Horizantal jaw relations/ cosmetic dentistry training

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  • JAW RELATION-Any spatial relationship of the maxilla to the mandible.
  • Thus an occlusion that is physiologically acceptable or desirable may not be applicable for the complete dentures.
  • Relaxes the closing muscles duing mastication
  • 1.The central bearing point and plate
    2.Stretch relax exercise given by boos. ,
  • Tilting the head back at the neck will place tension at the inframandibular muscles and pulls the mmandible into retruded position
  • The tracings are shaped like a type of architecture known as gothic arch hence they r described as gothic arch tracings
  • DOUBLE ARROW POINT TRACING IS SEEN WHEN INCREASING THE VERTICAL DIMENSION
  • Strips of celluloid or paper r placed between the rims r held tight while under closing pressure.if strip pulls out easily it indicates less pressure
    2. Heating one rim. This procedure does not remove the errors of unequal pressure
  • Path of the condyle in eccentric movmnts is not a straight line.
    Shape of the mandibular fossa is an OGEE curve viewed in sagital plane
    This double curve will cause the apparent path of the condyle to be different with varying amounts of protrusion.
    Ideal amount of protrusion is amount to bring anterior teeth end to end.
    Mechanical limitation of articulators require a minimum of 6mm to adjust condylar guidance.
  • Lateral tracing if done, should be recorded 6 mm on the tracing because its moves 3mm at the molar region. Because its appx middle between the tracing & working side condyle

Transcript

  • 1. 1 INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2.  Introduction  Definition  Significance of centric relation  Retruding the mandible to centric relation  Methods of recording centric relation  Factors influencing centric relation record  Interocclusal records 2 CONTENTS www.indiandentalacademy.com
  • 3.  Eccentric relation records  Recording of eccentric jaw relations  Review of Articles.  Conclusion  Bibliography. 3www.indiandentalacademy.com
  • 4. INTRODUCTION Horizontal relation are those that are established anterio posteriorly & mediolaterally, It is classified as 1, Centric relation 2, Eccentric relation- which includes -Protrusive -Left & Right lateral movements 4www.indiandentalacademy.com
  • 5.  The principles of good occlusion apply to both dentulous & edentulous patients.  Different requirements are necessary in the occlusion for the complete dentures because artificial teeth are not attached to the bone as in natural teeth. 5www.indiandentalacademy.com
  • 6.  To maintain stability of complete dentures, the opposing teeth must meet evenly on both sides of the dental arch when the teeth contact anywhere within the normal functional range of mandibular movements. 6www.indiandentalacademy.com
  • 7.  An occlusion for complete dentures that provides these even contacts can only be developed with centric occlusion in harmony with centric relation & smooth gliding contact from this position to any eccentric position with in the normal range of mandibular movements. 7www.indiandentalacademy.com
  • 8. DEFINITION “The maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior superior position against the slopes of the articular eminences” This position is independent of tooth contact and is clinically discernible when the mandible is directed superiorly and anteriorly. It is restricted to a purely rotary movement about the transverse horizontal axis - GPT 8www.indiandentalacademy.com
  • 9. Boucher defined as “The most posterior relation of the lower jaw to upper jaw from which lateral movements can be made at a given vertical dimension” Ramsfjord defined as “a clinically determined position of mandible placing both condyles into their anterior uppermost position. This can be determined in patients without pain or derangement in TMJ” 9www.indiandentalacademy.com
  • 10. TWO DIMENSIONS OF CENTRIC RELATION- DUAL CENTRIC Centric relation should be understood as a complex term with a condylar and mandibular dimension. the condylar centeric position should be differentiated from mandibular centric position. 1.condylar centric position - condyle disc fossa / eminentia relationship 2. mandibular centric position – maxillomandibular position both these components of centric relation coexist collectively known as centric relation 10www.indiandentalacademy.com
