Multifocal intraoral ductal ectasia with metaplasia and focal epithelial proliferation: A case report.

Ductal ectasia with metaplasia and focal epithelial proliferation in the oral cavity does not correspond to any existing salivary gland lesion. A 72-year-old man presented with a mass in the buccal mucosa, which was excised and initially diagnosed as a cystadenoma. An upper lip mass on the right side, which developed later, was also excised. The lesions were histologically similar, and since they were multifocal and in non-contiguous and independent sites with multiple dilated cystic structures that did not destroy the lobar architecture, the final diagnosis was confirmed as ductal ectasia with metaplasia and focal epithelial proliferation. This condition may mimic various neoplastic lesions.

Evaluation and Prediction of Healing Morphology After Closed Reduction for Unilateral Mandibular Condyle Fractures.

Although closed reduction is common for condylar fractures, bone fragments may heal improperly. This study aimed to investigate the healing morphology of unilateral condylar fractures. We retrospectively investigated 70 patients with unilateral condylar fractures. Clinico-statistical analyses were performed on the whole-condylar fracture, closed reduction, and observation/functional therapy groups. Among these patients, 52 patients aged older than 16 years underwent closed reduction. The extent of maximum mouth opening, the incidence of malocclusion, and the relationship between healing morphology and Arbeitsgemeinschaft für Osteosynthesefragen classification or trismus were analyzed in the closed reduction group. There were significant differences in age ( P= 0.008) and sex ( P =0.025) between the closed reduction and observation/functional therapy groups. However, there were no significant differences in trauma etiologies and concomitant fractures between the 2 groups. The average maximum mouth opening extent for unilateral fractures after closed reduction was 42.6±6.1 mm. Only 1 case (2.1%) of post-treatment malocclusion was observed. In all the MacLennan classification of deviation or more, regardless of the classification, upper fractures (head and upper neck) tended to heal through a spherical ( P <0.001) morphology, whereas lower fractures (lower neck and subcondylar) tended to heal through an L-shaped and lateral fusion ( P <0.001). There was no significant difference in the incidence of trismus between the healing morphology of unchanged type and others ( P =0.690). Our results elucidated the etiology, dysfunction, and healing morphology classification of unilateral mandibular condyle fractures treated with closed reduction.

Differences in the stemness characteristics and molecular markers of distinct human oral tissue neural crest-derived multilineage cells.

OBJECTIVES: Although multilineage cells derived from oral tissues, especially the dental pulp, apical papilla, periodontal ligament, and oral mucosa, have neural crest-derived stem cell (NCSC)-like properties, the differences in the characteristics of these progenitor cell compartments remain unknown. The current study aimed to elucidate these differences. MATERIAL AND METHODS: Sphere-forming apical papilla-derived cells (APDCs), periodontal ligament-derived cells (PDLDCs), and oral mucosa stroma-derived cells (OMSDCs) from the same individuals were isolated from impacted developing teeth. All sphere-forming cells were characterized through biological analyses of stem cells. RESULTS: All sphere-forming cells expressed neural crest-related markers. The expression of certain tissue-specific markers such as CD24 and CD56 (NCAM1) differed among tissue-derived cells. Surprisingly, the expression of only CD24 and CD56 could be discriminated in human tissues. Although APDCs and PDLDCs exhibited greater mineralized cell differentiation than OMSDCs, they exhibited poorer differentiation into adipocytes in vitro. In immunocompromised mice, APDCs formed hard tissues better than PDLDCs and OMSDCs. CONCLUSIONS: Although cells with NCSC-like properties present the same phenotype, they differ in the expression of certain markers and differentiation abilities. This study is the first to demonstrate the differences in the differentiation ability and molecular markers among multilineage human APDCs, PDLDCs, and OMSDCs obtained from the same patients, and to identify tissue-specific markers that distinguish tissues in the developing stage of the human tooth with immature apex.

