Soft Tissue Hyperplasia And Epulis Fissuratum Notes

Soft tissue hyperplasia/epulis fissuratum.
Answer:

The hyperplasia occurring around the border of a denture may be a fibrous growth referred to as epulis fissuratum.

Soft tissue hyperplasia Etiology

1. Changes in the alveolar sockets after extractions.
2. Trauma from denture wearing.
3. Gradual residual ridge reduction.
4. Changes in soft tissue profile and temporomandibular joint function.
5. Changes in the relative proportions of both jaws.
6. Habits and duration of wear.
7. Natural lower anterior teeth opposing a complete upper denture including parafunctional mandibular movements.
8. Excessive forces due to lack of balancing contacts in eccentric jaw positions.

Soft tissue hyperplasia Treatment

• Remove cause as chronic irritation from ill-fitting dentures, etc.
• Surgical excision of epulis fissuratum is indicated, but only after a period of prescribed tissue rest to reduce the edema. A program of regular and vigorous massage of the damaged site.
• If attached mucosa is absent over the residual ridge, a graft is usually placed and a splint is then inserted to maintain the patency of the sulcus.
• Sometimes the patient’s old denture is modified to serve as a splint that is circumferentially wired into place with a resin treatment liner.
• The splint is worn postoperatively until adequate epithelialization has taken place, which usually takes about 6 to 8 weeks.

Question 102. Significance of centric relation.
Answer:

Significance of centric relation Other names: Retruded mandibular position, centric jaw relation, Hinge axis position, and Ligamentous position.

Significance of centric relation Definition

1. The most retruded relation of the mandible to the maxilla is when the condyles are in the most posterior unstrained position in the glenoid fossa from which lateral movements can be made at any given degree of jaw separation. Or
2. The maxillomandibular relationship in which the condyles articulate with the thinnest
   an avascular portion of their respective discs with the complex in the anterosuperior position
   against the shapes of the articular eminences.

Significance of centric relation Significance Of Centric Relation

1. This position is more constant and definite than the vertical dimension and is independent of the presence or absence of teeth.
2. It is a recordable and reproducible position.
3. It serves as a reference relation.
4. If the centric relation coincides with centric occlusion in the natural dentition the supporting structures are healthy.
5. If artificial teeth are not arranged and occluded in centric relation dentures will be unstable.
6. Errors in mounting casts on the articulator can be detected when centric relation is used as the horizontal reference position.
7. An accurate centric relation orients the lower cast to the opening axis of the articulator and the mandible.
8. Accurately recorded centric relation aids in proper adjustments of condylar guidance for control of eccentric movements.
9. Helps in remounting procedures to correct occlusal discrepancies by selective grinding.
10. The dentist is able to verify the relationship of casts on the articulator.
11. It is a position from which all other eccentric movements occur. It is an intersection of the right and left border positions.

Question 103. Pre-extraction records
Answer:

It’s a mechanical means of recording the vertical dimension of an edentulous patient.

Pre-extraction records Types Of Pre-Extraction Records

1. Profile photographs.
2. Profile radiographs.
3. Lead wire adaptation.
4. Swenson’s method uses an acrylic face mask.
5. Willis gauge.
6. Dakometer.
7. Articulated models.

Pre-extraction records Profile Photographs

Photographs are enlarged to life size and made with teeth in maximum occlusion. Measurements of anatomical landmarks in the photograph are compared with measurements of landmarks on the face. These measurements are compared when records are made and in a selection of artificial teeth.

Pre-extraction records Profile Radiographs

A lateral cephalogram is made with teeth in occlusion. After extraction, trial rims are made to an appropriate vertical dimension. This is placed in the patient’s mouth and another radiograph is taken. The first and second radiographs are compared to make needed adjustments in the trial rim.

Pre-extraction records Disadvantages

1. Enlargement of radiographs can cause errors.
2. Time-consuming.
3. Exposure to radiation.

Pre-extraction records Lead Wire Adaptation

• Lead wires are adapted to pre-extraction profiles and this is transferred to a cardboard. This cutout is stored until extraction. During the vertical dimension assessment, this cut-out is placed against the patient’s profile to re-establish the original contour.
• Swenson’s method using acrylic face mask: Same as for lead adaptation method. Instead of Lead wire acrylic mask is placed and checked for.

Disadvantages

1. Time-consuming
2. Requires good skill.
3. Face assumes different shapes in different postures.

Pre-extraction records Willis Gauge

A gauge is used to measure two points of reference.

1. On the base of the nose
2. The lower border of the chin.
   The screw of the gauge is tightened after measuring the distance between these points before extraction and compared with the measurement after extraction.

Pre-extraction records Dakometer

An instrument used to record the vertical dimension and position of upper central incisors. The readings are noted from the instrument. Later after extraction, this instrument can be reassembled with the same readings.

