Overextension of Denture Borders

Slight overextension is preferred to slight underextension.

Remember, however, overextension is prejudicial to denture retention.

To examine the lower denture for overextension:

• Instruct patient to protrude tongue slightly until the tip rests upon the lower lip
• Place your index fingers on the occlusal surfaces of the lower teeth to determine if the lower denture remains firmly seated on the denture-supporting structures

If the denture lifts, consider 3 possiblities:

• Overextension in the region of the genioglossus muscle (contracts w/ forward movement of the tongue to dislodge denture) Anterior portion of denture lifts
• Overextension in the region of the premolar-molar area (denture dislodges by contraction of mylohyoid) Entire denture lifted from position
• Overextension of the extreme distolingual border of the lower denture (dislodgement of the forward movement of the retromylohyoid curtain) Entire denture dislodged from position and moved forward

To test buccal and labial flanges of the lower denture for retention, cheeks and lips are drawn outward. Keep index finger of the other hand on occlusal surface of the teeth on the same side. If denture lifts, border may be overextended.

Test buccal and labial flanges of the upper denture for retention the same way except hold index finger of the opposite hand in contact with palatal vault

Wharton’s (submaxillary duct)

• Occasionally a lower denture can cause complete or partial closure of Wharton’s duct
• This is clinically manifest by enlargement of the submaxillary gland
• The gland will usually return to normal soon after removal of the denture
• If mild duct closure, mild discomfort often disappears by itself during the adjustment period
• Sometimes a reduction of the lingual flange thickness, without disturbing the border, gives relief (avoid excessively reducing the border)

Faulty Vertical Dimension

• One of the most common denture faults

   

• Always check for this regardless of how remote the patient’s complaint may be
• Vertical Dimension is a combination of relaxed muscles, lips at rest, varying freeway space, harmony between lower and middle 1/3 of the face, ability to speak without bite rims contacting, tongue room for making the "th" sound, satisfaction of the patient’s tactile sense, and a consistent rest position measurement
• Two types of patient’s need a freeway space far in excess of the 2 – 3 mm generally recommended
• The patient accustomed to occluding in a very over-closed relationship for a long period of time (not a good idea to open a patient 10 – 12 mm all in one operation – important to rely on patient judgement, too)
• The mouth breather – lower jaw has been in an opened relationship for a long period of time (a tactile closure into soft wax is a good way to determine the vertical dimension in this case)
• In these 2 instances, don’t try to get proper VDO by subtracting 3 mm from rest position
• Determine the vertical component of centric occlusion which meets the requirement of the case, without regard to the extent of freeway space
• A good way to check VDO (provided the upper incisors are set in a normal position) = Push the lower lip with your index finger with the joints in centric occlusion. If the lower lip tends to slide under the incisors instead of impinging on them the VDO is generally opened too far ( however, horizontal overlap may do the same thing)
• The "th" sound is a good phonetic cue to correct vertical dimension.
  • When the patient says words beginning with "th" his tongue should pop forward between the bite rims. If the VDO is excessive, the forward movement of the tongue, is restricted by the height of the rims or set teeth

Speech Problems

It takes patients from 2 – 3 weeks to accustom themselves to dentures, so it is difficult to judge this early on, but some things to think about are:

• Patients are adaptable and generally will correct speech difficulties (not directly related to technical error) within 2 or 3 weeks, so most patients can be assured they will get past the difficulty
• The pronunciation of the letter "s" is the most common speech problem; the patient may even have involuntary hissing or whistle. This can be caused by:
• Rugae area too thick or too thin or the maxillary anterior teeth may be set too far lingually. If the patient has a heavy anterior ridge and the denture is thick, the rugae area should be thinned to allow more space for air to escape. If the anterior ridge is small and thin, likely too much air is escaping and wax on the palatal surface should correct the problem (autopolymerizing resin can then be added if the wax shows this to be an effective correction). If the maxillary anterior teeth are set too lingually, they must be reset or you may try heavy festooning just lingual to the teeth. If these remedies don’t work, sometimes adding a median ridge will help.
• Inability to speak clearly may be due to the lack of tongue room posteriorly on the mandibular denture.
• Overextension of the upper denture onto the soft palate results in speech difficulties, as the patient has to make a conscious effort to keep the denture in position when talking.

