Epithelium and bacteria in periapical lesions.

OBJECTIVE: The purpose of this study was to evaluate 50 human periapical lesions for bacteria and epithelium in a case study in dental practice. STUDY DESIGN: Specimens were obtained from the extraction of 50 untreated teeth that had lesions attached to their apices. The specimens were histologically evaluated using serial sections. RESULTS: Bacteria were found in all teeth, colonizing necrotic tissue in the main canal, dentinal tubules, or apical ramifications, and in the body of the periapical lesion in 18 abscesses or cysts. Twenty-one lesions were epithelialized; 14 abscesses, 20 granulomas, and 16 cysts were distinguished. In 18 root canals inflamed tissue was found in the apical part of the canal. A single foramen was present in 13 cases while apical ramifications were found in 37 cases. CONCLUSIONS: Granulomas were most common, and most epithelialized lesions were cysts. Bacteria were only detected periapically in abscesses or cysts. Inflamed tissue was present in the apical root canal in one third of cases.     

Limited cone-beam CT and intraoral radiography for the diagnosis of periapical pathology.

OBJECTIVE: To compare intraoral periapical radiography with 3D images for the diagnosis of periapical pathology. STUDY DESIGN: Maxillary molars and premolars and mandibular molars with endodontic problems and examined with periapical radiographs and a 3D technique (3D Accuitomo) were retrospectively selected and evaluated by 3 oral radiologists. Numbers of roots and root canals, presence and location of periapical lesions, and their relation to neighboring structures were studied. RESULTS: Among 46 teeth, both techniques demonstrated lesions in 32 teeth, and an additional 10 teeth were found in the Accuitomo images. As regards individual roots, 53 lesions were found in both techniques, and 33 more roots were found to have lesions in Accuitomo images. Artefacts were sometimes a problem in Accuitomo images. In 32 of the 46 cases, all observers agreed that additional clinically relevant information was obtained with Accuitomo images. CONCLUSIONS: A high-resolution 3D technique can be of value for diagnosis of periapical problems.     

Receptor activator NFkappaB-ligand and osteoprotegerin protein expression in human periapical cysts and granulomas.

OBJECTIVE: The purpose of this study was to determine the expression of receptor activator of NFkappaB ligand (RANKL) and osteoprotegerin (OPG) associated with bone destruction in periapical cysts and granulomas. STUDY DESIGN: Forty human dental chronic periapical lesions were collected after periapical surgery. The lesions collected were fixed in 10% buffered formalin and histologically processed. At least 2 sections of each specimen were stained with hematoxylin and eosin for microscopic diagnosis. After that, 10 human periapical granulomas and 10 cysts were selected for immunohistochemical analysis for RANKL, OPG, and CD68+. RESULTS: Polymorphonuclear neutrophils, macrophages, endothelial cells, and lymphocytes were stained for RANKL and OPG in both lesions. Epithelial cells were also stained for RANKL and OPG in periapical cysts. Quantitative analysis was conducted and the results were expressed as a ratio of the number of immunostained cells over the total number of cells in the field (n = 100). The ratio of RANKL+/total cells was higher than OPG+/total cells in periapical granulomas (0.553 +/- 0.153 and 0.483 +/- 0.189, respectively; P < .0012; paired t test) and in cysts (0.519 +/- 0.09 and 0.339 +/- 0.117, respectively; P < .0001; paired t test). The ratios of OPG+/total cells (P < .0001; paired t test) and RANKL+/total cells (P < .0322; paired t test) were greater in granulomas than in cysts. However, the ratio RANKL+/OPG+ in granulomas (1.336 +/- 0.723) and cysts (1.404 +/- 0.385) was not significantly different. The ratio of CD68+/total cells was significantly higher in granulomas (0.381 +/- 0.040) than in cysts (0.307 +/- 0.068) (P < .0001; unpaired t test with Welch correction). CONCLUSION: Taking into account the limitations of the experimental approach employed, our findings indicate the presence of RANKL and OPG in cysts and granulomas, strongly suggesting the involvement of these gene products in the development of periapical lesions.     

