Surgical Extraction and Resorptive Lesions Flashcards
Give 4 indications for surgical extraction
- big rooted teeth (eg. canine, mandibular M1)
- persistent deciduous canines (long fragile root)
- limitation of risk of iatrogenic jaw bone Fx (esp. toy breeds)
- dealing with/preventing extraction complications (root Fx, oro-nasal fistular formation)
Give 2 flap designs. When are these mostly used?
- envelope flap (no vertical release incision) - feline tooth resorption
- 1/2 release incisions (ensure they are longer than the tooth root) - if 2 incisions used should be divergent to ^ blood supply to flap and minimise elastic shrinkage
What should e used to elevate gingival flaps?
- periosteal elevators and fine tipped atraumatic tissue forceps
- do not pull flap, push from base
Which 2 structures should you actively avoid?
- Infraorbital foramen on maxilla - neurovascular bundle exits here. When making caudal oblique release incision for canine tooth extraction bundle should be palpated and pushed out of the way)
- Mental foramen - neurovascular bundle exits here. When making vertical release incisions for mandibular PM extractions. Will usually be visualised during flap retraction for these extractions.
how may mental foramens are usually present?
Usually more than one
What complication may occour specifically when attempting to remove canines?
Removal of neighbouring incisors
What structures should be avoided when surgically extracting the maxilarry PM4?
- infraorbital foramen
- Parotid duct and orifice (papilla) [located 1cm above distal root of PM4 ] when making distal release incision
- papilla of zygomatic salivary gland
What pathology is common in cats?
Tooth resorption
- 1/3 adult cats have lesions
What is the pathogenesis of tooth resorption?
- teeth attacked by odontoclasts (==osteoclasts)
- odontoclasts adhere to surface of root
- form resorptive lacunae using acid
- vascular granulation tissue -> bone and cementum like tissue (== alveolar bone on xray)
> thought to be due to lack of degeneration/narrowing of periodontal ligament
What are the 2 main anatomic landmarks of a healthy tooth root on dental radiograph?
> Peridontal ligament space: Thin black line around root
> Lamina dura: White line around root (alveolar bone of ^ density immediately around root)
What are the 3 types of resorptive lesion based on radiographic appearance? What extraction technique is required for each? Do any other treatment techniques exist?
Type 1. Focal lesion, periodontal ligament around root still intact - standard extraction technique
Type 2. Root resorption or partial loss of erpiodontal ligament - often crown amputation only necessary (intential root retention)
Type 3. Combination of both 1+2, very common - extract normally?
> medical therapy - preventative or minimising progression may be available in future
What is the dental formula of the cat?
3/3 1/1 3/2 1/1
Cats have no PM1 or PM2 in mandible
When is crown amputation for Type 2 resportive lesions not indicated?
- presence of infection or inflammation at root level - check for radiographic signs of this
- stomatitis patients
- systemic conditions -> compromised immune response eg. DM
What is the tenchique for crown amputation?
- elevate muco-gingival flap for exposure and closure of defect
- Only drill with visualisation
- Drill dental material to 1-2mm below alveolar margin
> refer if in doubt!
What are bisphosphonates used for in horses?
Navicular syndrome