  • 11. Significance of Centric Relation:  It is a definite learned position which is independent of the presence or absence of teeth.  It is reproducible ,repeatable and recordable position. 11www.indiandentalacademy.com
  • 12.  If the occlusion of artificial teeth do not coincide, there is instability of the dentures leading to pain & discomfort 12www.indiandentalacademy.com
  • 13. RELATING CENTRIC RELATION TO THE HINGE AXIS During mandibular opening movement the condyles rotate initially in a hinge and later in a translatory motion. A pure hinge movement of the condyle occurs only when the condyle is in its centric position. 13www.indiandentalacademy.com
  • 14.  Combinations of translation and hinge movement take place when the condyle moves anterior to centric relation. Hence ,centric relation is known as the Terminal hinge relation. 14www.indiandentalacademy.com
  • 15. RELATING CENTRIC RELATION TO CENTRIC OCCLUSION:  Centric relation is a bone to bone relation  Centric occlusion is a relationship of upper and lower teeth to each other.  Centric relation must be accurately recorded so that centric occlusion can be built to coincide with it. 15www.indiandentalacademy.com
  • 16. When natural teeth are removed,many receptors that initiate impulses resulting in positioning of mandible away from deflective occlusal contacts into centric occlusion are lost or destroyed. Therefore edentulous patients cannot control mandibular movements or avoid deflective occlusal contacts in centric relation as in dentulous patients. 16www.indiandentalacademy.com
  • 17. These deflective occlusal contacts in centric relation causes movement of the denture bases or direct the mandible away from the centric relation. Thus centric relation must be recorded for edentulous patients so that centric occlusion can be established in harmony with this position. 17www.indiandentalacademy.com
  • 18. CHARACTER OF OCCLUSION IN CENTRIC RELATION: There are two concepts: Point centric : Long centric/ Freedom in centric / Area centric: 18www.indiandentalacademy.com
  • 19. Point centric : This happens when centric occlusion and centric relation coincide. It is a precise location of centric occlusion in centric relation. It is a maximum intercuspation seen or given in centric relation. 19www.indiandentalacademy.com
  • 20. Long centric/ Freedom in centric / Area centric: When centric relation and centric occlusion do not coincide, a freedom is given to close the mandible either into centric relation or slightly anterior to it in centric occlusion with a smooth gliding, without effecting and change in vertical dimension of occlusion. 20www.indiandentalacademy.com
  • 21. 1) Minimal Closing Pressure :  Minimal displacement of the tissue  Opposing teeth to touch uniformly and simultaneously at their first contact. CONCEPTS AND OBJECTIVES IN RECORDING CENTRIC RELATION: 21www.indiandentalacademy.com
  • 22. ADVANTAGES  Uniform contact will not stimulate the patient to clench the teeth  Relaxes the closing muscles. 22www.indiandentalacademy.com
  • 23. 2) Heavy Closing Pressure:  Tissues under bases is displaced while the record is made  Produce same displacement of the soft tissues as would exist when heavy closing pressure are applied on the dentures. 23www.indiandentalacademy.com
  • 24. DISADVANTAGES  Uneven contacts which tends to clench the teeth  Thus causing soreness under the denture bases & changes in the residual ridges 24www.indiandentalacademy.com
  • 25. Retruding the mandible to centric relation: Difficulties seen are  Biological  Psychological  Mechanical 25www.indiandentalacademy.com
  • 26. Methods of assisting the patient to retrude the mandible: Instructing the patient to:  Relax the jaw ,pull it back and close slowly and easily on back teeth.[ never ask the patient to bite]  Get the feeling of pushing your upper jaw out and close your back teeth together. 26www.indiandentalacademy.com
  • 27.  Protrude and retrude the mandible repeatedly as the patient holds the fingers lightly against the chin.  Turn the tongue backwards towards the posterior border of the upper denture.  Ask the patient to swallow & conclude the act with the blocks in contact. 27www.indiandentalacademy.com
