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88 Cards in this Set
- Front
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Prosthodontics Intro
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Definition - Deals with replacing missing teeth and oral tissue to restore oral form, appearance, function, and health
Branches 1. Fixed 2. Removable - Complete and Partial 3. Implant 4. Maxillofacial |
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Removable Prosthodontics Intro
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Definition - Replacement of teeth and oral structures for substitutes which are readily removable
Ways they are retained - tissue, tooth, implant, and a combination of tooth and implant Objectives 1. Prevent Disease 2. Prevent Future lose of healthy structures 3. Restore comfort, mastication, phonetics, and esthetic Trends: -Changing patient demographic -Implant as a common part of the treatment -Elevated concern for esthetics -Complexities of the geriatric patient |
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Removable Denture Prosthesis
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Complete Def: Replaces the entire arch dentition and associated structures
Partial Def: Replaces some teeth and can be removed at ease |
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Edentulism
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Def - Without NATURAL teeth
Partial Edentulism - Missing one OR more teeth. Bound means the spaces are surrounded by teeth, unbound means some of the spaces are not surrounded by teeth |
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Statistics
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-While it is true that the number of edentulist individuals has been decreasing this century...
1. The population is increasing 2. The average life expectancy, and therefore the percent of people 65+ is also increasing 3. Even though it looks like the % of people with dentures is decreasing, if the elderly pop. is increasing and 60% of the people 65+ have some kind of denture, then prosth is going to be an important field into the future...expected that number of (if not the %) of edentulism will increase in the future |
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Edentulous Considerations
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1. Old patients can have trouble with
-denture support area - receeding alveolar ride -Lose of neuromuscular control -chewing forces -low salivary flow due to polypharmacy -Impaired healing capacity -Poor quality of denture bearing tissues What does edentulism eventually lead to? 1. Residual ridge resorption (RRR) -Without teeth the alveolar bone has no purpose and it resorbs. The maxilla resorbs .1mm/year and in a vertical + palatal direction. The mandible resorbs vertically, along the cross sectional shape of the mandible, and 4X as fast as the maxilla. This may be due to the hard palate resisting resorption at a slow ratw -The mucosa also undergoes atrophic changes 2. Changes in other intraoral structures 3. Trouble with mastication 4. Loss of facial support and muscle 5. Social effects and the stigma of no teeth |
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Loss of Dental Support
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-Edentulist people lose support of the midface
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Treatment Options
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-Given adequate finances, the 2-implant overdenture is the first choice to treat a edentulous MANDIBLE
Complete Edentulous Options 1. No treatment 2. Immediate (not form fitted) denture 3. Custom complete denture 4. Overdenture which can be implant OR tooth supported Comparison of removable, fixed, and implant -Implant is the only that preserves bone and teeth. Fixed and implant are the most stable and give good retention -Fixed and implant return the best chewing capacity and esthetics -The removable is the cheapest economical options -The removable requires the most maintenance and is the most disease suscpetible while the implants have the lowest disease susceptibility |
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Overview of Getting a Patient Complete Dentures
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Visit 1 - Diagnostic visit including patient history, examination, and treatment plan. Also a preliminary impression, cast, and custom tray
Visit 2 - Final impression. Fit and border mold the custom tray followed by the impression. Then do the final cast, record base, and wax rim Visit 3 - Maxillomandibular relationship - do a posterior palatal seal, adjust occlusal rims, facebow transfer, tooth selection, and mount model on articular while setting teeth Visit 4 - Try-in - Try in and refine. Also do final festoon and wax-up, facebow preservation, lab remount, and finish and polish Visit 5 - Insertion Visit 6 - Post-insertion adjustments |
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Complete Denture Visit Details 1
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Visit 1 - History, Exam, Treatment Plan, and Education. Take diagnostic impression and refer for pre-prosthetic care if needed
Lab 1 - Pour up the preliminary cast using the impression and make a custom tray. |
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Complete Denture Visit 2
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Visit - Border mold the custom tray with green stick to get the tissue periphery. Take a final impression with the border molded tray.
