Preprosthetic Surgery: A Comprehensive Overview

Posted on Aug 23, 2024 in Medicine & Health

Preprosthetic Surgery

Causes of Bone Loss

  1. Metabolic Factors
  2. Aging
  3. Trauma
  4. Periodontal Disease
  5. Long-Term Denture Usage
  6. Combination of Factors

Resorptive Pattern of the Edentulous Ridge

Type I: Minor Ridge Remodeling

Type II: Sharp Atrophic Residual Ridge

Type III: Basal Bone Ridge

Type IV: Basal Bone Resorption

Aims of Preprosthetic Surgery

  • Provide adequate bony tissue support for the placement of Removable Partial Dentures (RPD) or Complete Dentures (CD)
  • Provide adequate soft tissue support
  • Elimination of pre-existing bony deformities
  • Correction of maxillary & mandibular ridge relationship
  • Elimination of pre-existing soft tissue deformities
  • Relocation of frenal and/or muscle attachments

Evaluation of Supporting Soft Tissue

  1. Presence of hypermobile tissue
  2. Vestibular depth
  3. Frenum & muscle attachment

Classification of the Involved Procedures

1. Surgical Correction of Bony Abnormalities

  1. Alveoplasty
  2. Excision of torus palatinus
  3. Excision of torus mandibularis
  4. Reduction of Bony Enlarged Maxillary Tuberosity
  5. Reduction of mylohyoid ridge
  6. Reduction of genial tubercles

2. Surgical Correction of Soft Tissue Abnormalities

  1. Reduction of Fibrous Enlarged Maxillary Tuberosity
  2. Frenectomy (labial or lingual)
  3. Correction of Flabby Ridge

Excision of Denture Fissuratum and Palatal Papillary Hyperplasia

3. Surgical Correction of Alveolar Atrophy and Flat Ridges

a. Relative Heightening Procedures

i. Submucosal Vestibuloplasty

ii. Secondary Epithelialization Vestibuloplasty

iii. Mucosal Graft Vestibuloplasty

b. Absolute Heightening Procedures (Ridge Augmentation)

Alveoplasty

It is the surgical recontouring of the alveolar process.

Indications for Excision of Tori

  1. An extremely large torus that interferes with denture stability.
  2. Ulceration of the overlying mucosa.
  3. Deep bony undercuts.
  4. Interference with function.
  5. Cancer-phobic patients.
  6. Food lodgment under the folds of the tori.

Indications for Reduction of Bony Enlarged Maxillary Tuberosity

  1. Enlarged tuberosity may create prosthetic difficulties as it may interfere with the fitness of the upper denture.
  2. Pain in the soft tissue overlying the coronoid process.
  3. It reduces the interalveolar space (inadequate room for the upper and lower dentures).

Frenectomy

Frenectomy: Frenal attachment is a thin band of fibrous tissue and a few muscle fibers covered by mucous membrane.

Indications for Frenectomy

  1. High attachment of the frenum near the alveolar crest may cause displacement of the denture and interfere with the peripheral seal.
  2. Ulceration of the overlying mucosa.

Medically Compromised Patients

Diabetes Mellitus

Hypoglycemia:

  • Coma of sudden onset.
  • Too much insulin / No food.
  • Moist clammy skin.
  • Full pulse.
  • Shallow breathing.

Hyperglycemia:

  • Coma of slow onset.
  • Little or no insulin.
  • Dry skin.
  • Weak pulse.
  • Acetone odor of breath.

Oral Manifestations of DM:

  • Gingival inflammation and easily bleeding gums.
  • Alveolar bone resorption, periodontitis, and bleeding.
  • Pulpitis in non-carious teeth due to pulpal arthritis.
  • Delayed wound healing.

DM Treatment (Management):

  • Diet control and physical activity.
  • Hypoglycemic agents.
  • Insulin injections.
  • Short appointments during the daytime.
  • Prevent excess secretion of adrenaline.
  • Stress-free atmosphere. Diazepam 5-10 mg.
  • Pre and post-operative antibiotics.
  • Local hemostatic agent after surgery.

Thyroid Crisis

Predisposing Factors:

  1. Stressful Stimuli
  2. Severe Trauma
  3. Severe Infection
  4. Adrenaline and other vaso-pressor amines

Signs and Symptoms:

  1. Extreme restlessness
  2. Nausea and vomiting
  3. Abdominal pain
  4. Fever
  5. Profuse sweating
  6. Tachycardia

Thyroid Crisis Management:

  1. Large doses of anti-thyroid drugs (like carbimazole)
  2. Corticosteroids
  3. Glucose I.V.
  4. Oxygen supply
  5. Cooling to decrease temperature

Adrenal Insufficiency (Suprarenal Gland)

Chronic administration of corticosteroids resulting in the suppression of normal corticosteroids production.

Clinically:

  • Weakness
  • Skin and mucosal pigmentation
  • Hypotension
  • Anorexia
  • Loss of weight

Treatment Type 1: 20mg/day up to 40mg/day, double the dose the day of the appointment.

Type 2: More than 40mg/day, no additional treatment.

Surgical Manipulation: 100-200 mg hydrocortisone I.M. one hour before surgery.

  • Double the daily dose after the operation.
  • This regimen to be used in patients taking less than 40mg/day.

Hemophilia

Hemophilia Signs and Symptoms:

  • History of severe prolonged bleeding.
  • Episodes of hematuria and hematemesis.
  • Hemarthrosis (Bleeding in the joint cavity) causing limitation of movements, as in the knee joint.
  • Prolonged clotting time.
  • Diminished AHG level.

Substances Used to Raise the AHG Level:

  • Fresh or frozen blood or plasma: Raising by 20%, which is enough for minor injuries like extractions.
  • Human AHG: Raising by > 40%, enough for moderate injuries like multiple extractions.
  • Animal AHG: Raising by 100% for major surgeries and severe infections.

Dental Management:

  • Hospitalization: Preoperatively and until 5 days from bleeding postoperatively.
  • Anesthesia: General anesthesia may cause bleeding during intubation at the pharyngeal wall.
  • Local Anesthesia: Inferior alveolar nerve block is contraindicated due to the risk of severe bleeding in the pterygomandibular and parapharyngeal spaces.
  • Infiltration anesthesia may cause bleeding at each needle puncture.
  • Interdental local anesthesia is relatively the only safe method.