Calcifying odontogenic cyst: radiologic findings in 11 cases.

OBJECTIVE: This retrospective study examines the relationship between histopathologically diagnosed cases of in calcifying odontogenic cysts (COCs) on the adjacent dentition. STUDY DESIGN: The records including diagnostic radiograph images of 11 patients treated for COCs from 1991 to 2004 were analyzed and correlations made between radiologic and histopathologic features. Special attention was applied to the associations between COCs and adjacent teeth. RESULTS: Radiologic and histopathologic features of the 11 lesions were variable, with some lesions being more solid and others more cystic. Calcifications varied from small flecks to solid calcified areas of frank odontoma. In 7 cases, the COC was associated with an impacted tooth and 5 of these cases involved COC-enveloping teeth. All cases excepting one in an edentulous jaw segment showed positional changes of adjacent teeth, including impaction. CONCLUSIONS: The radiographical features of COCs are varied but there is a high frequency of changes in adjacent teeth, including dental impaction. The presence of impaction or displacement of teeth for COCs occurring in the posterior segments of the jaw, and absence of this finding for anteriorly placed lesions may be indicative of the timing of COC development.     

Stereotactic brainstem biopsy is indicated for the diagnosis of a vast array of brainstem pathology

BACKGROUND/AIMS: A meta-analysis of thirteen studies performing stereotactic biopsy of brainstem lesions is combined with our recent series of 12 patients with brainstem lesions comparing MRI findings to biopsy histopathology to determine whether these lesions could have been diagnosed radiographically. METHODS: 12 consecutive stereotactic biopsies and literature analysis were performed to analyze clinical, radiographic and histopathologic data. RESULTS: Stereotactic biopsy of lesions in the brainstem was in 96% diagnostic. There was one mortality (3% of cases) and 4% morbidity associated with the procedure. Pathology showed that half of the adult brainstem intrinsic lesions were gliomas, 10% were metastases, and the remainder were hematomas, vascular malformations, lymphomas, demyelination, cysts, radiation necrosis, abscesses, vasculitis, infarcts, leukemia, cryptococcus, or granulomas. CONCLUSIONS: Empiric treatment of adult brainstem lesions is not prudent because there is a wide spectrum of diverse pathology in this location. Stereotactic biopsy is a safe and effective method for determining histopathology.     

Digital imaging analysis with mathematical morphology and fractal dimension for evaluation of periapical lesions following endodontic treatment.

OBJECTIVE: To see if a method for digitizing trabecular pattern of bone could be used to quantitatively evaluate changes in bone pattern following endodontic treatment of teeth with periapical osteolytic lesions. STUDY DESIGN: Periapical radiographs were digitized and further processed with mathematical morphology operations known as skeletonization. The trabecular patterns resulting from this skeletonization process were further analyzed with fractal dimension analysis using box-counting. RESULTS: The periapical area in digitized radiographic images showed fractal behavior. Twenty-five of 27 patients showed increase of the fractal dimension after root canal treatment. Significant changes of the box-counting could be noted 3 months after root canal treatment (P < .05). CONCLUSIONS: Mathematical morphology operation and box-counting might be helpful in early detection of changes of periapical trabecular pattern after root canal treatment.     

锥形束CT与根尖片对牙根纵裂诊断的对比研究

目的:比较锥形束CT(CBCT)和X线根尖片在牙根纵裂诊断中的准确度,探讨CBCT对牙根纵裂诊断的价值。方法:选取临床检查中疑似牙根纵裂患牙50例,分别进行X线根尖片、CBCT检查诊断和外科手术诊断;对X线根尖片和CBCT对牙根纵裂的诊断结果进行统计分析。结果:CBCT诊断牙根纵裂的敏感度(83.33%)高于X线根尖片诊断牙根纵裂的敏感度为(47.61%),P<0.05。结论:CBCT比X线根尖片能更准确诊断牙根纵裂,有助于牙根纵裂诊断。     

Effect of rotary or manual instrumentation, with or without a calcium hydroxide/1% chlorhexidine intracanal dressing, on the healing of experimentally induced chronic periapical lesions.

