Page 759 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

734 CHAPTER 4

VetBooks.ir leaving the temporary incisors displaced labially but appearing to expose less clinical crown. Retention of
deciduous premolars is a common finding in racing
retaining the gingival attachments. Temporary pre-
molars are commonly retained in young horses, due
times attributed to deciduous premolar retention.
to compression in a rostrocaudal direction along the Thoroughbreds and reluctance to perform is some-
arcade, which results in failure of the deciduous teeth Removal of retained caps is indicated if the division
or ‘caps’ to be shed even after they have apparently between the temporary and permanent dentition can
lost their gingival attachments. It is most commonly be palpated on the buccal/palatal aspect of the tooth,
the deciduous 07s and 08s that are retained, and indicating that the gingival attachment has receded
accumulation of ingesta underneath the shell-like and that the cap is being retained solely by compres-
caps can exaggerate the mild periodontitis associ- sion between the adjacent teeth. Permanent hyper-
ated with normal eruption, resulting in painful or polydontia can be noted incidentally on an oral
gingivitis. In some breeds such as the Welsh sec- examination or due to clinical signs associated with
tion A, obstruction of the eruption pathway due to secondary consequences.
permanent premolar impaction can lead to retained
deciduous premolars. Permanent hyper-/polydontia Diagnosis
occurs most commonly in the maxillary arcade, and A thorough oral examination should reveal retained
bilateral symmetrical supernumerary distomolars deciduous dentition without gingival attachments.
are sometimes observed (Fig. 4.9). Incisor polydon- Commonly, supernumerary teeth are often over-
tia and hyperdontia of the mandibular teeth also looked on an oral examination and can be diagnosed
occur. Permanent hyperdontia can lead to malerup- incidentally when radiographs are viewed.
tions, impactions and periodontal disease, although
some cases remain asymptomatic and undetected Management
until an advanced age (Figs. 4.26, 4.27). To remove retained deciduous incisors, periodon-
tal attachments are easily separated with a flat or
Clinical presentation curved elevator after sedation and local analgesia
Although the deciduous teeth may resemble the of the horse, and the tooth may then be extracted
erupting teeth on the occlusal view, the labial aspect with minimal effort using a small single-handed
of the tooth appears much smaller, with the gingiva dental cap extractor with an excellent prognosis.

4.26 4.27

Fig. 4.26 Orthograde view of a supernumerary Fig. 4.27 Misaligned supernumerary incisors.
maxillary molar with areas of reduced wear causing
sharp ‘overgrowths’.