The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging (MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted (T2wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation (T1w/T1wFS), and contrast-enhanced fat-saturated T1-weighted (T1wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results (6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient (ICC), Cohen's kappa (κ), Mann-Whitney U-test and Fisher's exact test. Lesion identification and consecutive structured image analysis was possible on T2wFS and T1wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter (intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness (intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria (intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas: (1) outer margin of lesion, (2) texture of "peripheral rim" in T1wFS+C, (3) texture of "lesion center" in T2wFS, (4) surrounding tissue involvement in T2wFS, (5) surrounding tissue involvement in T1wFS+C and (6) maximum "peripheral rim" thickness (all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.
Contrast Media ; Diagnosis, Differential ; Humans ; Magnetic Resonance Imaging ; methods ; Periapical Granuloma ; diagnostic imaging ; Pilot Projects ; Radicular Cyst ; diagnostic imaging ; Reproducibility of Results ; Sensitivity and Specificity

OBJECTIVES: Periapical lesions, including periapical cyst (PC), periapical granuloma (PG), and periapical abscess (PA), are frequently affected by chemical/physical damage during root canal treatment or severe bacterial infection, and thus, the differential diagnosis of periapical lesions may be difficult due to the presence of severe inflammatory reaction. The aim of this study was to make differential diagnosis among PC, PG, and PA under polarizing microscope. MATERIALS AND METHODS: The collagen birefringence patterns of 319 cases of PC (n = 122), PG (n = 158), and PA (n = 39) obtained using a polarizing microscope were compared. In addition, 6 cases of periodontal fibroma (PF) were used as positive controls. RESULTS: Collagen birefringence was condensed with a thick, linear band-like pattern in PC, but was short and irregularly scattered in PG, and scarce or absent in PA. PF showed intense collagen birefringence with a short, palisading pattern but no continuous band-like pattern. The linear band-like birefringence in PC was ascribed to pre-existing expansile tensile stress of the cyst wall. CONCLUSIONS: In this study all PCs (n = 122) were distinguishable from PGs and PAs by their characteristic birefringence, despite the absence of lining epithelium (n = 20). Therefore, the authors suggest that the presence of linear band-like collagen birefringence of the cyst wall aids the diagnostic differentiation of PC from PG and PA.
Bacterial Infections ; Birefringence* ; Collagen* ; Dental Pulp Cavity ; Diagnosis, Differential* ; Epithelium ; Fibroma ; Periapical Abscess ; Periapical Granuloma ; Radicular Cyst*

OBJECTIVEThis study aimed to detect the immunoexpression of interleukin-21 (IL-21) and receptor activator. of nuclear factor KB ligand (RANKL) in periapical granulomas (PGs) and radicular cysts (RCs). The interaction of IL-21 with RANKL and its role in periapical pathogenesis were also speculated.

METHODSA total of 32 PGs and 23 RCs were selected as experimental samples. Lesion size and occurrence of tenderness were recorded. Up to 10 healthy gingival tissues were collected as normal control samples. All tissues were subjected to immunohistocheincal analysis with anti-human IL-21 and RANKL polyclonal antibodies. The correlations of IL-21 with RANKL, lesion size, and the occurrence of tenderness of the PGs and RCs were evaluated.

RESULTSIL-21-positive cells were detected in all periapical lesion tissues but not in normal tissues. In the cyst group and granuloma group, the corresponding expression levels of IL-21 were 59.92±6.57 and 36.80± 6.81, whereas those of RANKL were 68.81±18.59 and 36.12±14.87, respectively. Moreover, t-test revealed a significantly higher expression of IL-21 and RANKL in RCs than in PGs (P<0.05). IL-21 and RANKL were positively correlated in both PGs and RCs (P<0.05). Furthermore, IL-21 was correlated with lesion size (P<0.05).

CONCLUSIONThis study demonstrated that IL-21 is potentially involved in the pathogenesis of apical periodontitis lesions. A role in the exacerbation of chronic inflammation, as well as in bone resorption, is suspected. Further studies are required to elucidate the specific functions of IL-21 in periradicular inflammatory processes.

Humans ; Inflammation ; Interleukins ; physiology ; NF-kappa B ; metabolism ; Periapical Granuloma ; metabolism ; Periapical Periodontitis ; RANK Ligand ; Radicular Cyst ; metabolism

This is a case report of chronic maxillary sinusitis caused by root canal overfilling of Calcipex II (Techno-Dent). A 60 year-old male complained of dull pain in the right maxillary molar area after complicated endodontic treatment using Calcipex II paste and was finally diagnosed with a chronic maxillary sinusitis through a clinical and radiological observation. In the biopsy examination, the periapical granuloma contained a lot of dark and translucent Calcipex II granules which were not stained with hematoxylin and eosin. They were usually engulfed by macrophages but rarely resorbed, resulting in scattering and migrating into antral mucosa. Most of the Calcipex II granules were also accumulated in the cytoplasms of secretory columnar epithelial cells, and small amount of Calcipex II granules were gradually secreted into sinus lumen by exocytosis. However, chronic granulomatous inflammation occurred without the additional recruitment of polymorphonuclear leukocytes (PMNs) and lymphocytes, and many macrophages which engulfed the Calcipex II granules were finally destroyed in the processes of cellular apoptosis. It is presumed that Calcipex II granules are likely to have a causative role to induce the granulomatous foreign body inflammation in the periapical region, and subsequently to exacerbate the chronic maxillary sinusitis in this study.
Apoptosis ; Biopsy ; Cytoplasm ; Dental Pulp Cavity* ; Eosine Yellowish-(YS) ; Epithelial Cells ; Exocytosis ; Foreign Bodies ; Granuloma, Foreign-Body ; Hematoxylin ; Humans ; Inflammation ; Lymphocytes ; Macrophages ; Male ; Maxillary Sinus* ; Maxillary Sinusitis* ; Middle Aged ; Molar ; Mucous Membrane ; Neutrophils ; Periapical Granuloma

OBJECTIVETo examine the expression of interleukin-17F (IL-17F) in apical periodontitis lesions.

