Accentuated (Excessive) Transverse Ridges (ATR'S): Enlarged ridges that run across chewing surfaces of molars. Forms from a harder enamel ridges in one tooth dominating and wearing into a softer cementum and dentine in an opposing tooth. Can cause diastemas between adjacent teeth from forcing them apart.
Alveolar: Acts as the cushioning between the tooth and the bone where the tooth sits in the jaws.
Alveolar Socket: Is the tooth socket where the reserve crown sits.
Anelodont: The horse is anelodontic by nature due to their teeth stopping to grow.
Apical Abscess: This infection of the apical cavity is a condition can often be a result of feed having pocketed into diastemas between teeth and fermenting, initially causing gingivitis which gives the feed the opportunity to work its way down alveolar tooth socket between tooth and gum. It can be also caused through feed packing into split and fractured molars. If the abscess is located on the lower mandible for instance the infection will sometimes blow out through the skin.
Apical Cavity: Shape of the tip of the tooth root where the nerves and blood supply enter the tooth.
Arcades (Dental): Refers to the 4 individual rows of the 6 cheek teeth in the lower Mandibular and upper Maxillary.
Bit Seats: It is a technique where the height of the 1st cheek teeth of the mandibular arcades of performance type horses are reduced rostrally, with that same area of tooth being shaped into the appearance of the contemporary bullet trains we see in transit around the world.
Blind Wolf Teeth: Abnormal wolf tooth that does not break through gums. Blind Wolf Tooth erupt at an angle, often up to one inch forward of premolars. Angle of tooth does not allow it to penetrate gums.
Bolus: The rolling of feed particularly hay into saliva induced balls to help with enzymatic breakdown to aid in digestion.
Bone Spur (Sequestrum): Mandibular peritonitis or abnormal bony growth due to trauma. Most often caused by trauma from the bit to the lower jaw bone.
Buccal: Is the term used to describe the side of the dental arcades closest to the cheek or pertaining to the cheeks.
Buffing: Term used to describe the treatment of reducing height and sharpness rendered to overgrown and sharp canine teeth.
Calculus: Tartar build-up that occurs on the canine teeth, if not removed it can lead to Benign Gingival Hyperplasia and in time possibly Cancer.
Canines: Teeth the horse uses for defending and fighting out on the grassy plains, they are situated in the inter-dental space directly behind the corner incisors. Male horses usually have four canines with two situated in the upper and lower jaw respectively. Female horses usually do not have them, however if they do, they are generally much smaller. The canines need regular attention through buffing as they can become sharp and cut the tongue.
Caps: Refers to the deciduous teeth commonly called milk teeth or baby teeth that begin to shed at a specific time. They are routinely removed by the dentist during service.
Caries: Decay of the tooth, not overly threatening.
Caudal: Toward the back of the oral cavity.
Cementum: Softer than dentin and enamel due to it being less mineralized. Helps to anchor the tooth by attaching it via the periodontal ligament in the pulp chamber of the tooth.
Colic: Gastro-intestinal conditions causing clinical abdominal pain, can be fatal.
Congenital: Hereditary conditions of a foal which have developed before birth during foetal growth in the womb.
Cribbing: A stereotypical behavioral trait with the horse commonly gripping an edge such as a wooden fence, grain bin, metal round pen, stable door, etc. with his front teeth, arching his neck and swallowing air.
Crown: Part of the tooth sitting above the gum line.
Curve (Angle) of Spee: A naturally occurring phenomenon in some horses where a distinct dorsal-ventral curve appears halfway along the dental arcades following the natural alignment of the horses upper and lower jaws.
Deciduous Teeth: See “Caps”.
Dental Cup: A funnel or funnel-shaped structure or passage that fills with cementum. Wear of the occlusal surface causes the cup to get smaller and eventually disappear from all lower incisors at about 8 years of age leaving the enamel spot in its place.
Dental Pathologies: Term used to generalize problematic oral cavity conditions in need of correction.
