Clinical insights into the three-dimensional anatomy of cheek teeth in alpacas based on micro-computed tomography. Part 1: mandibular cheek teeth

Abstract

Background Despite dental disease being a common health concern in alpacas, important dental pathology including apical infection, remains poorly understood. Treatment options are limited compared to veterinary dentistry techniques in other species. The primary goal of this study was to increase understanding of the external and internal anatomy of mandibular cheek teeth to enable the development of tooth sparing techniques in this species. Also, an objective evaluation of the sub-occlusal dentinal thickness in normal mandibular cheek teeth is warranted to understand the risks associated with reduction of overgrown teeth. Results Overall pulp anatomy was variably characterized by the presence of a common pulp chamber in younger teeth, and segmentation of pulp cavities into multiple separate pulp entities within the same tooth with increasing age. A common pulp chamber was identified in 55.3% (26/47) of teeth with a mean dental age of 1 year and 11 months (± 1 year and 8 months). Columnar segmentation was recorded in the remaining teeth with a mean dental age of 6 years and 5 months (± 3 years and 11 months). Age of segmentation of the common pulp chamber into multiple separate pulp entities shows wide variation and is dependent of the specific Triadan position. The present study illustrates the presence of disto-mesial root contacts between adjacent tooth roots, often leading to morphological adaptations, most frequently observed between Triadan 09–10s (80%) and 10–11s (67%). The measured sub-occlusal dentinal thickness was as low as 1.11 mm over some pulp horns. The sub-occlusal dentinal thickness was lower than 2, 3, and 4 mm in 13.1, 38.1 and 61.4% of performed measurements, respectively. Conclusion This study provides detailed information on age-dependent mandibular cheek teeth anatomy in alpacas, which may support the use and development of advanced dental treatments in this species such as endodontics and tooth sectioning techniques. Apical morphological adaptations caused by disto-mesial root contact between adjacent mandibular cheek teeth are clearly illustrated. The limited amount of sub-occlusal secondary dentin warrants a cautious approach with regards to dental floating in alpacas.

A histological description of alpaca (Vicugna pacos) cheek teeth: Findings and anatomical variations in macroscopically normal molars

“…Hence, apical infections, previously termed tooth root abscesses, are the most common dental condition affecting alpacas, primarily involving the cheek teeth ( 1 ). Recently, micro-computed tomographic studies have confirmed that adjacent tooth roots from different cheek teeth can physically contact each other ( 7 , 8 ). However, up until now, no histological studies have been published focusing on the normal histological findings at the level of the cheek teeth in this species.…”

“…The microscopical characteristics of the dental hard substances and dental and periodontal tissues were described and alpaca specific structures were identified. Referencing to specific pulp horns and root canals was based on a specific numbering system for alpaca cheek teeth ( 7 , 8 ). A classification of different types of dentin was performed based on the classification system as proposed by Dacre et al ( 11 ) in other hypsodont species.…”

“…This has led to novel insights into diagnosis and treatment strategies of dental pathology in horses (4)(5)(6). An extensive µ-CT study of normal mandibular and maxillary cheek teeth anatomy in alpacas illustrated the presence of a complex and dynamic dental pulp architecture characterized by the age-related development of several separated pulp segments from an originally interconnected pulp system with a common pulp chamber as the central entity (7,8). Imaging studies have also shown close contacts between roots of adjacent cheek teeth which raised questions concerning its contribution to the development and spread of infectious dental disease (7)(8)(9).…”

“…An extensive μ-CT study of normal mandibular and maxillary cheek teeth anatomy in alpacas illustrated the presence of a complex and dynamic dental pulp architecture characterized by the age-related development of several separated pulp segments from an originally interconnected pulp system with a common pulp chamber as the central entity ( 7 , 8 ). Imaging studies have also shown close contacts between roots of adjacent cheek teeth which raised questions concerning its contribution to the development and spread of infectious dental disease ( 7 – 9 ). Further histopathological investigations and the characterization of dental diseases in alpacas are hampered by a lack of data describing the normal microanatomical appearance of dental substances as well as pulp and periodontal tissues in alpaca cheek teeth.…”

Micro-CT and histological examination of accessory canals in 34 equine cheek teeth

“…They have also been described in other brachydont species such as dogs ( 22 – 26 ) and cats ( 27 , 28 ). Additionally, even hypsodont cheek teeth of alpacas ( 29 ) and equine incisors can have accessory canals.…”