PROSTHODONTIC MANAGEMENT OF MANDIBULAR DEFECTS.pptx

Prosthodontic rehabilitation for mandibular defects

1. PROSTHODONTIC MANAGEMENT OF MANDIBULAR DEFECTS

2. Contents 1) Introduction 2) Classification of mandibular defects. 3) Factors affecting treatment of mandibulectomy patients. 4) Related surgical and prosthetic considerations. 5) Management of mandibulectomy patients. 6) Types of prosthesis used to rehabilitate mandibulectomy patient 7) Summary and Conclusion 8) References

3. INTRODUCTION The mandible is one of the most versatile bones of the human body. Apart from enclosing the floor of the oral cavity, it generates a variety of complex movements useful in speech, swallowing, mastication and respiration . The mandible along with the bilaterally attached muscles of mastication also give form to the lower third of the face . Thus defects of the mandible either due to trauma or any other pathology alters not only its functions but also, appearance of the patient.

4. MANDIBULAR DEFECTS DEVELOPMENTAL ACQUIRED TRAUMA PATHOLOGY Eg. Tumors Eg. Mandibular Prognathism/ Retrognathism Rx – Mainly Surgical Mandibulectomy After which, prosthodontic treatment may be required for restoration of appearance and function i.e. in conjunction with surgery. For fractures of edentulous mandible- Gunnings splint Loss of teeth – implants Loss of significant amount of alveolar bone –restoration of factor form i.e. soft tissue support to restore appearance.

5. CLASSIFICATION OF MANDIBULAR DEFECTS According to Laney (1979) Based on Etiology, Acquired Marginal Segmental a. Lateral to midline 1. Body only 2. Ramus – body with disarticulation b. Anterior body Subtotal Total

6. B) Congenital Incomplete formation Incomplete ossification ( Mandibulo -facial dysostosis) Eg. Hypoplasias , Micrognathia etc C) Developmental As a result of post-natal insults on the growth centers e.g. trauma during births, surgery, drugs.

7. Based on the amount of resection (Laney)   Continuity defect (Marginal resection) Discontinuity defect (Segmental resection) 1. Inferior border and its continuity is preserved Complete segment of mandible from alveolar crest to inferior border removed. 2. No deviation Mandible deviates to resected side. 3. Less facial disfigurement Marked facial disfigurement. 4. Occlusion rarely changed Occlusion altered. 5. Can be Anterior defect Posterior defect Can be Lateral discontinuity defect Midline discontinuity defect.  

8. Brown’s classification Brown JS, Barry C, Ho M, Shaw R. A new classification for mandibular defects after oncological resection. Lancet Oncol. 2016 Jan;17(1):e23-30.

9. Jewer’s and Boyd’s classification Mandible was divided into three segments. Here mucosal component was added by Boyd. H stands for lateral defects of any length up to midline including condyle, C for defects involve central segment containing 4 incisors and 2 canines and L constitutes lateral defects excluding the condyle.

10. ACCORDING TO CANTER & CURTIS (1971) AND REVISED (2016)

11. Class I – Radical alveolectomy with preservation of mandibular continuity Tissues resected: - Portion of alveolar process and body of mandible. - Mucoperiosteum. - Lingual and buccal sulcus mucosa. - Portion of base of tongue and mylohyoid muscle. - Lingual and inferior alveolar nerves. - Sublingual and sub-maxillary salivary glands. - Sometimes anterior part of digastric muscle.

12. - Sometimes resection of part of mylohyoid muscle and resultant scarring can raise floor of the mouth causing reduction in tongue mobility . - Ability to control the tongue may be lost due to loss of some intrinsic muscles . - Resection of lingual and inferior alveolar nerves results in loss of sensation in mucosa of cheek, alveolar process, lower lip, epithelium of lower part of face and loss of taste on anterior 2/3rds of tongue.

13. Revised JPD 2016: A revision in the basic Cantor Curtis classification is suggested here in which Class I is subdivided into ‘a’ and ‘b’ with no change in other classes. Class I - Radical alveolectomy with preservation of mandibular continuity. Subdivision a : resection of superior border of mandible Subdivision b : resection of inferior border of mandible

14. Class II – Lateral resection of mandible distal to canine Tissues resected: - Condyle, ramus and body of mandible distal to cuspid. - Mylohyoid, hypoglossal, anterior belly of digastric, internal pterygoid, masseter, external pterygoid, pharyngoglossal and palatoglossal muscles, most of intrinsic muscles of tongue. - Hypoglossal, lingual, inferior alveolar nerves. - Sublingual and sub-maxillary glands. - Mucoperiosteum and adjacent buccal and lingual sulcus mucosa.