  • 28.  Assist the patient to retrude the mandible by placing the index fingers on the buccal flanges on the premolar regions with the thumbs under the patients chin. 28www.indiandentalacademy.com
  • 29. Factors Influencing Centric Relation Records  The resiliency of the supporting tissue.  The stability of the recording bases.  The TMJ and its associated neuromuscular mechanism.  The nature of pressure applied in making the recording. 29www.indiandentalacademy.com
  • 30.  The technique in making the recording & the associated recording devices used  The skill of the dentist.  The health & the co-operation of the patient.  The maxillomandibular relationship 30www.indiandentalacademy.com
  • 31. Primary Requirements for Making Centric Relation Records  To record the correct horizontal relationship of the mandible to the maxilla.  To exert equalized vertical pressure.  To retain the record in an undistorted condition until the cast has been accurately mounted on the articulator. 31www.indiandentalacademy.com
  • 32.  Methods of recording the centric jaw relation  Physiological methods  Tactile or inter-occlusal check record method  Pressure less method  Pressure method  Functional method  Needle house method  Patterson method  Graphic method  Intraoral  Extraoral 32www.indiandentalacademy.com
  • 33. Physiological / tactile / interocclusal check record method: History  In 1756,Philip pfaff, the dentist of Frederick the great of Germany, was the first to describe this technique.  The direct interocclusal record during that period was a non-precision jaw record obtained with a thermoplastic material, usually wax or compound.  This was known as “mush” “biscuit” or “squash bite. 33www.indiandentalacademy.com
  • 34.  Hanau[1929] was the first individual to be concerned about equalization of pressure when recording the bite. He coined the word “realeff” which is formed by the beginning letters of the words “resilient and like effect”.  This became a major factor in “check bite” techniques. 34www.indiandentalacademy.com
  • 35.  Schuyler[1932] preferred modelling compound to wax for the occlusal records  Wright (1939) described the four factors which affected the accuracy of records- 1. Resiliency of tissues. 2. TMJ & neuromuscular control 3. Fit of bases 4. Pressure applied 35www.indiandentalacademy.com
  • 36.  Payne[1955] & Hickey[1964] stated a preference for plaster  Trappzzano[1955] stated that wax check bite method was the technique of preference  Boos[1959] stated that it was important to avoid torsion when recording centric relation & felt that plaster & zinc oxide eugenol paste was more accurate 36www.indiandentalacademy.com
  • 37.  Scyhyler, Payne and Trapozzano advocated the use of light pressure  The problem of pressure in any record was recognized by Boucher (1960) who wrote, “In addition to technical errors are the errors which occur as a result of failure to control jaw activities and pressure at the time of registration”. 37www.indiandentalacademy.com
  • 38. Interocclusal records 1. Impression compound 2. Wax 3. Zinc oxide eugenol paste 4. Impression plaster 5. Bite registration paste 38www.indiandentalacademy.com
  • 39. Physiological / Tactile / Interocclusal Check Record Method: It is particularly indicated in situation of  Abnormally related jaws  Supporting tissues that are excessively displaceable  Large tongue.  Uncontrollable or abnormal mandibular movements  To check the occlusion of the teeth in try-in dentures 39www.indiandentalacademy.com
  • 40. The technique for this record is divided into two steps- 1. Tentative records using occlusion rims attached to accurate stable bases. 2. Inter occlusal check records with teeth arranged for try-in. 40www.indiandentalacademy.com
  • 41. Nick and notch method:  Nick and notch are cut on the maxillary occlusal rim and a trough on the mandibular rim.  Interocclusal record material is placed on the troughs created on mandibular occlusal rim. 41www.indiandentalacademy.com
  • 42.  Patients is asked to close in centric relation.After the material is set,occlusal rims are removed and articulated.  In this method, the final centric relation is recorded after establishing a proper vertical jaw relation. 42www.indiandentalacademy.com
  • 43. Verification of Centric Relation Wax check bite record Palpating the temporalis and the masseter muscles. Use of guide lines on the occlusion rims 43www.indiandentalacademy.com
