A. Introduction Rationale According to the statistics at maxillofacial surgery departments, each year, there is a considerable number of patients with defect of the maxillary and mandible. The common reasons underlie the consequence after surgery of benign or malignant diseases of jaw bones. The number of patients with demand of prosthesis mandible which suffers from bone defect can account for 10-15% of total patients with maxillofacial prosthesis. After the patients have been formed the mandible defect, the functions of jaw bone must be recovered by the prosthesis. The types of removable prosthesis include frame work, plastics frame and prosthesis supported by implant. Plastic flame is uncomfortable, the masticatory force is weak. Prosthesis supported by implant has the good masticatory force but it required sufficient of amount and quality of bone tissues and attached gingival. Flame work does not require much condition but the results of rehabilitation process for masticatory, pronunciation and aesthetical functions are quite good. All over the world, the frame work rehabilitation for patients suffering from mandibular defects with bone graft has been mentioned by many authors for a long time. In Vietnam, there is no such deep research about this topic. Therefore, for the purpose of improving the quality of treatment for these patients, we decided to study the subject of thesis: “RESEARCH ON REHABILITATION FRAME FOR PATIENTS WHOSE TEETH LOST WITH DEFECTS OF THE MANDIBLE ” with two main purposes: 1. Describe the clinical characteristics and x-ray features of patients who have mandibular defects with bone graft or bone basement. 2. Review the effectiveness of functional and esthetic rehabilitation when treating with flame work for losing teeth of these patients. 1 Importance of thesis topic Mandible is considered as the supported-frame for complex functions of mouth, throat and facial shape. Therefore, mandibular defects negatively effects the eating, pronouncing and aesthetic functions. Psychologically, the patients may retreat from social activities. The large defects can be called disabilities. After the patients have been reformed the defects, the function rehabilitation process is required to help them to gain the work and socialization capacity. NEW CONTRIBUTIONS 1. The clinical characteristics and x-ray features of patient with mandibular defects has been carefully described in the thesis to help the surgeon make improvement in the operation. 2. The result of prosthetic treatment for edentulous people from mandibular defects after bone grafting was evaluated on the basis of many indexs, criteria, tests and observations in a long period. 3. The role of soft plastic with the unset Sillicone to neutral zone and add base in case of mobile saddle mucosa is confirmed for better stability 4. The techniques of functional anatomy are required for these patients with various materials: Sillicone with soft plastic and the compound of thermoplastics and soft plastics. 5. Application of MAI (Mixing Ability Index) in masticatory function evaluation is proved to be highly reliable. DISSERTATION STRUCTURE Addition to introduction, conclusion, the thesis has 4 chapters: Chapter 1: the overview of the study: 36 pages; Chapter 2: the objects and research methodology: 26 pages; Chapter 3: Results: 38 pages; Chapter 4: Recommendation: 38 pages. The apendix concludes of graphs: 48, charts: 22, imagines: 25 and 127 referent documents (English: 99 and Vietnamese:28) 2 B. CONTENT Chapter 1. OVERVIEW 1.1. Anatomy of mandibular bone Mention to: External structure, internal structure, inferior mandibular nerves the mandible, arteries feeding the mandible, the dominant muscles affecting movement of the mandible. 1.2. Mandibular defects and rehabilitation methods 1.2.1. Reasons and consequences of mandibular defects Reasons for mandibular defect: mainly to treat diseases after surgery. Consequences caused by mandibular defect: According to Peri và Coll, the defects will cause “jaw – teeth – muscle imbalance", leading to the distortion which will adversely affect the functional, aesthetic and psychological impacts. 1.2.2. Classification of mandibular defect: Classification by author: Julid Tam, Kadoda, Neal Garret and Brian J.B 1.2.3. Rehabilitation of mandibular defect: There are 2 main types: - Using compounded material to rehabilitate the losing bones using frame but no functionally retrievable ability. - Using biomaterials made from bone to have bone grafting and skin transplant if needed is the best method. The method with functional rehabilitation is bone grafting with vascular 1.3. Flame work - Aker (1918) is considered as the first proponent of seamless methods: claps, connector and saddle, marking the birth of flame work. - Advantages: Compared to partial removable dentures with the plastic ground, flame work brings the better effect for masticatory and pronouncing thanks to a casting over with the claps and rests at the real teeth, the masticatory force is delivered to the abutment và edentulous ridge. 3 - Indications: unsuitably fixing bridge for large losing gaps, losing teeth without limitation, vanishing edentulous ridge in the toothless area, decreasing supports in around teeth area, prosthesis after surgery. - Structure of the flame work: Major connector, manor connector, claps, indirect retention which is the rest of incisors. 