15. - Speech, swallowing, saliva control, manipulation of food is impaired. - Facial disfigurement apparent. - Disarticulation and loss of muscles of mastication which hamper mandibular movements. - Taste, sensory and motor losses more extensive as compared to Class I.

16. Class III – Lateral resection of mandible to the midline Resected tissues – All those described in Class II in addition to the anterior portion of the mandible, the genioglossus muscle, geniohyoid muscle, remaining portion of mylohyoid muscle with lingual and buccal mucosa. Structures remaining: - Cheek mucosa. - Small portion of palatoglossal and internal pterygoid muscles, portion of the tongue.

17. - Restricted tongue mobility due to loss of tip of tongue and genioglossus muscle . -Speech, swallowing, saliva control and manipulation of food severely restricted. - Facial disfigurement is worst due to loss of anterior part of mandible . Disarticulation and reduction in amount of basal bone reduce the prosthetic prognosis. - Scarring of orbicularis oris can interfere with expression of emotion .

18. Class IV – Lateral bone graft surgical reconstruction Lateral bone and split thickness skin or pedicle graft can be performed on patients who have had: 1. Radical alveolectomies . 2. Resection of mandible distal to cuspid with or without disarticulation.

19. Class V – Anterior bone graft surgical reconstruction Tissues resected at time of surgery: - Anterior portion of mandible (bicuspid to bicuspid). - Large bilateral portions of mylohyoid, geniohyoid, genioglossus and anterior digastric muscles. - Bilateral lingual and inferior alveolar nerves. - Bilateral sub maxillary and sublingual salivary glands. - Mucosa of lower lip, anterior floor of mouth and ventral surface of tongue.

20. The mucosa retained in the labial and buccal regions is sutured to the residual stump of the tongue and a Kirschner wire (K-wire) often is positioned to help maintain the mandibular fragments. Bone graft and split thickness (skin) graft or pedicle graft procedures can be used to restore anterior facial contour and bilateral mandibular function. Preservation of hypoglossal nerve is critical for tongue mobility.

21. FACTORS AFFECTING TREATMENT OF MANDIBULECTOMY 1) Location and extent of mandibular defect. 2) Presence of remaining natural teeth/ pre-existing implants. 3) Degree of post-mandibulectomy rotation and deviation. 4) Available mouth opening. 5) Functional limitation of tongue. 6) Compromise of vestibular extensions. 7) Skin grafting. 8) Radiation therapy.

22. 1. LOCATION AND EXTENT OF MANDIBULAR DEFECT 3 Types Radical alveolectomy Vertical discrepancy Defects of the symphyseal region

23. Radical alveolectomy Includes a significant portion of the alveolar process without loss of mandibular continuity . - Least debilitating. - Main problems – Loss of vertical ridge height and vestibular depth - decreased stability for soft tissue supported prosthesis as well as loss of load bearing tissues available for support.

24. VERTICAL DISCREPANCY – Important when prosthesis supported by dental implants is considered. Rule of thumb – The farther anterior the defect the more disfiguring and functionally debilitating it are likely to be. Reason : Loss of key muscle attachments( genioglossus and geniohyoid ) located in anterior mandible that control tongue function and mobility.

25. DEFECTS OF THE SYMPHYSEAL REGION (Most debilitating and difficult to treatment) – Surgical reconstruction necessary or at least segmental stabilization. Because in anterior resection loss of key muscle attachments (genioglossus, geniohyoid) are lost which control tongue mobility and function.

26. DEFECTS OF THE SYMPHYSEAL REGION Mandibulectomy defects in molar region are well suited for surgical reconstruction compared to anterior defects because linear grafts are more easier to perform compared to those requiring reconstruction of anterior mandibular curvature. If muscle attachments are intact – good prognosis and nearly normal appearance and function is achievable.

27. 2. PRESENCE OF REMAINING NATURAL TEETH/ PRE-EXISTING IMPLANTS Patients after mandibulectomy frequently present with few or no remaining natural teeth Mainly 2 reasons for this : 1) Patients with greatest risk of squamous cell carcinoma are heavy users of tobacco and alcohol. Their lifestyle is not conducive to a high level of oral hygiene resulting in early tooth loss. 2) Teeth are usually extracted prior to radiation therapy to prevent complication such as osteoradionecrosis unless they have an excellent prognosis.

