Dental implants cannot be installed without sufficient bone and patients lacking adequate bone volume may have a poor prognosis for implantation. Furthermore, there is increasing demand for esthetic restoration in dental implants. Accordingly, bone regeneration is required in many cases, not only for successful dental implant installation but also for esthetic and prosthetic reasons. However, bone regeneration is not an easy procedure to perform. Autologous bone grafts require a healthy donor site, and bone collection may cause donor site morbidity. Artificial bone substitutes can be used for relatively smaller defects. However, the application is limited and artificial materials are not generally accepted as a complete replacement for an autologous bone graft. Accordingly, less invasive and more efficient methods for bone regeneration are required. Tissue engineering is a new discipline for the restoration of lost or damaged tissue. In most cases, cultured cells, biodegradable scaffold materials and/or bioactive molecules have been used to aid naturally existing regenerating ability. The potential of bone tissue engineering has been actively explored since the discovery of osteogenic cells in bone marrow. In terms of alveolar bone tissue engineering, both basic research and clinical studies have been published recently. While clinical studies seem promising, they also highlight some problems, such as the unstable nature of somatic stem/progenitor cells and individual variation. Current studies are being performed to overcome those shortcomings, aiming to establish it as a novel treatment option in the near future.

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Our previous study have demonstrated that nasal administration of heat-killed recombinant Lactobacillus casei expressing 40-kDa outer membrane protein of Porphyromonas gingivalis (L. casei/40k-OMP) elicited high titers of 40k-OMP-specific serum IgG, IgA and salivary IgA antibody responses which provided significant protection against oral infection with P. gingivalis. In this study, we further elucidated nature of 40k-OMP-specific CD4⁺ T helper (Th) cells in those immunized mice. When CD4⁺ T cells that were isolated from spleen or cervical lymph nodes of mice immunized with heat-killed L. casei/40k-OMP were restimulated with 40k-OMP in vitro, significant levels of proliferation occurred. Furthermore, heat-killed L. casei/40k-OMP induced 40k-OMP-specific Th1 cells secreting IFN-γ as well as Th2 cells producing IL-4 and IL-5, with IgG1 and IgG2a antibody responses. These results suggest that nasal administration of heat-killed L. casei/40k-OMP elicits both Th1 and Th2 cytokines for induction of antigen-specific antibody responses in oral mucosal as well as systemic compartments and that provide further evidence of the potential of heat-killed recombinant L. casei vaccine for induction of protective immune responses against P. gingivalis infection.

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Periapical lesions represent local immune responses to bacteria and their products emanating from the root canal system. Mast cells are recognized for their immunoregulatory properties. The aim of this study was to examine the expression of mast cells in periapical granulomas and cysts as well as to compare the specificities of toluidine blue and astra blue stains for mast cells. Thirty periapical granulomas and 30 periapical cysts were stained with the basic stains astra blue and toluidine blue. The mean mast cell count using astra blue was 37.13±18.12 in granulomas and 59.5±22.75 in cysts. The mean mast cell count using toluidine blue was 25.90±18.45 in granulomas and 41.27±26.45 in cysts. On comparing mast cell numbers, it was found that cysts contained more mast cells than granulomas. Moreover, astra blue was found to be more specific for mast cells compared to toluidine blue.

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Our previous studies have shown that antigen-specific mucosal immune responses are induced in CD4 gene disrupted (CD4^-/-) mice after oral immunization with tetanus toxoid (TT) plus cholera toxin (CT) as mucosal adjuvant. Furthermore, CD4^-CD8^- T cells showed significant levels of antigen-specific proliferative responses in both mucosal and systemic lymphoid tissues. In this study, we further elucidated nature of antigen-specific CD4^-CD8^- T cells in those immunized mice. Analysis of TT-specific T cell responses showed that CD4^-CD8^-, but not CD8⁺, T cells in Peyer's patches (PP) produced Th2-type (IL-4 and IL-5) cytokines after oral immunization with TT plus CT. Furthermore, CD4^-CD8^- T cells isolated from PP of immunized CD4^-/- mice when added to B cell cultures induced increased number of TT-specific IgG and IgA producing cells. These results suggest that CD4^-CD8^- T cells in PP of CD4^-/- mice are capable of inducing antigen-specific T helper cytokines and provide help for mucosal IgA antibody responses in the absence of CD4⁺ T cells.