1.4. Removable denture prosthesis for patients having defects of the mandible with bone rehabilitation or jaw bone base. Removable conventional plastic: simple technique but the masticatory force is worse than flame work, steadiness and retention is at low level, large size and high mobility which all created the feeling of unsteadiness for patients. Indications: Patients with mandibular defects who lose all teeth or have small amount of teeth left with mobile level II or higher. Removable conventional frame work: be indicated when large edentulous gaps by bone defects that cannot do the bridge or patients do not have abutment left that far from the edentulous gap. Remaining teeth with dental and periodental meet requirement to make abutments. Prosthesis supported by Implant: should follow all the basic principles of normal procedure, notice the attached tissues is normally inadequate after bone grafting so it calls for the epithelial transplantation before putting implant or carry out at the same time of putting implant. 1.5. The study of prosthesis for patients who have mandibular defects The view point of doctors at different time periods: Kelly (1965), Kratochvil (1979), Henderson- Steffel (1981), Davis (1982) Kien Thomas (1994), Shu - Hui Mon (2001), John Beumer (2002), (2007). These authors have generalized and added new techniques to improve the rehabilitating process. In Vietnam, there is no deep study for this topic. 4 CHAPTER 2 SUBJECTS AND METHODS 2.1. Study subjects The subject for study is the patients with mandibular defects who have been grafted autologous bone or remain mandibular bone base and are assigned for frame work. Selection criteria: The patients have been bone grafted after at least 6 months or satisfied these conditions: patients have 4 teeth left which: hard tissues around teeth are unharmed or repaired, teeth with 1 root had wobble level 1 or 2 or teeth with multiple roots had wobble level 1; on Panorama X-ray: good grafted bone, no-suffered bone, the patients were rehalibitated by denture but it can not be used or broken, suffered jaw, the patients volunteer participating in the research. Exclusion criteria: patients with bone grafting to rehabilitate completely the mandibular, people did not cooperate in the study. 2.2. Place and time - Place: School of Odonto Stomatology - National Hospital of Odonto-Stomatology and Hanoi Medical University - Time: From 6/2008 to 6/2013 2.3. Methodology 2.3.1. Design study Open clinical trial study without references to evaluate the effectiveness of the before – after model. 2.3.2. Model collection method - Model collection: Random model ; all patients with mandible defect satisfied all these conditions. - Model size: Formula: q d.p Zn 2 )2/1( α− = Z: confidence level (95%), p: % with good or acceptable masticatory ability: 65%, d: degree of freedom 17% n = 31 actual test on 33 patients. 2.3.3. Data collection method 2.3.3.1. Research tools: clinical tools and labo. 5 2.3.3.2. Examine, review the clinical characteristics, x-ray, model of patients - Making the survey for info - Examine and evaluate the consequences after surgery, the characteristics of teeth and soft tissues for prosthesis. The surveyor makes the design of frame work. 2.3.3.3. Treatment Procedure: Treatment before prosthesis, mouth check, make the model, survey and design the frame work, mold frame at labo, trial flame and take the function frame: simple separated parts or combination of prosthesis space, determine the relationship of upper and lower jaw and set up the artificial teeth by articulators and articulators Quick master B2, trial teeth, complete the frame, fitting the frame works and soft plastic cushion. 2.3.3.4. Evaluate the effectiveness of the treatment a. After fitting the frame works: 3 main criteria: Retention, occlusion and aesthetics. Based on factors and time of fixing the frame after fitting the frameworks: to fix the occlusion. b. Evaluation after 2 weeks: Evaluate the adjustment and masticatory function. c. Evaluation after 1 month: MAI, life quality evaluation according to Albert d. Evaluation after 6 months: Features of frameworks, evaluate the effect of frameworks to abutment, periodental and oral hygiene and identify using add rebase. e. Evaluation after 1 years, 18 months, 2 years and over 2 years: similar to after 6months and added the comparison 2.4. Date processing: Data was treated with medical statistics; apply the software Epi-Info version 6.0 and some logic mathematics methods 2.5. Ethnics in research: all the patients were explained about the procedure of treatment. All volunteered to joint the study. The procedure of treatment was ensured to follow the safety. The info collecte is treated with secret and used with the research purpose to improve the life quality of patients. The thesis proposal has been approved by the commitee. The actual research is ensured to closely followed the thesis proposal. 