Dental Star: Exposed portion of the pulp chamber on the occlusal surface of the incisors.
Dentin: Has a degree of permeability which can increase the sensation of pain and the rate of tooth decay. Continues to form through life by stimuli and attrition.
Diastema: Refers to a space that is sometimes present between adjoining teeth in individual horses, food often packs into these areas and without regular and routine dental care the food can break down and ferment leading to serious secondary health issues. Often results as malocclusions force two teeth apart over time.
Diphysodonts: A horse is diphysodontic by nature due to the oral cavity containing both Deciduous (Baby Teeth) and Permanents.
Dorsal Curvature (Frown): Outer corner upper incisors grow longer relative to outer corner lower incisors. May occur when deciduous caps are retained on lower corner incisors preventing normal growth of permanent incisors. Often occurs from cribbing and wood chewing and can occur due to abnormal chewing secondary to molar malocclusions.
Enamel: Extremely hard, but brittle, encased in cementum to protect against fractures, splits, chips and breakage. The main cause of dominance of an adjacent tooth over another. The sharp edges of horse’s teeth are of the enamel component of an individual tooth, but because of the brittleness of enamel these points can be removed relatively easily, providing relief for the horse and, all other things being equal, a return to a normal chewing cycle.
Enamel Points: Sharp enamel points that occur buccally in the upper maxillary arcade and lingually on the mandibular arcade due to the natural grinding action required to chew.
Eruption: Horses teeth continue to erupt through their lifetime to off-set the 3 - 4mm of tooth that is abraded through the grinding action that is required to chew forage and grains.
Eruption Bumps: Young immature horses typically have what look to be bumps or cysts that are located along the jaw line, but these are usually skin distension caused by permanent teeth looking for space to grow and waiting for anatomical changes of the skull to catch up. I guess this phase is not to dissimilar to humans experiencing teething problems. Until the horse reaches maturity the skull will continue to change, with the bones reforming as the permanent teeth take shape within the jaw.
Floating: The term floating is given to the practice of maintaining horse’s teeth by regular and routine equine dentistry care. This has been done through the ages predominately by the use of hand floats. The use of hand floats to service the oral cavity of the horse is still the best way to adhere to the principles of regular and routine equine dentistry which includes taking away the sharp enamel points from the upper and lower arcades of the horses oral cavity and correcting any abnormal wear patterns.
Galvaynes Groove: Is a vertical tapering groove in the lateral surface of the upper permanent corner incisor tooth in the horse. It appears at the gum margin at 10 years of age, is halfway to the end of the tooth at 15 years, has reached the end at 20 years, has disappeared from the top of the tooth at 25 years and has disappeared completely at 30 years. The ages quoted are subject to variation.
Gingival: Pertaining to the gum. Pink mucosal tissue layering over the Alveolar Bone.
Gingivitis: Inflammation of the Gingiva. Can lead to Periodontal Disease.
Glassing/Glassed: This is a term used when a practitioner has taken so much of the occlusal or grinding surface of the molar arcade tables away it renders the molars smooth. This is the main contributing factor in horses being unable to eat for days and sometimes weeks after a dental service.
Hard Palate: Roof of the oral cavity. Helps with mastication.
Heterodonts: A horse is heterodontic by nature because of the appearance of Incisors, Canines, Pre-molars and Molars.
Hypsodonts: A horse is hysodontic by nature as their teeth continually erupt.
Hooks: Hooks usually occur on the last cheek teeth on the mandibular arcade and the first cheek teeth of the maxillary arcade. These hooks are more prevalent in horses that are over shot in front which generally dictates that the conformation of the oral cavity is skewwhiff or off-set with the opposing upper and lower arcades not directly opposing one another resulting in, incomplete occlusal contact when the horse grinds its food.