28. Prognosis of rehabilitative therapy depends upon number of teeth remaining or implants in the mandibular arch following resection. Greater the number of teeth – better the retention, stability and support of the prosthesis . Teeth present on both sides of the midline permit greater prosthesis support because the problem of straight line design can be avoided. All remaining mandibular teeth should be incorporated into design of the prosthesis to maximize stability and dissipate functional forces to greatest number of abutments.

29. 3. DEGREE OF POST MANDIBULECTOMY ROTATION AND DEVIATION Deviation towards defect and rotation of mandibular occlusal plane inferiorly. Deviation – Primarily due to loss of tissue involved in the surgical resection the need to gain primary closure required that the margins of the defect be drawn together, resulting in deviation of the remaining mandible towards the defect.

30. 3. DEGREE OF POST MANDIBULECTOMY ROTATION AND DEVIATION Rotation (inferior direction) vertical: 2 reasons: - Pull of suprahyoid muscles on the residual fragment causing inferior displacement and rotation around the fulcrum of the remaining condyle. - Gravity – loss of anchorage of levator muscles causes mandible to fall vertically.

31. Sequalae: - Facial disfigurement. - Loss of occlusal contact. - Loss of ability to bring lips together. - Drooling of saliva and difficulty to initiate swallowing process. Treatment: - Osseous grafting to restore mandibular continuity. - Early post resection physical therapy to reposition mandibular fragment to a more normal position and to minimize effect of scar formation that will make deviation more severe and less amenable to prosthodontic intervention.

32. Physical therapy: Gently the patient is made to push the mandible toward the normal side away from the defect side. While holding the mandible in this position the patient should open the mouth as wide as possible to stretch the musculature and the resection site. Repeated opening and closing: Trains the mandible and prevents scar formation.Should be carried out immediately. If delayed more than 6-8 weeks postoperatively will not be beneficial. Mandibular resection guidance prosthesis- If minimal pressure is required to maintain the mandible in its correct position. A mandibular guide flange/maxillary guidance ramp may be the solution.

33. Maxillary guide flange – When deviation is less severe. Neither mandibular guidance prosthesis nor palatal guidance ramps are indicated for edentulous patients without the use of dental implants to stabilize the denture on account of the lateral forces generated.

34. 4. AVAILABLE MOUTH OPENING Trismus – due to surgical trauma- Physical therapy should be started immediately postoperatively. Scar tissue formation – further decrease in mouth opening. Simple test – Insert a stock mandibular impression tray in the mouth . If this cannot be accomplished, rehabilitation is unlikely. Treatment – Stretching exercises, moist heat, analgesics indicated within week after surgery.

35. 5. FUNCTIONAL LIMITATION OF TONGUE Frequently surgical wound is closed by suturing the remaining tissues of the floor of the mouth or tongue to the remaining buccal tissues. This severely limits mobility of the tongue. Compromises: - Speech - Swallowing. - Mastication. - Control of food bolus. - Ability to control removable prosthesis. Lingual vestibuloplasty , skin or mucosal grafting used to increase tongue mobility.

36. Evaluation of tongue mobility – Patient is asked to extend tongue into each cheek and lick the lips. If this function can be performed, mobility is adequate for control of prosthesis and food bolus. Patients in whom anterior mandibular resection is done , ability to move the lips when artificial prosthesis is placed may become difficult (due to loss of genioglossus). In such cases, consideration is given to lowering the anterior occlusal plane to give the tongue a more direct path to the lips.

37. Another method is to set the teeth lingually reducing lip support thereby bringing them closer to tongue. - Speech therapy. - Partial/total glossectomy – palatal drop prosthesis or glossectomy prosthesis.

38. Loss of sensory innervation of buccal mucosa ( long buccal nerve ) and lower lip ( mental nerve ) will reduce the patient’s ability to control food and saliva, but are not as debilitating as loss of lingual sensory innervation. Loss of motor innervation of tongue ( hypoglossal ) is less frequent because it lies deep in the floor of the mouth at the base of the tongue. It is more likely to occur due to glossectomy than due to mandibulectomy. Motor innervation of tongue is sacrificed – prognosis for improved function and prosthodontic rehabilitation is poor. Motor innervation of cheek and lower lip is lost ( facial nerve )- patients ability to control saliva and food bolus is lost.