Pre-extraction records Articulated Models

Measurements between stable points such as incisive papillae and the crest of the lower ridge, the height of lower and upper buccal freni, or between two hamular notches, retromolar pads can aid in the selection of size, shape, and position of the tooth.

Question 104. Centric occlusion vs centric relation.
Answer:

Centric occlusion Definition

The maxillomandibular relationship in which the condyles articulate with the thinnest avascular
portion of their respective discs with the complex in the anterosuperior position against the shapes of the articular eminences. Centric occlusion is the maximum intercuspation of natural teeth.

Centric occlusion Differences

1. Centric relation is a bone-to-bone relationship. Centric occlusion is the relationship of upper and lower teeth to each other.
2. Centric relation is established for denture occlusion whereas centric occlusion is present in
   natural dentition.
3. Centric occlusion can be made to coincide with centric relation to providing a broad area of tooth contact (Freedom in centric) in dentures. In natural dentition, it may not coincide because of habitual occlusion.
4. In natural dentition, the centric occlusion is usually located anterior to centric relation (0.5 to 1 mm)
5. In natural tooth interferences in CR initiates impulses that direct the mandible away from effective
   contacts into CO. Once the tooth is lost there are no proprioceptive impulses to guide the mandible away from deflective contacts and hence centric occlusion cannot be reproduced by the patient.
6. If in natural dentition the CR and CO coincide then it is called Centric relation occlusion.

Question 105. Angular cheilitis/angular stomatitis
Answer:

It is a painful inflammation of the corners of the mouth.

Angular cheilitis Etiology

• Reduction of the vertical dimension of occlusion.
• Riboflavin and thiamine deficiency.
• Secondary to denture stomatitis.
• Candida infection from contaminated saliva.

Angular cheilitis Angular Cheilitis

1. The interface of skin and oral mucosa at the corner of the mouth, the angulus oris, is susceptible to inflammation (cheilitis).
2. The mucosal surface is nonkeratinized and more vulnerable to microbial invasion than the keratinized skin region.
3. The constant exposure to saliva and a large and varied microbial flora increases the chance of angular cheilitis.
4. The incidence appears to be higher among women and denture wearers.
5. The inflammation can occur unilaterally or bilaterally and is sometimes followed by atrophic
   glossitis.
6. The presence of an angular fold of tissue delays the healing of angular cheilitis.
7. Candida albicans and Staphylococcus aureus have been isolated from lesions of angular cheilitis, they need not be the cause of Angular cheilitis.

Angular cheilitis Treatment

• Antimicrobial treatment.
• The lesions recur frequently, even after antimicrobial treatment.

Question 106. Fixed condylar articulators
Answer:

An articulator may be defined as, “A mechanical device that represents the temporomandibular joints and jaw members to which maxillary and mandibular casts may be attached to simulate jaw movement.”

Fixed condylar articulators Types

1. Plane line or simple hinge
2. Mean value with fixed condylar path and incisal inclines
3. Adjustable: Again classified as semi-adjustable and fully adjustable. Semi-adjustable can be Arcon or Non-Arcon.
4. Fixed condylar articulators.

Fixed condylar articulators Fixed Condylar Articulators

• Are based on Bonwill’s theory of occlusion/Theory of Equilateral triangle (WGA Bonwill):
• Proposed that the teeth move in relation to each other as guided by the condylar controls and the incisal point. In this theory, there is a 4-inch distance between the condyles and between the condyles and incisor point.
• It permits lateral movements but as the condylar guidances are not adjustable they move in a horizontal plane.

Fixed condylar articulators Different Names

Fixed condylar articulator, Mean value articulator, Non-adjustable articulator, Three point articulator.

Fixed condylar articulators Features

1. It simulates mandibular movements but in a fixed condylar and incisal path.
2. It is a non-adjustable articulator but is fixed to average values.
3. Does not accept a face-bow record.

Question 107. Phonetics
Answer:

Phonetics is the production of speech sounds. All speech sounds are made by controlled air. The controls are valves in the pharynx, oral and nasal cavities.

Phonetics Importance

1. Aids inaccurate recording of vertical dimensions.
2. Helps in locating the correct closest speaking space.
3. Helps in positioning anterior teeth properly.

Phonetics Types Of Speech Sounds

Valves modify the flow of air through them and produce speech sounds.

1. Labial
2. Labiodental
3. Dentoalveolar(Anterior)
4. Alveolar sounds
5. Palatal
6. Velar (Posterior)
   Except for velar, all other sounds can be affected by the position of teeth.

Phonetics Labial sounds (B, p, m)

The above sounds are produced by air pressure built behind lips and released with or without sound.

Phonetics Affected by:

1. Wrong anteroposterior position of anterior teeth.
2. Thickness of labial flange.

Phonetics Labiodental (f, V)

When pronounced the upper incisors contact the posterior third of the lower lips.

