equine dentition

directional terminology

• Occlusal surface: surface doing the biting/chewing + contacts the upper/lower teeth

• Lingual surface: surface touching the tongue

• Labial (buccal) surface: surface touching the lips or cheeks

dental formula

• Upper Right = 100’s

• Upper Left = 200’s

• Lower left = 300’s

• Lower right = 400’s

wolf teeth

• Technically first premolar

• Not always present

• Very rare in mandible

• Equally present in M/F

• Can interfere with bit placement and comfort, so often need to be surgically removed

tooth development

• Horses have 2 sets of teeth: 

  • Temporary = deciduous teeth, milk teeth, or baby teeth

    • Begin to erupt in pairs, sometimes before birth

  • Permanent: begin to replace after 2.5 yrs

    • Start with center incisors

    • By 5 yrs, most horses have full permanent set

• Only one set of permanent molars!!

incsicors vs cheek teeth

Incisors

• For cutting/shearing grass and hay

• Implanted deep into jaw, roots converge together
  

Cheek teeth: premolars and molars

• For grinding down plant material

• Have 3-4 deep roots

• Continuously erupt throughout life (replaces teeth from grinding)

• Premolars and molars create continuous grinding surface with no gaps

dental pathologies: general

• Can results in: anorexia, weight loss, choke (lodged food bolus in esophagus, but can still breathe)

• May require: floating (filing teeth), surgery, altered diet/feeding strategies (soaking feed, alternate feed)

retained caps

Retained deciduous teeth

• Permanent teeth erupt without loss of baby teeth

• Requires surgical removal if they don't resolve on their own

• Can result in malalignment of permanent teeth

Malocclusions

• Normal occlusion (teeth contact) = level incisor bite (no overbite like humans)

• Malocclusion = any deviation

  • Overbite (parrot mouth) or underbite

• Can result in uneven wear of cheek teeth, abnormal temporomandibular (jaw) articulation

Cheek teeth abnormalities (4)

• Points: sharp points develop on buccal surface of maxillary cheek teeth

• Hooks: areas of rostral or caudal maxillary or mandibular cheek teeth that aren’t worn down by opposing tooth

• Wave mouth: wave pattern develops on occlusal surfaces of cheek teeth, may be due to retained caps, molars that erupt too slowly, or missing teeth

• Step mouth: one tooth much longer than others in same row, due to opposing teeth being missing/malformed

*Generally corrected by filing down (floating)

Wry nose

Lateral deviation of premaxillary + incisive bones of skill (one side of nose longer)

• Congenital malformation

• Can result in difficulty breathing

• Malocclusion is guaranteed

• Requires reconstructive surgery if severe

Tooth root abscess

Painful infection of cheek tooth root

• Can destroy maxillary bone

• Classic signs

  • Halitosis: bad breath

  • Nasal discharge: due to cheek teeth root interaction with paranasal sinuses

  • Swelling on bridge of nose or mandible

  • Possible draining tract where infection has progressed and exits the skin