Basic Concept in Full Mouth Rehabilitation An Overview

Transcription

1 Basic Concept in Full Mouth Rehabilitation An Overview Dr Ankush Jain*,Dr Umesh Palekar**, Dr Rajeev Srivastava***, Dr Vivek Choukse*** ABSTRACT: Full mouth rehabilitation continues to be the biggest challenge toany clinician in restorative dentistry. It requires efficient diagnosis and elaborates treatment planning to develop ordered occlusal contacts and harmonious articulation in order to optimize stomathognathic function, health and esthetics which then translates to patient's comfort and satisfaction. Aim of this article is to discuss about application and selection of different technique for full mouth rehabilitation. Several techniques of full mouth rehabilitations are available and a clinician should ascribe to one after a comprehensive diagnosis of the patient's clinical condition and prospective consideration of his/her oral college &Research centre, Indore. health, function, comfort and esthetic requirements. Key Words: Full mouth rehabilitation, Pankey-Mann-Schyuler philosophy, twin stage procedure, functionally generated path technique INTRODUCTION- Full mouth rehabilitation continues to be the biggest challenge toany clinician in restorative dentistry. It requires efficient diagnosisand elaborate treatment planning to develop ordered occlusal contacts and harmonious articulation in order to optimize stomathognathic function, health and esthetics which then translates to patient's comfort and satisfaction. Thorough knowledge of the various concepts of articulation is therefore integral to any full mouth rehabilitation that is taken up to address the patient's problem related to restoration of multiple teeth that are either decayed, worn, broken, discolored, missing or suffer developmental deficits. 1 Several techniques of full mouth rehabilitations are available and a clinician should ascribe to one after a comprehensive diagnosis of the patient's clinical condition and prospective consideration of his/her oral health, function, comfort and esthetic requirements. 1 OBJECTIVES Restore impaired occlusal function Maintain healthy periodontium *Post Graduate Student, **Professor & HOD, ***Professor Department of Prosthodontics, Modern dental Eliminate pain and discomfort of teeth and surrounding structures. To correlate centric occlusion with the unstrained centric relation To obtain the maximum distribution of occlusal stress in centric relation To retain vertical dimensions To establish smooth guiding tooth inclines To reduce the steepness of inclines of guiding tooth surfaces so that occlusal stresses may be more favourably applied to the supporting tissues To increase the number and size of food exits To decrease the size of the occlusal contact surfaces. 2 Indications for full mouth rehabilitation: Collapsed occlusion due to loss of teeth Loss of vertical dimension Repeated fracture of restorations Para functional habits Lack of inter-occlusal space Trauma to occlusion Loss of occlusal function Unacceptable esthetics TMJ disorders Developmental anomalies in dentition Mal-occlusion (class-ii malocclusion, class- III malocclusion) 3 NJDSR Volume I number 4 January 2016 Page 1

2 Contra-indications for full mouth rehabilitation: There are many malfunctioning mouths that do not need extensive dentistry and have no joint symptoms. These cases are best left alone. One or two "good" teeth may have to be operated on in order to satisfactorily accomplish our objective. In short, no pathology -no treatment. 4 PHILOSOPHIES OF OCCLUSAL REHABILITATION- I)PANKEY-MANN-SCHYULER PHILOSOPHY One of the most practical philosophies for occlusal rehabilitation is the rationale or treatment that was originally organized into a workable concept by Dr. L.D. Pankey. The philosophy has had as its goal the fulfilment of the following principles of occlusion as advocated by Schuyler: 1. A static coordinated occlusal contact of the maximum number of teeth when the mandible is in centric relation. 2. An anterior guidance that is in harmony with function in lateral eccentric position on the working side. 3. Disclusion by the anterior guidance of all posterior teeth in protrusion. 4. Disclusion of all nonworking inclines in lateral excursions 5. Group function of the working side inclines in lateral excursions. Proper sequence advocated by PANKEY- MANN-SCHYULER philosophy: Part1:Examination,diagnosis,treatment planning and prognosis. Part-2:Harmonization of the anterior guidance for best possible esthetics, function and comfort. Part-3: Selection of an acceptable occlusal plane and restoration of the lower posterior occlusion in harmony with the anterior guidance in a manner that will not interfere with condylar guidance. Part-4: Restoration of the upper posterior occlusion in harmony with the anterior guidance and condylar guidance ADVANTAGES- 1. Possible to diagnose and plan treatment for the entire rehabilitation before a single tooth is prepared. 2. Well organised and a logical procedure. 3. Never a need for preparing or rebuilding more than eight teeth at a time. 4. Divides the rehabilitation into separate series of appointments. 5. No danger of getting lost at sea and loosing the patient s present vertical dimension. 6. Functionally generated path and centric relation are taken on the occlusal surface of the teeth to be rebuilt at the exact vertical dimension. 7. All posterior occlusal contours are programmed by and are in harmony with anterior and condylar guidance. 8. There is no need for time consuming techniques and complicated equipment. 9. Laboratory procedures are simple and controlled to an extremely fine degree by the dentist. 5,6 II) TWIN STAGE PROCEDURE The twin-stage procedure was developed by Hobo and Takayama in They derived a kinematic formula to calculate anterior guidance from condylar path. Factors that determine disclusion: 1. Angle of hinge rotation 2. Cusp shape factor Angle of hinge rotation Posterior disclusion occurs when anterior guidance is steeper than condylarguidance. The mandible rotates around the intercondylar axis during eccentricmovements when anterior guidance NJDSR Volume I number 4 January 2016 Page 2