METHODSHuman apical periodontitis lesions were collected after periapical surgery from November 1, 2009 to August 1, 2011. After histological processing, serial sectioning, HE staining, and microscopic analysis, 33 periapical cysts and 18 periapical granulomas were selected for immunohistochemical analysis for IL-17F. Five alveolar bone samples were obtained from a group of impacted third molars recommended for extraction. These bone samples did not show any inflammation and were used as normal samples. Differences in IL-17F expression between the tissues with periapical cyst and periapica granuloma were subsequently analyzed by rank-sum test.

RESULTSIL-17F was expressed in epithelial cells, lymphocytes, fibroblast and endothelial cells of both types of lesions. Both types of lesions presented increased IL-17F expression when compared to healthy periapical alveolar bone. The expression of IL-17F in apical cyst (0.2365 ± 0.0708) and apical granuloma (0.8852 ± 0.0576) was significantly different (Z = 3.735, P < 0.01).

CONCLUSIONSIL-17F could be observed and might be involved in the inflammatory response and bone resorption of periapical tissues. The expression of IL-17F in periapical cyst and periapical granuloma was significantly different.

Adult ; Endothelial Cells ; metabolism ; Epithelial Cells ; metabolism ; Female ; Fibroblasts ; metabolism ; Humans ; Interleukin-17 ; metabolism ; Lymphocytes ; metabolism ; Male ; Periapical Granuloma ; metabolism ; pathology ; Periapical Periodontitis ; metabolism ; pathology ; Radicular Cyst ; metabolism ; pathology

OBJECTIVETo investigate the expression of receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) in periapical cyst and periapical granuloma by comparison with the expression in the normal periodontal tissue as control, and to identify their functional mechanism in the bone destruction of periapical cyst and granuloma.

METHODS20 periapical cyst tissues (cyst group), 20 periapical granuloma tissues (granuloma group), and 20 normal periodontal tissues (control group) were collected respectively. Immunohistochemical technology was performed to detect the expression of RANKL and OPG in above three groups.

RESULTSIn cyst group, granuloma group and control group, the expression of RANKL were 75.00 +/- 7.54, 68.40 +/- 6.74 and 29.40 +/- 2.46, respectively. The expression of OPG were 38.10 +/- 7.09, 47.65 +/- 13.85 and 58.60 +/- 5.88, respectively. The differences among the three groups were statistically significant (P<0.05). RANKL and OPG in cysts group were negatively correlated (r=-0.56, P=0.01) and were not correlated with granuloma and control group (P>0.05).

CONCLUSIONRANKL and OPG play roles in the bone absorption of periapical disease. In periapical disease, abnormal expression of RANKL and OPG are detected, RANKL significantly increase, OPG decrease, bone absorption accelerate and osteolytic lesion are observed. In periapical cyst, the bone absorption is more active compared with periapical granuloma.

Humans ; Male ; Osteoprotegerin ; Periapical Granuloma ; RANK Ligand ; Radicular Cyst ; Receptor Activator of Nuclear Factor-kappa B

The purpose of this study was to find out the relationship of radiographic lesion size, gender, age of patients and radiographic character to the diagnosis of periapical cyst and granuloma. The data was collected from 187 periapical lesions of 167 patients who undergone apical surgery at Department of Conservative Dentistry, Seoul National University Dental Hospital from 2003 to 2005. The lesion were surgically removed and send for biopsy to the Oral Pathology Laboratory. From the initial radiograph, lesion size was calculated using PiViewSTAR(R) (INFINITT, Korea) program. The obtained data were statistically evaluated using SPSS (p < 0.05). The result were as followings: 1. From 187 biopsy samples, the incidence of periapical cyst was 28.34% and granuloma was 65.24%. 2. There was a significant correlation between periapical cyst and the size of radiographic lesion (p < 0.01). 3. There were no significant correlations between age, gender, location of lesion and the final diagnosis (p > 0.05). 4. There was a significant correlation between the non-demarcation of the lesion and the incidence of periapical granuloma (p < 0.01).
Biopsy ; Dentistry ; Granuloma ; Humans ; Incidence ; Pathology, Oral ; Periapical Granuloma ; Radicular Cyst

Chronic Disease ; Cone-Beam Computed Tomography ; Humans ; Periapical Abscess ; pathology ; Periapical Granuloma ; pathology ; Periapical Periodontitis ; diagnostic imaging ; pathology ; Problem Solving ; Prognosis ; Radicular Cyst ; diagnostic imaging ; pathology

Acute Disease ; Anti-Bacterial Agents ; therapeutic use ; Chronic Disease ; Disinfectants ; therapeutic use ; Humans ; Periapical Abscess ; diagnosis ; therapy ; Periapical Granuloma ; diagnosis ; therapy ; Periapical Periodontitis ; classification ; diagnosis ; pathology ; therapy ; Problem Solving ; Prognosis ; Root Canal Irrigants ; therapeutic use ; Root Canal Therapy

Adult ; Female ; Humans ; Nasal Polyps ; etiology ; pathology ; Periapical Granuloma ; complications ; Tomography, X-Ray Computed