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Maxillomandibular RelationsMaxillomandibular Relationsfor Complete Denturesfor Complete Dentures

Lecture 09: Maxillomandibular Relations

Presentation Details: Slides: 44 Duration: 00:20:02 Filename: C:\Documents and Settings\Mark Dellinges\My Documents\My Lectures\CD ppt Lectures with notes_05_06\Lecture_09_Maxillomandibular_Relations_revised_06.ppt Presenter Details: Name: Dr. Mark Dellinges Title: Clinical Professor Email: [email protected] Bio:


Slide 1 Maxillomandibular Relations for Complete Dentures Duration: 00:00:18 Advance mode: Auto

Maxillomandibular RelationsMaxillomandibular Relationsfor Complete Denturesfor Complete Dentures

Notes: Maxillomandibular relationship records for the fabrication of complete dentures. Record bases constructed on the master casts will be used to transfer maxillomandibular relations from the patient to the articulator.

Slide 2 Slide 2 Duration: 00:00:29 Advance mode: Auto

““our goal for complete denture therapy our goal for complete denture therapy should be to optimize comfort and function should be to optimize comfort and function

for thefor the patientpatient””

conform denture to the oral environment conform denture to the oral environment –– soft soft tissues and musculaturetissues and musculature

include an appropriate vertical dimension of include an appropriate vertical dimension of occlusionocclusion

provide stable occlusal contacts in harmony withprovide stable occlusal contacts in harmony withthe existing TMJ and masticatory muscle the existing TMJ and masticatory muscle functionfunction

Notes: Our goal for complete denture therapy should be to optimize comfort and function for the patient. This is best achieved by conforming the denture to the oral environment including both the soft tissues and musculature. The denture should be made at an appropriate vertical dimension of occlusion and provide stable occlusal contacts in harmony with the existing TMJ and masticatory muscle function.


Maxillomandibular Relations Maxillomandibular Relations for Complete Denturesfor Complete Dentures

Orientation

Vertical

Horizontal

Notes: Jaw relations are classified into three groups to make them more easily understood. These are the orientation, vertical and horizontal relations. First, let’s consider the orientation records. These establish the references in the cranium and are transferred with the aid of a facebow.




Orientation

Vertical

Horizontal

Notes: Next are the vertical relations that establish the amount of jaw separation allowable for dentures.



Orientation

Vertical

Horizontal

Notes: And Lastly there are the horizontal jaw relations which establish the front-to-back and side-to-side relationships of one jaw to the other.

Slide 6 Record Bases & Occlusion Rims Duration: 00:00:10 Advance mode: Auto

Record Bases & Record Bases & Occlusion RimsOcclusion Rims

““Record bases and occlusion rims are trial dentures used Record bases and occlusion rims are trial dentures used as a substitute for the planned complete denture.as a substitute for the planned complete denture.””

Notes: Record bases and wax occlusion rims are trial dentures used as a substitute for the planned complete denture.



Record bases can be fabricated fromRecord bases can be fabricated from

autopolymerizingautopolymerizing resinresin

light cured resinlight cured resin

Notes: Record bases are commonly fabricated from autopolymerizing resin, like self curing orthodontic resin.


Record bases can be fabricated fromRecord bases can be fabricated from

autopolymerizingautopolymerizing resinresin

light cured resinlight cured resin

Notes: They are also commonly fabricated using Triad, light cured record base material.


Record bases & occlusion rims areRecord bases & occlusion rims areused to establish:used to establish:

the level of the occlusalthe level of the occlusalplaneplane

the arch formthe arch form

the jaw relation (maxillothe jaw relation (maxillo--mandibular relationship)mandibular relationship)recordrecord

Notes: Record bases & wax occlusion rims are used to establish: the level of the occlusal plane, the arch form and the jaw relation (maxillomandibular relationship) record of the patient.


Slide 10 Classification of Maxillomandibular Relations Duration: 00:00:26 Advance mode: Auto

Classification of Classification of Maxillomandibular RelationsMaxillomandibular Relations

orientationorientation

verticalvertical

horizontalhorizontal

““Are those established by theAre those established by theamount of separation of the amount of separation of the maxilla and mandible undermaxilla and mandible underspecified conditions.specified conditions.””