Lab - Surround final impression with bead/box wax and then get final cast -Take final cast and make a record base to serve as a TEMPORARY denture base. Build occlusal rims where the teeth would be |
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Complete Denture Visit 3
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Visit - Find posterior extent of maxillary denture and determine compressibility of tissue anterior to this. Score a posterior palatal seal
-Evaluate record base on patient for extent, adaptation, and accuracy of detail -Adjust occlusal rims for proper occlusal plane, facial support, VDO, centric relation, and landmarks of and dimensions of future teeth -Take facebow to orient maxillary cast to articulator like maxilla is oriented to the TMJ -Get centric relation by having patient bite into bite registration material with occlusal rims in centric relation -Select teeth with patient there, choosing different colors and sizes Lab - Using facebow information, transfer maxillary cast to the articulator. Using the centric relation registration, mount mandibular cast on articulator -Set fake teeth into the wax |
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Complete Denture Visit 4
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Visit - Try in wax denture in order to verify adequacy of master cast, aesthetics, phonetics, and MMR
Lab - Refine dentures, for example you would modify the wax gingiva to be anatomically accurate -Put final cast (plus record base and such) into a flask and invest it. After boiling the wax is removed leaving behind teeth and a space. You fill the space with acrylic and polymerize it. Finally, the dentures are removed and lab mounted to adjust for processing errors -Clean, trim, polish the dentures |
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Complete Denture Visit 5
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Visit - Evaluate denture on patient and look out for interference, pressure area (future sore spot), and over extention of peripheral borders
-After the adjustment do a clinical remount -Review realistic expectations with patient and how to take care of them from home. Give the patient the dentures. |
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Complete Denture Visit 6
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-Get patient reaction to dentures and make adjusts like where sore spots have popped up and any overextensions
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RPD Visit 1
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Diagnostic visit - history, exam, treatment plan, primary impression
Lab - Pour up primary impression and cast, make custom tray. Also, design RPD |
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RPD Visit 2
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Visit - Prepare abutments, fit custom tray and border mold. Take the final impression and select the tooth shade/size
Lab - Final cast and make record base and wax rim. Do final survery and fabricate the RPD framework |
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RPD VIsit 3
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Visit - Try in the framework and make adjustments. After this you take a altered cast impression
Lab - Pour up the altered cast |
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RPD Visit 4
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Visit - Use the facebow and centric relation to get the MMR. Take jae records
Lab - Mount models on articulator and set the teeth |
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RPD Visit 5
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Visit - Try in the dentures and refine the set up
Lab - Final festoon and wax-up, lab remount, cast with acrylic, and finish and polish |
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RPD Visit 6 + 7
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Visit - Put in the dentures and do preliminary adjustments. Give education and home care instructions
Visit 7 - Post-insertion adjustments like overextention and sore spots. Schedule routine follow ups |
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Prosthodontics History Intro
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-There is no routine in prosth, each patient requires a different treatment plan
-some of the limitations include anatomy, medical, financial -Need to perform a medical/dental history, intra/extra oral exam (soft/hard tissue pathology/contours, occlusal skeletal relationships), and a prosth assessment looking for support, retention, and stability |
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Dental History
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Need to find out the following concerning dentures
1. Why are they edentulist 2. How long have they been without teeth 3. Have they ever worn dentures before 4. If they have dentures now, what is their opinion What is their patient attitude-house classification 1. Philosophic-idea 2. Indifferent 3. Skeptical/histerical 4. exacting and critical - different Physical Exam 1. normal anatomical landmarks 2. distorted/abnormal/missing 3. severe bone resoprtion 4. disease processes 5. previous surgical alterations 6. natural physical variation |
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Physical Exam
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What kinds of findings might come along..