39. 6. COMPROMISE OF VESTIBULAR EXTENSIONS Vestibular depth is critical for stability and peripheral seal . It is also critical when mandibular continuity is restored with bone grafting and implants are considered.

40. In case of a bone grafted mandible , the crest of the residual ridge or bone graft is at the base of the ‘V’ shaped sulcus between the surgically altered buccal soft tissues and the floor of the mouth or residual tongue. In such cases the soft tissues will fall over the implant abutments leading to tissue trauma. This mainly occurs during the treatment phase. The problem usually subsides once the prosthesis is placed. The other problem is oral hygiene maintenance which will compound the soft tissue problem. Surgical location of vestibular depth should be considered.

41. 7. SKIN GRAFTING - Pedicle flaps. - Free fibula flaps. - Vascularized bone. - Soft tissue grafts. Advantages: 1. Effective load bearing tissues. 2. Can withstand pressure and chafing from prosthesis. 3. Protects underlying bone and connective tissue due to rapid turnover of keratin producing cells. Disadvantages: 1. No sensory innervation. 2. Full thickness grafts may incorporate hair follicles therefore split thickness grafts should be used. 3. Skin is not very compatible with titanium surface of dental implants.

42. 8. RADIATION THERAPY Irradiated tissue is fragile, sensitive to manipulation, desiccated, slow to heal, prone to infection and at risk of osteoradionecrosis. Thus treatment should be carefully planned for such patients.

43. Relating surgical considerations and prosthetic prognosis 1. MARGINAL MANDIBULECTOMIES Soft tissues are used to reconstruct marginal mandibulectomies: They may be: - Skin graft. - Local flap. - Pedicle flap. - Neurovascular free flap. Skin grafts: - Thin and avascular. - Bound to the mandible similar to attached gingival tissues. - Not compressible.

44. Local and pedicle flaps: - Bulky. - Tether adjacent structures (primarily tongue). - Displaceable and mobile. - Poor prosthesis bearing surfaces due to bulk and may impinge on space for dentition. - Sutured to adjacent structures such as cheeks, lips, tongue because when these structures move, flap moves and unseats prosthesis.

45. Neurovascular free flaps: - Ideal when associated structures in addition to mandible are resected. - Offer volume and resistance to the bulk of soft tissue. Do not tether residual tongue function. - Ideal for reconstruction in irradiated areas as they anastomose with blood vessels in head and neck. - However when they cover mandible, they are compressible and mobile creating an unstable prosthesis bearing surface. - Whenever soft tissue bulk is not required and recipient bed is not previously irradiated, skin graft reconstruction should be considered for prosthodontic advantages.

46. 2. DISCONTINUITY MANDIBULECTOMY Reconstruction of discontinuity defects has been revolutionized by MVFF(Microvascular Free Flap). Previously soft tissue local flaps with residual tongue were sutured to the border of the defect for primary closure and pedicle flaps (pectoralis flap rotated on a vascular pedicle from the chest and tunneled through the neck to be positioned into the oral cavity) were used. Disadvantages: Local soft tissue – tethering of tongue causing speech and swallowing defects.

47. 2 primary sites for microvascularized bone: 1) Fibula – most common. 2) Iliac crest. For posterior lateral defects only soft tissue MVFF’s can be used : Sites – 1) Forearm, 2) Rectus muscle. Mandibular malposition after bony reconstruction : Patients may present after bony reconstruction with residual deviation and rotation to the surgical side. 2 reasons: 1) Minimal proximal mandible on the surgery side to attach bone graft. 2) Mandibular segments are not stabilized and maintained in their pre-operative relation to each other during the grafting procedure.

48. Methods of recording denture space for the mandibulectomy patient Shifman and Lepley (1982) (Marginal mandibulectomy) discussed a method for fabrication of RP dentures for mandibulectomy patients with no flange or base. They termed this approach as the neutral zone or ‘denture space’ concept . They supported this concept by quoting Fish (1933) who gave this concept, and stressed on the importance of polished surface for the retention and stability of the denture.

49. Cantor and Curtis (JPD 1971) – Swallowing technique (edentulous patients) Primary (irreversible hydrocolloid) impression in modified stock tray. Narrow area supported by bone and free of any muscular activity drawn over the diagnostic cast. Perforated resin tray constructed over this. Two lateral columns that extend toward maxillary ridge constructed over tray. Modeling compound stops placed under column tray for stability and to provide space for impression material. Modeling compound is then added to the lateral columns, extending them superiorly until firm bilateral contact is made with the maxillary residual alveolar ridge.