  • 44. Functional/chew in Method : HISTORY  Functional recordings were described as early as 1910 by Greene where he used a pumices and plaster mixture in one of the rims and instructed the patient to grind the rims together. The teeth were set to the generated paths. 44www.indiandentalacademy.com
  • 45.  Boos (1959) felt that it was essential that all registrations be made under the biting force so that the displacement of the soft tissues which occur in function would occur during bite registration 45www.indiandentalacademy.com
  • 46. Functional/chew in Method :: Needles-house technique:  Compound occlusal rims with 4 metal styli placed in the maxillary rim.  When the mandible moves with the styli contacting the mandibular rim , the styli cuts 4 diamond shaped tracings. 46www.indiandentalacademy.com
  • 47.  The pathways cut into the modeling compound indicate both the centric position and the eccentric mandibular excursions.  The records are placed on a suitable articulator to receive and duplicate the records. 47www.indiandentalacademy.com
  • 48. Disadvantages 1. The displaceable basal tissues, the resistance of the recording medium and the lack of control of equalized pressure in the eccentric relation contribute to inaccuracies. 2. Patients should have a good neuromuscular co- ordination and should be capable of following instructions. 48www.indiandentalacademy.com
  • 49. The Patterson method:  Uses wax occlusal rims.  A trench is made in the mandibular rim and a mixture of half pumice and half carborundum paste is placed in the trench. 49www.indiandentalacademy.com
  • 50.  When the pumice and carborundum are reduced to the pre determined height the patient is asked to retrude the mandible and the occlusion rims are joined with metal staple pins.` 50www.indiandentalacademy.com
  • 51. GRAPHIC METHOD/NEEDLE POINT TRACING: HISTORY  The earliest graphic recording were based on mandibular movements by Blackwill in 1866. The intersections of the arcs produced by the right and left condyles formed the apex of what is known as the “Gothic arch tracing”.  The first known”Needle point tracing” was by Hesse in 1897, and the technique was improved and popularized by Gysi around 1910” 51www.indiandentalacademy.com
  • 52.  Gysi’s tracer was an Extraoral incisal tracer in which the plate was attached to the mandibular rim & spring loaded pin was mounted on the maxillary rim. 52www.indiandentalacademy.com
  • 53.  Phillips(1927) recognized that any lateral movement of the jaw would cause interference of the rims resulting in a distorted record.  He developed a plate for the upper rim under tripoded ball bearing mounted on a jack screw for the lower rim. The innovation was named the “Central bearing point”, which was supposed to produce the equalization of pressure on the edentulous ridges. 53www.indiandentalacademy.com
  • 54.  Later gothic recording methods used the central bearing point to produce gothic arch tracing. Various tracing devices were designed by Flight, Phillips, Terrell, Sears, House, Messerman and others 54www.indiandentalacademy.com
  • 55.  The graphic recording like the check bites records received much praise and criticism. Critics of Gothic arch tracing stated that equalization of pressure did not occur, prognathic and retrognathic patients could not be used, flabby tissues and large tongues could cause shifting of the bases and finally too much of patient cooperation was needed. 55www.indiandentalacademy.com
  • 56. Graphic Methods: Graphic methods are of two types:  Arrow point tracing. - Extra oral tracing. - Intra oral tracing. 56www.indiandentalacademy.com
  • 57. Intra-oral Extra-oral . Tracing not visible when being made Tracings are small as they are located close to the centre of rotation. Therefore difficult to locate the apex. More accurate than extra oral as it is made closer to the center of rotation of the condyle . Plate and styles not hindered by the position of lips and cheeks. Lips and cheeks in passive relation . Accuracy of the record cannot be assessed as the record bases may shift during the recording . Example: Seidal tracer Ballard tracer Messermar tracer Cobble tracer Visible when the tracing is being made Larger tracings easier to locate the apex . Less accurate than intra oral as made further away from the center of rotation. The lips and cheek interfere with the position of the plate and the styles. Does not keep the lips and cheek in passive relation. Accuracy can be assessed virtually. Example: Hight tracing device Stansberry tracers Philips extra-oral tracer Sears trivet 57www.indiandentalacademy.com