Impacted Teeth: Is a condition where teeth cannot erupt into occlusion due to overcrowding by other teeth, which do not leave enough room. Impactions or partially emerged teeth can trap food, plaque, and other debris in the soft tissue around it, leading to inflammation and tenderness of the gums and unpleasant mouth odor. Infection can set in extending into the jaw or sinuses.
Incisors: Are teeth at the very front of the horse’s mouth. A horse contains 12 Incisors 6 in the upper and lower jaw (Centrals, Laterals and Corners) which are firstly deciduous before being replaced by permanent teeth at a certain stage through shedding. These teeth are used for cutting and ripping forage.
Infundibulum: A funnel or funnel-shaped structure or passage that fills with cementum. Commonly referred to as the "Dental Cup" in the incisors. Wear of the occlusal surface causes the cup to get smaller and eventually disappear from all lower incisors at about 8 years of age leaving the enamel spot in its place.
Labial: Towards the lips of the horse.
Less Is More: Research today tells us that the less tooth we take off, the more benefit is attributed to the horse. One important concept in equine dentistry to remember is this; it is easier to take more tooth off, but you can never replace tooth. Power tools take so much tooth off very quickly so the overall job takes very little time at all, and there is a general assumption that these guys feel they should be doing more to take up more time which invariably means a few more swipes of the dental arcades and before you know it the horses' teeth have been glassed, rendering the horse unable to eat for days and sometimes weeks at a time.
Lingually: Is the term used to describe the side of the dental arcades closest to the tongue or pertaining to the tongue.
Malocclusion: Is a term used to describe when an individual horses molar or incisor teeth are out of alignment or occlusion.
Mandibular/Mandible: The lower jaw, narrower in width.
Mastication: Is the act of grinding the feed with the teeth with help from the tongue and ridges of the hard palate before swallowing.
Maxillary/Maxilla: The upper jaw, wider in width.
Molars: Do not have deciduous precursors and are used for the grinding of food during the act of chewing and mastication.
Monkey Mouth (Prognathia): Also common referred to as Sow Mouth. Occurs when the mandible is longer than the maxilla.
Mucous Membrane: Healthy horses have pink membranes, the deeper the colour the more blood flow. They are essentially a lining of tissue that lines not only the cheeks of the horse, but also other body cavities. It is sensitive to the sharp enamel points that are present in the oral cavity of the horse with lacerations and ulceration of the mucous membrane common.
Occlusion: Surface to surface contact by opposing teeth.
Palatine Artery: An artery lying lingually to the upper maxillary molar arcades.
Parrot Mouth (Brachygnathia): Occurs when the mandible is shorter than the maxilla.
Periodontal Ligaments: Tough fibrous tissue connects the tooth to the bony alveolar tooth socket. Normally, teeth do not contact the bone directly; a tooth is suspended in its socket by the fibers of the ligament. This arrangement allows each tooth limited individual movement. The fibers act as shock absorbers to cushion the force of the chewing impact of mastication.
Periodontal Sockets: Gum disease around a tooth causing an area for feed to pocket. Results from malocclusion or miss-alignment of teeth. Progresses as horses are unable to chew correctly.
Periodontal Disease: The periodontium is all of the supporting tissue surrounding the teeth. Periodontal Disease is defined as inflammation of the gums, periodontal ligament and the alveolus (socket) that all act to hold the tooth firmly in place. When conditions exist to compromise these structures, pain develops, the tooth loosens and ultimately the tooth is lost. Studies have shown that up to 60% of horses over 15 years of age have identifiable periodontal disease so this is a problem that must be diagnosed and treated to forestall tooth loss as long as possible.
Premolars: Are deciduous precursors to the permanent teeth that will erupt into occlusion at specific times throughout the young horse’s life.
Protuberant Teeth: A tooth that has grown unopposed and is out of occlusion in comparison the the other aligned teeth in the dental arcade.
Pulp Chamber: Pulp is found in large quantities in and around developing teeth. With age more secondary dentin is laid down as development of the tooth, requiring large quantities of pulp. This makes them stronger and more solid.
