17.2 Dentoalveolar Surgery, Tooth Extraction, and Surgical Complications

8.2 Dentoalveolar Surgery, Tooth Extraction, and Surgical Complications

Dentoalveolar surgery encompasses tooth extraction, alveoloplasty, surgical flap management, and the treatment of intraoperative and postoperative surgical complications. Mastering dentoalveolar surgery requires a firm command of surgical anatomy, mechanical physics, instrument mechanics, and clinical protocols.

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Physics of Surgical Elevators and Extraction Instrumentation

Exodontia is governed by simple physics machines designed to expand the bony socket walls and sever the periodontal ligament (PDL) fibers.

Mechanical Principles of Elevators

Elevators function via three main physical principles:

1. Lever Principle (First-Class Lever): Converts a small force applied at a long distance into a large force over a short distance. The fulcrum is the crest of the alveolar bone, the short arm is the elevator tip engaging the purchase point on the tooth, and the long arm is the elevator handle. Example: Straight elevators (#301, #34S).
   • INBDE Surgical Trap: Never use an adjacent tooth as a fulcrum unless that adjacent tooth is also scheduled for immediate extraction.
2. Wedge Principle: Forces a triangular instrument blade parallel to the long axis of the root into the PDL space between the root and alveolar bone wall. This expands the bony socket and displaces the root occlusally. Example: Periotomes, straight elevators, and root tip picks.
3. Wheel-and-Axle Principle: Rotation of the elevator handle around its long axis acts as a wheel, causing the working tip (the axle) to sweep through an arc, exerting powerful elevating forces. Example: Triangular elevators (Cryer / East-West #31 and #32).
   • Clinical Application: Cryer elevators are specifically used to elevate a retained root fragment of a mandibular molar after the adjacent root canal/socket has been emptied.

Extraction Forceps Selection & Mechanics

Forceps act as double levers of the first class, transferring force applied to the handles to the beaks, which expand the alveolar bone through rotational and luxation forces:

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Surgical Extraction Principles & Flap Design

When a tooth cannot be removed by simple closed elevation and forceps delivery, open surgical extraction with flap reflection is indicated.

Mucoperiosteal Flap Principles

A full-thickness mucoperiosteal flap includes the mucosa, submucosa, and periosteum. The periosteum must be reflected cleanly off the underlying bone using a periosteal elevator (e.g. #9 Molt).

• Envelope Flap: Created by making a sulcular incision around the necks of several teeth (typically two teeth anterior and one tooth posterior to the surgical site) without vertical releasing incisions. Provides excellent blood supply and easy closure.
• Three-Corner Flap: Created by adding an anterior vertical releasing incision to an envelope flap. Provides superior surgical exposure for deeply impacted teeth or root tip retrieval.

Essential Rules of Flap Design

1. Base Wider than Apex: The base of the flap must always be wider than the free margin (apex) to preserve adequate blood supply and prevent ischemic flap necrosis.
2. Incision Over Sound Bone: Incision lines must rest over intact, healthy bone at least 3 to 5 mm away from the anticipated surgical bone defect to prevent wound dehiscence.
3. Releasing Incision Placement: Vertical releasing incisions must be placed at the line angles of teeth. Never place a releasing incision directly over the mid-facial root surface or through the center of an interdental papilla.

Bone Troughing & Root Sectioning

• Buccal Bone Troughing (Guttering): Removal of buccal cortical bone using a surgical rotary bur (#702 friction-grip fissure bur or #8 round bur) under copious sterile saline irrigation to create a purchase point and expose root structure.
• Root Sectioning Techniques:
  • Mandibular Molars: Sectioned in a buccal-to-lingual direction, dividing the tooth into mesial and distal halves, which are elevated independently.
  • Maxillary Molars: Sectioned in a T-shape pattern, separating both buccal roots from the palatal root.

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Surgical Complications and Management

Alveolar Osteitis (Dry Socket)

Alveolar osteitis is a painful postoperative complication occurring 3 to 5 days following tooth extraction due to the premature destruction of the intra-alveolar blood clot.

• Pathophysiology: Plasminogen conversion to plasmin leads to local fibrinolysis of the blood clot, leaving exposed, un-covered bone walls within the socket.
• Clinical Presentation: Intense, severe, throbbing pain radiating to the ear or temporal region, empty socket lacking a clot, exposed hyperesthetic bone, foul odor (fetor oris), and bad taste. Fever and suppuration are absent.
• Risk Factors: Extraction of mandibular 3rd molars (highest incidence: 20-30%), female gender, use of oral contraceptives (estrogen increases systemic fibrinolytic activity), heavy tobacco smoking, traumatic extraction, and poor oral hygiene.
• Clinical Treatment Protocol:
  1. Gently irrigate the socket with warm sterile saline to flush out food debris.
  2. Place an obtundent eugenol-impregnated dressing (e.g. Alvogyl, socket paste on iodoform gauze) loosely into the socket to provide rapid pain relief.
  3. Instruct patient to return for dressing change/removal every 24-48 hours as needed.

INBDE High-Yield Warning: DO NOT curette or scrape the socket walls. Curettage strips remaining viable bone, increases pain, and delays healing by restarting the osteitis cycle.

Tooth / Root Fragment Displacement

During elevation, excessive or improperly directed force can displace root fragments into adjacent anatomical spaces:

• Maxillary Sinus: Displacing the palatal root of a maxillary 1st or 2nd molar into the maxillary sinus. If small (<3 mm) and non-infected, leave in place or attempt retrieval via suction; if larger, retrieve via a Caldwell-Luc procedure.
• Infratemporal Fossa: Displacing a maxillary 3rd molar posteriorly through the thin posterior maxillary wall. Elevate under antibiotic coverage or retrieve surgically via an intraoral approach.
• Submandibular Space: Displacing a mandibular 3rd molar root medially through the thin lingual cortical plate below the mylohyoid muscle.

Oroantral Communication (OAC) Management Protocol

An Oroantral Communication (OAC) occurs when an extraction (most commonly maxillary 1st molar palatal root) creates an unnatural opening between the oral cavity and maxillary sinus. Management depends strictly on the diameter of the defect:

Sinus Precautions: Instruct patient to avoid blowing nose, sneeze only with mouth wide open, refrain from drinking through straws, avoid smoking, and avoid playing wind instruments for 14 days.