50. Lower part of oral cavity is filled with alginate impression material. It is made certain that the sublingual space is filled. Column tray is then seated through hydrocolloid material until it is firmly seated on oral mucosa. The mandible is then closed with the maxillary ridge seated against the columns and the tongue in between them. At this point, the patient begins to swallow and between each swallowing cycle he puckers his lips. This continues till the alginate sets. Because marginal mandibulectomy defects are narrow buccolingually, the width of the retentive mesh needed for the framework is lacking. It is possible to place the acrylic resin retentive elements of the framework in a vertical plane rather than horizontal.

51. Disjardens (JPD 1979) Gave the importance of occlusion as important factor, for stability of a prosthesis. Continuity defects: - Multiplicity of occlusal contacts in centric position. - Long centric concept. - Slightly decreased vertical dimension of occlusion. - Group function on working cusps in eccentric position and no function on balancing cusps in eccentric positions.

52. Discontinuity defects: Retaining of remaining mandibular muscles to provide acceptable maxillo-mandibular relationship for repeatable occlusion. Debate exists whether to accept post-surgical mandibular position or to retain the mandible to control its mediolateral position to prevent scar contracture.

53. Adisman (JPD 1962) Fabricated guide plane splints that were used as postoperative inter maxillary splints. After healing the fixed prosthesis was replaced by a mandibular removable partial denture guide plane. The RPD framework was made of cast metal with an acrylic resin or heavy wire loop that extended into the maxillary mucobuccal fold. The extension functioned against the maxillary posterior teeth and helped limit degree of mandibular deviation.

54. Scanell (JPD 1968) Stated that a mandibular resection patient should be seen by the dentist within 7-10 days. He noted that a corrective guide flange prosthesis inserted early could avoid later difficulty in mandibular movement.

55. Swoope (JPD 1969) While treating edentulous mandibular resection patients formed a palatal ramp on the maxillary denture to broaden the occlusal table and make it easier for the patient to obtain stabilizing occlusal contacts.

56. Schaff (JPD 1976) Described a removable partial denture flange prosthesis for the patient with remaining natural teeth. In partially edentulous patients if teeth are strong enough, a mandibular cast removable partial denture flange prosthesis can be used to reduce mandibular deviation.

57. Armany and Meyers (JPD 1977) Advocated use of inter maxillary fixation at the time of surgery for 5-7 weeks. For edentulous patients if mandibular deviation is observed after fixation is removed, a guide flange prosthesis can be used until the patient returns to intercuspal position. Aramany MA, Myers EN. Intermaxillary fixation following mandibular resection. J Prosthet Dent. 1977 Apr;37(4):437-44.

58. Chalian et al (JPD 1979) Indicated that a guide plane prosthesis must be used if the resection includes the body of the mandible, ramus and condyle. This prosthesis consists of a maxillary and mandibular cast removable partial denture framework. A lower inverted U shaped flange slides against a upper horizontal bar on the non-defect side.

59. Robinson and Rubright (JPD 1964) Described the use of mandibular guidance prosthesis. It was a removable partial framework with a metal flange extending 7 to 10mm laterally and superiorly on the buccal aspect of the bicuspids and molars on the nondefect side. This flange engages the maxillary teeth during mandibular closure thereby directing the mandible into appropriate intercuspal position. J.E. Robinson, W.C. Rubright , Use of a guide plane for maintaining the residual fragment in partial or hemi-mandibulectomy, The Journal of Prosthetic Dentistry, Volume 14, Issue 5, 1964, Pages 992-999, ISSN 0022-3913

60. Mandibular guide flange prosthesis Features: - Used as a training device till inter occlusal position can be attained. - Due to strong lateral forces, palatal retainer provided to resist palatal movement of maxillary teeth. - Best positioned in 2nd premolar – 1st molar area. - If used indefinitely constant monitoring required. - Permits only vertical movements of mandible. Patil, P. G., & Patil, S. P. (2011). Guide flange prosthesis for early management of reconstructed hemimandibulectomy : a case report.  The journal of advanced prosthodontics ,  3 (3), 172–176.