Physiologic Failures

• Weight loss can affect denture fit. Clothes get loose; dentures can get loose
• Patients with diabetes or periodontal disease are subject to rapid loss of supporting structures when dentures are inserted and should be forewarned of frequent re-fittings
• Malignant growths can cause dentures to be ill-fitting
• Sometimes patients just can’t successfully wear dentures; check to see if they are using good denture "tricks" such as tightening the corners of the mouth against the lower flange when the mouth is opened wide, trying to chew in an up and down motion with a minimum of lateral excursion, and keeping the tongue low and well forward in the mouth to stabilize the lower denture.

Mucosal Irritations

• Frenum impingement is common; the upper frenae need the most room to move
• Mucosal soreness is often seen on the buccal surface of the R and L maxillary tuberosities. Careful adjustment of the tissue surface of the denture in this area usually solves problem. The size of the ulceration will correlate to the size of the prominence in the denture, ie pointed, or broad and shallow.
• Sharp, bony projections should be removed prior to denture construction, but only remove the sharp point; avoid extensive aveolectomy!
• To relieve a sore spot on the mucosa, it must be correlated exactly with the corresponding spot on the denture that is causing the trouble – try marking the area with a Thompson stick and transferring it to the denture
• Expect to have adjustments with a flat or concave ridge and forewarn your patient

Sialorrhea (hypersalivation)

• May be a short-term major problem; patient may actually refuse to wear denture
• Usually lasts only a few days and gradually tapers off to normal
• Dentist must maintain calm, kind attitude and offer emotional support
• Physiologic symptoms noted are a flow of blood through the salivary glands and their excessive stimulation
• Etiology is emotional stress, pain in the oral cavity, reflex stimulation by the dentures, or a combination
• Causes arising from the dentures are:
• Incorrect centric jaw relation registrations
• Excessive VDO
• Overextension of denture borders
• Pain and excessive pressure on the oral mucosa
• Pressure upon nerves
• Excessive stimulation of the salivary glands from the denture acting as a foreign body
• Excessive thickness of the dentures restricting the tongue in its static state, as well as in function
• The patient’s anxiety about possible failure of the dentures
• Treatment options:
• Small doses of opiates or atropine sulfate for the first day may be desirable
• Kind, sympathetic treatment with understanding and reassurance are essential (this alone may effect the cure)

Xerostomia

• Possible causes:
• Insertion of new dentures
• Diabetes
• Chronic infection
• Drugs (antianxiety, antidepressant, antihistamine, antihypertensive, diuretic, decongestant, antiparkinsonism, antipsychotic, anorexiant)
• Biological aging
• Sjogren’s Syndrome
• Vitamin deficiencies
• Stress and depression
• Treatment:
• Address etilogic factors
• Prescribe a balanced diet rich in vitiamins and essential minerals
• Moisturizing gel such as Oralbalance
• Saliva substitutes
• Sugar free candy to stimulate saliva production

Stomatopyrosis (burning mouth)

• This is a tough one!
• Affects menopausal and post-menopausal women more than men
• Etiology is unknown in many cases
• Definite psychological component in many cases (All the articles I’ve read suggest this)
• Onset often connected with major adverse life event
• Possible causes
• Systemic/ oral disease (candida, fissured tongue, geographic tongue, foliate papillitis, carcinoma-burning is localized vs. more widespread as in BMS-burning mouth syndrome)
• Nutritional deficiencies
• Emotional disturbances (this is a big one)
• Allergy (very small percentage due to this! Another type of denture acrylic probably will not work; could be due to excess monomer)
• May be neuralgia—consider help from neurology department