3 is steeper than condylar guidance. The fact thatcompensates for the difference in steepness is the angle of hinge rotation. Cusp shape factor When slopes of posterior cusps are parallel to condylar path inclination andanterior guidance is parallel to condylar guidance, the opposing cusps slide duringprotrusive movement without discluding, despite the degree of steepness. If anterior guidance is steeper than condylar path, the posterior teeth disclude. However, if the cuspal inclination of molars is parallel to anterior guidance, there isno posterior Disclusion even though anterior guidance is steeper than the condylarpath. The posterior teeth disclude only when the cusp inclination of the molar isparallel to the condylar path and anterior guidance is steeper than condylar path. Basic concept of twin stage procedure In order to provide disclusion, the cusp angle should be shallower than the condylar path. Since anterior teeth help produce disclusion, when waxing of the occlusal morphology is done, to produce shallow cusp angle, the anterior portion of the working cast becomes an obstacle. Therefore a cast with a removable anterior segment is fabricated. The occlusal morphology of the posterior teeth without anterior segment is produced so that the cusp angle is coincident with the standard value of effective cusp angle. This is referred to as condition I. Secondly, the anterior morphology of the anterior segment is produced to provide anterior guidance with standard amount of disclusion. This is referred to as conditionii. The application of the two conditions described to fabricate the cusp angle andanterior guidance are termed as Twin Stage Procedure. Articulator adjustment values Condylar path For canine guided occlusion: CONDITION For Group Function Occlusion CONDITION I II I II Sagittal condylar path inclination Bennett angle Anterior table guide Sagittal inclination Lateral wing Contraindications of twin-stage procedure The twin-stage procedure is contraindicated in the following cases 1. Abnormal curve of Spee 2. Abnormal curve of Wilson 3. Abnormally rotated tooth 4. Abnormally inclined tooth. 7 III) FUNCTIONALLY GENERATED PATH: It is a method of rehabilitating the upper posterior teeth using functionally generated path record based on a modification of the principles outlined by Meyer and Brenner in The functionally generated path technique is to be followed after the anterior guidance has been harmonized according to the patient s esthetic and functional requirements and after the lower posterior contours has been harmonized to the anterior guidance. Prepare teeth and make a master cast. Make a wax tray over the prepared teeth on the mastercast. Coat the tray s occlusal surface with a functional wax. Take the tray to the mouth and carefully seat it onto the teeth. Coach the patient to carve the soft wax with movements of his opposing NJDSR Volume I number 4 January 2016 Page 3