6 Chapter 3 Research Result 3.1. Clinical characteristics, x-ray of patients 3.1.1. General features of models: Majority is young patients under 34: 18 patients, equal to 54,5%. The youngest patient was 16, the oldest was 65. About gender, 54,5% female patients. The main reasons for mandibular defects is from the surgery to treat diseases: 93,9%. Patients who have vascular bone grafting mainly surgery in 1st stage: 30,3%, patients who have avascular bone grafting mainly surgery in 2 nd stage 42,4%. Dental hygiene status at low level were 54,5%. According to Kadoda, mandibular defects had 9,1% of patients who still have bone base, 87,9% of patients who losed bone pieces. There were 36,4% of patients with small and big losing molars, 18,2% of patients with 2-side-losing maxillary teeth, canine teeth and 1-side losing small and big molars. 3.1.2. Complications, functions and aesthetics features Complications and function in post-surgery patients: 72,8% of patients had trouble with talking loundly and fast; 12,1% found it hard to pronounce s and tr sounds; 30,3% were difficult to open surgical side; 60,6% losing or decreasing the sense at inferior mandibular nerves; 81.8% sometimes biting their own tongue, check and lips when chewing; 36,4% making the sounds at temporo-mandibular when doing activities, 66,7% increasing movement amplitude of condyle. When opening mouth, there were 75,8% of patients suffering deviating jaw arch toward the operated side, 72,7% deviating to the other sides. 78,8% with zic zag movement lines accordance with Posselt’s graph. 30,3% have changed curve of Spee and of Wilson. The relationship of mastication coefficient and mastication function with the scale of 100 point of patients before wearing flame work. There was 52,4% of patients with mastication coefficient from 50 – 75, at the good level (70- 80 point); 75% with the coefficient of under 50 at the acceptable level (50- 60 point). Average of mastication fuction and mastication coefficient: the average mastication function was 65.2 ±15.0; mastication coefficient was 50.2 ± 14.1 on average. 7 3.1.2.2. Facial form and facial aesthetics Facial form: 60.6% having clearly flat faces, 24.2% having lower lip corners at the surgical side. Change of horizontal branches and jaw angle of patients with bone rehabilitation: there were 36.4% of patients with asymmetrical horizontal branches, 87.9% with clearly concave jaw angle. MAI by observing the color waxing block before putting frame: large number of patients got the good review: 81,8%; 12,1% at low level. 3.1.3. Condition of edentulous ridge, teeth and structure of dental surrounding 3.1.3.1. Conditions of edentulous ridge and frenums Almost patients had the straight edentulous ridge and asymmetrical with next jaw arch (87.9%); 75.8% with edentulous ridge lower than mouth floor, 60.6% with scars on the top of edentulous ridge and 63.6% had mucosa on the moving edentulous ridge. Majority of patients had buccal frenum, labial frenum and lingular frenum on the top of edentulous ridge with the rate of 45.5%; 18.2%; 24.2% respectively while these percentages on the top of moving edentulous ridge were 21.2%; 12.1% và 6.1%. 3.1.3.2. Dental and periodental Condition of hard parts and surrounding structure of abutment Popular issues were worn occlusal, occlusion margin with GI = 1 (n2) was 42.0%, n1: 17.9%. Classify patients with loss of adhesion around the abutment and the time for prosthesis after the surgery to graft bone: majority of abutment lost adhesion < 3mm: after 2 - 5 years, n1 abutment: 8.8%; n2 abutment: 17.5% and after 5 years n1: 8.8%; n2: 11.3%; only 3 n1 abutment (8.8%) lost adhesion equal 3 - 6mm. Classify patients with shape of abutment’s root and alveolar bone resorption X – ray: Patients with long and thin teeth roots at n1 abutment accounted for 57.1% (no alveolar bone resorption group), 33.3% (under 3 mm alveolar bone resorption group); for n2 abutment: 72.7% (no alveolar bone resorption group), 27.3% (under 3 mm alveolar bone resorption group) 8 Mobile level of abutments with ages: highest level in the age of 35- 65 happened with degree 1 at n2 abutment: 63.8%, at n1 abutment: 47%. 3.2. Effectiveness of functional and aesthetics rehabilitation of frame works 3.2.1. Frame work prosthetic treatment The procedure of making the frame for prosthesis by bone grafting method: the method making the frame by Silicone and normal trays was used for patients who had vascular bone grafting (87.5%). Frame by Silicone and individual trays were used for avascular bone grafting (56%). In 2 nd time making frames, it was mainly partial + prosthetic by Silicone with avascular bone grafting of 53.3% and avascular bone grafting of 40.0%. Locating the major connectors, indirect retainer, saddle type and alloy: the lingual plate was used for 20/33, equal to 60.6%; indirect retainers were mainly occlusal rest and cingular rest (100%), 51.5% of major connectors were mono bar type, the length of the arches were to 1/2 toward tooth No.7 (90.9%); alloy was used for frame at 90.9%. Of methods of setting up artificial teeth, articulator was used at 57.6%. Type of claps and supporting type: 100% double Aker claps were used for n2 abutment, T-claps were for n3 abutments at 81.8% and I-claps were for n1 abutments accounted for 100%. Mono Acker and double Acker claps were used mainly for 0,5mm under cutting area with 75.8%; followed by 0.75mm area with 23.4%. T- claps were for 0.5mm under cutting area (63.6%) and for 0.25 mm (36.4%). Otherwise, I-claps were seen in under 0,25mm area, equal 69.6%. Demand for fixing occlusion contact when mandible moved horizontally: having statistical meaning with p < 0.0001. In which the number of patients with demand for occlusal fix was 71.4% and for articulator was 42.1%. 