BDS11078 Flat and Flabby Ridges PDF

BDS11078 Anatomic considerations and their effects on treatment planning: Flat and Flabby ridges Date : 2023 Ideal Denture Bearing Surfaces • Well rounded crest with vertical walls • Keratinized attached mucosa • Accessible vestibules • Favorable tongue and floor of mouth position Flat Ridges...

BDS11078 Anatomic considerations and their effects on treatment planning: Flat and Flabby ridges Date : 2023 Ideal Denture Bearing Surfaces • Well rounded crest with vertical walls • Keratinized attached mucosa • Accessible vestibules • Favorable tongue and floor of mouth position Flat Ridges • Classification • Occurrence and direction • Factors affecting ridge resorption • Problems and complaints • Management Flat ridge • • • • Impaired denture stability Impaired denture support Difficulty to achieve seal Fracture of the mandibular denture Classifying residual ridge form According to Atwood (JPD, 1971) Occurrence • Mandible > Maxilla. • Anterior part of mandible : Anterior part of the maxilla 4:1 Such difference may be attributed to the broader and more cortical residual ridge found in the maxilla than the mandible. Direction of residual ridge resorption • Maxilla → upward and inward →Maxilla become smaller. • Mandible → downward and outward →Mandible become larger. One constant unchanged structure on the mandibular denture bearing area is the retromolar pad area: → contains glandular tissues, loose areolar connective tissues and muscle fibers, → act as a cushion which absorb energy, so the bone beneath does not resorb secondary to the pressure associated with denture use. Factors influencing ridge resorption • Metabolic factors • Anatomic factors • Functional/Prosthodontic factors Metabolic Factors Include • Age: as age  ridge atrophy  due to increased osteoclastic activity. • Sex: Ridge atrophy increase in females after menopause due to hormonal imbalance. • Nutritional deficiency: Calcium deficiency, decrease vitamin C intake • Systemic disorder: as diabetes. • Treatment of systemic diseases: as radiotherapy and chemotherapy Anatomic factors Type of bone: • Cortical bone resorbs slower than cancellous bone. • Size and shape of ridge are co-factors which also affect rate of bone resorption. Functional / Prosthodontic factors Functional: • Remodeling of bone is influenced by force factors. So, with or without dentures patients could have little or severe bone resorption which is related to either disuse or abuse atrophy. • Bad habits with complete denture as bruxism. Prosthodontic • Use of ill-fitting denture for prolonged time. • Use of improperly designed denture e.g: high vertical dimension. • The use of porcelain teeth or anatomic teeth which will increase force transmitted to the ridge. • Wearing dentures during sleep • Natural teeth opposing denture. Problems of flat ridge • Muscles and frena show proximity to the crest of the ridge → affects seal and strength of denture • Crest at the level of the mental foramen → parasthesia of the lower lips and chin unless relieved. • Genial tubercles or torus mandibularis are often higher than the residual ridge Clinical Picture • Most common in the mandible. • The genial tubercles are often higher than the residual ridge • On the buccal side the mental foramen is exposed as well as the mandibular canal (dehiscence) which could be felt by palpation. • Soft tissue overlying the residual ridge that has been subjected to resorption may be either normal, inflamed, edematous or otherwise abused. Radiographically • Lateral cephalometric radiographs provide the most accurate method for determining the amount of residual ridge and the rate of resorption over a period of time. • Panoramic radiograph. What will the Patient complain about?? • 1. Excessive denture mobility. • 2. Persistent tissue ulceration. • 3. Painful neuralgia. Aim of management of flat ridge • To provide a denture with adequate support and retention so that the denture function comfortably without loss of the remaining supporting structures. Conservative conventional prosthodontic treatment without surgical intervention Prosthetic management with Surgical intervention Implants Conservative conventional prosthodontic treatment without surgical intervention The impression (fitting) surface • Maximum extension without muscle impingement. • Intimate contact to the tissues. • Proper extension of the peripheries to provide proper peripheral seal and aid in stability and retention. • Proper relief of the hard and sensitive areas. → Different impression techniques requirements could be made to fulfill these Impression techniques for flat ridge 1. Mucocompressive impression technique. 2. Butterfly impression technique. 3. Dynamic impression technique. Mucocompressive impression technique Indication : in cases presenting flat ridge with firm mucosa in order to provide maximum coverage of the denture bearing area. Primary impression :is made using impression compound in a stock tray. Final impression : is made using zinc oxide in a special tray with an occlusion block. Describe special tray Butterfly impression technique Indication : in cases of advanced resorbed ridge with projecting sublingual salivary gland. Primary impression : made using alginate in a modified stock tray. Final impression : • made using a special tray with a butterfly extension over the sublingual crescent area and an occlusion block. • Three applications of tissue conditioning material are used for making this impression with closed mouth technique. The polished surface • It should be of proper contour, so that the border structures (tongue, floor of the mouth, lips and cheeks) help in retention and stability of the denture. The occlusal surface • • • • • • • Occlusal plane is lowered in order to decrease lateral forces and ensure lever balance without interfering with tongue space. Adequate interocclusal distance Buccolingual dimension of the teeth is reduced. Number of teeth is decreased. Teeth are put at right angle to the ridge. . Use of acrylic teeth instead of porcelain one. Use of cuspless teeth or modified anatomic teeth. Prosthetic management with Surgical intervention Includes: 1. Vestibuloplasty. 