title: Infundibula of equine maxillary cheek teeth: Part 2: Morphological variations and pathological changes.
abstract: Incomplete cemental filling of the infundibula of equine maxillary cheek teeth (CT) is a common feature. Depending on the extent of the defect, three stages of infundibular decay have been suggested. However, histomorphological criteria to identify non-pathological abnormalities and destructive changes have not been defined. Six hundred and eighty eight CT with no evidence of dental diseases and 55 diseased permanent, fully erupted maxillary CT were evaluated on a macroscopic level by assessing the occlusal surface and horizontal sections, including porphyrin assays to detect residual blood within the infundibular cementum. Selected specimens were investigated on a microscopic level using routine and immunohistological staining methods to identify possible routes for the spread of infectious agents from the infundibulum into the endodontic system. Infundibular cemental hypoplasia was defined as a non-pathological developmental abnormality and was detected in >50% of CT with no evidence of dental diseases and in >70% of diseased CT. The first molar (Triadan 09) showed the highest prevalence (75%) of infundibular cemental hypoplasia. The mesial infundibulum was more often affected than the distal infundibulum. Infundibular erosion was considered as the most appropriate term to describe destructive infundibular changes. Infundibular erosion was present in <6% of CT with no evidence of dental diseases, but was detected in >27% of diseased teeth, always accompanied by endodontic disease. This suggests that teeth affected by infundibular cemental hypoplasia are prone to destructive erosion, which possibly leads to endodontic disease. Morphological factors that supplement this ethological hypothesis were described. In 74% of infundibula residual blood was identified, although no vital blood vessels were detected. It is assumed that this content of blood remained in the ample infundibular cemental blood system after tooth eruption and creates a favorable environment for microbial growth. The infundibular enamel was characterised by numerous infoldings to variable degrees and depths. In certain areas focal enamel aplasia was observed. These morphological features might contribute to microbiological settlement and spread of infectious agents through the infundibular wall into the endodontic system.
authors.affiliation: Institute of Veterinary-Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Suske
authors.affiliation: Institute of Veterinary-Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Pöschke
authors.affiliation: Large Animal Clinic for Theriogenology and Ambulatory Services, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 29, Leipzig 04103, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Müller
authors.affiliation: Institute of Veterinary-Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany; Institute for General Zoology and Developmental Biology, Justus Liebig University Giessen, Stephanstr. 24, 35390 Giessen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wöber
authors.affiliation: Institute of Veterinary-Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Frankfurter Str. 98, 35390 Giessen, Germany. Electronic address: Carsten.Staszyk@vetmed.uni-giessen.de.
authors.forename: C
authors.initials: C
authors.lastname: Staszyk
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000033:anatomy & histology / Q000473:pathology; D003739:Dental Cementum / Q000033:anatomy & histology*; D003743:Dental Enamel / Q000033:anatomy & histology*; D003744:Dental Enamel Hypoplasia / Q000473:pathology / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses / Q000033:anatomy & histology*; D008297:Male; D008963:Molar / Q000033:anatomy & histology / Q000473:pathology; D014077:Tooth Erosion / Q000473:pathology / Q000662:veterinary*
keywords: Caries; Cemental hypoplasia; Erosion; Horse; Infundibulum