OBJECTIVE: To evaluate the healing of experimentally induced chronic periapical lesions in dogs at 30, 75, and 120 days after root canal instrumentation with rotary NiTi files or manual K-files, with or without a calcium hydroxide/1% chlorhexidine paste intracanal dressing. STUDY DESIGN: The second, third, and fourth mandibular premolars and the second and third maxillary premolars of 5 dogs (12 to 18 months of age, weighing 8 to 15 kg) were selected for treatment (a total of 82 root canals). After pulp removal, the root canals were left exposed to the oral cavity for 7 days to allow microbial contamination, after which the root canals were sealed with ZOE cement until periapical lesions were confirmed with radiography. Group I and II teeth were instrumented with manual K-files using the crown-down technique. In group III and IV teeth, NiTi rotary files were used. The apical delta was perforated by using #20 to #30 K-files at the length of the tooth, thus creating a standardized apical opening. The apical stop was enlarged to size 70, with 2.5% sodium hypochlorite irrigation at each file change. Teeth in groups II and IV were dressed with calcium hydroxide (Ca(OH) 2 )/1% chlorhexidine (CHX) paste for 15 days before root filling. Group I and III teeth did not receive an intracanal dressing. The access openings of the teeth were permanently restored with silver amalgam condensed on a glass ionomer cement base. Pairs of standardized periapical radiographs were taken at the beginning of the treatment (0 days) and at 30, 75, and 120 days after filling. RESULTS: There was no significant difference in the rate of radiographic healing of the periapical lesions between manual and rotary instrumentation. Radiographs taken at 120 days showed that the treatment with Ca(OH) 2 /1% CHX paste resulted in a significant reduction in mean size of the periapical lesions in comparison to single-session treatment. These findings were also true for histologic observations. CONCLUSION: The findings support the hypothesis that, regardless of the instrumentation technique (manual or rotary), the use of an intracanal dressing is important in the endodontic treatment of dog's teeth with experimentally induced chronic periapical lesions.     

Histologic evaluation of periradicular tissues in dogs treated with calcium hydroxide in combination with HCT20 and camphorated P-chlorophenol.

OBJECTIVE: The aim of this study was to evaluate the biocompatibility of calcium hydroxide suspended in HTC20 or calcium hydroxide plus CMCP and their effects on the healing of periapical lesions in dogs. STUDY DESIGN: Experimental apical periodontitis was induced by opening the pulp chamber of 36 mandibular premolars in 6 3-year old dogs. The teeth were left opened for 1 week and then closed with IRM for 60 days in order to induce periapical lesions. The teeth were divided into 1 control and 2 experimental groups. Both experimental groups received intracanal dressings with a calcium hydroxide slurry. In the first experimental group calcium hydroxide was mixed with a detergent vehicle and in the second group with camphorated parachlorophenol. The medications were kept in the root canal for 2 periods of 30 days each. Afterwards, the dogs were killed and the periapical areas were studied histologically. RESULTS: Based on biocompatibility and tissue remodeling in the periapical area, the best results were observed when calcium hydroxide was mixed with the detergent. The difference was statistically significant (P < .05). CONCLUSION: Calcium hydroxide plus CMCP intracanal dressing was the most irritating to the periapical region, and the group of calcium hydroxide plus HCT 20 showed the best results whenever biocompatibility and the capacity of new bone formation was considered.     

Effect of a calcium hydroxide-based root canal dressing on periapical repair in dogs: a histological study.