1. Lack of supporting bone - alveolar ridge has degressed 2. undercuts 3. tissue displaceability/friability (solid tissue crumbles under little stress) 4. Tissue compressibility 5. muscle pull -know which muscles attach where -Between 8-9/24-25 are the labii superioris and labii inferioris 6. compromised healing |
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House Classification
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-psycho-social attitudes
1. Philosophical - rational, real expectations, overcomes conflicts 2. Exacting - Methodical and accurate, must reach a understanding before starting 3. Indifferent - Apathetic and uncooperative - unfavorable prognosis 4. Histerical - emotionally unable, may require outside help before starting |
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Extra Oral Exam
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-Includes the TMJ, neck, adenopathy (lymph nodes of neck - location, size, mobility, consistency, tenderness) - additionally, use 2 hands to palpitate your patient
-Voice, swallowing, and larynx -lips and cheek - cracked corner of lips, angular cheilitis, could be a sign of fungus like chronic candidiasis |
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Dentures General
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-Tooth loss and alveolar atrophy causes collapse of the mid-face and loss of VDO
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Intra Oral Exam
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-Look at the lips, cheeks, tongue, alveolar ridge, palate, tonsillar regions, and vestibules
-Look for leukoplakia, hairy tongue, fragile tongue -Some mucosal problems could indicate systemic disease Ex: 1. Wickham's striae are white lines in the mouth that indicate lichen planus. While lichen planus is not associated with a particular thing, it is associated with medications or disease. It is a chronic disorder and can be seem by lesions or a rash Pemphigoid Lesions - Fibrous Hyperplasia - Growth of fibrous tissue in the mouth Papillary Hyperplasia - A bubbly growth often accompanying denture wearers with poor hygiene or a bad fit. Occurs under dentures like around the tongue or hard palate Leukoplakia - Precancerous white lesion of the oral cavity that is often seen in smokers Erythroplakia - Red, flat, lesion of the mouth often associated with a carcinoma Squamous Cell Carcinoma - Cancerous lesion of the epithelium. Elevated and bumpy |
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Oral Cancer Detection
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Obstacles to Early Diagnosis
-head and neck sites are often ignored -focus is placed precancerous and late lesions Early Detection 1. High Risk Population - over 40 males who smoke/drink. Also look for a occupational/geographical (actinic - sun) risky person or a person with a previous malignancy -People with HPV 32X more likely to get oropharyngeal cancer. Gardasil is a vaccine that protects against the oral cancer linked strains of HPV 2. High Risk Sites - anterior floor of mouth - tongue - ventral (top) and posterolateral - soft palate (tonsillar/pillar complex, lingual retromolar trigone) 3. High Risk Lesions - Can biopsy, stain with toluidine blue -Red (erythroplasia - 33%) or red/white (erythroplasia with white - 60%) -usually asymptomatic but persistent - look asymmetric with textural granularity |
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Types of Lesions
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1) Benign - keratosis, acanthosis, hyperplasia, inflammation, papilloma, fibroma, cyst
2) Premalignant - dysplasia, carcinoma-in-situ 3) Malignant - carcinoma (squamous cell, adeno, cystic) and thyroid cancer |
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Prosthesis Prognosis
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1) Support - Resistance to vertical forces of occlusion. At the bearing surface that absorb the masticatory load
2) Stability - Resistance to lateral displacement 3) Retention - Resistance to vertical displacement of the denture Factors that impact SSR -oral mucosa quality -More keratinized gingiva is better because it is attached and doesn't move as much -contour of the alveolar ridge - Want a more built up alveolar ridge. The mandible regresses down/forward 4X as fast as the maxilla regresses up/backward -muscle attachments -saliva quality and quantity - Less saliva creates a sandpaper surface between mucosa and denture. Also, less of a seal -neuromuscular control -patient adaptability |
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Support Areas
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Mandible