Notes: Classification of Maxillomandibular Relations. I would like to cover the three classifications of maxillomandibular relations in the order that they would be obtained clinically. The first is the vertical relations. Vertical relations are those established by the amount of separation of the maxilla and mandible under specified conditions.


Vertical Dimension of Rest =Vertical Dimension of Rest =distance between jaws when the distance between jaws when the mandible is at restmandible is at rest

Notes: To do this we must first determine the vertical dimension of rest. The vertical dimension of rest is the distance between the jaws when the mandible is relaxed.


VerticalVertical Dimension of Occlusion =Dimension of Occlusion =distance between jaws when the distance between jaws when the occluding members are in contactoccluding members are in contact

Notes: Next we adjust the occlusion rims to an appropriate vertical dimension of occlusion. The vertical dimension of occlusion is the distance between the jaws when the occluding members are in contact.



Freeway Space Freeway Space (interocclusal distance)(interocclusal distance) ==distance between occluding members distance between occluding members when mandible is at rest (3 mm)when mandible is at rest (3 mm)

Notes: For skeletal class I patients the approximately 3mm of Freeway Space or interocclusal distance should be available for normal jaw function. The Freeway Space is the distance between the occluding members when the mandible is at rest.


Therefore:Therefore:

the vertical dimension of occlusion =the vertical dimension of occlusion =

the vertical dimension of rest (minus)the vertical dimension of rest (minus)

the freeway space (interocclusal distance)the freeway space (interocclusal distance)

*about *about 3 mm3 mm for skeletal class Ifor skeletal class I’’ss

Notes: Therefore: the vertical dimension of occlusion = the vertical dimension of rest (minus) the freeway space of interocclusal distance. For skeletal class I’s, 3mm of freeway space is required. Class II’s usually require more than 3 mm and Class III’s need less than 3mm.

Slide 15 Symptoms of Excessive VDO Duration: 00:00:40 Advance mode: Auto

Symptoms of Excessive VDOSymptoms of Excessive VDO

Strained muscle toneSore muscles Contact of teeth on speechClicking noisesSore ridges

Notes: When dentures are delivered to a patient with insufficient freeway space or excessive VDO the following symptoms might be present. The patient might present with strained facial muscle tone and complain of sore jaw muscles. You might notice contact of the teeth in the premolar area while the patient speaks with associated clicking noises as the teeth make premature contact. Premature contact of the teeth during normal function and speech might explain why the patient has complaints of generalized soreness over the


ridges.


Notes: This patient had a denture made at an excessive vertical dimension of occlusion. Notice the strained facial appearance on the picture on the left. The picture on the right shows a new denture that was made at an appropriate vertical dimension of occlusion that restored a more normal appearance and optimal function for the patient.

Slide 17 Slide 17 Duration: 00:00:25 Advance mode: Auto ““Improper VDO with inadequate interocclusalImproper VDO with inadequate interocclusal

space was the most common error found in space was the most common error found in examining complete denture patients duringexamining complete denture patients duringpeer review.peer review.”” KoperKoper, A.: Why Dentures Fail. , A.: Why Dentures Fail.

DCNA 1964 Nov. 721DCNA 1964 Nov. 721--3434

Notes: Over-opening a patient with a denture is probably the most common cause of denture failure. As Koper reported the Dental Clinics of North America in 1964, “Improper VDO with inadequate interocclusal space was the most common error found in examining complete denture patients during peer review.”


Slide 18 Symptoms of Decreased VDO Duration: 00:00:31 Advance mode: Auto

Symptoms of Decreased VDOSymptoms of Decreased VDO

Facial collapseCommissural chelitusRetruded tongueImpaired swallowingGagging

Notes: If a denture is delivered with decreased VDO or excessive freeway space the following symptoms might present. Facial collapse and associated commissural chelitus due to pooling of saliva in the exaggerated folds in the corners of the mouth. Since the tongue is forced posteriorly due to the lack of tongue space, the tongue may appear retruded which might result in impaired swallowing and gagging.


Notes: The picture on the left shows a patients profile without dentures in place. Note the facial collapse and lack of lip support. The picture on the right shows the same patient with properly made dentures that restore posterior jaw and lip support to an appropriate level and give the patient a more normal and youthful profile.