OBJECTIVE: To compare the periapical repair of teeth with periapical lesion following root canal treatment by using a calcium hydroxide-based intracanal dressing for several time periods or filling in a single visit. STUDY DESIGN: After induction of periapical lesions in 4 dogs, the root canals were prepared using 5.25% sodium hypochlorite for irrigation, and animals were separated into 4 experimental groups; in group I, root canals were filled in a single session; in groups II, III, and IV, a calcium hydroxide-based dressing was kept in place for 15, 30, or 180 days, respectively. Root canals from groups I, II, and III were filled with gutta-percha cones and AH Plus sealer. After 180 days, animals were killed and histological sections were stained with hematoxylin-eosin to evaluate periapical repair. RESULTS: Periapical repair was better in groups II, III, and IV (intracanal dressing) compared with group I (single session; P < .05). CONCLUSION: The use of a calcium hydroxide-based intracanal dressing was important for periapical repair in teeth with periapical lesion. Dressing with calcium hydroxide paste results in better periapical repair than when the root canal is filled in a single-session treatment.     

Lack of correlation between ex vivo apical dye penetration and presence of apical radiolucencies.

OBJECTIVE: The aim of this study was to determine if there is a significant correlation between the in vivo presence of periapical radiolucency and ex vivo apical dye penetration on the same human teeth. STUDY DESIGN: Eighty-four endodontically filled teeth that were scheduled for extraction were classified into 2 groups according to the presence or absence of a periapical radiolucency and further divided into 2 subgroups according to the quality of the root canal filling. After extraction, the apical filling was evaluated by a dye penetration method. RESULTS: The dye extraction evaluation showed no correlation between apical dye penetration and the presence of a periapical radiolucency (not significant), but a statistically significant correlation with the quality of the root canal filling (P = .03). CONCLUSION: The results of the dye penetration study were correlated to the quality of the root canal filling but had no predictive value for the development of periapical radiolucency.     

Sine Qua Non: Dentigerous Cyst

Dentigerous cysts, also known as follicular cysts, are among the most common developmental cysts of the gnathic bones. The majority of cases are clinically asymptomatic and discovered incidentally on panographic radiographs during routine dental care. The cyst appears as a radiolucency, classically unilocular, associated with the crown of an unerupted or impacted tooth. Usually diagnosed in the 2nd–3rd decade, third molars of the mandible are the most commonly affected teeth. Histologically, dentigerous cysts demonstrate a fibrous or fibromyxoid connective tissue wall lined by squamous epithelium, classically lacking rete ridges. Inflammation may introduce histologic changes, however. The differential diagnosis includes hyperplastic dental follicle, periapical or radicular cyst, unicystic ameloblastoma, odontogenic keratocyst, and other odontogenic cysts and tumors. While the findings are generally classic and pose no diagnostic dilemma, the diagnosis is best made in the context of the appropriate clinical and radiographic setting. Submitted tissue with a lack of history, to include a detailed relationship with the affected tooth, may result in misdiagnosis and subsequent confusion for the clinician. So, despite its simple features, dentigerous cysts are not uncommonly mischaracterized. Therefore a review of a classic case of dentigerous cyst is presented.     

Study of the localization of radiopacities similar to calcified carotid atheroma by means of panoramic radiography.

OBJECTIVE: To determine the location in soft tissues of the calcifications, similar to calcified carotid atheromas, that can be observed radiographically in the cervical region in panoramic radiographs. STUDY DESIGN: In each anatomic cadaver specimen preserved in formol, consisting of the head and neck, radiopaque spheres (made from gutta-percha) were positioned in anatomic structures of the cervical region that can be sites of calcification. For each anatomic structure marked in this way, panoramic radiography was performed, consisting of 17 radiographs. The images obtained were analyzed by 24 examiners who indicated which radiographs, in their opinion, presented the radiopaque reference projected in the region of bifurcation of the carotid artery. Analysis of 2 proportions from agreement and disagreement was used to determine radiopacities that could be confused in panoramic radiographs with calcified atheromas in the carotid artery. RESULTS: The results showed that 75% (18) of the examiners correctly indicated the reference in the bifurcation of the carotid artery and 79.2% (19) indicated a triticeous cartilage as calcified atheroma of the carotid artery. CONCLUSIONS: Calcified atheromas of the carotid artery are not the only features that can produce radiopaque images lateral to the panoramic radiograph; the presence of calcification in the triticeous cartilage also can induce an erroneous diagnosis of calcified carotid atheroma.     