1) retromolar pad 2) buccal shelf - the buccinator is the limit of this area. The shelf includes the masseter groove area. The shelf is posterior alveolar ridge 3) alveolar ridge - If the ridge regresses enough the sharp mylohyoid ridge will be palpable. Residual ridge resoprtion (RRR) is a major problem for people in need of dentures - do we have osseous irregularities or is it a smooth surface. Can we figure out the resorption rate. Bone is replaced with hypertrophic fibrous tissue. 4) Amount of attached keratinized mucosa |
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How to Prevent Resoprtion
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1. Make well adapted/extended dentures
2. Want retention of residual tooth roots in key locations 3. Osseointegrated implants -Why? The retained roots and implants absorb occlusion locally so there is less compression of the periosteum to prevent resorption |
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Denture Periphery
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-affected by several factors
1. Soft Tissue - The labial, buccal, and lingual frenum can get in the way of dentures. Need to mold dentures around it 2. Tongue Position - The tongue hypertrophies when given space like in a edentulous arch 3. The floor of the mouth (alveolingual sulcus depth) |
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Maxillary Support Areas
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1. Amount of keratinized mucosa
2. Alveolar ridge contour 3. Palatal Shelf area/contour - Contains the posterior palatal seal with lots of glandular tissue. |
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Saliva
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Low Salivary Flow
-primarily affects the mandible because more friction at the contact surface. Mandible denture has more of a tendency to slip and slide -hard to achieve peripheral seal of the maxillary denture -compromised adhesion and cohesion |
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Factors of Stability
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Mandible:
-alveolar ridge height -floor of mouth contour -tongue position -neuromuscular control -flabby tissue surface Maxilla -alveolar ridge height -flabby tissue on ridge -Well formed, well shaped maxilla including consistency of tuberosity are they fibrous or osseous -Is the palata a broad/flat or high vault (not wanted) |
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Factors of Retention
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Mandible:
Primary Factors - tongue position, floor of mouth, neuromuscular control Secondary - Peripheral seal, adhesion/cohesion Maxilla -Shape if palatal vault (posterior peripheral seal) -Presence of well-shaped tuberosity -Height of alveolar ridge -Quality/quantity of saliva (imp. for peripheral seal) -Soft palate drape |
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Soft Tissue/Hard Tissue Problems
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Soft -fibrous connective tissue that is not rigid is not good denture support
-Also leads to undercuts Hard -tori -exotosis -large osseous tuberosity -residual shape of ridge - irregularities and undercuts vs. smooth -Loose teeth and prostheses - are you working with healthy teeth, look at radiographs (impacts, sutures, pathology, implants, fractures, TMJ, location of nerves (mental and inferior alveolar) |
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Prosthesis Prognosis
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1) Support - Resistance to vertical forces of occlusion. At the bearing surface that absorb the masticatory load
2) Stability - Resistance to lateral displacement 3) Retention - Resistance to vertical displacement of the denture Factors that impact SSR -oral mucosa quality -More keratinized gingiva is better because it is attached and doesn't move as much -contour of the alveolar ridge - Want a more built up alveolar ridge. The mandible regresses down/forward 4X as fast as the maxilla regresses up/backward -muscle attachments -saliva quality and quantity - Less saliva creates a sandpaper surface between mucosa and denture. Also, less of a seal -neuromuscular control -patient adaptability |
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Support Areas
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Mandible
1) retromolar pad 2) buccal shelf - the buccinator is the limit of this area. The shelf includes the masseter groove area. The shelf is posterior alveolar ridge 3) alveolar ridge - If the ridge regresses enough the sharp mylohyoid ridge will be palpable. Residual ridge resoprtion (RRR) is a major problem for people in need of dentures - do we have osseous irregularities or is it a smooth surface. Can we figure out the resorption rate. Bone is replaced with hypertrophic fibrous tissue. 4) Amount of attached keratinized mucosa |
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Combination Syndrome
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...