• Treatment:
• All systemic sources of inflammation (i.e. candida) should be eliminated
• All sources of local irritation and undue pressure by the dentures should be thoroughly eliminated
• Centric relation should be checked and double-checked. A new centric occlusion that is in harmony with centric relation should be established. The dentures should be remounted on an adjustable articulator to correct occlusal disharmony.
• Border extension and stability of the dentures should explored with utmost care
• When indicated, hormones should be administered
• Balanced diet rich in vitamins and minerals should be prescribed
• Psychotherapy by a psychiatrist (in order for this to work, the dentist must be fully acquainted with the past history of the patient)
• Don’t undertake or continue the treatment of burning mouth unless you are sure of the utmost confidence and cooperation of the patient.
• Reassurance is an important factor
• Some patients just need to know they don’t have a malignancy and therefore don’t insist on any type of treatment

Action of the Denture as a Foreign Body

• Some patients experience hypersalivation and some xerostomia (not due to technical problems with the denture; consider other things first)
• You may also see considerable redness of the palate not associated with pain or discomfort
• Disturbances that complete dentures cause as a foreign body are usually within the limits of tolerance of the tissues. Re-adaptation of the mucosa to a newly established physiologic pattern is the rule. Everyone is different, however, and it is impossible to predict these type of reactions and may be difficult to manage them – no good answers here.

Contraindications to a Denture Reline

• Unresolved TMJ dysfunction and myofacial pain
• Unsuccessful resolution of inflamed tissue caused by pathologic basal seat on mucosa
• Malposition of artificial teeth that results in unfavorable mechanics, poor phonetics and unacceptable/esthetics
• Multiple-fractured and severely worn artificial teeth (cause of this should be determined!)
• Unfavorable occlusal plane that produces a poor appearance
• Artificial teeth that are grossly malpositioned in relation to the residual alveolar ridge
• A vertical dimension that must be increased more than 3 mm
• A vertical dimension that is too great

DENTURE REFERENCE

(Dr. Kenneth Barrack, Medical University of South Carolina)

 

Signs/Symptoms Causes Solutions

Fullness under nose   Depressed philtrum and/or nasolabial sulcus Upper lip sunken in   Shows too much of the teeth   Artificial look             Whistle on "S" sound Lisp on "S" sound "Th" and "T" sounds indistinct "T" sounds like "Th"   "F" and "V" sounds indistinct     Sore Spots In vestibule On posterior limit of maxillary denture base Single sore spot over ridge     Generalized soreness over ridge       Soreness under labial flange of mandibular denture Burning Sensation Anterior hard palate & anterior ridge area Premolar area to molar tuberosity Lower anterior ridge Tongue and cheek biting       Fiery redness of all tissues contacted by denture, including tongue and cheeks Redness of bearing tissues Pain in TMJ         Instability/ Retention When not occluding     When incising food                                   When occluding in centric occlusion                   Interference Swallowing                           Gagging                                     Clicking     Deafness Muscles of mastication become fatigued General feeling dentures are not right, but with absence of pain (patient has high pain tolerance)

