Page 776 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Gastrointestinal system: 4.1 The upper gastrointestinal tr act 751

VetBooks.ir 4.64 4.65

Fig. 4.65 Rostral maxillary overgrowths (hooks)
such as on this specimen are the consequence of
malocclusion.
Fig. 4.64 Extreme dysmastication can lead to
extreme occlusal angles termed shear mouth.

Management Aetiology/pathophysiology
Removal of these overgrowths is a fundamental Focal dental overgrowths at the rostral and caudal
part of routine dental prophylaxis. Correction aspects of either the maxillary or mandibular arcades
of severe shear mouth may be a long-term proj- can result from several mechanisms. Anisometria
ect, necessitating gradual reduction of the over- of the maxillary and mandibular arcades can lead
growths over a period (e.g. 6 months) in several to the development of a rostral overgrowth (hook)
treatments. on the 106 and 206, or on the 311 or 411 (Fig. 4.65).
Correction of focal overgrowths is achieved The presence of overgrowths (hooks) on these teeth
using a variety of instruments including rasps of is probably due to a relatively caudal displacement
different handle types fitted with blades made from of the mandible during mastication resulting in
chipped or solid tungsten carbide. Electrically incomplete occlusion. It is possible that domesti-
and battery-operated diamond-coated burrs with cated horses that are fed with the head raised may
water cooling are the most efficient instruments at be more susceptible to this. The presence of caudal
achieving reduction of overgrowths. Good patient mandibular overgrowths, which may cause trauma
restraint with sedation of the horse, the use of to the tongue and other soft tissues, can remain
water cooling to avoid overheating the tooth and undetected in cursory visual examinations of the
precise visual control all reduce the possibility of mouth. Rostral overgrowths, in addition to interfer-
iatrogenic damage when performing malocclusion ing with mastication, can be a contributing factor to
corrections. equitation problems when ridden due to pain caused
by entrapment of gingival mucosa between bits and
ROSTRAL AND CAUDAL OVERGROWTHS the sharp buccal/rostral overgrowth.
(‘HOOKS, BEAKS, RAMPS’)
Clinical presentation and diagnosis
Definition/overview Hooks may present as masticatory disorders,
Prominent overgrowths on the rostral and cau- oral pain, hypersalivation and equitation problems.
dal aspects of the arcade resulting from uneven Careful oral examination and palpation will demon-
wear. strate the presence of such overgrowths.