In vitro assessment of local computed tomography for the detection of longitudinal tooth fractures.

OBJECTIVE: To test the accuracy of local computed tomography (LCT) in detecting longitudinal fractures in comparison with conventional periapical radiographs. STUDY DESIGN: Longitudinal fractures were induced in 30 of 60 teeth. The teeth were placed in a dry dentate mandible with soft tissue simulation. A laboratory LCT unit was used to acquire 180 basis projections with 1 degree separation along a 180 degree arc. Conventional radiographs served as the control modality. Correlated axial, coronal, and sagittal views were presented to 10 observers. The observers determined the presence of a root fracture by using a 5-point receiver operating characteristic confidence scale. RESULTS: The mean A(z) for LCT was 0.91 (SD = 0.07). The mean A(z) for conventional radiography was 0.70 (SD = 0.07). The difference between the modalities was statistically significant (analysis of variance: P < .0002), whereas the differences between the observers was not (analysis of variance: P = .319). CONCLUSION: Local CT significantly improves the detection of longitudinal fractures in vitro compared with conventional periapical radiography.     

Nonsurgical retreatment of teeth with periapical lesions previously managed by either endodontic or surgical intervention.

OBJECTIVE: The purpose of this study was to evaluate the outcome of nonsurgical retreatment of teeth with periapical lesions, which had been previously managed by either endodontic or surgical intervention, and to identify factors that might influence the prognosis. STUDY DESIGN: Seventy-five endodontically and 11 surgically treated teeth with persisting periapical lesions ranging in size from 2 to 11 mm in diameter were included in this study. The teeth were nonsurgically retreated, using calcium hydroxide as intracanal medicament, and were followed for a period of 2 to 8 years. RESULTS: Clinical and radiographic assessment of retreatment showed that complete healing for all cases was 61.6% with an additional category of incomplete healing of 14%; 24.4% failed. The size of the periapical lesions and previous surgical treatment had marginally negative influences on the prognosis, but the differences were not statistically significant. CONCLUSION: The favourable results of this study demonstrated that nonsurgical root canal retreatment is an alternative to surgical intervention of postendodontic or postsurgical failure.     

Operative treatment of intracranial epidermoid cysts and cholesterol granulomas: report of 21 cases

Thirteen patients had operations to remove intracranial epidermoid cysts, and long-term follow-up was obtained. Total or nearly total tumor and capsule removal was accomplished in 7 patients during the initial operation. This group required no additional operations. The other 6 underwent subtotal tumor removal and required multiple operations for symptomatic tumor recurrence. This latter group had a poorer neurological outcome. We conclude that initial total or near-total tumor resection is highly desirable in treating intracranial epidermoid cysts, particularly in physiologically young individuals. Five patients were followed after operations to remove pure cholesterol granulomas of the petroclival bone, and 3 additional patients were followed after operations to remove tumors with combined histopathological features of both an epidermoid cyst and cholesterol granuloma. Four patients with some component of a cholesterol granuloma had concurrent middle ear infections, and 4 did not. Intracranial subtotal excision and drainage of these lesions was the initial operative management in 7 patients, 5 of whom have required multiple operations for symptomatic tumor recurrence. Therefore, we conclude that subtotal excisional procedures for tumors with histopathological features of cholesterol granulomas are not usually successful in establishing long-term cures. Total excision, as recommended for epidermoid cysts, tumors frequently confused with cholesterol granulomas when occupying the petroclival region, may be warranted for these tumors as well. We postulate that when a congenital epidermoid cyst occurs in the petroclival bone, it may incite a local inflammatory reaction, producing lesions which have the histological features of both epidermoid cysts and cholesterol granulomas.     