Notes: The slides on the top show a patient with a denture made at a decreased VDO. Notice how the chin appears to touch the nose and contribute to the “denture look”. The slides on the bottom show this same patient with a new denture made at an appropriate VDO which supports the lower half of the face, supports it better and contributes to a more normal facial profile.





verticalvertical

horizontalhorizontal““The basic horizontal relationshipThe basic horizontal relationshipis is centric relationcentric relation when thewhen themandible is in the most retrudedmandible is in the most retrudedposition at the established verticalposition at the established verticaldimension.dimension.””

Notes: After determining vertical dimension of occlusion horizontal maxillomandibular relations are made. The basic horizontal relationship is centric relation when the mandible is in the most retruded position at the established vertical dimension.”


Centric RelationCentric Relation = The maxillomandibular relation= The maxillomandibular relation--ship in which the condyles articulate with the thinnship in which the condyles articulate with the thinn--est avascular portion of their respective disksest avascular portion of their respective diskswith the complex in the anteriorwith the complex in the anterior--superior positionsuperior positionagainst the shapes of the articular eminences. against the shapes of the articular eminences. This This position is independent of tooth contact.position is independent of tooth contact.

Maximum Intercuspation (MIP)Maximum Intercuspation (MIP) = The complete = The complete intercuspation of the opposing teeth intercuspation of the opposing teeth independent independent of condylar position. of condylar position.

Notes: It is very important that you have a good understanding of the difference between centric relation and centric occlusion or M.I.P.. Centric Relation = the maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disks with the complex in the anterior-superior position against the shapes of the articular eminences. This position is independent of tooth contact. Maximum Intercuspation (MIP) = the complete intercuspation of the opposing teeth and is independent of condylar position.


Slide 23 Slide 23 Duration: 00:00:08 Advance mode: Auto For Complete DenturesFor Complete Dentures

C.R. = M.I.P.C.R. = M.I.P.

Notes: For complete dentures centric relation equals maximum intercuspation position.

Slide 24 Why C.R. for Complete Dentures? Duration: 00:00:23 Advance mode: Auto

Why C.R. for Why C.R. for Complete Dentures?Complete Dentures?

C.R. is a repeatableC.R. is a repeatableborder positionborder position

C.R. is a functionalC.R. is a functionalpositionposition

C.R. position can beC.R. position can betransferred to antransferred to anarticulatorarticulator

Notes: Why C.R. for Complete Dentures? C.R. is a repeatable border position. C.R. is a functional position while bracing the jaw for swallowing or during certain parafunctional or bruxing habits. Lastly, C.R. position can be transferred to an articulator.

Slide 25 C.R. = M.I.P. Duration: 00:00:11 Advance mode: Auto

C.R. = M.I.P.C.R. = M.I.P.

Notes: For complete dentures the occlusion must be established at an appropriate vertical dimension with the condyles seated in centric relation position.


Slide 26 If C.R. is not used! Duration: 00:00:35 Advance mode: Auto

If C.R. is not used!If C.R. is not used!

unstable TMJunstable TMJ

skidding of denturesskidding of dentures

loss of loss of stablitystablity

bone loss due to bone loss due to trauma & irritationtrauma & irritation

Notes: If C.R. is not provided patients might try to interdigitate the denture teeth, by posturing the jaw forward or backward and this would destabilize the TMJ. If the patients close with the mandible in C.R. but the denture teeth not interdigitated in C.R. the denture bases might skid on the ridges, resulting in a loss of denture base stability and chronic denture sore spots which might lead to accelerated pressure induced bone resorption due to localized irritation and trauma.




verticalvertical

horizontalhorizontal

Notes: Orientation relations are the last maxillomandibular relationship record that is made.


Slide 28 Orientation Relations Duration: 00:00:12 Advance mode: Auto

Orientation RelationsOrientation Relations

establishes the establishes the relationship of therelationship of themandible to the mandible to the craniumcranium

this relationship isthis relationship istransferred with atransferred with afacebow recordfacebow record

Notes: Orientation Relations: establishes the relationship of the mandible to the cranium. This relationship is transferred with a facebow record.