Phonetics Affected by:

1. If upper central incisors are too short or long.
2. If placed in place too forward or lingually.
3. The contact of the upper central should be at the posterior third and not in any other position.

Phonetics Dentoalveolar (“th” in these, this, etc.)

When pronounced the tip of the tongue should contact between the upper and lower anterior teeth close to the alveolus.

Phonetics Affected by:

Labiolingual position of an anterior tooth. Ideally, 3 mm of the tip of the tongue should be visible when ‘th’ is pronounced. If not the anterior teeth positioning is wrong.

Phonetics Alveolar (t, n, D, s) and sibilants as sh, zh, ch and j

When pronounced the tip of the tongue should contact the anterior aspect of the palate or the lingual side of the anterior teeth.

Phonetics Affected by:

1. Teeth placed too anteriorly.
2. The palate portion of a denture base is too thick in the rugae area.

Phonetics Sibilants as sh, j, s:

When spoken the upper and lower incisors should approach edge to edge but not contact.

Phonetics Affected by:

1. Vertical and horizontal overlap
2. Positioning of anterior teeth.
3. The shape of the lingual flange of a lower denture.

Phonetics Palatal and Velar sounds (year, she) and velar (k, g)

• Do not affect the dentures as the other sounds.
• By asking the patient to pronounce these sounds the dentist should observe the relationships of the lips and tongue to the teeth and the denture bases instead of the clarity of sounds.

Question 108. Transfer bases/recording bases
Answer:

Defined as a temporary or permanent form representing the base of a denture.

• The base plate is used for making jaw relation records, arranging artificial teeth, for the try-in stage, and checking the accuracy of previous records (Keyworth, 1929).
• Stabilized baseplate is a baseplate lined with a plastic or other material, to improve adaptation and stability.

Transfer bases Criteria For Recording Bases

1. Well-adapted and accurate
2. Stable on the cast and in the mouth
3. Free of voids
4. 1 mm thickness over the crest and the facial slope of the ridge.
5. 2 mm in the hard-palate area of the maxillary base and the lingual flange of the mandibular base.
6. Ability to be removed with ease from the cast
7. Reproduce contours and the dimensions of the final cast
8. Made from materials that are dimensionally stable.

Transfer bases Types

1. Temporary recording bases.
2. Permanent recording bases.

Transfer bases For Temporary Bases, Four Materials Are Used

1. Shellac
2. Cold-curing acrylic resin
3. Vacuum-formed vinyl or polystyrene
4. Baseplate wax.

Transfer Bases Four Basic Materials Used For Permanent Bases

1. Processed acrylic resin
2. Gold
3. Chromium-cobalt alloy
4. Chromium-nickel alloy.
   Permanent bases become part of the actual base of the completed denture.

Transfer bases The ideal base material should be:

1. Readily adapted to the required shape and contours.
2. Rigid and strong.
3. Should be stable at mouth temperature
4. Should not warp or distort during procedures
5. A contrasting color from the tooth.

Transfer bases Shellac Recording Base Material

• It is a brittle material, hence should be reinforced with wires of 12 to 14 gauge. For the maxillary cast, the wire is placed across the posterior palatal seal area. The mandibular cast is adapted within the lingual flange.
• To adapt the shellac, a brush flame from a Bunsen burner is moved slowly over the surface of the shellac. The trimmed edges are readapted using a Hanau torch and folded onto themselves, and burnished with a No. 7 wax spatula.

Transfer bases Autopolymerizing Resin Recording Base Materials

Transfer bases Three techniques are used:

1. Non-flasking.
2. Alternating applications of powder and liquid.
3. Flashing.

Transfer bases Non-flaking

After applying petrolatum, acrylic is mixed when it reaches the doughy stage, it is rolled into a cigar shape, placed on a roller board, and rolled to the desired thickness (2 to 3 mm).

Transfer bases Flashing Method

A wax pattern of specific thickness is adapted to cast and dewaxed after flashing. Once dewaxing is over acrylic resin is mixed according to manufacturer’s instructions and cured after trial closure.

Transfer bases Sprinkle on Method

Consists of coating the cast with tin foil substitute, sifting polymer powder on the cast, and saturating it with monomer (liquid).

Transfer bases Vacuum-Formed Bases

• The vacuum method provides a fast and efficient means of forming rigid, accurate-fitting recording bases.
• The cast is prepared by blocking out the existing undercuts. A sheet of baseplate resin is inserted in the frame, and the heater is activated. Heating is continued until the resin sheet begins to sag.
• At this time, the softened resin is lowered onto the cast by means of the supporting frame, and the vacuum is turned on. The sheet of softened resin is adapted closely to the cast.
• The heater is then turned off and the base is allowed to cool for one minute. After removal from the cast, the base is trimmed and finished.