Identification of malocclusion risk factors after closed treatment of condylar fractures using a novel three-dimensional computed tomography approach.

The condyle is the most common site of mandibular fracture. In the present study, an attempt was made to utilize three-dimensional computed tomography (3D-CT) images to evaluate mandibular condyle fractures and identify prognostic indicators of malocclusion after closed treatment. Accurate morphometric measurements were performed using 3D-CT images obtained before trauma, after trauma, and after healing. Morphometry revealed significant differences in loss of ramus height (LRH) and lateral movement length in patients with malocclusion, and significant LRH differences in patients with other maxillomandibular fractures after healing, or in those with dislocation-displacement. The present method of 3D-CT image analysis appears useful for evaluation of condylar fractures.

Corrigendum to "Topographical distribution of neurovascular canals and foramens in the mandible: avoiding complications resulting from their injury during oral surgical procedures" [Heliyon 4 (9) (September 2018) e00812].

[This corrects the article DOI: 10.1016/j.heliyon.2018.e00812.].

Topographical distribution of neurovascular canals and foramens in the mandible: avoiding complications resulting from their injury during oral surgical procedures.

PURPOSE: Certain oral surgical procedures can injure neurovascular canals and foramens in the mandible. Hence, before performing surgical procedures, it is important to assess the distribution of the bifid mandibular canal (BMC), accessory mental foramen (AMF), medial lingual canal (MLC), lateral lingual canal (LLC), buccal foramen (BF), and lingual alveolar canal (LAC). This study aimed to assess the distribution of different types of canals and foramens. Furthermore, we investigated the limitations associated with finding these structures in panoramic images. METHODS: Fifty-eight patients who had undergone panoramic radiography and computed tomography (CT) scans at our hospital were randomly selected for this study. Imaging data obtained from these patients were retrospectively reviewed. RESULTS: We found that the occurrence of BMC was 60.3%, AMF was 6.9%, MLC was 98.2%, LLC was 75.9%, BF was 43.1%, and LAC was 98.3%. Edge-contrasted inverted panoramic images revealed BMCs in 21.7% and AMFs in 25%; however, most of these canals could not be detected. In the panoramic images, the average diameter of the BMC was significantly different between the detected group and not detected group. The number of canals and foramens in the anterior region to the molar region decreased on the buccal and lingual sides, and most BMCs were in the retromolar to the ramus region. CONCLUSION: Our results indicated different distributions and occurrence rates of each type of neurovascular canal and foramens.

Property of Human Bone Marrow Stromal Cells Derived From Bone Fragments Removed in Sagittal Split Ramus Osteotomy.

Bone tissue engineering is in the process of making the shift from bench to bed. Organ as a cell source is important for tissue engineering. The appropriate cells should be harvested without invasiveness and ethical problems. The authors focused on mandibular cortex bone fragments removed in sagittal split ramus osteotomy as a cell source for bone tissue engineering. These bone fragments were discarded after surgery until now. Bone marrow stromal cells (BMSCs) were harvested from inside of bone fragments, which is an endosteal region. Endosteal region is known to be a hematopoietic stem cell niche and harbors osteoblasts, preosteoblasts, and mesenchymal stem cells (MSCs). Bone marrow stromal cells could be cultured easily, and grew rapidly in vitro under ordinary serum-supplemented culture condition. The expression pattern of surface markers of BMSCs was the same as that of MSCs. Bone marrow stromal cells could differentiated into multiple mesenchymal lineages (osteoblasts, adipocytes, chondrocytes, and smooth muscle cells). These results indicated the existence of MSCs in BMSCs. The osteoblastic characters of BMSCs were examined more closely. Bone marrow stromal cells showed a high alkaline phosphatase activity, and expressed osteoblastic markers (PTHr, bone sialoprotein, Type I collagen, Rnut-related transcription factor 2, and osteocalcin). In transplantation experiments, BMSCs generated ectopic bone tissues on the border of hydroxyapatite scaffold without osteogenic differentiation-inducing agents such as dexamethasone (Dex) or bone morphogenetic protein. The results of this study suggest that mandibular cortex bone fragments removed in sagittal split ramus osteotomy are a good cell source for bone tissue engineering.

