An anatomical study to evaluate the risk of pulpar exposure during mechanical widening of equine cheek teeth diastemata and ‘bit seating’

Abstract

SummaryReasons for performing study: Cheek teeth (CT) diastemata are a major equine dental disorder that can be treated by mechanically widening the diastemata. There is limited anatomical knowledge of the spatial relationships of the individual pulps to the adjacent interproximal surfaces; on the risks of exposing the 6th pulp horn when performing the clinically unproven 'bit seating' procedure on Triadan 06s. Objectives: To describe the anatomical relationships between the occlusal and interproximal surfaces of CT and the adjacent pulp horns; and between the 6th pulp horn and the occlusal and rostral surfaces of Triadan 06s. Methods: The CT from 30 skulls of horses subjected to euthanasia for non-dental reasons were sectioned to expose the rostrally and caudally situated pulp horns to allow the anatomical relationships between the pulp horns and the occlusal and interproximal aspects of the CT to be assessed. Results: Pulp horns were mean Ϯ s.d. of 5.74 Ϯ 1.45 (range 1.3-10.8 mm) from the nearest interproximal surface, with 5.3% of pulp horns being <3.5 mm from the interproximal surface. In contrast to expectations, pulps tended to became closer to the interproximal surface (and also to the occlusal surface) with increasing age. Teeth with physiologically tall clinical crowns, and also those in the Triadan 09 position had pulps that were closer to the interproximal surfaces than the remaining CT. The more caudally situated pulp horns, i.e. in particular, the 4th maxillary and 5th mandibular pulp horns were closer to the interproximal surfaces than the remaining pulp horns and these pulp horns also had the thinnest sub-occlusal secondary dentine. Pulps that were close to the interproximal surface were also found to be close to the occlusal surface of the CT. Conclusions and potential relevance: While diastema widening is theoretically safe between the majority of CT, a small proportion of pulp horns are only 1.3 mm from an interproximal surface and others lie just 1.6 mm beneath the occlusal surface, and such pulps are at risk of pulpar exposure and to thermal injury during this procedure. The risk of pulpar exposure increases when dental tissue is removed from the caudal aspects of CT.

Equine dental and periodontal anatomy: A tutorial review

“…The distance of the vital pulp to the mesial (rostral) and the distal (caudal) border of the cheek teeth varies between <3 mm and 9 mm (Kopke and Staszyk ; Bettiol and Dixon ; Dixon et al . ), with a mean distance of approximately 5–6 mm.…”

Pulpar temperature changes during mechanical reduction of equine cheek teeth: Comparison of different motorised dental instruments, duration of treatments and use of water cooling

“…Rasping periods of >30 s are more applicable for reduction of more significant focal dental overgrowths, where multiple pulp horns are likely to be susceptible to thermal damage. Recent studies have shown that subocclusal secondary dentine thickness in overgrown teeth can be as low and as variable as normal values . Marshall et al .…”

Is your practice diagnosing cheek teeth diastemata?

“…The burr is then placed vertically into the diastema and moved across the interdental space. As the distal pulp horns of cheek teeth lie very close to the caudal aspect of the teeth, an attempt must be made to remove most of the dental tissue from the rostral aspect of the tooth lying caudal to the diastema (Bettiol and Dixon ; Dixon et al . ).…”