Slide 29 Facebow Duration: 00:00:17 Advance mode: Auto

FacebowFacebow

relates the maxillaryrelates the maxillaryarch to the mandibulararch to the mandibularhorizontal hinge axishorizontal hinge axis

this transfer assuresthis transfer assuresthat the opening axisthat the opening axisof the jaw will be the of the jaw will be the same as the openingsame as the openingaxis of the articulatoraxis of the articulator

Notes: The Facebow: relates the maxillary arch to the mandibular horizontal hinge axis this transfer assures that the opening axis of the jaw will be the same as the opening axis of the articulator.

Slide 30 Clinical Procedures for Maxillomandibular Relations Duration: 00:00:10 Advance mode: Auto

Clinical Procedures forClinical Procedures forMaxillomandibular RelationsMaxillomandibular Relations

Vertical Relations = Vertical DimensionVertical Relations = Vertical Dimension

Horizontal Relations = C.R. RecordHorizontal Relations = C.R. Record

Orientation Relations = Facebow TransferOrientation Relations = Facebow Transfer

Notes: For lets take a clinical case and make maxillomandibular relationship records for our complete denture patient.


Slide 31 Slide 31 Duration: 00:01:23 Advance mode: Auto 22mm

Notes: On the top left slide a bead of sticky wax is applied to the ridge crest area of the maxillary cast. A sheet of extra hard base plate wax is softened over a Bunsen burner flame, rolled and positioned over the ridge. The arch form of the wax occlusion rim should mirror the arch form of the master cast. Adapt and contour the wax occlusion rim on the record base with a hot plate and a #7 or #31 wax spatula. The top right slide shows that using a flat hot plate warmed in a Bunsen burner flame, adjust the occlusal, buccal and labial contours of the wax occlusion rim. The length of the maxillary wax rim should be 22 mm below the tissue reflex of the labial vestibule. The width is 10 mm and the labial surface should end 8 to 10 mm anterior to the middle of the incisive papilla. These dimensions are just a starting point and will be refined later with the patient. The slides on the bottom show that in a similar manner the mandibular wax occlusion rim is fabricated. It should be positioned over the ridge. Its anterior position is arbitrary at this time.


Notes: A small line is then placed one side of the face with a straight edge. The straight edge is positioned at points above the tragus of the ear and below the ala of the nose. This line represents Camper’s line. The maxillary occlusal plane will be adjusted on the wax rim until it is parallel with Camper’s line.


Slide 33 Slide 33 Duration: 00:00:27 Advance mode: Auto VDR

VDRminus3mm= VDO

Notes: Reference marks will be placed on the patient’s skin with an indelible marking stick. (These marks can be removed after the procedure with an alcohol 2X2.) Place a small dot on the chin and tip of the nose. Determine the Vertical Dimension of Rest. Subtract 3mm to determine the Vertical Dimension of Occlusion. Readjust the Boley Gauge to the V.D.O..


Notes: Place the record base with the wax rim in the mouth and check the length and lip support provided by the wax rim. A properly contoured maxillary wax rim should emulate the final positions of the maxillary teeth. The labial aspect is increased or reduced to give the same lip support that will exist when the teeth are set. The length of the maxillary wax rim should be adjusted with a hot plate until it is located 1 mm below the lower limit of the resting upper lip. In making this adjustment the wax rim should be made into a flat plane with the hot plate and checked in the mouth with the aid of a Fox Plane. This plane should be parallel to the interpupillary line (an imaginary line which runs from the center of one pupil of an eye to the center of the pupil of the other eye) and Camper’s line. Before proceeding check again the position and contour of the maxillary rim. This will be your only guide for setting the anterior teeth.


Slide 35 Slide 35 Duration: 00:00:22 Advance mode: Auto Pre-Deter-

mined VDO

VDO withunadjustedwax rim

VDO withadjustedwax rim

Notes: The mandibular wax occlusion rim is now adjusted to the appropriate vertical dimension of occlusion. Remove the record base and adjust the mandibular wax rim with the hot plate or add wax to the surface of the wax rim until the opposing wax rims meet evenly at the predetermined vertical dimension of occlusion.


Notes: Mark the midline on the maxillary occlusion rim. (The labial frenum is a good landmark to begin the determination of the midline.) This midline determination may be verified with a piece of dental floss stretched over the middle of the face. Sometimes the labial frenum is not in the middle of the face! Make appropriate esthetic compensations. Extend the midline from the maxillary wax rim to the mandibular wax rim. Now recheck the record bases and wax rims in the mouth. There should be even contact of the wax rims at the determined vertical dimension of occlusion.