Sphere-Derived Multipotent Progenitor Cells Obtained From Human Oral Mucosa Are Enriched in Neural Crest Cells.

UNLABELLED: : Although isolation of oral mucosal stromal stem cells has been previously reported, complex isolation methods are not suitable for clinical application. The neurosphere culture technique is a convenient method for the isolation of neural stem cells and neural crest stem cells (NCSCs); neurosphere generation is a phenotype of NCSCs. However, the molecular details underlying the isolation and characterization of human oral mucosa stromal cells (OMSCs) by neurosphere culture are not understood. The purpose of the present study was to isolate NCSCs from oral mucosa using the neurosphere technique and to establish effective in vivo bone tissue regeneration methods. Human OMSCs were isolated from excised human oral mucosa; these cells formed spheres in neurosphere culture conditions. Oral mucosa sphere-forming cells (OMSFCs) were characterized by biological analyses of stem cells. Additionally, composites of OMSFCs and multiporous polylactic acid scaffolds were implanted subcutaneously into immunocompromised mice. OMSFCs had the capacity for self-renewal and expressed neural crest-related markers (e.g., nestin, CD44, slug, snail, and MSX1). Furthermore, upregulated expression of neural crest-related genes (EDNRA, Hes1, and Sox9) was observed in OMSFCs, which are thought to contain an enriched population of neural crest-derived cells. The expression pattern of α2-integrin (CD49b) in OMSFCs also differed from that in OMSCs. Finally, OMSFCs were capable of differentiating into neural crest lineages in vitro and generating ectopic bone tissues even in the subcutaneous region. The results of the present study suggest that OMSFCs are an ideal source of cells for the neural crest lineage and hard tissue regeneration. SIGNIFICANCE: The sphere culture technique is a convenient method for isolating stem cells. However, the isolation and characterization of human oral mucosa stromal cells (OMSCs) using the sphere culture system are not fully understood. The present study describes the isolation of neural crest progenitor cells from oral mucosa using this system. Human OMSCs form spheres that exhibit self-renewal capabilities and multipotency, and are enriched with neural crest-derived cells. These oral mucosa sphere-forming cells can generate ectopic bone tissue in vivo. Therefore, the results of the present study show that the sphere culture system can be applied, without the need for complex isolation techniques, to produce multipotent spheres with the properties of neural crest stem cells. Furthermore, a convenient strategy is demonstrated for the isolation and culture of human OMSCs that could have clinical applications.

Confirmation of immunoglobulin heavy chain rearrangement by polymerase chain reaction using surgically obtained, paraffin-embedded samples to diagnose primary palate mucosa-associated lymphoid tissue lymphoma: A case study.

INTRODUCTION: Intraoral mucosa-associated lymphoid tissue (MALT) lymphoma is a rare lymphoma that has a good prognosis if diagnosed correctly and treated in time. PRESENTATION OF CASE: A 64-year-old woman was referred to our department with asymptomatic swelling of the left hard palate. Computed tomography and magnetic resonance imaging revealed a mass in the left hard palate. We performed a pre-surgery biopsy; however, it was difficult to differentiate MALT lymphoma from other reactive lymphoproliferative disorders via gross or microscopic examination. Although the lesion was completely excised, histological findings did not allow a definitive diagnosis due to an absence of visible monoclonality. We then performed polymerase chain reaction (PCR) using DNA extracted from formalin-fixed, paraffin-embedded surgical samples. Capillary electrophoresis showed monoclonal peaks of immunoglobulin heavy chain gene rearrangement, thus facilitating a definitive diagnosis of MALT lymphoma. DISCUSSION: PCR technique is rapid, accurate, and enables a definitive diagnosis without relying on traditional histological or molecular diagnostic techniques, such as Southern blotting. CONCLUSION: We suggest that, if histological examination is ambiguous or fresh material is insufficient, PCR can be performed using paraffin-embedded materials to definitively diagnose low-grade lymphomas, such as MALT lymphoma.