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How to Prevent Resoprtion
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1. Make well adapted/extended dentures
2. Want retention of residual tooth roots in key locations 3. Osseointegrated implants -Why? The retained roots and implants absorb occlusion locally so there is less compression of the periosteum to prevent resorption |
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Denture Periphery
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-affected by several factors
1. Soft Tissue - The labial, buccal, and lingual frenum can get in the way of dentures. Need to mold dentures around it 2. Tongue Position - The tongue hypertrophies when given space like in a edentulous arch 3. The floor of the mouth (alveolingual sulcus depth) |
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Maxillary Support Areas
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1. Amount of keratinized mucosa
2. Alveolar ridge contour 3. Palatal Shelf area/contour - Contains the posterior palatal seal with lots of glandular tissue. |
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Saliva
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Low Salivary Flow
-primarily affects the mandible because more friction at the contact surface. Mandible denture has more of a tendency to slip and slide -hard to achieve peripheral seal of the maxillary denture -compromised adhesion and cohesion |
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Factors of Stability
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Mandible:
-alveolar ridge height -floor of mouth contour -tongue position -neuromuscular control -flabby tissue surface Maxilla -alveolar ridge height -flabby tissue on ridge -Well formed, well shaped maxilla including consistency of tuberosity are they fibrous or osseous -Is the palata a broad/flat or high vault (not wanted) |
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Factors of Retention
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Mandible:
Primary Factors - tongue position, floor of mouth, neuromuscular control Secondary - Peripheral seal, adhesion/cohesion Maxilla -Shape if palatal vault (posterior peripheral seal) -Presence of well-shaped tuberosity -Height of alveolar ridge -Quality/quantity of saliva (imp. for peripheral seal) -Soft palate drape |
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Soft Tissue/Hard Tissue Problems
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Soft -fibrous connective tissue that is not rigid is not good denture support
-Also leads to undercuts Hard -tori -exotosis -large osseous tuberosity -residual shape of ridge - irregularities and undercuts vs. smooth -Loose teeth and prostheses - are you working with healthy teeth, look at radiographs (impacts, sutures, pathology, implants, fractures, TMJ, location of nerves (mental and inferior alveolar) |
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Diagnose Existing Dentures
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-Look at extentions and quality of occlusal surface (is it worn - if yes, then bruxism problem)
-Test denture for stability, retention, and support -Test denture using border molding movements - look for overextension and dislodigin upon facial movement -Look for denture esthetics - position, size, form, shade -Make sure midlines are on (between denture and face) |
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Principles of Impression Intro
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-A impression is a negative likeness or a copy in reverse
-The tray is selected upon the type of tissue being impressed and the material being used |
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Types of Impressions
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Preliminary - Made for initial diagnosis, treatment plan, and fabrication of a custom tray
Final - The impression that represents the completion of surface registration Master - A impression used to design a prosthesis Can also classify impression by type of prosthesis to be made: complete denture, removable partial denture |
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Types of Casts
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Diagnostic Cast - Life-size reproduction of the oral cavity made for study and treatment planning
Preliminary Cast - A cast made from a preliminary impression and used to study or make a custom tray Master/Definitive - Life-size reproduction of the oral cavity used to make a prosthesis or restoration Preliminary/Diagnostic Cast - Covers all of the oral anatomy, made from a stock tray, and extended beyond anticipated prosthesis borders Master/Definitive Cast - Made from a custom tray, covers only the anatomy in the prosthesis, extends to the border of the prosthesis |
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Classification of Impression
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-Classified into 4 categories