3.2.2. Effectiveness of functional and aesthetic rehabilitation Effectiveness of functional and aesthetic rehabilitation was evaluated by: time, method to treat bone defects and edentulous status. 3.2.2.1. Effectiveness of functional and aesthetic rehabilitation with time. 9 Occlusion contact at the time of fitting the frame works: 12.1% of patients having occlusion contact at acceptable level. Frame work retention by time: Declined gradually. After 1 year, the good level fell to 86.7%. After 2 years, the number was 76.9%; no patients at low level. Masticatory function marked with scale of 100 with frame works: after 2 months, there were 27.3% patients with good masticatory function but after 1 month, the number increased to 39.4% and there was no low level. After 2 years, 15.4% patients were at good level, 30.8% were in an acceptable level and 53.8% were with low level. Mastication indexes before and after treatment: the clear improvement of masticatory function after fitting the frame work: good level before fitting is 9.1% ,after fitting is 39.4%. The average level before fitting 51.5% and decreased to 27.3%. Mastication index before and after using frame works: the number of patients whose mastication index before using frame was 50% was 36.4%; was 50-75 accounted for 63.6%; no patients with mastication index over 75%; after using frame, mastication index which was over 75 had 63.6% of patients, the rest was at 50-75. MAI of the artificial jaw when observing the color of masticatory wax after 1 month: 63.6% at good level, 33.3% at low level. MAI when observing the color of masticatory wax before and after fitting the frame works with real teeth: before using frame works it was 81.8% but after it was 90.9% MAI when observing the color of masticatory wax before and after fitting the frame works in real teeth side and after fitting the frame works in denture side: after fitting, MAI which was equal to 0.81±0.23 was much higher than before which was 0.67 ± 0.50; MAI of artificial teeth was 0.26 ± 0.21. The adjustment of patients to flame works (after 1 month) Majority of patients feels stability at good level, meaning that can eat and chew properly but still suffering movement (51.5%); the effectiveness of chewing at average level (51.5%); good pronunciation (84.9%), rehabilitation process caused pain for patients 27.3%, the popular adjustment time was 2 weeks (48.5%). 10 [...]... patients with buccal frenums which create scars from the contact point with the last teeth next to tooth loss gap must be appointed to a preprosthetic surgery 4.1.3.2 Status of the teeth chosen as abutment The teeth chosen as abutment all have good hard crown tissue and periodontium  Dental The patients in the research are young, do not have multi-decayed teeth and periodontitis, therefore all abutment... first choice is plate Following research by Kim, SEongKyun (2007): On the biomechanics of abutment, when the cylinders are linked together, the force to the abutment will decrease compared to the abutment standing individually Then the plate is suitable  Types of claps: Claps play an important role in retention of dentures and in protecting frame work from the torsional by rests Kinds of claps are chosen... are worn occlusal surface, 05 mm in depth of ivory This causes difficulty in grinding teeth to create rests and claps  Status of the periodental: According to Yoav Grossmenn: the important issues when choosing abutment is the ratio between the length of the crown and the tooth root: the smaller the ratio, the better the abutment This ratio is determined in X-ray of periopex 85.26% of patients in this... highest proportion belongs to the good masticatory function group MAI method gives accuracy without too many complicated techniques MAI’s results reflect the masticatory characteristics, the patients’ psychology as well as masticatory habits MAI reflects not only masticatory functions of teeth but also manipulated abilities by tongues, cheeks and masticatory activities of oral cavity The results from the... bridge saddle are for patients with inconvenient edentulous ridges but short defecting gap (9/33 patients, accounted for 27.27%); for patients with narrow width and long defecting gap, saddle nail head are chosen to avoid the torsional of major connetor: 17/33 patients as 51.51% These kinds are mentioned about their advantages and disadvantages by Stewart In comparison with studies of Zlataric, Walid and . gap must be appointed to a pre- prosthetic surgery. 4.1.3.2. Status of the teeth chosen as abutment The teeth chosen as abutment all have good hard crown tissue and periodontium.  Dental The. imbalance", leading to the distortion which will adversely affect the functional, aesthetic and psychological impacts. 1.2.2. Classification of mandibular defect: Classification by author: Julid. rehabilitate completely the mandibular, people did not cooperate in the study. 2.2. Place and time - Place: School of Odonto Stomatology - National Hospital of Odonto-Stomatology and Hanoi Medical University