1. 3. History and Exam John Beumer III, DDS, MS and Robert Duell, DDS Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry UCLA School of Dentistry This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission.

12. Oral Lesions and Disease Factors Diabetes (long term insulin dependent) Epithelium is thinner and less keratinized. Result: Compromised, support and impaired tolerance of complete dentures. Impact on Complete Dentures

13. Oral Lichen Planus – Erosive lesions and subsequent scarring in the buccal shelf area limit denture extension in this region and make it difficult for some patients to tolerate their dentures . Result – Compromised support and tolerance of the mandibular denture . Disease Factors Wickham’s striae

14. Pemphigoid – Chronic ulceration with subsequent scarring of the oral mucosa. Result – Limited denture extensions compromising support, stability, retention and tolerance of complete dentures. Disease Factors

15. Low saliva flow rates leads to increased numbers of fungal organisms leading to a high incidence of chronic Candidiasis . Mild Candidiasis Severe Candidiasis Angular cheilitis secondary to chronic Candidiasis. Chronic Candidiasis

16. Clinical Manifestations Burning and irritation of the denture bearing mucosa, making tolerance of complete dentures difficult. In addition the fungus is keratolytic, further compromising support and tolerance.

17. Treatment Topical antifungal therapy followed by relining of the dentures (Nystatin is the drug of choice. It can be dispensed as a cream, a powder or an oral lozenge).

18. Begins as a traumatic ulcer secondary to an overextended denture flange. Common Oral Lesions Inflammatory fibrous hyperplasia

19. Continued denture wear and irritation leads to inflammatory fibrous hyperplasia (epulis fissuratum). Therapy – Surgical excision Common Oral Lesions Inflammatory fibrous hyperplasia

20. Common oral lesions Secondary to ill fitting maxillary dentures. Usually complicated by chronic candidiasis. Inflammatory papillary hyperplasia Therapy: Antifungal medications applied topically. In extreme cases,surgical excision.

22. Other Oral Lesions of Importance Premalignant Lesions Both these lesions can transform into Squamous Cell Carcinomas Leukoplakia Erythroplakia

25. Oral Exam Clinical Factors Influencing Stability, Retention, and Support of Complete Dentures

27. What factors associated with the denture bearing tissues influence the quality of retention, stability, and support provided the complete denture?

29. Keratinized Attached mucosa is the Remnant of Attached Gingiva. Attached Gingiva Keratinized attached mucosa Mucogingival junction The more available on the denture bearing surfaces, the better the support.

31. Loss of Keratinized Attached Mucosa Result: (a) Reduced support. (b) Reduced tolerance to occlusal load. Zone of keratinized mucosa

32. What is the impact of bone resorption on retention, stability, and support? All three are negatively impacted . Ridge Resorption

34. Resorption patterns in the edentulous patients* Ridge Resorption *From Zarb et al , 1983

35. Ridge Resorption Note the sharp mylohyoid ridge (arrow)

37. The pad contains glandular tissue, loose areolar connective tissue,the lower margin of the pterygomandibular raphe, fibers of the buccinator, and superior constrictor and fibers of the temporal tendon. The bone beneath does not resorb secondary to the pressure associated with denture use. It is one of the primary support areas . Retromolar Pad One constant, relatively unchanging structure on the mandibular denture bearing surface is the retromolar pad (dotted line).

38. Buccal Shelf Boundaries of the buccal shelf: The external oblique line and the crest of the alveolar ridge (area within the dotted lines ). The buccal shelf is a prime support area because it is parallel to the occlusal plane and the bone is very dense. It is relatively resistant to resorption. Masseter groove area Buccinator limits the extension in this area

39. Buccal Shelf Buccal shelf area (area within the dotted lines). The greater the access to the buccal shelf the more support there is available for the denture. Access is determined by the attachment of the buccinator .

40. B Mandible – initially buccal lingual dimension of the alveolar ridge is narrowed, compromising support (A, B, C). A Patterns of Resorption - Mandible C

41. But thereafter, the height is affected compromising support,stability, and retention (D,E). D Patterns of Resorption - Mandible E

42. Continued calcification of the attachment of the mylohyoid muscle leads to the development of a sharp bony projection on the lingual surface. The mucosa overlying this region is poorly keratinized and prone to perforation secondary to trauma from complete dentures. Mylohyoid ridge Patterns of Resorption - Mandible

43. Following extraction, resorption is from buccal-labial towards the lingual . Labial plate Result: Some compromise of stability and support . Pattern of Resorption - Maxilla