Biopsy of hand, wrist, and forearm tumors

This article describes three biopsy methods currently used for treating masses arising in the hand, wrist, and forearm: open biopsy, fine needle aspiration, and core needle biopsy.The forearm, wrist, and hand comprise a complex and diverse anatomic region, and biopsy is emphasized as the most important element in the diagnosis of the musculoskeletal tumor. Biopsy methods for assessing true neoplasms, bony protuberances, cysts,infection and abscesses, foreign bodies, reactive granulomas, tenosynovial proliferation,and skin and fascial lesions are discussed.     

Interactive magnetic resonance imaging-guided management of intracranial cystic lesions by using an open magnetic resonance imaging system.

OBJECT: The authors present their experience with neurosurgical procedures requiring real-time imaging feedback such as aspiration of a cystic structure or abscess cavity, decompression of hydrocephalic ventricles, management of arachnoid cysts, and installation of permanent or temporary drainage conduits, in which interactive magnetic resonance (MR) imaging guidance was used to monitor structural alterations associated with the procedure. METHODS: Drainage of eight intraparenchymal brain abscesses in seven patients, decompression of space-occupying cystic or necrotic brain tumors in four patients, and endoscopic management of hydrocephalus associated with arachnoid cysts in three patients were performed using MR imaging-guided frameless stereotaxy in an open-configuration 0.5-tesla superconducting MR imaging system. Intraoperative MR imaging guidance provided accurate information on the course of the surgical procedure and associated intraoperative changes in tissue position, such as the degree of cyst aspiration, the presence or absence of hemorrhage or induced swelling, and changes associated with decompression of adjacent brain parenchyma and the ventricular system. No clinically significant complications were encountered in any patient. There were no targeting errors, and procedural objectives were accomplished in all cases. CONCLUSIONS: Drainage of brain abscesses, punctures of cystic or necrotic intracranial lesions with subsequent aspiration, and management of hydrocephalus can be performed safely and accurately by monitoring the procedure using real-time MR imaging to obtain immediate feedback on associated dynamic tissue changes.     

Accuracy of extraoral tuned aperture computed tomography (TACT) for proximal caries detection.

OBJECTIVES: The objectives of this study were to compare the difference in the accuracy of proximal caries detection by extraoral tuned aperture computed tomography (TACT), intraoral TACT, and film radiographs. STUDY DESIGN: Eighty proximal surfaces of 40 extracted human maxillary teeth were used. A digital sensor was the image receptor for TACT. Film radiographs were acquired using Insight film. Nine basis images were acquired to reconstruct TACT slices. Seven observers scored the presence or absence of proximal caries using the 3 imaging modalities. The true presence of caries and its depth were determined using the sectional images obtained by micro CT. Among the image modalities and observers, possible differences in the area under the receiver operating characteristic curve were assessed by analysis of variance (ANOVA). RESULTS: ANOVA indicated no statistically significant differences between observers (P = .845), modalities (P = .657), and observer-modality combinations (P = .593). CONCLUSION: Within the limited range of this study, extraoral TACT was not statistically different from intraoral TACT or film radiographs for proximal caries detection. This suggests that extraoral TACT may have some clinical utility for caries diagnosis and that further study may be warranted.     

根尖周囊肿样病变的非手术性治疗研究

目的 根尖周囊肿是最常见的颌骨囊肿，选择合适的治疗方案不仅可以减轻患者痛苦和创伤，对于治 疗的预后也具有重要的影响。根尖周囊肿样病变的治疗一般分为手术治疗和非手术治疗两大类，手术治疗 通常适用于根尖周真性囊肿，而根尖周袋状囊肿则可以通过非手术治疗的方式达到较好的临床效果。本文 主要就根尖周囊肿样病变的非手术治疗作一综述，以期为临床医生提供更多可供选择的治疗方式。