Notes: To make Horizontal Relations a Centric Relation Record will be made at the Pre-Determined Vertical Dimension of Occlusion.


Notes: From the cuspid position posteriorly make a series of diagonal notches in the maxillary wax rim with a Bard Parker blade warmed in a Bunsen burner. Lubricate the notches with Vaseline. From the cuspid line posteriorly on the mandibular wax rim remove 2 mm of wax. Make sure there is contact of the wax rims in the anterior region to maintain the determined vertical dimension. Three, 1 mm thick strips of warmed Aluwax are adapted to the posterior cut out on the mandibular wax rim. The Aluwax strips are sealed to the base plate wax rim with a #7 wax spatula and warmed with a Hanau Torch.



Notes: Place the lubricated maxillary wax rim and the tempered mandibular wax rim in the mouth and instruct the patient to open, relax the jaw and then slowly close on the back teeth. The index fingers should stabilize the mandibular record base over the buccal shelf areas and the thumbs should be positioned along the body of the mandible. Slight pressure is directed superiorly and posteriorly to seat the condyles in the centric relation position. Ideally, when recording a centric relation record at a pre-determined vertical dimension of occlusion the midlines previously scribed on the maxillary and mandibular wax rims should coincide. There should be a visible space, about the thickness of a business card, between the anterior portion of the two opposing wax rims. This space is left to ensure posterior occlusal force when seating the record bases. Remove the record bases and wax rims from the mouth and inspect them visually. The Aluwax recording on the mandibular arch should be clean and distinct. Chill the mandibular record base in cool water. The maxillary wax rim should fit precisely onto the mandibular wax rim.






Notes: Orientation Relations are transferred with the Facebow!



Notes: A Hanau bitefork is heated in a Bunsen Burner and attached the maxillary wax rim. (Be careful not to melt wax into the notches of the centric relation recording or obscure the midline mark and interpupillary lines.) The wax rim/bitefork assembly is placed in the mouth. Use cotton rolls or have the patient close into the mandibular wax rim to hold it steady. Note: When properly positioned the attachment rod for the bitefork should have its bend to the patient’s left side. Attach the mounting assembly and spring bow onto the bitefork then rotate and release the spring bow into the patient’s external auditory meatus. The spring bow is self-centering. Swing the third point of reference indicator out and adjust the superior/inferior position of the spring bow until the third point of reference indicator lines up with the infraorbital notch on the patient. The three tightening screws on the facebow are labeled 1,2, & 3 and should be tightened in that sequence.


Notes: Remove the facebow and mounting assembly from the patient. The mounting assembly can be detached from the facebow for indirect mounting on the Hanau articulator with the Hanau mounting jig. Prior to mounting on the articulator the casts should have large “V”-shaped notches cut into the thickest portion of its bases. The otches will allow exact re-relating of the casts to the articulator for laboratory remount procedures following denture processing. Lubricate the notches with Vaseline and soak in slurry water before mounting. The indirect mounting technique can be used to relate the maxillary edentulous cast to the upper member


of the Hanau articulator. Remove the bite fork and mounting assembly from the earbow and attach it to the mounting jig. Adjust the cast support (arrow) so that it contacts the wax occlusion rim. Mix mounting stone or laboratory plaster and apply it to the base of the cast. Close the upper member of the articulator into the wet stone.


Notes: After the attachment of the maxillary cast has set remove the mounting jig and bitefork from the maxillary wax rim. Interdigitate the mandibular wax record into the maxillary wax rim and secure the position with wood sticks and green stick compound. Invert the articulator and attach the mandibular cast to the lower member of the articulator with mounting stone or laboratory plaster. After the stone or plaster has set, finesse the mountings. It might be necessary to add extra stone to voids or trim excess stone with a laboratory knife. Sand the mountings smooth with course wet/dry sand paper followed by fine wet/dry sand paper to make the mounted casts look acceptable to your patient.



Notes: Remove the record bases and wax rims from the casts and observe the relationship of ridges. With the casts mounted at the vertical dimension of occlusion, you can verify skeletal relations, ridge parallelism and interarch space. This information should be considered for posterior tooth selection.