Investigation of the sensitivity and specificity of radiological signs for diagnosis of periapical infection of equine cheek teeth

An application of the density standard and scaled-pixel-counting protocol to assess the radiodensity of equine incisor teeth affected by resorption and hypercementosis: preliminary advancement in dental radiography

BACKGROUND

Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) syndrome is a dental disease where the radiographic signs may be quantified using radiographic texture features. This study aimed to implement the scaled-pixel-counting protocol to quantify and compare the image structure of teeth and the density standard in order to improve the identification of the radiographic signs of tooth resorption and hypercementosis using the EOTRH syndrome model.

METHODS AND RESULTS

A detailed examination of the oral cavity was performed in 80 horses and maxillary incisor teeth were evaluated radiographically, including an assessment of the density standard. On each of the radiographs, pixel brightness (PB) was extracted for each of the ten steps of the density standard (S1-S10). Then, each evaluated incisor tooth was assigned to one of 0-3 EOTRH grade-related groups and annotated using region of interest (ROI). For each ROI, the number of pixels (NP) from each range was calculated. The linear relation between an original X-ray beam attenuation and PB was confirmed for the density standard. The NP values increased with the number of steps of the density standard as well as with EOTRH degrees. Similar accuracy of the EOTRH grade differentiation was noted for data pairs EOTRH 0-3 and EOTRH 0-1, allowing for the differentiation of both late and early radiographic signs of EOTRH.

CONCLUSION

The scaled-pixel-counting protocol based on the use of density standard has been successfully implemented for the differentiation of radiographic signs of EOTRH degrees.

Diagnostic value of full-mouth radiography in horses

In this observational study, oral examinations and full-mouth dental radiographs were performed on 248 horses presented for routine oral health care. The findings were assessed to determine how often disease was diagnosed by radiographs without having related findings on oral examination. In 50 horses (20%), there were radiographic signs of disease that would not have been predicted based upon the oral examination. 113 horses (46%) had oral examination findings that would have prompted dental radiography, according to the criteria of the study. Of these 113 horses, 24 (21%) had radiographic signs of disease that would have been missed if only targeted radiographs had been taken, rather than a full-mouth survey.

Standing Intraoral Extraction of the Right Mandibular Third Molar Tooth in a Cow Utilizing Tooth Sectioning

A 2-year-old Holstein heifer presented to a university teaching hospital with an apical tooth infection of the right mandibular third molar. A standing oral extraction technique was attempted for tooth removal; however, the molar could not be delivered intact. A tooth sectioning technique was performed, and the affected molar was successfully delivered. Three months postextraction, the heifer had fully recovered, and the extraction site had healed. To the authors' knowledge, this is the first description of a tooth extraction in a cow using a tooth sectioning technique. This case describes an alternative technique for tooth removal in cattle with an apical tooth infection. The clinical, diagnostic, and therapeutic features of this case may be helpful to clinicians when they approach similar cases in the future.

A computed tomographic study of endodontic and apical changes in 81 equine cheek teeth with sagittal fractures

BACKGROUND

Sagittal fractures of equine cheek teeth are commonly observed during oral examination. There are few reports on the apical and endodontic pathology associated with such fractures seen during computed tomographic (CT) examination.

OBJECTIVES

This study aimed to document the prevalence of CT changes indicative of apical disease in equine cheek teeth, which have suffered a sagittal fracture involving the clinical ± reserve crown.

STUDY DESIGN

This study is a retrospective case series.

METHODS

CT examinations of equine heads with sagittal fractures of cheek teeth present were reviewed: 81 teeth from 49 horses were identified to have a sagittal cheek tooth fracture. The images were evaluated for apical pathology including gas (in the endodontic system and periapically), widened periodontal space, periapical sclerosis, apical clubbing, cementoma/hypercementosis, lamina dura loss, associated sinusitis and sinus mucosal swelling. An apical infection grading system was created to give each tooth a score. Hounsfield units were used to measure the density of the endodontic, apical and periapical regions. The fracture length ratio was recorded. Statistical analysis was performed using a generalised estimating equation to evaluate predictors of apical infection and associations between clinical signs and CT abnormalities.

RESULTS

Eighty-seven sagittal fractures (56 buccal, 17 palatal/lingual and 14 midline) from 81 teeth were recorded (74 maxillary and 7 mandibular). Apical infection was diagnosed in 73% (37/51, P = .05) of buccal, 55% (6/11, P = .07) of palatal/lingual, 100% (13/13) of midline, 100% (6/6) of multiple fractures and 96% (23/24, P = .008) of fractures involving infundibula. There was no significant relationship between apical infection and the presence of clinical signs associated with dental pathology (P = .4). There was no significant association between fracture length ratio and apical infection (P = 1.0). Midline sagittal fractures were significantly associated with sinusitis when compared with all other maxillary fractures (odds ratio [OR] 5.92, 95% confidence interval [CI] 1.67-20.83, P = .006). Loss of the lamina dura was not significantly associated with apical infection (P = .5).

