The prevalence of equine odontoclastic tooth resorption and hypercementosis and the role of interincisal angulation in disease severity in a representative cohort of horses in Switzerland

INTRODUCTION

Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is an increasingly diagnosed degenerative dental disease in aged horses. The primary aim of this retrospective study was to determine the prevalence of EOTRH in horses admitted to the Equine Hospital, University of Zurich, for dental procedures from 2004 to 2017. A secondary goal was to measure and compare interincisal angles on two-dimensional radiographs of horses with EOTRH to determine whether the interincisal angle is associated with age and severity of the disease. Radiographs were assessed for the presence of lysis and/or hypercementosis, and the number and position of the teeth affected were determined. Each tooth was also evaluated using the modified classification system introduced by Rehrl et al. (2018), in which stage 0 indicates no radiographic abnormalities and stage 3 denotes severe abnormalities. The overall stage was defined by the tooth with the most severe lesions. The interincisal angle was determined in horses that had suitable radiographs. The medical records of 838 horses admitted for dental procedures were evaluated, and 85 (10,1 %) had clinical evidence of EOTRH. The mean interincisal angle was 136,06 ° in horses with mild to moderate EOTRH and 135,10 ° (SD = 11,90 °) in severely affected patients. In conclusion, the angle measurements on lateral radiographs were highly reproducible. However, the interincisal angle was not associated with age or the severity of EOTRH. The interincisal angle and the disease pattern were not correlated.

Concrescence: assessment of case by periapical radiography, cone beam computed tomography and micro-computed tomography

The aim of this article was to describe imaging aspects of concrescence analyzed by three imaging modalities. A second molar joined together with a third molar was imaged using digital periapical radiography, cone beam computed tomography (CBCT) and micro-computed tomography (Micro-CT). On periapical radiograph, the mesial root of the third molar is superimposed on the distal root of the second molar. On CBCT images, a large cementum union between bulbous roots was detected, confirming the diagnosis of concrescence. On micro-CT images, the cementum union appeared limited to the apical third of the roots. In conclusion, both computed tomography modalities allowed for the diagnosis of concrescence. However, only micro-CT provided the real extension of the cementum union.

Lobodontia: the unravelling of the wolf teeth

Abnormalities of tooth shape and size generally coexist, as both are determined during the morphodifferentiation stage of odontogenesis. This report describes a case of lobodontia exhibiting multiple dental anomalies of which, "fang like" cuspids, multituberculism of molars, hypodontia along with severe generalized microdontia are distinctive. Radiographic features, diagnostic convolutions, differential diagnosis and clinical significance have also been highlighted.

Effect of HIP/ribosomal protein L29 deficiency on mineral properties of murine bones and teeth

Mice lacking HIP/RPL29, a component of the ribosomal machinery, display increased bone fragility. To understand the effect of sub-efficient protein synthetic rates on mineralized tissue quality, we performed dynamic and static histomorphometry and examined the mineral properties of both bones and teeth in HIP/RPL29 knock-out mice using Fourier transform infrared imaging (FTIRI). While loss of HIP/RPL29 consistently reduced total bone size, decreased mineral apposition rates were not significant, indicating that short stature is not primarily due to impaired osteoblast function. Interestingly, our microspectroscopic studies showed that a significant decrease in collagen crosslinking during maturation of HIP/RPL29-null bone precedes an overall enhancement in the relative extent of mineralization of both trabecular and cortical adult bones. This report provides strong genetic evidence that ribosomal insufficiency induces subtle organic matrix deficiencies which elevates calcification. Consistent with the HIP/RPL29-null bone phenotype, HIP/RPL29-deficient teeth also showed reduced geometric properties accompanied with relative increased mineral densities of both dentin and enamel. Increased mineralization associated with enhanced tissue fragility related to imperfection in organic phase microstructure evokes defects seen in matrix protein-related bone and tooth diseases. Thus, HIP/RPL29 mice constitute a new genetic model for studying the contribution of global protein synthesis in the establishment of organic and inorganic phases in mineral tissues.

Hypercementosis and odontogenic epithelial hyperplasia associated with a tooth root remnant mimicking a neoplasm. A case report

Hypercementosis presents as painless, single or multiple non-neoplastic cementum formation beyond the physiological limits of the tooth. It often occurs in the apical area of the involved tooth following infection, chemical or mechanical trauma. We report on radiographic and histopathological findings in a single case of late intraosseous hypercementosis and odontogenic epithelial hyperplasia associated with a minute apical tooth root remnant years after its extraction, mimicking a tumour.

Generalised hypercementosis: a case report

The following case report describes the clinical and radiographical presentation of a female who attended a general dental practice as a new patient. The patient was diagnosed with generalised hypercementosis, possibly attributable to oral neglect. Hypercementosis is associated with a number of aetiological factors, which may be local or systemic in nature. It is important that the general dental practitioner is aware of these factors and is able to distinguish presentation due to a local cause from that of a systemic disease process. The aims of this paper are to illustrate an unusual presentation of hypercementosis and to discuss the radiographic differentiation that led to diagnosis.