Cast alloys

Cast alloys Advantages

1. Rigid, accurate, and dimensionally stable.
2. More weight to mandibular dentures.
3. Thermal conductivity to maxillary dentures.

Cast alloys Disadvantage

Expensive and time-consuming.

Cast alloys Stabilization Of Recording Bases

Cast alloys Materials used are:

1. Zinc oxide and eugenol
2. Light-bodied rubber base impression
3. Soft denture-liner resin.

Question 109. Classification of residual ridge resorption
Answer:

1. Atwood classification
2. Neil classification
3. Branemark classification.

Classification of residual ridge resorption Atwood Classification

• Order 1: pre-extraction
• Order 2: post-extraction
• Order 3: high, well-rounded
• Order 4: knife-edged
• Order 5: low, well rounded
• Order 6: depressed.

Classification of residual ridge resorption Neil Classification

In relation to the floor of the mouth and mylohyoid ridge:

• Class 1: 0.5-inch space exists between the mylohyoid ridge and the floor of the mouth.
• Class 2: Less than 0.5-inch space exists between the mylohyoid ridge and the floor of the mouth.
• Class 3: the mylohyoid muscle is at the same level as the mylohyoid ridge.

Classification of residual ridge resorption Branemark Classification

Residual ridge resorption depends on bone quality and quantity.

Classification of residual ridge resorption Bone Quantity

• Class A- Most of the alveolar bone is present.
• Class B- Moderate residual ridge resorption occurs.
• Class C- Advanced residual ridge resorption occurs.
• Class D- Moderate resorption of the basal bone occurs.
• Class E- Extreme resorption of the basal bone occurs.

Classification of residual ridge resorption Bone Quality

• Class 1- Almost the entire jaw is composed of homogenous compact bone.
• Class 2- A thick layer of compact bone surrounds a core of dense trabecular bone.
• Class 3- A thin layer of compact bone surrounds a core of dense trabecular bone.
• Class 4- A thin layer of compact bone surrounds a core of low-density trabecular bone.

Question 110. Residual Ridge Resorption
Answer:

Residual ridge resorption is a chronic, progressive, irreversible, and cumulative disease.

Residual Ridge Resorption Pathology

The porosity of medullary bone on the crest of the ridge, osteoclastic activity, and smooth lamellar bone on all aspects except on the crest of the ridge.

Residual Ridge Resorption Bone loss can be classified as :

1. Pre-extraction
2. Post-extraction
3. High well rounded
4. Knife edge
5. Low well rounded
6. Depressed.
   The amount of bone loss can be determined by a cephalometric radiograph.

Residual Ridge Resorption Pathophysiology

Mechanism of disordered functioning of bone. It is a localized process of bone loss with no bone deposition, and hence the bone loss is not reversible.

Residual Ridge Resorption Etiology

1. Anatomic
2. Metabolic
3. Mechanical
   • Functional
   • Prosthetic.

Residual Ridge Resorption Anatomic Factors

1. Size and shape of the ridge
2. Type of bone
3. Type of mucoperiosteum.

Residual Ridge Resorption Metabolic Factors

1. Age
2. Sex
3. Hormonal balance
4. Vitamins
5. Diet
6. Osteoporosis.

Residual Ridge Resorption Age

Old persons have more resorption than young patients.

Residual Ridge Resorption Systemic Factors

Diabetic Mellitus, Tuberculosis increase resorption.

Residual Ridge Resorption Local Factors

Osteoclast activating factor, Prostaglandins, Human gingival – bone resorption stimulating factor increase resorption.

Residual Ridge Resorption Sex

Female patients after menopause are prone to osteoporosis which increases bone resorption.

Residual Ridge Resorption Hormonal

If high values of parathyroid hormone are present it increases bone resorption.

Residual Ridge Resorption Vitamins

Vitamins A, D, and C are important. Excess of vitamin D can cause resorption. Vitamin A and C deficiency affect bone growth.

Mechanical Factors

Mechanical Factors Functional Factors

• The frequency, direction, and amount of force applied to the mucoperiosteum affect the rate of bone resorption.
• Cancellous bone can withstand compressive forces better than any other type of bone.

Mechanical Factors Prosthetic Factors

As the form and type of teeth, arrangement of teeth, interocclusal distance, etc.

Mechanical Factors Management Of Residual Ridge Resorption

1. Preventive methods
   • Overdentures
   • Submerged roots to preserve alveolar ridge structure
   • Implants.
2. Surgical methods
   • Removal of high frenal attachments
   • Extension procedures (Vestibuloplasty)
   • Ridge augmentation procedures
   • Implants.
3. Prosthetic management
   • Minimum pressure impressions.
   • Use of tissue conditioners.
   • Teeth arranged in bilateral balanced occlusion with acrylic material as an ideal choice.
   • Teeth arranged in neutral zone.
   • Well-contoured flanges and denture base.