ESTHETICS OF DENTURES Labial flange of maxillary denture base too long or too thick Labial flange of maxillary denture base too short or too thin Maxillary anterior teeth too far lingual Vertical dimension too great Incisal plane too low Cuspids and laterals too prominent Technique setup, the alignment of the teeth are too regular All teeth same shade Lack of grinding incisal edges and angles Lack of individualizing gingival contours and color of denture base   PHONETICS OF DENTURES Too narrow an air space on the anterior part of the palate Too broad an air space on the anterior part of the palate Inadequate interocclusal distance Maxillary anterior teeth too far lingual Improper position of maxillary anterior teeth either vertically or horizontally   COMFORT OF DENTURES Overextended borders Posterior palatal seal too deep Sharp posterior palatal seal Overextensions Malocclusion in that area Inaccurate denture base (esp 1Ú stress bearing areas)   Bubbles in acrylic resin Vertical dimensions too great Inaccurate denture base Centric occlusion not in harmony with centric relation; drives lower denture forward Excessive overbite Patient’s habit, wants to masticate in protrusive Overextended labial flange Pressure on anterior palatine foramen Pressure on posterior palatine foramen Pressure on mental foramen Posterior teeth edge to edge (minimal reduction of buccal aspect of teeth)   Overclosure Posterior teeth too far lingual or buccal Denture base allergy         Ill-fitting denture A vitaminosis VDO too small Centric occlusion not in harmony with centric relation Arthritis   Function of Dentures Overextension of borders and posterior limit Underextended borders Loss of posterior palatal seal Posterior palatal seal on hard palate Posterior limit not in hamular notches Insufficient posterior palatal seal Dehydration of tissues due to medications or alcohol "Flabby" tissues displaced when making impressions Loss of posterior palatal seal (same as above) Anterior teeth placed too far labially Poor denture foundation ("flabby" anterior tissues) Improper incising habits   Malocclusion Premature individual tooth contacts High occlusion on one side of arch High occlusion in bicuspid areas Maxillary denture "riding" on median hard palate "Flabby"tissues over the ridge Teeth set too far bucally Centric occlusion not coincident with centric relation Maxillary Denture base overextension in posterior Denture base too thick in posterior Mandibular Denture base overextension in the lingual Denture base too thick in lingual posterior flanges Overclosure of the VDO Posterior teeth too far lingual, crowds tongue Too great a VDO Immediately upon insertion Maxillary Overextension Too thick posterior border Mandibular Distolingual flange too long Delayed gagging (2 wks – 2 mo post) Incomplete border seal allowing saliva under denture Lack of denture stability and/or loose denture Malocclusion causing denture to loosen, allowing saliva under denture Undetermined, uncontrollable or neuromuscular malocclusion causing denture to loosen, allowing saliva under denture VDO too great Unstable mandibular (borders overextended) VDO too small VDO too small VDO too great   Malocclusion Centric occlusion not coincident with centric relation Incorrect VDO Lack of confidence in retention

A,D   J   G   G G G O O O O   G G G G   G         A A D A C A A,R F P B,G     B,G B,G A A A A G E,Q G   M,Q       J,P H E B,C,G I     A   A     K   J   K   H,M,N   L,P   K   G,O   L   G   B,C   B   B,F A   L G B,C       A   D     A   D   E G   F       A D   A   J     K,P     B,C     N         F A     E   E F     B B,C   B,G N

SOLUTIONS

 

1. PIP and disclosing wax to identify over-extensions, and/or tissue impingement and adjust accordingly. Determine whether problem is due to excessive length or excessive pressure spot (ie mylohyoid ridge)
2. Remount to identify occlusal discrepancies
3. Selective grinding to eliminate occlusal discrepancies
4. Feel for sharp edges, thin out borders, then adjust and polish
5. Add acrylic resin to occlusal surfaces to increase VDO
6. Remount and grind occlusal surfaces to decrease VDO
7. Remove teeth from denture base, reposition in wax, re-evaluate and reprocess
8. Nutritional analysis
9. Rheumatology consult to rule out arthritis in TMJ
10. Add to borders with compound or wax and reprocess to correct under-extensions
11. Add posterior palatal seal area and reprocess to correct
12. Reduce flabby tissue surgically or alter impressioning technique
13. Review medical history for medications that may cause xerostomia or refer for medical evaluation
14. Use denture adhesive to augment retention and delay/retard saliva flow under denture base
15. Communicate with patient and laboratory technician concerning the characterization of artificial tooth arrangement while at the wax try-in step of denture fabrication to try to meet the patient’s expectations
16. Re-impression/remake denture
17. Appropriate referrals
18. Repair with hard reline material

The Complete Denture Remount Procedure

Contributed by Dr. Ana Arnold

(from Leary, JM, Diaz-Arnold, AM, Aquilino, SA. The complete-denture remount procedure. Quintessence International 1988;19(9)623-629.