MAIN LIMITATIONS

There is a maxillary cheek tooth bias in the data set and the subjective grading system.

CONCLUSIONS

A large proportion of fractured cheek teeth have evidence of apical infection on CT examination and therefore warrant treatment.

Multidetector CT and cone-beam CT have substantial agreement in detecting dental and sinus abnormalities in equine cadaver heads

The performance of cone-beam CT (CBCT) systems compared to conventional helical multidetector CT (MDCT) imaging of the equine head is unknown. The aim of this prospective, method-comparison study was to compare the ability of CBCT and MDCT to detect abnormalities in equine cadaver heads. Eleven equine cadaver heads were scanned using a CBCT scanner and a 64-slice MDCT scanner. Consensus evaluations for CBCT and MDCT scans were performed by three observers. Identified abnormalities were grouped into subcategories with a focus on dental abnormalities. Kappa agreement values between detected abnormalities for CBCT and MDCT methods were calculated. Of 468 teeth evaluated, 122 (26.1%) were found to have abnormalities (including in 58 infundibula and 7 pulps) using MDCT and 105 (22.4%) were found to have abnormalities (including in 52 infundibula and 2 pulps) using CBCT. The agreement between CBCT and MDCT was almost perfect for overall detection of dental abnormalities (k = 0.90) with k = 1 for diastema k = 0.95 for clinical crown abnormalities, and k = 0.93 for infundibular abnormalities. However, the detection of pulp changes by CBCT was only moderate k = 0.44. Increased scatter radiation, non-calibrated Hounsfield Unit and artefacts in CBCT images made accurate identification of the pulp density difficult. In conclusion, CBCT results were similar to conventional MDCT for the majority of dental abnormalities, however, pulp abnormalities were not reliably identified using CBCT, potentially limiting its clinical use for detecting endodontic disease in its current form. Further comparison with more cases with confirmed dental disease and studies in clinical cases are warranted.

Equine Standing Surgical Extraction Techniques

Dental repulsion techniques reported in the past decades have a high incidence of complications. Although the practice of surgical extractions in horses is limited because of the training, instrumentation, and experience required to perform these techniques, veterinarians should be aware these procedures are available, general anesthesia is not required, and when performed by skilled veterinary dentists they have low complication rates. Surgical techniques are often used after failure of other extraction techniques to remove retained tooth root and fragments or to debride chronically contaminated orofacial lesions. However, surgical extractions should be considered during initial treatment planning of all complicated cases.

Assessment of clinical and computed tomographic findings for association with the outcome of intraoral cheek tooth extraction in horses and ponies

OBJECTIVE

To describe clinical and CT findings for horses and ponies undergoing intraoral cheek tooth extraction and assess potential associations between these features and outcome of the procedure.

ANIMALS

74 horses and 7 ponies.

PROCEDURES

Medical records were searched to identify horses and ponies that underwent CT and intraoral extraction of ≥ 1 cheek tooth with standing sedation. Signalment and clinical variables were recorded, and CT scans were reviewed. Anatomic location and measurements of affected teeth; abnormalities of the periodontium, pulp, infundibula, roots, and tooth shape; fracture presence and type; presence of sinusitis; and affected sinus cavities were assessed by a surgeon and a radiologist. Intraoral extraction outcome was recorded as successful (complete removal of the tooth in 1 intraoral extraction procedure) or unsuccessful. Univariable and multivariable logistic regression analyses were performed to assess associations between clinical or CT findings and outcome.

RESULTS

89 cheek teeth (80 maxillary and 9 mandibular) were included in the analyses. Sixty of 89 (67%) cheek teeth were extracted successfully (56/80 [70%] maxillary and 4/9 [44%] mandibular cheek teeth). Only presence of a simple fracture (vs no fracture) was associated with outcome on multivariable regression analysis; odds of successful intraoral extraction were significantly lower when this feature was present.

CONCLUSIONS AND CLINICAL RELEVANCE

Most extractions of cheek teeth in the study sample were successful, and results may be useful for practitioners in refining cheek tooth extraction plans for horses and ponies. Further studies are required to assess whether specific CT findings can be used to predict the outcome of intraoral extraction in equids.

A Comparison of Computed Tomographic, Radiographic, Gross and Histological, Dental, and Alveolar Findings in 30 Abnormal Cheek Teeth from Equine Cadavers

Background

Equine cheek teeth disorders, especially pulpar/apical infections, can have very serious consequences due to the frequent extension of infection to the supporting bones and/or adjacent paranasal sinuses. Limited studies have assessed the accuracy of computed tomographic (CT) imaging in the diagnosis of these disorders, and no study has directly compared imaging and pathological findings of the alveoli of diseased equine cheek teeth.