Neural crest stem cell property of apical pulp cells derived from human developing tooth.

Recent reports have described that NCSCs (neural crest-derived stem cells) are not only present in the embryonic neural crest but also in the adult tissues. Dental pulp is one of mesenchymal soft tissues origin from cranial neural crest cells, and thought to be a source of adult stem cells. Here, we investigated the existence of NCSC-like cells in apical pulp of human developing tooth. Human impacted third molars with immature apex freshly extracted were obtained. The cells derived from the apical pulp tissue not framed by dentin or the coronal pulp tissues were cultured by primary explant culture. APDCs (apical pulp-derived cells) and CPCs (coronal pulp cells) formed spheres under neurosphere culture condition. The number of spheres from APDCs was larger than that from CPCs. The sphere-forming cells derived from APDCs had self-renewal capacity, and expressed neural crest-associated markers (p75, Snail and Slug) and NSC (neural stem cell) markers (Nestin and Musashi1). The expression pattern of mesenchymal stem cell markers, CD105 and CD166, on the surface of sphere-forming cells derived APDCs was different from that of APDCs. These sphere-forming cells could differentiate into multiple mesenchymal lineages (osteoblasts, adipocytes, chondrocytes and smooth muscle cells) and neural lineage (neurons) in vitro, and generated ectopic bone tissues on the border of HA (hydroxyapatite) scaffold in vivo. The results of this study suggest that APDCs contain cells with characteristics of NCSCs reported previously in mice. Humans developing tooth with immature apex is an effective source of cells for neural crest lineage tissue regeneration.

Characterization of the radioresponse of human apical papilla-derived cells.

BACKGROUND: The purpose of this study was to characterize the radiobiological properties of stem/progenitor cells derived from apical papilla-derived cells (APDCs) compared to bulk APDCs. METHODS: APDCs were isolated from freshly extracted human third molars with immature apices. Multipotent spheres, which are thought to contain an enriched population of stem/progenitor cells, were formed from the APDCs, using a neurosphere culture technique. After γ-irradiation, papillary sphere-forming cells (PSFCs) and bulk APDCs were subjected to radiosensitivity and hard tissue-forming assays. RESULTS: Compared to bulk APDCs, the PSFCs exhibited a radioresistant phenotype and a higher capacity for DNA double strand break repair. Irradiation induced a significant increase in a senescence-like phenotype in both cell types. Neither type of cells exhibited a significant induction of apoptotic changes after 8 Gy of irradiation. Ability to form hard tissue in vivo was significantly decreased in PSFCs, but not in APDCs following 4 Gy of irradiation. CONCLUSIONS: We demonstrated for the first time that stem/progenitor cells derived from APDCs exhibit a radioresistant phenotype; however, the hard tissue forming ability in vivo, but not bulk APDCs, was significantly reduced after irradiation.

Hard tissue regeneration capacity of apical pulp derived cells (APDCs) from human tooth with immature apex.

Recent studies indicate that dental pulp is a new source of adult stem cells. The human tooth with an immature apex is a developing organ, and the apical pulp of this tooth may contain a variety of progenitor/stem cells, which participate in root formation. We investigated the hard tissue regeneration potential of apical pulp derived cells (APDCs) from human tooth with an immature apex. APDCs cultured with a mineralization-promoting medium showed alkaline phosphatase activity in porous hydroxyapatite (HA) scaffolds. The composites of APDCs and HA were implanted subcutaneously in immunocompromised rats and harvested at 12 weeks after implantation. In histological analysis, the APDCs/HA composites exhibited bone- and dentine-like mineralized tissues in the pore areas of HA. This study suggests that the human tooth with an immature apex is an effective source of cells for hard tissue regeneration.