1. Purpose - diagnostic, preliminary, master 2. Tissue - teeth, implants, gums, which arch, extra-intra oral 3. Impression Technique Mucostatic - Type of impression that is very fluid so it does not displace the soft tissue. It records the tissue in a undisplaced state. Oral cavity does not change when forces are placed on it. Based on pascal law. Basically, liquid in closed container (denture over mucosa) captures just the oral mucosa Selective Pressure - Decide what happens to tissue as they are displaced. WHich areas are able to best support our restoration so we add more load there. Functional Impression - Generate functional load and capture tissue under function. Neutral Zone - Capture impression of negative space which will be filled by denture. Example is space btw lips and chests Altered Cast - Used for partially edentulist. First, get impression of teeth, and then impression of edentulous space. Alter master cast by capturing another impression of just soft tissue Type of Impression Material -Elastic vs rigid, irreversible vs. reversible |
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Impression Making Objectives
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-Provide a record of existing conditions
-Allow for extra-oral evaluation to allow for diagnosis and treatment planning -Allow for cast made for the final prosthesis -Allow for accurate reproduction, including what was (lip support) but is now missing |
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Techniques in Making a Good Impression
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1) Do not use excessive pressure - Denture will be too tight and unseated when tissue returns to normal position. Will cause increased irritation to the tissue. Cuts off blood circulation increasing the likelihood of bone resoprtion
2) Support, Stability, and Retention! Support - Resistance to occlusal forces felt at the basal seat Stability - Resistance to horizontal movement/forces Retention - Resistance to vertical movement/forces. Also, resistance to removal along path of insertion -impacted by adhesion, cohesion, atm pressure,musculature, undercuts, cap. attraction |
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More Factors in a Good Impression
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Esthetics - Want to restore facial contour and lip support with a good border thickness
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Custom Tray
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-Individualize tray for making a final impression
-Custom trays are made on a diagnostic cast -Custom trays helps with retention once border molded. Custom tray also helps to make impression thickness even and to reduce material waste -Custom trays also minimize tissue distortion since a less viscous material can be used |
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Making a Good Custom Tray
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-wax blockout undercuts
-2-3mm thickness -2-3mm short of vestibule depth -Handle avoids vestibule and lips -Finger rest at 2nd Pre, 1 Molar so fingers don't distort during border mold |
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Custom Tray Spacer
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Why Use?? - Allows us to get more material in the impression for better strength, rebound, and memory. Additionally, when we create a wax spacer it forms to the tooth and then our impression material goes on top. Once the wax relief is remove, we have a even, non-distorted impression
-We don't use since our impression material is a low viscosity |
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Denture Differences
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-Size and shape of jaws are different
-All have different peripheral borders -Variations in muscle and muscle attachments and the quality of tissue where the denture is |
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Factors of Success
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Mucosa - Attached and keratinized the best. To be attached we need a good connective tissue base (heavily collagenous). The unattached mucosa is usually on the vestibule sulci
-As bone resorbs the mucosa becomes more mobile Saliva - Good quantity and quality. Helps with adhesion to maintain retention Good Support - Resistance to vertical forces of occlusion. Want to choose areas of support that do not change over time |
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Stress Bearing Areas
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A) Maxilla
-Hard palate - broad/flat better -buccal/lingual slopes of alveolar ridge -Easier to get retention since it is a broad surface with keratinized attached mucosa without interference of tongue. |
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Factors of Success
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Osteology -
1. Maxilla (2 bones) makes up greater upper face skeleton since they make the side and front. Consist of frontal, zygomatic, alveolar, and palatine processes with a body (has sinus). Maxilla makes primary support for dentures |
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Maxilla
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-Made of the body and 4 processes
-2 maxilla meet at the palatine part at the intermaxillary suture -Maxilla is less dense than the mandible. It has thick cortical bone at the palate and thinner cortical bone other places -Maxillary variations include tori (dense cortical bone with a thin attached mucosa) and cleft -Maxilla primary denture support is the palate which is covered with thin and highly attached mucosa 1) Alveolar - Supports the teeth with bony sockets. 2 parallel planes of cortical bone (buccal/palatal) 2) Frontal - Connects with nasal part of frontal anteriorly and the lacrimal posteiorly 3) Palatine 4) Zygomatic |
