CAD/CAM-produced surgical guides: Optimizing the treatment workflow

The increased availability of devices for 3D radiological diagnosis allows the more frequent use of CAD/CAM-produced surgical guides for implant placement. The conventional workflow requires a complex logistic chain which is time-consuming and costly. In a pilot study, the workflow of directly milled surgical guides was evaluated. These surgical guides were designed based on the fusion of an optical impression and the radiological data. The clinical use showed that the surgical guides could be accurately placed on the residual dentition without tipping movements. The conventional surgical guides were used as a control for the manual check of the deviation of the implant axis. The direct transfer of the digital planning data allows the fabrication of surgical guides in an external center without the need of physical transport, which reduces the logistic effort and expense of the central fabrication of surgical guides.     

One germline mutation of PTCH gene in a Chinese family with non-syndromic keratocystic odontogenic tumours

Keratocystic odontogenic tumours (KOCTs) are common benign cystic tumours that arise sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). PTCH mutation can be found in sporadically or NBCCS associated KOCTs. Few PTCH mutations in families with non-syndromic KOCTs have been reported. Through PCR and gene sequence analysis, the authors discovered one missense mutation c.3277G>C in exon 19 of PTCH gene in a Chinese family with non-syndromic KOCTs. This mutation causes one highly conserved glycine residue transit to arginine on the 10th transmembrane region of PTCH protein. This work revealed that the missense mutation of PTCH is the causative and dominant gene of KOCTs in this family.     

Effect of mechanical loading on electrical conductivity in porcine TMJ discs

The objective of this study was to examine the impact of mechanical loading on solute transport in porcine temporomandibular joint (TMJ) discs using the electrical conductivity method. The electrical conductivity, as well as ion diffusivity, of TMJ discs was determined under confined compression with 3 strains in 5 disc regions. The average electrical conductivity over the 5 regions (mean ± SD) at 0% strain was 3.10 ± 0.68 mS/cm, decreased to 2.76 ± 0.58 mS/cm (-11.0%) at 10% strain, and 2.38 ± 0.55 mS/cm (-22.2%) at 20% compressive strain. Correspondingly, the average relative ion diffusivity (mean ± SD) at 0% strain was 0.273 ± 0.055, decreased to 0.253 ± 0.048 (-7.3%) at 10% strain, and 0.231 ± 0.048 (-15.4%) at 20% compressive strain. These results indicated that compressive strain impeded solute transport in the TMJ disc. Furthermore, our results showed that the transport properties of TMJ discs were region-dependent. The electrical conductivity and ion diffusivity in the anterior region were significantly higher than in the posterior region. This regional difference is likely due to the significant differences of tissue hydration between these 2 regions. This study provides important insight into the electrical and solute transport behaviors in TMJ discs under mechanical loading and aids in the understanding of TMJ pathophysiology related to tissue nutrition.     

Influence of proinflammatory cytokines on Actinobacillus actinomycetemcomitans specific IgG responses

OBJECTIVE: High levels of serum anti-Actinobacillus actinomycetemcomitans immunoglobulin G (IgG) correlate with reduced extent and severity of periodontal disease and the present study was undertaken to begin testing the hypothesis that proinflammatory cytokines are important in the induction of optimal anti-A. actinomycetemcomitans IgG responses. BACKGROUND: Studies with pokeweed mitogen indicate that interleukin-1alpha (IL-1alpha) and IL-1beta are necessary for optimal IgG1 and IgG2 production and that prostaglandin E(2) (PGE(2)) and interferon-gamma (IFN-gamma) selectively promote IgG2, which is a major component of the anti-A. actinomycetemcomitans response in vivo. The pokeweed mitogen results suggest that these proinflammatory cytokines would also be necessary for optimal production of IgG specific for A. actinomycetemcomitans. METHODS: Peripheral blood mononuclear cells from A. actinomycetemcomitans-seropositive subjects with localized aggressive periodontitis were stimulated with A. actinomycetemcomitans in immune complexes capable of binding follicular dendritic cells that participate in the induction of recall responses in vivo. Cultures were manipulated with anti-IL-1alpha, anti-IL-1beta, anti-IFN-gamma, anti-IL-12, anti-CD21, indomethacin, and PGE(2). Actinobacillus actinomycetemcomitans specific IgG production was monitored by enzyme-linked immunosorbent assay (ELISA). RESULTS: Addition of follicular dendritic cells to peripheral blood mononuclear cells cultures resulted in follicular dendritic cell-lymphocyte clusters and increased anti-A. actinomycetemcomitans IgG responses (3-40-fold increases) compared with controls lacking follicular dendritic cells. Anti-IL-1alpha, anti-IL-1beta, anti-IFN-gamma, anti-IL-12, anti-CD21 and indomethacin suppressed anti-A. actinomycetemcomitans IgG production by half or more. PGE(2) restored IgG responses suppressed by indomethacin. CONCLUSIONS: The cytokines IL-1alpha, IL-1beta, IFN-gamma, IL-12, and PGE(2) were all necessary for optimal production of human anti-A. actinomycetemcomitans and the need for proinflammatory cytokines including the T helper 1 (Th1) cytokines is consistent with a response with a significant IgG2 component.     