Objective

To validate the accuracy of CT and radiographic imaging of cheek teeth disorders by comparing CT and radiographic imaging, gross and histological findings in abnormal cheek teeth and their alveoli extracted from equine cadaver heads.

Study design

Ex vivo original study.

Methods

Fifty-four cadaver heads from horses with unknown histories that had died or been euthanized on humane grounds obtained from a rendering plant had radiography, CT imaging, and gross pathological examinations performed. Based on imaging and gross examination findings, 30 abnormal cheek teeth (26 maxillary and 4 mandibular) identified in 26 heads were extracted along with their dental alveoli where possible, and further CT imaging, gross, and histological examinations were performed. Eight maxillary cheek teeth (including four with attached alveolar bone) from these heads, that were normal on gross and CT examinations, were used as controls.

Results

Gross pathological and histological examinations indicated that 28/30 teeth, including two supernumerary teeth, had pulpar/apical infection, including pulpar and apical changes. A further supernumerary and a dysplastic tooth were also identified. Abnormal calcified tissue architecture was present in all three supernumerary and in the dysplastic tooth. CT imaging strongly indicated the presence of pulpar/apical infection in 27 of the 28 (96.4%) pulpar/apically infected teeth, including the presence of intrapulpar gas (N = 19/28), apical clubbing (N = 20), periapical halo (N = 4), root lysis or fragmentation (N = 7), and periapical gas (N = 2). Also present were alveolar bone sclerosis (N = 20), alveolar bone thickening (N = 3), and lytic/erosive changes (N = 8). Radiographic abnormalities strongly indicative of pulpar/apical infection including periapical sclerosis (N = 8/28) and apical clubbing (N = 14/28) were found in 14/28 (50%) of apically infected teeth. Histological changes were present in alveolar bone of all 21 cases of apical infection where alveolus remained attached to the tooth and was marked in 16 cases, all which had CT alveolar changes. Histological changes included disruption of the normal trabecular pattern, increased osteoclastic activity, and the presence of islands of bone with a scalloped profile within the thickened attached periodontal ligament. No gross pathological or histological changes were present in the eight control teeth or their alveoli (N = 4).

Main limitations

No history or breed-related information was available on these cases.

Conclusion

There was a 96.4% correlation between a CT diagnosis and confirmative pathological findings in 28 apically infected teeth confirming the accuracy of CT imaging in diagnosing equine pulpar/apical infections. There was also excellent correlation between CT and histological alveolar bone findings.

Advanced imaging in equine dental disease

Dental and sinus disorders are relatively common and of major clinical importance in equine medicine. Advanced diagnostic imaging has become an integral part of equine veterinary medicine. Advanced imaging has progressed the understanding, diagnosis, and treatment of dental- and sinus-related diseases. As a clinician, it is important to realize the value of advanced diagnostic imaging. Although computed tomography and magnetic resonance imaging are both significantly more expensive compared with other diagnostic tools, the financial cost of inaccurate diagnosis and treatment can often result in higher overall costs.

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments

REASONS FOR PERFORMING STUDY

There is a lack of objective information on the value of ancillary diagnostic techniques used to investigate equine sinus disease, and also on which sinus compartments are commonly affected in this disorder.

OBJECTIVES

To record the ancillary diagnostic findings used to investigate equine sinus disease and to document which compartments are affected.

MATERIALS AND METHODS

The clinical case records of 200 consecutive cases of sinus disease, including subacute (<2 months' duration) primary (n = 52); chronic (>2 months' duration) primary (n = 37); dental (n = 40); traumatic (n = 13); sinus cyst (n = 26); sinus neoplasia (n = 10); dental related oromaxillary fistula (n = 8); mycotic sinusitis (n = 7) and intra-sinus progressive ethmoid haematoma (n = 7) were retrospectively examined.

RESULTS

Nasal endoscopy showed exudate draining from the sino-nasal ostia in 88% of cases and a sino-nasal fistula was present in 15% of cases. Sinoscopy was performed in 79% of cases and was of great diagnostic value. More recently, 22% of cases had fenestration of the ventral conchal bulla performed to allow sinoscopy of the rostral sinus compartments. Radiography was performed in 97% of cases and showed intra-sinus fluid lines to be common (69% prevalence) in subacute primary sinusitis. Radiographic dental apical changes were not specific to dental sinusitis, e.g. 29% of chronic primary sinusitis cases had radiographic dental changes. Scintigraphy was performed in 20% of cases and was helpful in identifying dental apical changes when radiography was inconclusive. Overall, the caudal maxillary (78% involvement) and rostral maxillary (61%) sinuses were most commonly affected, with the ventral conchal sinus (VCS) (54% involvement) and conchofrontal sinuses (48%) less so. The VCS showed the greatest tendency to contain inspissated pus (present in 46% of all affected VCS).

CONCLUSIONS

Nasal endoscopy, sinoscopy and skull radiography are of great value in diagnosing the presence and causes of equine sinus disease.