Chapter 25: Dentoalveolar & Preprostethic Surgery Flashcards
Why is it necessary to use a bite block when removing mandibular 3rd molars?
To diminish pressure on the contralateral TM joint
Why is distilled water not used for irrigation?
Distilled water is a hypotonic solution and will enter cells down the osmotic gradient. This will cause cell lysis and rapid death of bone cells
What is the anatomic structure that can interfere with efficient removal of a maxillary first molar?
Root of zygoma
What anatomic layers are penetrated or contacted when performing an IAN block?
Mucosa, buccinator, pterygomandibular space and periosteum
What muscles insert on the pterygomandibular raphe?
Buccinator & superior pharyngeal constrictor
What two structures form a V-shaped landmark for an IAN block?
Deep tendon of temporalis muscles and the superior pharyngeal constrictor
What is the orthodontic indication for removal of an impacted third molar?
Facilitate distal movement of the second molar
What is the SLOB rule?
Same lingual (palate), opposite buccal. Used to determine location of impacted tooth
What is the advantage of an apically positioned mucoperiosteal flap for exposure of a buccally positioned impacted canine?
This flap design allows for the impacted tooth to erupt into attached mucosa and minimizes possible development of periodontal defects and pocket formation
Where is the IAN most often located in relation to the roots of the mandibular 3rd molar?
Buccal to the roots and slightly apical
The root of which tooth is most often dislodged into the maxillary sinus during extraction?
Palatal root of the maxillary first molar
When the root tip of a mandibular third molar disappears from vier, where might it be dislodged?
- IAN canal
- Cancellous bone space
- Submandibular space
What is the usually recommended sequence of extractions?
Maxillary teeth before mandibular teeth, posterior before anterior
What complications are associated with the removal of freestanding, isolated maxillary molar?
- Alveolar process fracture
2. Maxillary tuberosity fracture
How do you minimize the chance of dislodging an impacted max 3rd molar into the infratemporal fossa during surgical removal?
A FTMP flap that is up to the 2nd molar for appropriate visibility. Use a broad retractor distal to the molar while elevating it.
When performing a surgical removal, should you completely section through the mandibular molar?
No. The lingual plate is often thin, and completely sectioning may perforate the plate and injure the lingual nerve.
How is bleeding from pulsating nutrient blood vessels controlled following surgery on alveolar bone.
- Burnish bone
- Crush bone with rongeurs
- Bone wax
What are some common causes of postoperative bleeding following dental extractions?
- Failure to suture
- Failure to remove all granulation tissue
- Rebound blood vessel dilation following use of LA with a vasoconstrictor
- Torn tissue
- Torn surgical flaps
Why is a mucoperiosteal flap designed to be broad at the base?
To ensure adequate blood supply to the flap margin
What are the two basic flaps used in dentoalveolar surgery?
- full thickness
2. split thickness
What are the two basic types of full thickness flaps?
- envelope
2. envelope with a releasing component
Where are releasing incisions contraindicated?
- palate
- through muscle attachments
- lingual surface of the mandible
- in the region of the mental foramen
- Canine eminence
What is Gelfoam and how does it aid in homeostasis?
Absorbable gelatin sponge. Gelatin sponges form a matrix or scaffold upon which the clot can form. It is not incorporated into the clot. Does not delay healing
What is Surgicel and how does it aid in homeostasis?
Oxidized regenerated cellulose. Like Gelfoam, it forms a matrix or scaffold upon which a clot can form. It is incorporated into the clot and can delay healing (unlike Gelfoam); however, it is a better hemostatic agent
What is Avitene and how does it aid in homeostasis?
Microfibrillar collagen. Unlike Gelfoam or Surgicel, Avitene produces an actual collagen matrix which then attracts platelets and triggers thrombus formation. It thus assumes an active rather than passive role in homeostasis.
Why are conventional dental handpieces that expel forced air contraindicated when performing dentoalveolar surgery?
Can cause tissue emphysema or air embolism. An air embolism can be fatal.
What are the cardinal signs and symptoms of localized osteitis (dry socket)?
- throbbing pain (often radiating)
- bad taste
- fetid/foul odor
- Poorly healing extraction site w/clot loss and exposure of bone.
What causes a dry socket?
Etiology is not fully clear but is thought to be increased fibrinolytic activity causing lysis of the clot. Thought to have a bacterial component but known risk factors include:
- smoking
- premature, forceful mouth rinses
- trauma
- oral contraceptives
- female predilection
Why should flaps be repositioned and sutured over sound bone?
Unsupported flaps can collapse into bony defects causing tension on the sutures; the sutures subsequently will pull through the tissue, allowing the suture line to open and the wound to dehisce.
What percentage of dentoalveolar injuries include the primary maxillary central incisor?
70%
How do you treat an avulsed primary tooth?
No treatment; replantation is not indicated in deciduous teeth.
How is an extruded primary tooth treated?
If grossly mobile or interfering with opposing tooth => extraction
If minimal mobility without interference =>repositioning (without fixation) or observation
What is the incidence of pulp necrosis after intrusion injuries of teeth?
Depends on apex. If closed ~95%, if open and immature then 65%.
How long should dentoalveolar fractures be splinted?
4-6 weeks