Equine Dentistry 3010 Past Paper PDF (October 24)

EQUINE DENTISTRY Dr Karen Moore BVSc Cert AVP (ED) FHEA CATE MRCVS LEARNING OBJECTIVES By the end of this lecture you should be able to: Understand the use of the Triadan system when descri...

EQUINE DENTISTRY Dr Karen Moore BVSc Cert AVP (ED) FHEA CATE MRCVS LEARNING OBJECTIVES By the end of this lecture you should be able to: Understand the use of the Triadan system when describing the dentition of horses Understand the principles of aging horses using dentition Relate the anatomy, physiology and natural occlusion of equine teeth to the requirement for routine dental care in horses Understand the basic principles of equine dentistry With thanks for some photos to: Ben Portus from Paton and Lee Equine Vets The Donkey Sanctuary Illustrations and photos from Equine Dentistry 3rd Edition by Easley, Dixon & Schumacher TRIADAN SYSTEM TRIADAN SYSTEM 100 200 400 300 (right) (left) 500 600 Photo credit: BP 400 300 800 Adult teeth 700 Deciduous teeth Anisognathic: 11 08 mandible wider 10 09 07 06 100 than maxilla 200 (right) 11 (left) 10 09 08 06 07 4 #uniofsurrey  WOLF TEETH AND CANINES Always numbered, even if not present Photo credit: BP  A N AT O M Y O F A T O O T H Cementum Enamel Dentine Secondary dentine at pulp horns pulp may lie as little as 2mm below this Infundibulae Maxillary only MAXILLARY CHEEK TEETH 3 roots: 2 buccal, 1 palatial 2 infundibulae 06 / 07 roots within maxillary bone 08/09 roots within Rostral Maxillary Sinus 10/11 roots within Caudal Maxillary Sinus 7 #universityofsurrey MANDIBULAR CHEEK TEETH 2 Roots: rostral and caudal No infundibulae Narrower bucco-lingually compared to maxillary teeth 8 #universityofsurrey AGING HORSES A G I N G ( E S T I M AT E S ! ) Eruption times 05’s (Wolf 01’s 02’s 03’s 04’s (Canines) teeth) Deciduous 1st week of life 4-6 weeks 6-9 months - - Permanent 2.5 years 3.5 years 4.5 years 4 – 5 years 5-18 months Eruption times Molars 06’s 07’s 08’s 09’s 10’s 11’s Deciduous 1st week of life 1st week of life 1st week of life - - - Permanent 2.5 3 4 1 2 3.5 A G I N G ( E S T I M AT E S ! ) A: 6 year old Belgian draft horse B: 16 year old Standardbred horse Note the shape of the incisors (wide vs tall) and the angle between lower and upper incisors. A G I N G ( E S T I M AT E S ! ) E: Enamel (white) D: Primary dentin (yellow) I: Infundiulum C: Cement P: Pulp cavity Cup: The top part of the infundibulum that is filled with food particles and stained. Mark: The enamel ring and enclosed cement core of the infundibulum. Star: Transverse cross section of pulp cavity (filled with secondary dentin). Note the shape of the tooth from oval to triangle as it ages. https://www.mitchellplainfarm.com/dental-care-and-development.html  R E L A T I N G A N A T O M Y, P H Y S I O L O G Y A N D N AT U R A L OCCLUSION TO ROUTINE D E N TA L C A R E CAPS Caps are the deciduous teeth that cover the permanent teeth. In some cases they may need to be removed. If removed too soon they can damage the growth of the permanent teeth below. EMBRYOLOGY The crown and occlusal surface of a multicusped hypsodont tooth with an infundibulum (i.e. upper cheek tooth) A: Immediately prior to eruption B: Immediately following eruption, showing loss of the dental sac over the occlusal surface C: Following wear of the primary occlusal surface to expose the permanent occlusal surface A N AT O M Y R E L AT E D T O P U R P O S E Equids are grazers The 6 cheek teeth function as a single chewing unit due to the angulation of the 06’s and 11’s THE CHEWING CYCLE Diagrams from Equine Dentistry 3rd Edition 1 2 3 Lateral excursion to molar occlusion test S A L I VA RY G L A N D S Three (paired) salivary glands: Mandibular Parotid Sublingual  W H Y P E R F O R M D E N TA L S ? Diet Equids have evolved as grazers and browsers. Chewing motion is altered from fibre (side to side) to concentrates (up & down). What we feed matters. Age In the wild equids with dental disease / unable to eat would be the ones picked off by predators. We keep equids a lot longer so they need more care. Evolution / Breeding Horse vs Donkeys vs Miniature shetlands. Arabs. DIET Excessive Transverse Ridges (ETR’s) Transverse ridges are normal – increase surface area. Do not remove. Beware individual ETR’s – look for a cause (diastema opposite?) If abnormal – reduce. DIET Sharp Buccal and Lingual Points (BLP’s) Enamel overgrowths. Remember anisognathic so Mandibular lingual BLP’s. Maxillary buccal BLP’s. Need reducing to prevent soft tissue trauma. Correct with routine floating (rasping). DIET Shear mouth > 45º angle of occlusion. Due to minimal side to side movement when chewing. Usually due to diet or pain…check carefully for an inciting cause. Reduce over several treatments. AGE Equids have a finite length of crown. Teeth erupt at approximately 2mm per year. Tooth roots have no enamel. Mouth will have gaps as teeth are lost and remaining teeth will be smooth which affects chewing ability (smooth mouth). Diet needs to change as a result. EVOLUTION / BREEDING Cheek teeth displacements Can be medial or lateral. More common in miniature breeds – overcrowding. Varying degrees. Care with rasping – beware pulp horns. Best treatment may be extraction. Photos: The Donkey Sanctuary BASIC PRINCIPLES OF EQUINE DENTISTRY BASIC PRINCIPLES First do no harm! If you do not have the required skills or equipment get someone who has then get some training! Every dental exam starts with a detailed history and clinical exam. The aim of a dental is to leave the horse more comfortable than when you started. R O U T I N E D E N TA L : E Q U I P M E N T Essential equipment Helpful equipment Gag Sedation Headlight Analgesia Head stand Picks / Probes Gloves Goggles / Face mask Flush Chair / stool Rasps Endoscope Bucket Disinfectant Dental charts and pen Dental mirror 27 #universityofsurrey R O U T I N E D E N TA L : C H A R T I N G Part of your clinical records Note Findings Treatment Sedation given Management advice Re-exam date Most horses - 12 months If findings ‘severe’ but mostly resolved - 6-9 months If findings require more than 1 session to resolve – 3 months 28 #universityofsurrey P E R F O R M I N G A D E N TA L : R A S P I N G Manual vs Power tools Manual tools Power tools Operator Fatigue Greater Lesser Time taken Greater Lesser Heat produced Negligible Yes Potential for soft tissue Yes Negligible damage Precision Not precise Can be very precise RESOURCES