 

Purpose: Correction of denture occlusion under controlled conditions no matter what the cause of the occlusal disharmony.

Reasons:

• Reduces patient participation
• Done on solid base
• Dry field
• Clear visibility
• Corrections made away from patient

Procedure to remount a denture begins at the time the processing of the denture is complete. It can be broken into four phases: two laboratory and two that involve patient manipulation. The sequence would be initial laboratory correction, patient interocclusal records, laboratory correction, and finally patient evaluation and finalization of denture occlusion. The first laboratory phase may not be done by you, the dentist, and can be done by the laboratory technician, depending on your laboratory directions and philosophy.

The basic procedures are as follows:

• Preliminary laboratory occlusal adjustment
• Patient chairside tissue surface and peripheral extension evaluation and adjustment
• Laboratory occlusal adjustment utilizing interocclusal records to mount complete dentures
• Denture insertion and post insertion care

 

Preliminary laboratory occlusal adjustment involves occlusal adjustments resulting from processing error that occurs in the laboratory. Adjustments are done in the labs before delivery to the dentist.

 

 

Patient participation involves the evaluation and necessary adjustment done by the dentist on the tissue surface and periphery of the complete denture which results in a properly fitting prosthesis. At this time interocclusal records, using the patients new and properly adjusted maxillary and mandibular dentures are made for remounting these complete dentures.

 

Laboratory occlusal adjustment is the procedure of denture adjustment done at the laboratory bench after remounting the prosthesis on the articulator

 

Denture insertion is the final delivery of the denture. It includes intraoral inspection for accuracy of laboratory occlusal adjustment and review of home care instructions for the prosthesis and the patient’s mouth. These instructions are sent home with the patient.

More detailed breakdown of this remount procedure is as follows:

Procedure

1. Preliminary laboratory occlusal adjustment

• Unflask complete denture
• Reattach indexed maxillary and mandibular dentures to articulator and correct processing errors
• Preserve facebow relationship with remount index
• Remove, finish and polish complete denture
• Make maxillary and mandibular denture remount casts with plaster blocking out undercuts
• Mount maxillary denture cast to articulator using facebow index

1. Patient participation

• Try-in, evaluate, and adjust complete denture bases and extensions
  • Undesirable pressure spots – PIP adjustment
  • Complete basal seat with no over or under extension by using disclosing wax or PIP
• Make centric relation occlusal index on patient
• Mount mandibular complete denture remount cast with denture to the articulator
• After mounting, verify index by repeating centric relation and checking this with the remounted prostheses on the articulator
  3. Laboratory occlusal adjustment
• Adjust centric relation discrepancies
• Adjust eccentric movements – lateral working, balancing, and protrusive to develop
  • Smooth movement
  • Balanced occlusion (when desired)

   

• Mill in denture (monoplane teeth set flat only)
  • Use a maximum of 10 strokes each
  • Right lateral (RL), left lateral (LL), and protrusive
• The end result is contact between the incisal guide pin and incisal table

1. Denture insert

• Re-evaluate
• Re-adjust and remount when necessary
• Reinforce previous instructions and oral hygiene instructions.

The following is a step by step laboratory occlusal adjustment that will result in elimination of occlusal errors of anatomic teeth. A different procedure is used with monoplane teeth set flat.