Cemento-osseous dysplasia of the jaws in 54 Japanese patients: a radiographic study

OBJECTIVE

The aim of this study was to describe the radiographic patterns of cemento-osseous dysplasia.

STUDY DESIGN

Fifty-four patients affected with benign fibro-osseous jaw lesions that showed periapical radiopacities and/or radiolucencies in a focal or a multiplex form were studied. The clinical, radiographic, and histopathologic features of the patients with cemento-osseous dysplasia were retrospectively studied. Radiographic features of the cemento-osseous dysplasia lesions were classified according to the appearance of calcified bodies. Radiographic visibility of periodontal ligament spaces of related teeth was assessed.

RESULTS

Forty-nine (91 %) of the 54 patients were women. The mean age of the total group was 50.8 years, and that of the male group was 64.6 years. The cemento-osseous dysplasia lesions could be classified into 6 types radiographically. Eighteen patients had at least 2 or more types of cemento-osseous dysplasia lesions. Of 147 related teeth, 142 had periodontal ligament spaces clearly visible. Six of 9 patients who had a total of 25 teeth with active hypercementosis showed concomitant occurrence of other types of cemento-osseous dysplasia lesions. Biopsy specimens showed various amounts of bonelike and cementumlike tissues.

CONCLUSIONS

It is likely that cemento-osseous dysplasia consists of 3 variations of a single entity, all with the same unknown cause. In one variation, the entity originates from the periodontium; in another, it is of medullary bone origin; and in the third it results from the simultaneous involvement of both tissues.

Periapical and localized radiopacities

Anatomic conditions and pathologic entities that commonly present as periapical and solitary radiopacities are categorized according to radiographic appearance. Clinical criteria for establishing a differential diagnosis are presented, and the rationale behind treatment objectives is discussed.

Clinical, radiographic and histological characteristics of secondary retention of permanent molars

Secondary retention refers to the cessation of eruption of a tooth after emergence neither due to a physical barrier in the path of eruption nor as a result of an abnormal position. In this study, the clinical and radiographic features of 81 secondary retained permanent molars in a group of 53 patients were evaluated. Retained molars removed for therapeutic reasons (n = 38) were examined histologically to detect any areas of ankylosis. The first molars in the mandible and maxilla were most frequently affected. The mean infraocclusion at the patients' first visit was 4.3 +/- 1.9 mm. After 6 months, infraocclusion increased in adolescents but was stable in adults. Tilting of the adjacent teeth was observed in 39 cases. A sharp, solid percussion sound and a partial absence of the periodontal ligament space on radiographs were noted in less than one-fifth of the affected molars, while histological evaluation revealed that local areas of ankylosis were present in all cases. From the data relating to the 38 molars removed for therapeutic reasons, the sensitivity of the percussion test and radiographic evaluation was found to be 29 and 21 per cent respectively. During a period of 4 years, six new cases of secondary retention were observed in the same population. From this study it is concluded that secondary retention of permanent molars seems to be associated with focal ankylosis and that percussion tests and radiographs are not sufficiently reliable to exclude the presence of ankylotic areas. The presence of ankylotic areas and tendency of infraocclusion to increase in adolescents but to be stable in adults have major implications for therapy.

[Evaluation of the periapical tissue lesions by roentgenogram]

Most of the periapical tissue lesions appear as radiolucent areas in a reontgenogram. However, several lesions of pulpal and periodontal origin as well as lesions caused by benign or malignant tumors appear in the roentgenogram as radiopaque areas. This article deals in detail with the classification, differential diagnosis and treatment of oral diseases which appear radiopaque in an X-ray film. Special attention is given to apical condensing osteitis, hypercementosis, chronic osteomyelitis and odontogenic tumors. These lesions are fairly common and the general practitioner should be familiar with their diagnosis and treatment.

Multiple radiopaque masses in the jaws

In this report, the less common oral findings occurring in Gardner's syndrome are described, which occurred concurrently with colorectal polyposis. In addition, what clinically appeared as small intestinal polyps, microscopically represented nodular lymphoid hyperplasia, as reported in the literature. Review of the literature showed the oral findings reported here are not common and that enzyme assays can help detect polyps at an early stage of this complex syndrome.

Generalized hypercementosis

The case of an elderly female patient with a long-standing history of generalized hypercementosis is described. A thorough review of the literature indicates that this may be one of the most extensive cases of hypercementosis to be reported. Possible etiologic factors--including heredity, systemic disorders, chronic periapical infection, and abnormal occlusal trauma--are discussed.

Hypercementosis--an important clue to Paget disease of the maxilla

Paget disease of the maxilla and mandible is not rare. There appears to be a significant correlation between skull involvement in the form of osteoporosis circumscripta and maxillofacial changes. The maxillary component can be of the typical form of Paget disease or be in the form of hypercementosis. The latter change is not well recognized and we present two cases with such involvement.