incision • Extend 1-1.5 cms beyond area requiring contouring • Flap
Small Undercuts • Common location : • Anterior maxilla or Mandible • Fill with autogenous or allogenic bone
Expose undercut with vertical incision Subperiosteal tunnel (periosteal elevator) Technique
Autogenous/allogenous material Cover with resorbable membrane Impressions-3-4 weeks
Palatal vault irregular Crestal incision (Extend slightly beyond the area of exostoses) Reflection of mucoperiosteal flap Careful about the greater palatine vessels No surgical splint required Lateral Palatal Exostoses
Mylohyoid Ridge reduction • Commonly responsible for dislodging of denture • Sharp ridge-Painful • Extreme resorption of ext. oblique ridge and mylohyoid ridge may form the most prominent areas of mandible • Technique • Immediate placement of denture-facilitates inferior relocation of muscular attachment
Tori Removal • Palatal Tori Removal • Mandibular Tori removal
Maxillary Tori • Bony exostosis in the area of the palate • Origin-Unclear • 20% female population • > females than in males • Various shapes • Few problems with dentate jaws • Interferes with fabrication of prosthesis
Linear midline incision Oblique vertical releasing incisions Mucosa is THIN Flap reflection may be challenging A full palatal flap may sometimes be helpful Technique
Incision Flap reflection Segmenting w/ fissure bur
smoothing Remove bone stripes
Transparent surgical stent w/ iodoform gauze 2y post-op
Technique • Small pedunculated tori removed using an osteotome and mallet • Smoothen area, ensure all undercuts are removed • Re-inspect, tension free closure • Prevent hematoma formation • Pressure dressing • Temporary denture • Prefabricated splint
Fracture or perforation of floor of nose Flap necrosis Ulceration Hematoma formation Complications