  • 58. Extra Oral Tracing Assembly  It has a central bearing device consisting of a central bearing point & a plate  It has a tracing device consisting of a stylus & a recording plate 58www.indiandentalacademy.com
  • 59. Hight extra oral tracer assembly Sears extra oral tracer assembly Swissdent ball bearing bite recorder Microtracer for intra oral use 59www.indiandentalacademy.com
  • 60. 60www.indiandentalacademy.com
  • 61.  When the patient is proficient in executing the mandibular movements prepare the tracing plate to record the tracing by coating with thin coat of precipitated chalk in denatured alcohol.  Develop an acceptable tracing by dropping the stylus to the record plate. 61www.indiandentalacademy.com
  • 62.  When a definite arrow point tracing with a sharp apex is made, have the patient retrude the mandible to the centric relation.  Inject quick setting dental plaster between the occlusion rims.  Remove the assembly and mount the mandibular cast with the new record. 62www.indiandentalacademy.com
  • 63. ADVANTAGES  Tracing point is much larger because they are made farther from the centers of rotation & the apex is more discernible  Extra oral tracings are visible when the tracings are made, therefore patients can be guided & directed more intelligently 63www.indiandentalacademy.com
  • 64.  The stylus can be observed in the apex of the tracing during the process of injecting plaster between the occlusal rims & no hole is required. 64www.indiandentalacademy.com
  • 65. Classical, pointed form The symmetry indicates an undisturbed movement sequence in the joints and uniform muscle guidance. Evaluation of Gothic Arch Tracings: Classical flat form Indicates distinct lateral movements of the condyles in the fossa. 65www.indiandentalacademy.com
  • 66. Weak Gothic arch tracing Indicates a lax and negligent performance of the movements. The registration must be repeated: Stronger movements must be demanded from the patient. Asymmetrical form The tracing indicates a distinct inhibition of the forward movement on one side of joint. 66www.indiandentalacademy.com
  • 67. Miniature Gothic arch tracing This tracing points restricted mandibular movements. •Due to badly fitting and pain- causing record bases or •Long standing edentulous state with inhibited movement in the joints. 67www.indiandentalacademy.com
  • 68. Double arrow point Interupted gothic arch Atypical form - bruxism 68www.indiandentalacademy.com
  • 69. Intra-oral tracing devices  It is a combination of a central – bearing point and plate with a needle point tracing made inside the mouth.  The bearing point is sharp which makes a tracing on the opposing central bearing plate . 69www.indiandentalacademy.com
  • 70. 70www.indiandentalacademy.com
  • 71. A hole may be drilled at the apex of the tracing to ensure that the patients jaw is in the most retruded position while the registration is being recorded. A plastic piece with a hole in the center can also be placed at the apex. 71www.indiandentalacademy.com
  • 72. DISADVANTAGES  Tracings are small, hence its difficult to find the apex.  The tracer must be seated in the hole at the point of the apex to assure accuracy when injecting plaster between the occlusion rims.  If the patient moves the rims before they are secured, the records shift on their basal seat which destroys the accuracy. 72www.indiandentalacademy.com
  • 73. Williamson, Bowley and Randy : Mandibular denture base stability has been reported to be increased by using an central bearing intra oral gothic arch tracing device, as it provides equalization of occlusal pressure. 73www.indiandentalacademy.com
  • 74. Digital Gothic Arch Tracing: 74www.indiandentalacademy.com
  • 75. Other methods of recording centric relation:  Strips of celluloid placed between the rims  Heating the surface of one of the rims  Heating the posterior portion of mandibular wax rims and leaving the anterior portion cold to maintain the predetermined vertical relation of occlusion.  Soft cones of wax placed on the lower denture bases and pt. instructed to swallow 75www.indiandentalacademy.com