Quidding: Occurs when the horse is suffering from dental pathologies rendering the horse unable or unwilling to swallow. The food is rolled into a bolus before the horse drops the feedback to the ground.
Ramps: Excessive height to predominately the lower premolar tables quite unlike a hook. May occur when premolar deciduous cap or baby tooth is retained preventing normal growth of permanent premolar. Can occur if a tooth is reduced without corresponding correction to opposing tooth. Generally seen is a gradual rising of the molar table either rostrally or caudally.
Reserve Crown: The part of the tooth under the gum line that is attached into the alveolar tooth socket via the periodontal ligament.
Root of Tooth: Starts below the reserve crown, in aged horses when the reserve crown has expired the tooth root will be exposed.
Rostrally: Toward the front of the oral cavity.
Shear Mouth: Extreme angulation of the occlusal molar table. Results from lack of lateral excursion or side to side chewing. This may result in an angle at 60-75 degrees, opposed to the normal 15 degree angle seen on most horses. Lateral excursion is nrarly impossible, and the angle of the tables only becomes greater by abnormal abrasion. Shear teeth are usually only seen on one side of the mouth.
Slant Mouth (Diagonal Bite): Upper incisors on one side of mouth are excessively long and lower incisors on opposite side are excessively long, causing incisors to meet on a diagonal. May develop over time if horse chews more in one direction. Can result from cribbing and wood chewing and may occur secondary to molar malocclusion or as a result of a missing incisor or incisor damage causing opposing incisors to become excessively long.
Step Mouth: Molar arcade develops stepped-like appearance. Most often occurs due to a missing tooth allowing the opposing tooth to grow into the void. Can occur from extreme uneven wear. May occur when a deciduous cap or baby tooth is retained too long delaying normal growth of permanent tooth and allowing opposing tooth to grow too long.
Supernumerary: Extra teeth not normally part of the nomenclature.
Temporo-Mandibular Joint (TMJ): The TMJ of the horse refers to an area of the cranium or skull where the jaw, or the mandible, contacts and articulates with the temporal bone through a joint formed by the temporal fossa and the coronoid process. It is made up of muscles, ligaments and tendons that surround the synovial joints that contains a joint capsule, synovial membrane, synovial fluid, articular cartilage and ligaments formed between the condyles of the mandible and the temporal bone.
Trephine: An instrument saw used to cut a circular piece of bone from the skull of the horse in order to extract molars.
Triadan System: System used for the equine dentition nomenclature as well as for other species, including humans.
Ulceration: Ulceration of the cheeks and tongue occurs when horses teeth become very sharp due lack of attention. The grinding action required to chew allows for sharp enamel points to form on the outside (Buccal) of the upper maxillary arcade and on the inside (Lingual) of the lower mandibular arcade. These points shred the mucosa of the horse’s cheeks and the tongue whenever the horse is trying to chew.
Ventral Curvature (Smile): Outer corner lower incisors grow longer relative to outer corner upper incisors. May occur when deciduous caps are retained in the upper corner incisors which may prevent normal growth of permanent incisors. Can occur due to abnormal chewing secondary to molar malocclusions.
Wave Mouth: Molar arcade develops an uneven "wavelike" appearance generally involving many premolars and molars. Often occurs secondary to other malocclusions such as retained deciduous caps, missing teeth, hooks, ramps, etc. Results from horse being unable to obtain free side to side chewing.
Wolf Teeth: Wolf teeth are also known as the first premolar, they're a vestigial remnant tooth left over from the modern day horses equine ancestors. They are situated in the majority of cases directly in front of the 1st cheek teeth of the upper maxillary arcades; though rare they can also be found in the same position in the lower mandibular arcade. The most common number for a horse to have is one or two, but they can have up to four. They have no function for chewing but can contribute to problems with horses being educated with a bit. The removal of these teeth is often advantageous.