Molars

Caudal Hooks

DEFINITION - Dominant lower or upper last molar overhanging opposing molar. 

Causes - Hereditary - May result from horse born with over or underbite. Developmental - May result secondary to molar malocclusion that forces jaw out of alignment.

RESULTING PROBLEMS - Prevents horse from chewing freely side to side resulting in improper and excessive molar wear. Tight soft tissues are very susceptible to lacerations from sharp molar points. Can cause extreme discomfort as head carriage or frame is changed when riding.

SOLUTION - Reduce dominant molar to prevent excessive wear to opposing molar and carefully round to prevent soft tissue trauma.


Rostral Hooks

DEFINITION - Dominant upper front premolars overhang lower premolars. 

Causes - Hereditary - May result from horse born with an overbite. Developmental - May result secondary to molar malocclusion that forces jaw out of alignment.

RESULTING PROBLEMS - Prevents horse from chewing freely side to side resulting  in improper and excessive molar  wear. Can cause excessive wear to opposing lower premolars,  severe bit problems, riding issues and trauma to soft tissue.

SOLUTION - Reduce dominant portion of upper premolars, rounding unopposed portion of upper premolars smoothly toward gum. Requires preventative maintenance to prevent reoccurrence.

Ramps

DEFINITION - Excessive height to lower front premolars.

Causes - May occur when upper front 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.

RESULTING PROBLEMS - Prevents horse from chewing freely side to side resulting in improper and excessive molar wear. Can cause severe discomfort with bit, can force lower jaw forward over time causing underbite.

SOLUTION - Reduce dominant teeth to allow opposing teeth to recover over time.

1) Enamel Points 2) Asymmetrical Arcades (Sheared Molar Tabl

1) DEFINITION - Sharp points that generally form on the outside of the upper molars and the inside of the lower molars.

Causes - A natural occurance that over time as a horse chews side to side, results in the erupting teeth getting longer and the enamel forming razor sharp points.

RESULTING PROBLEMS - Enamel points traumatize soft tissues causing pain and discomfort when eating, bitted and wearing halters/bridles which pulls cheeks and tongue into these points. Can cause horse to ride very stiff and unhappy.

SOLUTION - Remove sharp enamel points (floating).


2) DEFINITION - Extreme angulation of chewing surface of molars.

Causes - Results from lack of lateral excursion or side to side chewing.

RESULTING PROBLEMS - Very severe problem. Does not allow horse to chew sideways resulting in very poor utilization of feed.

SOLUTION -  Look for asymmetry of the face and body, the temperal muscles and the roof of the mouth. Correct molar table angle of upper and lower molars to allow horse freedom to chew side to side.

Wave Complexes

DEFINITION - Molar arcade develops an uneven “wavelike” appearance generally involving many premolars and molars.

Causes - Often occurs secondary to other malocclusions such as retained deciduous caps, missing teeth, hooks, ramps etc.. Caused by dominant teeth oppsosing weaker teeth and uneven wear.

RESULTING PROBLEMS - Causes gradual excessive wear to many molars, resulting in prematurely worn out teeth, periodontal pockets, decay and loss of teeth. Can prevent side to side chewing and inhibit proper grinding. Can cause abscessing, bone infections and fractured molars.

SOLUTION - Reduce high complexes to allow recovery of opposing teeth and allow freedom to chew freely. Equilibrate excessive crowns to allow proper eruption rate of opposing teeth, especially in young horses. Preventative maintenance over time.

Stepped Molars

DEFINITION - Molar arcade develops  stepped-like appearance.

Causes - 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 deciduous cap or baby tooth is retained too long delaying normal growth of permanent tooth and allowing opposing tooth to grow excessively long.

RESULTING PROBLEMS - Prevents or blocks the horse from being able to chew freely resulting in uneven and improper wear to molars and incisors. Facial swelling and infection may occur.

SOLUTION - Reduce high molar to allow freedom to chew correctly. Requires maintenance to prevent unopposed tooth from growing into space.

Excessive Transverse Ridges (ETR)

DEFINITION - Enlarged ridges that run across chewing surfaces of molars.

Causes - Can result from a shift in jaw alignment. Forms from a harder area in one tooth overpowering and wearing into a soft area in an opposing tooth. Also can occur if horse is not chewing in proper sideways motion.

RESULTING PROBLEMS - Interfere with normal chewing and jaw motion front to back. Cause excessive wear to opposing molars. Can result in severe periodontal disease and diastema.