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It has been noted that the fragrance of grapefruits has a refreshing and exciting effect, which suggests the activation of sympathetic nerves. In salivary glands, the activation of sympathetic or parasympathetic nerves induces the secretion of proteins (such as the digestive enzyme α-amylase (amylase) and the glycoprotein mucin) or water and ions, respectively. Here, we investigated the effects of the scent from grapefruit oil on body weight and food intake, and its acute effects on salivary fluid and amylase secretion into the oral cavity of rats. When rats were exposed to the scent from grapefruit oil for 5 weeks, their body weight and food intake decreased. When rats were treated with the scent for 20 min, salivary amylase secretion was enhanced without changes in fluid secretion. These findings suggest that the scent from grapefruit oil activates sympathetic nerves, but not parasympathetic nerves, resulting in an anti-obesity effect.

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A fibromyxoma is a rare odontogenic mesenchymal tumor of the jaws. It is benign and painless but locally destructive. The mandible is more commonly involved than the maxilla. Its histological and radiological features make a fibromyxoma difficult to differentiate from other odontogenic tumors and it may occasionally be misinterpreted as a malignant lesion. In this paper, we present an aggressive case of a fibromyxoma of the maxilla with radiological consideration, postoperative follow-up, and a brief review of the literature.

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Aspergillosis is a fungal infection characterized by invasive and noninvasive forms. Noninvasive aspergillosis usually affects a healthy host, appearing either as an allergy or a cluster of fungal hyphae. Localized invasive infection of damaged tissue may be seen in a healthy host, but more extensive infection is often evident in immunocompromised patients. Its incidence in recent years has shown a marked increase and it is believed to account for many cases of nonspecific sinusitis. The purpose of this paper is to report two cases of aspergillosis involving the maxillary sinus in immunocompetent patients with an emphasis on early diagnosis because delay in the initiation of treatment can be life-threatening due to the propensity of fungi to invade adjacent blood vessels and embolize to distant organs.

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Leiomyosarcoma is an uncommon malignant mesenchymal neoplasm that exhibits smooth muscle differentiation. Rare occurrence of this neoplasm in the oral cavity is attributed to the paucity of smooth muscle in this location. Leiomyosarcomas of the oral cavity are associated with aggressive clinical behavior and low survival. To the best of our knowledge, only 69 cases of leiomyosarcoma involving the oral cavity have been reported in the English language literature, with 44 cases manifesting intraosseously in the maxilla and mandible. The purpose of this report is to present an additional case of intraosseous mandibular leiomyosarcoma in a 15-year-old girl and to summarize the data of isolated case reports of primary mandibular leiomyosarcomas that have been published in the English language literature during the past 75 years.

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Adenomatoid odontogenic tumor is an uncommon tumor of odontogenic origin. It is a benign, non-invasive lesion with slow but progressive growth. It is sometimes categorized as a hamartomatous lesion rather than a true neoplasm. Adenomatoid odontogenic tumor, which accounts for 1% to 9% of all odontogenic tumors, is predominantly found in young and female patients, located more often in the anterior maxilla, and is in most cases associated with an unerupted permanent tooth. This report illustrates an unusual case of Adenomatoid odontogenic tumor seen in the anterior mandible.

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Obstructive sleep apnea is recognized as a major respiratory disorder in adults, characterized by a sharp decline or periodic interruption of airflow during sleep. The exact cause of this condition is uncertain and apparently multifactorial. Prognathic (Class III) cases are generally subject to the procedures of mandibular retrusion through sagittal ramus osteotomies that change the characteristics of the oropharynx, causing reduction of the airway space. The aim of this paper is to review the literature on the influence of orthognathic surgery for the correction of prognathism in the development of postoperative respiratory disorders such as obstructive sleep apnea.

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