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More Maxilla Anatomy
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-The greater foramen is surrounded by spiny projections which can irritate the denture
-Behind the tuberiosities is the hamular notch |
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Maxillary Muscles
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-muscles of facial expression are limits of denture extension
-Labial frenum are mucus membrane made of fibrous tissue that connect muscle to the maxilla -Can be damaged by a over-extended denture flange -labial frenum attaches orbicularis oris to maxilla -Buccal frenum attaches levator anguli oris, buccinator, and orbicularis oris to the maxilla -Buccal frenum are the dividing line between the labial and buccal vestibule -Obicularis oris pulls it forward and the buccinator pulls it posterior. -Impingement of the denture flange can lead to dislodgement while smiling |
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Muscles of the Soft Palate
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-Form a sling to separate the oral cavity from the mid-airway larynx
Palatoglossus, palatopharyngeus, tensor veli palatini, levator veli palatini, musculus uvulae -Gag due to firm pressure on tongue, not soft palate |
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Vestibules
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-Vestibule is the same between the lips/cheek and the maxilla
-Between the labial and buccal frenum is the labial vestibule -The vestibule is covered by thin mucosa and holds the denture flange -The vestibule contributes to stability and retention -Buccal vestibule defined by the buccal frenum and the hamular notch -Filled with highest portion of the denture flange -Size of buccal is affected by the buccinator, coronoid of the mandible, and the alveolar ridge -The coronoid influence the distobuccal flange in the buccal vestibule and can cause bad stability/retention |
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Hamular Notch
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-Behind the maxillary tuberosity and extends to the pterygoid muscles
-It is a narrow cleft with soft tissue on it and critical to retention of the denture -Want to capture it in impression or lose retention and get soreness |
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Pterygomandibular Raphe
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-Attaches to the thin curved pterygoid hamulus which is on the medial pterygoid.
-The raphe runs through the hamular notch |
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Soft/Hard Palate Separation
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1) Fovea Palatini - Small pits near the median palatine suture forms by collections of mucus gland ducts. Always in soft tissue and near the vibrating line. Relative landmark to the posterior border of the denture
2) Vibrating Line - Imaginary line in soft palate posterior to dividing line where first movable tissue when patient says "ah". It extends from hamular notch to hamular notch. The more vaulted the palate, the more broad and thin the vibrating line is. |
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Incisive Papilla
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-Fibrous connective tissue overlying the nasopalatine canal foramen which transmits the nasopalatine nerve and BV
-Denture should NOT put pressure in this area |
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Canine Eminence
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-Great at providing denture support and stability (reduce rocking)
-Helps you figure out where canine dentures are placed |
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More Maxillary Structures
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1) Residual Ridge - Covered with thick keratinized epithelium support by connective CT. Provides secondary denture support.
-Subject to combination syndrome - Denture forces against alveolar ridge can cause resoprtion, usually in the pre-maxillary alveolus 2. Tuberosities - Can be bony or fibrous and have primary denture support. Great for retention since they resorb at a slower rate than the rest of the maxilla. Also good for stability -Come in different sizes/shapes. A vertically large they will interfere with occlusion. If laterally large then can create undercuts or interfere with the coronoid process 3. Zygomatic Arch -Likened to the buccal shelf in the mandible. Mucosa is not good for a stress bearing area, it is poorly keratinized |
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Palate
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-Contains adipose anterolaterally and glandular tissue posterolaterally
-Offers primary denture support. Ruggae offer secondary stress bearing assistance |
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Salivary Glands
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-Large collection of minor salivary glands in the posterior third of the hard palate.