  • 76. Pantographic tracing  It is defined as, “A graphic record of mandibular movement in three planes as registered by the styli on the recording tables of a pantograph; tracings of mandibular movements recorded on plates in the horizontal and sagittal planes” – GPT. 76www.indiandentalacademy.com
  • 77.  It is a three-dimensional graphic tracer. It is the most accurate method available to record centric jaw relation.  Even eccentric jaw relation can be recorded using these instruments.  These equipments are very sophisticated and are generally not used in the fabrication of complete dentures 77www.indiandentalacademy.com
  • 78.  The instrument used to do a pantographic tracing is called a pantographic tracer.  A pantographic tracer is defined as, “An instrument used to graphically record one or more planes paths of the mandibular movement and to provide information for the programming of the articulator” – GPT 78www.indiandentalacademy.com
  • 79.  A pantographic tracer has six flags:  Two flags located perpendicular to one another near the condyles.  Totally there are four flags adjacent to the right and left condylar guidance's. They locate the actual (true) hinge axis.  Two flags are placed in the anterior region. They record the antero-posterior movements. 79www.indiandentalacademy.com
  • 80. Consequences of recording incorrect centric relation 1. Denture instability 2. TMJ dysfunction 3. Mucosal ulceration and irritation 4. Spasm of muscles 5. Resorption of bone 80www.indiandentalacademy.com
  • 81. Eccentric relation records  An eccentric maxillo-mandibular relation is any relationship of the mandible to the maxillae other than the centric relation. GPT  It is recorded to adjust the lateral and horizontal condylar inclinations. 81www.indiandentalacademy.com
  • 82.  The adjustment permits the condylar elements to travel to and from the centric and eccentric positions and make it possible to arrange the teeth for complete dentures in balanced occlusion.  The eccentric positions to be recorded are the protrusive and the right & left lateral. 82www.indiandentalacademy.com
  • 83. Tactile or Inter Occlusal Check Record  The preferred time to make the record is during the try-in procedure  The trial dentures are inserted & the patient is instructed to protrude his lower jaw to approximately 5-6 mm  Midline of maxillary & mandibular incisors should coincide 83www.indiandentalacademy.com
  • 84.  Once the patient has learned this position, 3 layers of wax is placed over the mandibular teeth, seal the wax on the lingual & buccal surface of the teeth.  The wax is softened over the controlled water bath. 84www.indiandentalacademy.com
  • 85.  Try-in dentures are re-inserted & the lower jaw is protruded until the upper teeth contact the wax.  The wax is allowed to harden and transferred to the articulator to record the horizontal inclination. 85www.indiandentalacademy.com
  • 86. Recording of eccentric jaw relations: Gothic arch tracing : (protrusive relation records)  Measure a distance of 5 to 6 mm from the apex of the arrow point tracing on the protrusive tracing and mark this point  Instruct the patient to protrude until the point of the stylus rests in the marked point 86www.indiandentalacademy.com
  • 87.  Inject quick setting dental plaster between the occlusal rims.  Free the horizontal condylar adjustment on the articulator.  Raise the incisal pin about one half inch from the top of the guide table.  Carefully seat the record bases on the cast. 87www.indiandentalacademy.com
  • 88.  Using the locknuts as handles manipulate one side ,then the other.  An accurate seating of both record bases must be secured without forcing so that the protrusive record is not destroyed.  Secure the lock nuts. 88www.indiandentalacademy.com
  • 89. Lateral relation records : Gothic arch tracing:  Two records are required – one of right lateral and one of left lateral  The articulator is adjusted as each record is made.  However with complete dentures, it is more difficult to secure accurate & reproducible records. 89www.indiandentalacademy.com
  • 90.  Hanau recommended a formula to arrive an acceptable lateral inclination L =H/8+12 L- Lateral condylar guidance H- Horizontal condylar inclination in degrees as established by the protrusive record  The value of this formula is neither proved or disproved 90www.indiandentalacademy.com
