Dental Blocks and Oral Tumors PDF

Dentistry 2 -- Lecture 4 **Benefits of Local Anesthesia** - Nerve cells work by sending small electrical currents through adjacent nerve cells - Currents are caused by the exchange of sodium & potassium ions - Local anesthetics work by blocking the channels sodium ions use to get i...

Dentistry 2 -- Lecture 4 **Benefits of Local Anesthesia** - Nerve cells work by sending small electrical currents through adjacent nerve cells - Currents are caused by the exchange of sodium & potassium ions - Local anesthetics work by blocking the channels sodium ions use to get into nerve cells Bupivicaine 0.5% (lasts 4-10hrs) (8-30 mins onset) Lidocaine 2% (lasts 60-120mins) (onset within 5 mins) Combination of the two interfere with the MOA of each drug and cancel each other out - Toxicity/reactions can include anaphylactic reactions, toxicity to skeletal muscle, permanent nerve damage - Rule of thumb to avoid toxicity 2mL/kg Max Dose per patient - Amount per site to be blocked varies per practitioner Cats and small dogs = 0.1mL Medium dogs 0.2mL Large dogs 0.3mL **General Techniques for Nerve Blocks** - 25g needle and 1mL syringe - As needle is placed in desired area you must ensure there is no trauma to the nerve and you are not in a blood vessel - Regular aspiration to ensure there is no blood - Atraumatic entry into foramen - Pressure over the foramen to keep the anesthetic in the area to take effect **The Foraemen & The Blocks** Infraorbital Foramen = Rostral Block Caudal Maxillary Block Inferior Alveolar Foramen = Caudal Mandibular Block Middle Mental Forame (Uncommon) = Rostral Mandibular Block Infraorbital Foramen = Rostral Block - Rostral approach - Will block the max 3^rd^ premolar and all teeth mesial to it on one side - Hopefully all maxillary teeth on one side as well as adjacent bone and soft tissue IF the needle is advanced deep in th foramen and the local anesthetic stays in the foramen - Firm pressure required on the foramen for 60 seconds and tilting the nose to the sky for best effect - Landmark, mesial root of 3^rd^ premolar Caudal Maxillary Block - Affects the branches of maxillary nerve, the infraorbital nerve, then pterygopalatine nerve and the major & minor palatine nerve - Includes bones, teeth and soft tissues of upper jaw, including bones of the hard palate, mucosa of the hard and soft palate on corresponding side - Needle is only advanced 3-5mm to avoid the eye Middle Mental Foramen - Not commonly used - Dental nerve block in dogs affects incisors and canine tooth of corresponding side along with the adjacent bone and soft tissue - Very difficult to landmark & enter foramen Inferior Alveolar Nerve Block - Block affects all mandibular teeth, mandibular bone and soft tissue on corresponding side, rostral to injection site - Palpate for the facial vascular notch, needle goes underneath on inside of mandible, draw back and inject. Hit bone before finding foramen **Oral Tumors** - Malignant -- will spread to other body parts - Benign -- localized - Can be metastatic - Excision can be curative - Histopathology is the only way to know - Regional lymph node biopsies may be done as well Step 1 -- Recognizing Normal - Starts with knowing normal - Bilateral lesions are likely a normal anatomical feature Step 2 -- What to know - Detailed location of lesion including size must be established - Charting code = OM/\_\_ - Rads needed bone involvement & other diseases Melanoma (MM) - Most common oral cancer in dogs (rare in cats) - Anywhere in oral cavity - Highly metastatic (lungs, lymph nodes, bone) - Prognosis is poor and recurrence is high Squamous Cell Carcinoma (CC) - \#1 in cats, \#2 in dogs - Anywhere in oral cavity - Invades bone cavity - Further from tonsils the better the prognosis - Important risk factor is second hand smoke