The role of cyclic-AMP on arginase activity by a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

AIMS: The aim of the present study was to determine the role of cyclic adenosine monophosphate (cAMP) on arginase activity in a murine macrophage cell line (RAW264.7 cells) stimulated with lipopolysaccharide (LPS) from Actinobacillus actinomycetemcomitans. MATERIALS AND METHODS: The cells were treated with A. actinomycetemcomitans LPS for 24 h. The effects of SQ22536 (an adenylyl cyclase inhibitor), ODQ (a guanylyl cyclase inhibitor), dibutyryl cAMP (a cAMP analog), 8-bromo cyclic guanosine monophosphate (a cGMP analog), forskolin (an adenylyl cylase activator), and cycloheximide (a protein synthesis inhibitor) on arginase activity in A. actinomycetemcomitans LPS-stimulated RAW264.7 cells were also determined. Arginase activity was assessed in LPS-stimulated cells in the presence of 3-isobutyl-1-methylxanthine (IBMX), siguazodan and rolipram [phosphodiesterase (PDE) inhibitors] as well as KT5720 [a protein kinase A (PKA) inhibitor]. RESULTS: Arginase activity in A. actinomycetemcomitans LPS-stimulated RAW264.7 cells was suppressed by SQ22536 but not ODQ. Enhancement of arginase activity was observed in the presence of cAMP analog or forskolin but not cGMP analog. Cycloheximide blocked arginase activity in the cells in the presence of cAMP analog or forskolin with or without A. actinomycetemcomitans LPS. IBMX augmented arginase activity in A. actinomycetemcomitans LPS-stimulated cells. Rolipram (a PDE4 inhibitor) increased the levels of arginase activity higher than siguazodan (a PDE3 inhibitor) in the antigen-stimulated cells. The effect of cAMP analog or forskolin on arginase activity in the presence or absence of A. actinomycetemcomitans LPS was blocked by the PKA inhibitor (KT5720). CONCLUSION: The results of the present study suggest that A. actinomycetemcomitans LPS may stimulate arginase activity in murine macrophages (RAW264.7 cells) in a cAMP-PKA-dependent pathway.     

An audit of the UK national cancer referral guidelines for suspected oral mucosal malignancy

BACKGROUND AND OBJECTIVE: This study aimed to assess the effectiveness of the UK National Guidelines for identifying patients with potentially malignant oral disease which were introduced in 2000. DESIGN: Retrospective audit. SETTING: The oral medicine unit in a university teaching hospital in London. METHODS: All new referrals over a one year period were retrospectively reviewed in a departmental audit to evaluate guideline effectiveness. Reasons for referral and final diagnosis were compared in a randomly selected sub-population. RESULTS: Four hundred and eighty-seven of 901 new patients referred were classified as having potentially malignant disease from the referral letter. In a randomly selected subgroup of 241 patients, 18 actually had malignant (8) or dysplastic lesions (10). Of 75 patients referred with a persistent oral ulcer, only nine were actually malignant or dysplastic. Eight of 116 patients referred with a white patch and none with red patches were found to have dysplastic or malignant lesions. The criteria failed to identify three carcinomas and two severely dysplastic lesions (15% of the malignant or dysplastic lesions). All of the latter had been referred by primary care physicians with orofacial pain of unknown cause. CONCLUSIONS: UK National Guidelines discriminate poorly between potentially malignant and other oral mucosal disease.     

Caries-risk assessment: the role of salivary tests

Although the incidence of caries has diminished dramatically over the past 3 decades, small groups of subjects remain highly susceptible and do not respond to conventional preventive programs. An accurate individual caries-risk assessment allows to identify the etiological factors responsible for the disease and design a rational approach to treatment, addressed to the specific needs of the patients. The use of appropriate caries-risk prediction models, which include the use of simple chairside caries-susceptibility salivary tests, is the most suitable and modern approach to the problem. A review of the literature on salivary tests, at present available, able to identify the factors contributing to caries susceptibility, is presented. Each test is accurately described, with regard both to its procedure and the interpretation of its results:     

Epithelial malignancies of the salivary glands: clinical experience of a single institution-a review

In this retrospective study we give a clinical review of our experience with different subtypes of salivary gland cancer. Between January 1983 and December 2002, a total of 155 patients with carcinomas of the salivary glands received initial treatment at the Department of Oral and Maxillofacial Surgery, Hanover Medical School. There were 79 (51.0%) adenoid cystic carcinomas, 42 (27.1%) mucoepidermoid carcinomas, 12 (7.7%) adenocarcinomas, 10 (6.5%) polymorphous adenocarcinomas and 12 (7.7%) other tumor entities of smaller number. Complete resection was reached for 63.5% of patients with high grade carcinomas and for 80.0% of patients with low grade carcinomas. 26.2% of patients with high grade carcinomas and 13.3% of patients with low grade carcinomas received postoperative radiation. Overall survival rates at 5, 10 and 15 years were 65.9, 48.0 and 39.8% with significant difference for patients with high grade and low grade carcinomas. Histopathologic subtype, tumor stage and margin status significantly influenced prognosis. Statistically, we were not able to demonstrate a positive effect for postoperative radiation. In the future, patients with salivary gland carcinomas should be randomised for prospective multicentric clinical trials, which could provide reliable information about adjuvant treatment modalities and their results even for rare subtypes of salivary gland cancer.     

Rhino-sinusitis related to endosseous implants extending into the nasal cavity. A case report

Rhino-sinusitis may develop as a result of an altered airflow in the nasal cavity causing irritation of the nasal mucosa. A patient is presented who developed recurrent rhino-sinusitis complaints following placement of endosseous implants in the maxilla. Inspection of the nasal floor revealed that two implants had perforated the floor of the nasal cavity. The part of the implants protruding in the nasal cavity was surgically resected via an endonasal approach whereupon the rhino-sinusitis complaints disappeared.