61. Maxillary occlusal table In edentulous patients, maxillary occlusal table can provide an alternate surface against which the natural or artificial teeth of the residual mandible can function Koralakunte PR, Shamnur SN, Iynalli RV, Shivmurthy S. Prosthetic management of hemimandibulectomy patient with guiding plane and twin occlusion prosthesis. J Nat Sc Biol Med 2015;6:449-53.

62. Maxillary inclined plane prosthesis (Desjardins) - Used as training device. - An acrylic resin ramp is given on the palatal incline of the non-affected side. This is a functionally generated platform that slopes occlusally away from the maxillary dentition and engages the remaining mandibular teeth as closure begins. - The mandibular fragment is guided to a position of acceptable occlusion through the path of this ramp.

63. Palatal augmentation prosthesis Considered if patients have residual food on the palate or in the sulci of the oral cavity, complain of swallowing difficulties or have impaired speech sounds. In normal palate tongue relationship, palate cups around tongue at rest and in function. The contours of the palatal augmentation should also cup the residual tongue. In dental patients the occlusal vertical dimension will determine the thickness of palatal augmentation. The thickness is increased until the tongue contacts the palate in swallowing.

64. Refinements in speech will evaluate the posterior contact of the palate (k sound). During speech air may leak laterally along the borders of the deviated tongue. Slight addition of wax should be made to the augmentation to stop lateral air escape during S sounds. Anterior contact for the ‘t’ and ‘d’ sound should be added at the anterior elevation of the residual tongue which is the new functional tip. Tissue conditioner can be used for this purpose if the processing of the prosthesis has already been completed.

65. Implant retained prosthesis Nag, P. V. R., & Bhagwatkar , T. (2020). Prosthetic management of a hemimandibulectomy patient using tilted implant protocol with 3-year follow-up.  Journal of Indian Prosthodontic Society ,  20 (3), 326–330.

66. Gunning splint - Used in case of fracture of edentulous mandible. - Consists of 2 separate parts both having small metal hooks for inter maxillary fixation. - The lower part is secured by circumferential wiring. - The maxillary and mandibular parts are then fixed together by inter maxillary fixation.

67. Dharaskar , S., Athavale , S., & Kakade , D. (2014). Use of gunning splint for the treatment of edentulous mandibular fracture: a case report.  Journal of Indian Prosthodontic Society ,  14 (4), 415–418.

68. Summary and Conclusion Management of mandibular defects is one of the most challenging aspects of maxillo-facial prosthetics. These defects affect not only function but also appearance and thus the prosthodontist has to fulfill the dual responsibility of restoring function and appearance. With the advent of advanced surgical and bone grafting techniques, satisfactory prosthodontic prognosis can be achieved for such patients. However there are still some inherent problems in these procedures which have not been completely overcome. The prosthodontist should be able to efficiently plane and execute treatment because the scope of patients with mandibular defects may vary form the completely edentulous patient to the patient with few teeth remaining or patients requiring implant supported prosthesis.

69. REFERENCES Ackerman AJ:- “The prosthodontic management of oral and facial defects” J Prosthet Dent,1955;5:413-432. Aramany MA and Myers EN:- “Intermaxillary fixation following mandibular resection” J Prosthet Dent,1977;37:437-443. Cantor R and Curtis TA:- “ Prosthetic management of edentulous mandibulectomy patients - Part 1” J Prosthet Dent,1971;25:447- 455, Part 2- J Prosthet Dent,1971;25:547-555, Part 3- J Prosthet Dent, 1971;25:671-678. Chalian VA :- “Maxillofacial prosthetics” Desjardins RP:- “ Occlusal considerations in partial mandibulectomy patients” J Prosthet Dent,1979;41:308-311.

70. Kelly EK:- “ Partial denture design applicable to the maxillofacial patient” J Prosthet Dent,1965;15:168-173. Laney WR :- “ Maxillofacial prosthetics, postgraduate dental hand book series”, Vol 4, 1979. Scannell JB:- “Practical considerations in dental treatment of patients with head and neck cancer”. J Prosthet Dent,1965;15:764-778. Schaff NG:- “Oral reconstruction for edentulous patients after partial mandibulectomies” J Prosthet Dent,1976;36:292-297. Shifman A and Lepley JB:- “ Prosthodontic management of postsurgical soft tissue deformities associated with marginal mandibulectomies J Prosthet Dent,1982;48:178-183. Swoope CC:- “ Prosthetic management of resected edentulous mandibles” J Prosthet Dent,1969;21:197-201. Taylor TD :- “Clinical maxillofacial prosthetics”,1st edition 2000.