• Adjustment is accomplished by selective grinding permitting both tooth form and occlusion to be retained.
• Articulating paper/ribbon of minimum thickness is used, thicker paper gives inaccurate markings and deceptive results.
• Centric relation deflective contacts are adjusted first.
• Complete dentures cannot be loose on the remount casts. It may be necessary to sticky wax the denture to the casts to prevent movement.
• Place articulating paper between complete denture teeth and lightly tap together. Both sides can be done at same time by fastening paper together in from with a paper clip.
• Basic rule: Grind fossas and deflective inclines and not cusp tips.
• Repeat marking and grinding until posterior teeth have contact in centric occlusion.
• During centric occlusion marking and grinding, incisal guide pin is raised 1 mm out of contact to compensate for the thickness of the wax interocclusal record.
• REMEMBER: After centric occlusion has been perfected the centric cusps must not be shortened.
• REMEMBER: The maxillary lingual cusps and the mandibular buccal cusps are usually centric cusps.
• After centric occlusion, deflective contacts are eliminated. The incisal guide pin is placed in contact with the incisal guide table and kept in contact during elimination of eccentric deflective movements, working and balancing.
• Place articulating paper between teeth on both sides of the arch and move articulator into lateral movement. I f the pin raises form the incisal table, reduce the appropriate marking.
• Reduce the appropriate non-functional cusp inclines on the working side first – lingual incline of maxillary buccal cusps or buccal incline of mandibular lingual cusps.
• Reduce the appropriate cusp inclines on the balancing side. The lingual incline of mandibular buccal cusps are reduced before the buccal inclines of the maxillary lingual cusps.
• Marking and grinding is continued in lateral movement until the incisal pin stays flat and contact is made on as many posterior teeth as possible. Contact on all posterior teeth is ideal
• REMEMBER: Grinding to correct occlusion in lateral movement is usually limited to non centric cusp inclines. These include the lingual inclines of the upper buccal cusps and the buccal inclines of the lower lingual cusps on the working side. The lingual inclines of the lower buccal cusp on the the balancing side are reduced before the buccal inclines of the upper lingual cusps.
• After correction of right and left lateral movement, deflective contacts in protrusive are addressed.
• Relief is accomplished for protrusive interference on the distal inclines of maxillary cusps and mesial inclines of mandibular cusps.
• Light posterior contact is desirable in protrusive movement as long as the incisal guide pin stays on the incisal guide table.
• Anterior teeth should just clear without interference. This is usually addressed during the trial arrangement, but adjustment may be necessary
• Elimination of occlusal errors with rational teeth set to a flat occlusal plane is accomplished on the lower arch. The maxillary teeth are sanded flat with "220 wet or dry" sandpaper on a flat surface. This arch is then maintained while adjustment are made on the mandibular teeth.
• Finalization of the adjustment can be accomplished with milling past. All ground teeth should then be light polished to provide smooth movements.

REFERENCES:

Barrack, K. DENTUREREFERENCE©. Perspectives in Prosthodontics, American College of Prosthodontics 1997.

Jumbelic, R., Nassif, J. General Considerations Prior to Relining of Complete Dentures. J Prosthet Dent 1984;51(2):158-163.

Landa, JS: Trouble Shooting In Complete Denture Prosthesis. Part 1. Oral Mucosa and Border Extension. J Prosthet Dent 1959;9(6):980-987.

Landa, JS: Trouble Shooting In Complete Denture Prosthesis. Part 4. Proper Adjustment Procedures. J Prosthet Dent 1960;10(3):490-495.

Landa, JS: Trouble Shooting In Complete Denture Prosthesis. Part 7. Mucosal Irritations. J Prosthet Dent 1960;10:1022-1028.

Landa, JS: Trouble Shooting In Complete Denture Prosthesis. Part 9. Salivation, Stomatopyrosis, and Glossopyrosis. J. Prosthet Dent 1961;11:244-246.

Leary, JM, Diaz-Arnold, AM, Aquilino, SA. The complete-denture remount procedure. Quintess Int. 1988;19(9)623-629.

Morstad, AT, Petersen, AD. Postinsertion denture problems. J. Prosthet Dent. 1968;19(2):126-132.

Van der Waal, I. The Burning Mouth Syndrome. (ed 1) Munksgard, Copenhagen 1990.