44. Continued resorption leads to loss of vertical height of the alveolus. Result: a. Significant compromise of stability of the denture. b. Pseudo-class III jaw relation. c. Secondary affect – compromised retention because of compromised stability. Peripheral seal of the denture is more easily broken because there is little resistance to lateral displacement of the denture during function . Patterns of Resorption - Maxilla

46. Result: (a) Resorption of premaxilla (b) Hypertrophy (fibrous hyperplasia) of maxillary tuberosity. (c) Occlusal plane problems. Combination Syndrome Occlusal plane Hypertrophic maxillary tuberosities Resorbed premaxilla

47. Mandible – Similar Phenomenon Observed Resorption can be so severe as to require augmentation with bone grafts in order to prevent pathologic fracture of the mandible .

48. Measures to Prevent or Slow Resorption . 1. Well adapted and properly extended dentures with properly designed and executed occlusion. 2. Retention of residual tooth roots in key locations . 3. Use of osseointegrated implants Retained roots and osseointegrated implants are useful because they absorb much of the occlusal load locally, thereby preventing compression of the periosteum and in turn preventing resorption of the adjacent bone.

49. Retained root tips (A) and Osseointegrated implants (B, C) A B C The denture rests on the implants or root tips. Compression of the mucoperiosteum is minimized, preventing resorption of the underlying bone. Preventive Measures

50. Note tissue bar connected to the implants Bar facilitates retention, stability and provides support in the anterior region . Preventive Measures

51. Frenum – Folds of mucus membrane containing fibrous connective tissue (A) (arrows). A Frenum are of little consequence. However, they may limit denture extensions (B) (arrows) or make seal difficult to maintain, and occasionally affect the retention of the maxillary denture. B Other Factors – Frenum Attachments

53. Floor of mouth posture and tongue position (depth of retromylohyoid space) affect stability and retention. Favorable anatomy as seen here (A, B,) permits development of a longer lingual flange. A B Result: Improved stability and retention of the mandibular denture Floor of Mouth Posture and Tongue Position

54. Impressions and dentures made for patients with favorable floor of mouth posture and favorable (anterior) tongue position. Note length of lingual flange. Stability and retention are enhanced. Favorable Floor of Mouth Posture

55. Patients with unfavorable floor of mouth posture and tongue position (A, B). The tip of the tongue has lost its definition and is retruded and the floor of the mouth is elevated. Result: Length of lingual flange of the denture will be limited, compromising stability, retention and the ability of the patient to control the lower denture. A B Unfavorable Floor of Mouth Posture and Retruded Tongue Position

57. Result: a. Improved retention. Note denture snaps onto retention bar. b. Improved stability (from the implants and the tissue bar). c. Improved support (anteriorly). d. Better control of the bolus (tongue no longer must position denture and control the bolus simultaneously). Solutions - Retruded Tongue Position and Unfavorable Floor of Mouth Contour. 1. Dentures retained with osseointegrated implants

58. This surgical procedure has been used to overcome problems caused by a retruded tongue position, unfavorable floor of mouth posture and a narrow residual zone of keratinized attached tissue. Muscle attachments in the floor of the mouth are lowered and the zone of attached keratinized tissue is widened with the skin graft. a.Result : Improved stability and retention of the denture because the lingual flange is lengthened. b.Result : Improved support, because the zone of attached keratinized tissue is dramatically widened. 2. Skin graft vestibuloplasty Solutions - Retruded Tongue Position and Unfavorable Floor of Mouth Contour . Skin grafted areas Residual keratinized attached mucosa

59. Impact of Saliva and Salivary Glands Palatal glands

60. Glandular tissue Posterior palatal seal area The presence of these glands permit compression of the tissues helping to overcome poor adaptation of the denture in this area secondary to shrinkage of the acrylic resin during processing. Peripheral seal of the denture is thereby maintained. Posterior Palatine Salivary Glands

61. When making impressions this area of tissue is compressed, allowing us to compensate for shrinkage of the acrylic resin during polymerization and movement of the denture base during function. Result: Tissue adaptation of the denture is maintained and therefore peripheral seal and retention of the maxillary complete denture is maintained. When these glands atrophy, the tissue become less compressible making it more difficult to obtain and maintain peripheral seal. Posterior Palatine Salivary Glands

62. Shrinkage of acrylic resin is also accounted for by scoring the cast in the postdam area (arrow ). Posterior Palatal Seal Area

72. Prosthodontic Assessment Stability - Maxilla