  • 91. Review of literature Atwood, D.A. Acritique of research of the posterior limit of the mandibular position. J Prosthet Dent 20:21-36, 1968. Posterior limit of the mandible at VDO is established by structures anterior and lateral to the condyles rather than posterior to them.(lateral pterygoid and temporomandibular ligament) The temporomandibular ligaments contain proprioceptive nerve endings susceptible to stretching leading to inhibition of the retrusive muscles(temporalis and digastrics), and stimulation of the protrusive antagonist muscles (lateral pterygoids). 91www.indiandentalacademy.com
  • 92. . 1. In biomechanical terms the centric relation is a nonfunctional position. 2. Over relatively long periods of time, the morphology of all functional surfaces of the TMJ is capable of significant adaptive alterations. These are normal compensatory responses of skeletal units to the prior alterations of functional matrices. 3. In much shorter time periods, the dynamically fluctuant state of the neuromuscular apparatus makes it reasonably certain that intra-individual variation in condylar positions can exist. A functional cranial analysis of centric relation. DCNA 19:431-442, 1975. 92www.indiandentalacademy.com
  • 93. Shafagh I, Yoder JL, Thayer KE. Diurnal variance of centric relation position. J Prosthet Dent 34:574-582, 1975. 1. Centric relation was repeatable for a few patients but in most there was variation. The greatest variation was in the superoinferior direction. 2. In many patients the condyles were in their most anteroinferior position in the morning and in their most superoposterior position in the evening. This may indicate that there is a diurnal pattern in the position of centric relation possibly related to fluid content in the joint. 93www.indiandentalacademy.com
  • 94. 3. Depending on one's definition of centric relation, one time of day may be favored over another due to diurnal bias. If the most retruded and superior position of the condyles is desired, the evening seems to be a better time for making CR records. 4. Freedom to move to some degree around a clinically determined centric relation position may have merit as a treatment philosophy. 94www.indiandentalacademy.com
  • 95. Serrano, P.T. and Nicholls, J.I. Centric Relation Change During Therapywith Occlusal Prostheses. J Prosthet Dent 51:97-105, 1984. 1. Corrective occlusion prosthesis therapy did not improve the reproducibility of centric relation in asymptomatic patients. 2. Centric relation is not one position but is a range of positions. 3. The range of CR variation is greater laterally than antero-posteriorly 95www.indiandentalacademy.com
  • 96. The accurate determination,recording & transfer of jaw relation records from the edentulous patient to the articulator is essential for the restoration of function,facial appearance and the maintenance of patient health. 96www.indiandentalacademy.com
  • 97.  Therefore it is emphasized that irrespective of the method used, subsequent clinical checking and rechecking must be done throughout the entire denture construction phases.  The skill of the dentist & the co-operation of the patient being most important factor. 97www.indiandentalacademy.com
  • 98. References 1.Evaluation, diagnosis and treatment of occlusal problems- Peter E. Dawson 2.Essentials of complete denture- sheldon winkler 3.Text book of complete dentures – charles heartwell 4.Treatment planning for completely edentulous – boucher 5. Fundamentals of occlusion and temporomandibular disorders- Jeffery P.Okeson 6.A critique of research of the posterior limit of the mandibular position. J Prosthet Dent 20:21-36, 1968. 98www.indiandentalacademy.com
  • 99. 8. Clinical implications of mandibular repositioning and the concept of an alterable centric relation. DCNA 19:543-570, 1975. 9. A reviewof some problems associated with centric relation. J Prosthet Dent 2:307-319, 1952. 10. Diurnal variance of centric relation position. J Prosthet Dent 34:574-582, 1975. 11. Centric Relation Change During Therapy with Occlusal Prostheses. J Prosthet Dent 51:97-105, 1984. 12. centric relation records review. J prosthet dent 1982 feb; 47; 141. 13. factors influencing centric relation records in edentulous mouths. J prosthet dent 2005;93;305 99www.indiandentalacademy.com
  • 100. 100 For more details please visit www.indiandentalacademy.comwww.indiandentalacademy.com