2. Ridge augmentation. 3. Removal of genial tubercles. 4. Reduction of mylohyoid ridge. 5. Distraction osteogeneses. 6. Lowering floor of the mouth. 7. Correction of sharp mental foramen. Vestibuloplasty It is a surgical procedure done to deepen the oral vestibule by changing the level of the soft tissue attachments to increase the size of the denture bearing area and the height of the residual alveolar ridge. Removal of genial tubercles • Genial tubercles are often prominent following advanced resorption of alveolar ridge • Usually, we remove only the superior border of the tubercle and the portion where the genioglossus muscle is attached to is left free. • Complete removal of the genial tubercles should be avoided, as lack of attachment of the genioglossus muscle will lead to impaired tongue functions. Ridge augmentation • It is a technique used to increase the width and height of the residual ridge when vestibuloplasty can not offer enough height. Before After Reduction of Mylohyoid ridge • In extreme alveolar atrophy the mylohyoid ridge should be recontoured to permit better flange placement and border seal without compromising retention Lowering the floor of the mouth • Indications: when the contents of the mouth floor extend above the ridge at relaxed tongue position. Implants • In patients with atrophic edentulous mandible, two or more implants could be placed interforaminally to support an overdenture which will improve stability and retention. • Standard of care for completely edentulous patients The McGill consensus statement on overdentures: Mandibular two-implant overdentures as first choice standard of care for edentulous patients, 2002. Flabby Ridges • Hyperplasia and hypertrophy • Causes of flabby tissues • Location • Management • Construction of complete denture for flabby ridge patient Hyperplasia It is the abnormal multiplication or increase in the number of normal cells in normal arrangement in tissue (irreversible). Hypertrophy It is the bulk of tissue beyond normal caused by an increase in size but not in number of tissue elements (reversible). Location of Flabby Tissue • The lesion may be localized or generalized over the entire ridge crest. • Most common: the anterior segment (maxilla & mandible). Etiology • Badly constructed dentures such as loose ill-fitting dentures as well as dentures with wrong centric occluding relation, occlusal disharmony and traumatic occlusion. • Dentures constructed with anterior porcelain teeth and posterior resin teeth. • Over-eruption of natural teeth against edentulous span. • Not removing the dentures during night to allow the basal seat mucosa to regain its resting form. • Rapid bone resorption that is not compatible with soft tissue remodeling • Excessive relief over thin wiry ridge or incisive papilla may act as a pump that causes proliferation of the tissues Recovery Program • • • Instruct the patient to dissolve one-half teaspoon of table salt in a half glass of warm water and rinse 3 times per day. Remove old dentures from the mouth for at least 8 hours every 24 hours for few days before making new impressions to allow the inflammation to subside. Massage of the soft tissues two or three times a day to stimulate the blood supply and aid recovery. • Detect and remove any pressure areas or sore spots using pressureindicating paste. • Relining the old dentures with soft tissue conditioning material to aid recovery before constructing new dentures. • Correction of occlusal disharmonies by clinical remounting and Restoring (VDO) the occlusal vertical dimension occlusion. • Elimination of any contact between natural anterior teeth and opposing artificial teeth.. Tissue conditioning material application Management of flabby ridges To provide a denture with adequate support and retention so that the denture function comfortably without loss of the remaining supporting structures. Prosthetic Management Surgical removal of flabby tissues Prosthetic Management Impressions • If the fibrous tissue is distorted during impression making, elastic recoil of displaced tissue will displace the denture and eliminate retention. • In addition, intermittent occlusion can traumatize the tissues. • Primary impressions are made in stock trays using low viscosity alginate. • The final impression is made applying the selective impression technique or the sectional impression technique. How is pressure controlled? Spacer Perforations Material viscosity Selective Pressure Impression Technique Sectional impression technique • Special tray is constructed with a window opposing the flabby areas • Pressure is varied on the tissues by using different materials or materials of different viscosities • Perforations could also be made in the special tray opposite flabby areas to decrease pressure. Jaw relation record • The jaw relation is recorded using the check bite technique with the least possible displacement of the supporting structures. • Teeth are placed in relation to the neutral zone and the bucco-lingual width should be reduced. • Flat cuspless teeth to reduce lateral forces • After denture insertion the patient is recalled for periodic check-ups. Summary • Flat and flabby edentulous cases are special clinical situations could affect retention and support of complete dentures. • Some cases require surgical modifications to improve the denture supporting structures before denture fabrication. • Prosthetic measures during impression making and jaw relation recording should be taken into consideration. • Frequent recall visits for follow-up are important. • Clinical and laboratory manual of implant overdentures, Hamid R. Shafie. (Chapter 2) • Prosthodontic treatment of edentulous patients, 13th edition. Zarb, Hobkirk, Eckert and Jacob. (chapter. 5) • Textbook of complete dentures, 6th edition. Arthur Orahn, John R. Ivanhoe and Kevin D. Plummer, 2009. (chapters 3 and 5)