4 teeth. Chill, box, and seat the tray onto the master cast. Fasten the master cast to an articulator. A simple hinge articulator may be used. Pour the boxed functional path and fasten it to the articulator. Wax prostheses into the stone functional path as desired. Cast the wax pattern, seat the metal prosthesis on the master dies, and refine the prosthesis to fit the stone functional path matrix. 8,9 IV) FULL MOUTH SIMULTANEOUS TECHNIQUE 10 : It involves full arch preparations, impression, provisional restorations and mastercasts. Advantages: Flexibility in developing: 1. Occlusal plane 2. Occlusal scheme 3. Embrasure 4. Crown and esthetics Disadvantages: 1. Arduous unpredictable patient visit 2. Full arch anaesthesia 3. Multiple occlusal records 4. Possible loss of vertical dimension of occlusion 10 V)QUADRANT/SEGMENTTECHNIQUE: It involves completing one quadrant before beginning another. Advantages: Preparation and final impression of selected teeth at one time will lead to- 1. Maintenance of vertical dimension 2. Quadrant anaesthesia 3. Shorter predictable appointments Disadvantages: Restriction of achieving ideal occlusion when altering 1. Vertical dimension 2. Occlusal plane 3. Embrasure development Functionally generated path technique can be used when restoring one quadrant at a time. 10 VI) SEGMENTED SIMULTANEOUS: It is combination of the desired characteristics of the full mouth simultaneous rehabilitation and the programmed quadrant approach into a single reconstructive technique. Technique:Tooth preparation and chair side temporary fabrication: teeth are prepared and temporary restorations are fabricated chair side segment by segment during several appointments. The patient s vertical dimensions of occlusion are maintained by using unprepared teeth or provisional restorations as occlusal vertical stops. Occlusal records: after teeth preparation alginate impression are taken and face bow transfer are made. Casts are used for making heat processed acrylic resin treatment restorations. Centric relations are recorded by removing chair side temporary restorations in opposing segments and placing Duralay resin between maxillary and mandibular preparations. When this resin has set in onesegment it is used as an index to maintain vertical relation while additionalquadrant relationships are recorded. Fabrication of heat processed treatment restorations: a complete wax- up of the reconstruction is performed directly on the mounted casts and then heat processed in acrylic resin. Articulation of casts: alginate impressions are made of occlusally adjusted heat treatment restorations and face bow transfer is made. Relate the mandibular cast with the upper. These casts are facsimile of final reconstruction and are opposing cast for framework waxing during metal framework fabrication. Incisal guide table is set from the anterior guidance of the facsimile mounting. NJDSR Volume I number 4 January 2016 Page 4

5 Final impression and working casts: 3 full arch final impressions are made for each arch, with tooth preparation recorded in one segment. Heat processed treatment restorations remains except where impressions are being made. Working casts are thus obtained and mounted to previously mount opposing facsimile model of heat cured treatment restorations. Metal framework fabrication: it consists of total of six working casts or three per arch, with each cast containing one segment of dies. Occlusion for each quadrant is then refined by attaching appropriate mandibular and maxillarycast with patterns. Pattern are thus cut back to facilitate porcelain application later. Castings are obtained. Full arch cast fabrication: full arch intraoral elastomeric impressions are made of seated frameworks. Frameworks are reseated in impression and dies are made by flowing Duralay resin into lubricated framework.porcelain application and try in is done for occlusal adjustments. Restorations are then permanently cemented. 10 CONCLUSION For proper diagnosis, treatment planning and execution of full mouth rehabilitation, a thorough understanding of operative and restorative procedures is required. All functioning factors including teeth, muscles of mastication, temperomandibular joint and periodontal structures are interrelated, so each of them should be given enough attention to establish functional harmony. At the same time esthetic requirements of the patient should be fulfilled within physiological limits. The occlusal rehabilitation procedure requires proper dentistpatient relationship because it is a long term procedure that needs patient s co-operation.the object of complete mouth rehabilitation must be the reconstruction, restoration and maintenance of the entire oral mechanism. REFERENCES 1. Sudhir N, Parkash H:Full Mouth Rehabilitation with Group FunctionOcclusal scheme in a patient with severedental Fluorosis.Ind J dent adv.2011;3(3), Jones SM. The Principles Of Obtaining Occlusion In Occlusal Rehabilitation.J Prosthet Dent 1963;13: Turner K., Missirlian D. Restoration Of The Extremely Worn Dentition. JProsthet Dent 1985;52: Landa J. An Analysis Of Current Practices In Mouth Rehabilitation. J ProsthetDent 1955;5: Mann AW., Pankey LD. Part I. Use Of P-M Instrument In Treatment PlanningAnd In Restoring The Lower Posterior Teeth. J Prosthet Dent 1960;10: Mann AW., Pankey LD. Oral Rehabilitation Part II: Reconstruction Of UpperTeeth Using A Functionally Generated Pathway Technique. J Prosthet Dent1960;10: Hobo S, Takayama H. Twin Stage Procedures Part I: A New Method To Record Precise Eccentric Occlusal Relations. Int J Periodont Rest Dent 1997;17: Shillinburg HT, Hobo S, Whitsett LD, Jacobi R.Fundamentals Of FixedProsthodontics. H. T. Shillinburg: Quintessence Publication; Curtis SR. Functionally Generated Path For Ceramometal Restorations. JProsthet Dent 1999;81: Binkley T. A Practical Approach To Full Mouth Rehabilitation. J Prosthet Dent 1987;57: Corresponding Author: Dr Ankush Jain P.G Student Dept. of Prosthodontics Modern dental college & research centre, Indore NJDSR Volume I number 4 January 2016 Page 5