-The tissue is glandular and displaceable -This glandular area is the posterior palatal seal or post dam and used for the denture posterior seal -The posterior palatal seal is posterior to soft/hard palate junction and just anterior of the vibrating line (area btw hamular notch, extent of the maxillary denture) -Class 1 palate is not angled and has a large posterior palatal seal. The class 3 has an angled soft palate so there is a lot of movement and the posterior palatal seal is smaller |
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Ideal Maxillary Ridge
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1) Lots of keratinized attached tissue
2) No undercuts 3) Well-defined tuberosity 4) High frenum 5) Square arch 6) U-shaped palatal cross section 7) Moderate palatal vault |
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Mandible Dentures
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-Mandible has a smaller denture support surface so these are harder to keep in place
-Stability is harder on the mandible denture -Retention is more difficult because the greater periphery + smaller surface area + muscles/tongue/lips makes adhesion/cohesion harder to get -Support is also harder to get since the basal seat is smaller, unlike the maxilla that has a nice broad/flat palate |
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Stress Bearing Areas
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Primary Support - Buccal shelves (cortical bone) and retromolar pad
Secondary Support - Alveolar ridge (it resorbs) and has a underlining of cancellous bone on several patients |
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Mandible Areas
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Mental Foramen - Anterior exit of the IANV bundle. As the mandible resorbs this area gets higher until dentures can cause nerve compression
2. External Oblique Ridge - Dense bone that courses from the mental foramen to the ramus. Site of buccinator attachment and lateral flange of the denture Buccal Shelf - Anterior of the retromolar pad and laterally surrounded by the buccinator. Becomes wider with alveolar ridge resorption. A primary support of denture. -Even though buccal shelf has less keratinized loose mucosa, it has dense cortical bone undernearth, it has a broad/flat surface, and it has a slow rate of resoprtion -Also, the buccal shelf position makes it great for primary support. Why? Because it is // to occlusal plane and perpendicular to occlusal force |
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Mandible Areas 2
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Mylohyoid Ridge (Internal Oblique Ridge) - Sharp, irregular line from mental symphysis to the third molar. It connects the mylohyoid muscle forming the mouth floor. Also, it is the extent of the lingual flange
-Subject to trauma since it is dense cortical bone that is sharp -Cover by thin mucosa -As ridge resorbs it goes superior and can become the most superior portion of the mandible Genial Tubercles - Located at the anterior mandible, lingual sie at the midline. Connect to the genioglossus and geniohyoid |
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Mandible Frenum
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Labial Frenum - Like the maxilla, it is a mucus membrane covering fibrous tissue that connects the obicularis oris with the mandible
Buccal Frenum - Separates the labial and buccal vestibule. Connect mandible to the depressor anguli oris Lingual Frenum - Anterior tongue attachment and overlies the genioglossus muscle which originates from the genial tubercles |
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Mandible Vestibule
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Labial Vestibule - Goes from buccal frenum to buccal frenum and is limited by the mentalis inferiorly (chin to alveolar crest), lips anteriorly, and ridge posteriorly (mentalis raises the lower lip)
Buccal Vestibule - Extends from the buccal frenum to the posterolaterally aspects of the retromolar pad. Shape is determined by the buccinator (modiolus to pterygomandibular raphe). Buccal vestibule contains the buccal shelf |
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Mandible Areas 3
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Masseteric Notch - Posterior to the retromolar pad.
Sublingual Folds - Formed from superior surface of sublingual glands and ducts of the submandibular glands. End at the labial frenum Retromylohyoid Fossa - Distal end of the lingual vestibule, posterior to the mylohyoid ridge |
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Retromolar Pads
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-Posterior alveolar ridge and acts as both the mandible primary support and the posterior seal
-Contains glandular tissue and loose areolar connective tissue -Good for primary support due to broad/flat area and on top of non-resorbing bone |
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Idead Mandibular Ride
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-Well-defined retromolar pads
-Non-sharp (blunt) mylohyoid ridge -Deep retromylohyoid space -Low frenum attachments -No undercuts -Attached keratinized mucosa -Broad buccal shelves -Good alveolar height |
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Mandible Borders
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7 borders/flange
1) Labial - buccal frenum to labial frenum 2) Buccal Border - Buccal frenum to masseteric notch 3) Distobuccal Border - Masseteric notch 4) Distal Border - Retromolar pad 5) Distolingual Border - Retromylohyoid space behind the mylohyoid ride 6) Midlingual 7) Anterior Lingual Mandible Muscles to Know 1)Obicularis Oris - Labial frenum attach 2) Mylohyoid - Attach to mylohyoid line and make floor of mouth 3) Buccinator - Originate around 2nd premolar, a buccal one 4) Masseter - Posterior to masseteric notch 5) Genioglossus and geniohyoid - Anterior mandible |