SOLUTION - Reduce enlarged ridges to allow opposing teeth to recover and allow the horse to chew correctly. Then will improve on its own when existing malocclusions are corrected.

Periodontal Pocket

DEFINITION - Gum disease around tooth causing an area for feed to pocket.

Causes - Results from malocclsion, fracture or misalignment of teeth. Progresses as horse is unable to chew correctly. 

RESULTING PROBLEMS - Gum disease leads to bone erosion around teeth and eventually can lead to facial swelling, adscessing, infection and loss of tooth.

SOLUTION - Correct malocclusions as early as possible. It is very difficult to stop progression of periodontal disease if it is not stopped early on. Prevention and regular dental equilibration is the best course of action.

Diastema

DEFINITION - Space that occurs between two adjoining teeth.

Causes - Often results as malocclusions force two teeth apart over time.

RESULTING PROBLEMS - Causes feed to get trapped between teeth resulting in progressive and severe periodontal disease. Results in overall poor oral health.

SOLUTION - Very difficult to solve after damage has occured. Reduce unopposed overgrowth of opposing teeth. Prevention equilibration of malocclusions is the key.

Incisors

Diagonal Bite (Offset)

DEFINITION - Upper incisors on one side of mouth are excessively long and lower incisors opposite side are excessively long, causing incisors to meet on a diagonal.

Causes -  May develop over time if horse chews more in one direction. Often caused by asymmetry of the arcades and tables.May occur secondary to molar malocclusions or as a result of a missing incisor or incisor damage causing opposing incisors to become excessively long.

RESULTING PROBLEMS - Cause horse to excessively wear molars on one side of mouth and opposite side molars become overly long resulting in a sheared molar table angle. Can result in major TMJ pain. Look for lack of symmetry of face, body, TMJ and temporal muscles. When ridden, stiff and lack of flexion on one rein verses the other.

SOLUTION - Reduce wedged incisors allowing proper lateral excursion and molar contact. Equilibrate corresponding molar malocclusions. For the horse to reach his potential will need accurate and detailed proper equine dentistry to follow up on corrections on a regular basis.

Ventral Curvature (Smile)

DEFINITION - Outer corner of lower incisors grow longer relative to outer upper incisors.

Causes -  May occur when deciduous caps are  retained on upper corner incisors preventing normal growth of permanent incisors. Can occur due to abnormal chewing secondary to molar malocclusions.

RESULTING PROBLEMS - Inhibits horse from chewing freely side to side often resulting in improper and excessive molar wear.

SOLUTION - Reduce length of upper central incisors and lower corner incisors to allow free side to side movement. Equilibration of the molars is imperative.

Dorsal Curvature (Frown)

DEFINITION - Wolf tooth that does not break through gums.

Causes -  Can come in at an angle anywhere in upper and lower arcades.Sometimes the angle of the tooth does not allow it to penetrate gums.

RESULTING PROBLEMS - Can cause severe riding/bit problems, as it is in a location that the bit contacts. Often missed due to being buried under gums.

SOLUTION -  Remove the wolf tooth and alveolar socket.  

OverBite (OverJet)

DEFINITION - Upper incisors protrude in front of lower  incisors.

Causes -  Hereditary - horse may be born with a relatively small overbite, resulting in rostral and/or caudal hooks progressively getting larger and driving/shifting the mandible towards the back. 

RESULTING PROBLEMS - Prevents horse from chewing freely side to side resulting in improper and excessive molar wear. Rostral  and caudal hooks, transverse ridges, wave complexes and sheared molar table angles will become more severe as horse is forced to chew incorrectly over time. Can also cause severe discomfort with the bit, Temporal Mandibular Joint (TMJ), atlas issues and difficulty for the horse to hold/maintain flexion while being ridden.

SOLUTION - Reduce length of upper incisors. Correct       molar malocclusions.

UnderBite

DEFINITION - Lower incisors protrude in front of upper incisors.

Causes  - Hereditary - Horse may be born with underbite. Developmental - Ramps on lower premolars can cause lower jaw to shift forward resulting in an underbite.

RESULTING PROBLEMS - Prevents horse from chewing freely resulting in improper and excessive molar wear. Ramps, transverse ridges, wave complexes and sheared molar table angles will become more severe as horse is forced to chew incorrectly. Can also cause severe discomfort with the bit. Ramps can cause pain to the horse, i.e., TMJ etc., and create inversion, overflexion and rearing while being ridden with a bit.

SOLUTION - Equilibrate incisors, arcades and individual dominante molars.