Chinese Journal of Dental Research, 01/2018

Burning mouth syndrome (BMS) is a chronic pain condition characterised by a persistent burning sensation in clinically normal oral mucosa. BMS most commonly occurs in middleaged and elderly women. Various local and systemic factors can cause oral burning symptoms. When all possible local and systemic factors are excluded, burning mouth symptoms can be diagnosed as BMS. Psychophysical tests and histopathological data suggest the involvement of peripheral and central neuropathic mechanisms in BMS etiopathogenesis. Psychological problems are frequently observed in BMS patients. Several mechanisms, including increased parafunctional habits, steroid dysregulation, central disinhibition due to taste dysfunction, and low dopamine levels in the brain, have been proposed as an explanation for the role of psychological factors in BMS pathophysiology. However, the causal relationship between BMS and psychological problems remains controversial. Given the neuropathic nature of BMS, treatment for it is similar to other neuropathic pain conditions. Although various treatment modalities, including pharmacological intervention, behavioural therapy and psychotherapy, have been proposed, there is no definitive treatment always effective for the majority of BMS patients. In conclusion, for better understanding of the relationship between BMS and psychological factors, well-designed prospective studies are needed. In addition, the evaluation and treatment of psychological problems are essential for successful management of BMS patients. Keywords: burning mouth syndrome, pathophysiology, psychological factors

Objective: To develop a bioreactor for automated culture, maintenance, and collection of normal human keratinocytes using an enzyme-free propagation method. Methods: The culture of normal human epithelial keratinocytes was compared in two culture methods - a study team-developed automated bioreactor utilising an enzyme-free passage method, and a manual culture method. Cell size, glucose utilisation, and the proliferative capacity of the two cultures were evaluated. Results: An automated bioreactor, not using enzymes for passage, but instead using the novel Epithelial Pop Up Keratinocytes (ePUK)1 culture technique, resulted in an extended culture longevity and proliferative capacity in normal primary human keratinocytes. Daughter cells were collected up to three times per day utilising the bioreactor. The daughter cells produced by the bioreactor were smaller than daughter cells produced by the manual culture method. The proliferative capacity and health of the parent monolayer within both the bioreactor and the manual culture flask was dependent upon sufficient glucose availability. Due to the contact inhibition nature of epithelial keratinocytes, the bioreactor enabled the study of an adherent cell type soon after cytokinesis and before the cell has integrated as part of an adherent matrix. Conclusion: The study demonstrates that increasing the number of media changes per day as necessary, based on glucose utilisation, is necessary for prolonged longevity and functional productivity of ePUK cultures. Keywords: bioreactor, cytokinesis, epithelial, glucose, keratinocytes

Objective: To investigate the Sonic Hedgehog (SHH) signalling molecules and activated leukocyte cell adhesion molecule (ALCAM) expression in the mechanisms regulating invasion and metastasis in oral squamous cell carcinoma (OSCC). Methods: The expressions of SHH signalling molecules Gli family zinc finger 1/2 (Gli1/Gli2), as well as ALCAM expression, was analysed in 101 OSCC patients by immunohistochemistry. The potential relationship between Gli1/Gli2 and ALCAM in regard to invasion and metastasis were studied by western blot, invasion and wound-healing assays. Results: Gli1, Gli2 and ALCAM were expressed in 54.5%, 49.5% and 47.5% of the 101 OSCC specimens, respectively. High expression of ALCAM was associated with shorter survival in the patient population (P = 0.018), which was independent of other clinical parameters. Notably, when both ALCAM expression and positive nodal status were considered, an enhanced prediction of clinical outcomes was achieved (P = 0.001). In OSCC cell lines, down-regulation of ALCAM resulted in reduced cell invasion and metastasis. Importantly, SHH activation increased the half-life of ALCAM leading to ALCAM accumulation and increased cell invasion and migration. Conclusion: ALCAM over-expression in OSCC is an independent prognostic factor for OSCC patients. Its over-expression may be the result of the activation of the SHH signalling pathway and contributes to OSCC progression. Keywords: ALCAM, Gli1, Gli2, invasion, migration, OSCC

Objective: To identify a panel of differentially expressed candidate biomarkers for patients undergoing accelerated osteogenic orthodontics (AOO). Methods: This study included 36 saliva samples taken from six Class III surgical patients at six time points: the date before the corticotomy procedure (T1) and at 1 week, 2 weeks, 1 month, 2 months and 6 months after the procedure (T2, T3, T4, T5 and T6, respectively). After the maxillary dental arch was aligned and levelled, AOO procedures were performed in the maxillary alveolar bone. Saliva samples were used to create peptide mass fingerprints using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic beads. Results: When the six groups were compared, 182 peaks were significantly different (P 0.01), and the biomarker profiles changed over time. After corticotomy, the mass peaks predicted to be the Apolipoprotein A-I precursor (APOA1) increased sharply in T2 then decreased. The peptides predicted to be complement component 3 decreased in T2, then gradually increased and declined in T6. The peptides predicted to be the vitamin D-binding protein precursor increased in T2, then fell to the preoperative level. The mass peaks of the peptides predicted to be Isoform 1 of the fibrinogen alpha chain precursor (FGA) first decreased, then increased with time. Conclusion: The salivary protein profiles changed with accelerated tooth movement induced by AOO. This method provides a tool for investigating corticotomy-induced accelerated tooth movement in humans, and explored the critical factors responsible for the regional acceleratory phenomenon. Keywords: peptidome, saliva; MALDI-TOF MS, corticotomy, accelerated osteogenic orthodontics

Objective: To develop standard experimental methods to minimise technical variance in matrix preparation for MALDI-TOF MS (matrix-assisted laser desorption/ionisation time-offlight) profiling. Methods: Matrix factors in saliva and serum samples of 20 healthy volunteers were examined, assuring their peptide components using seven different matrix type/preparation methods, HCCA(a-cyano-4-hydroxycinnamic acid)/SM(sample/matrix), SA(sinapinic acid)/DD(dried droplet), SA/SM, DHB(2.5-dihydroxyhenz-zoic acid)/DD, DHB/SM, DHAP(2.5-dihydroxyacetophenone)/ DD, DHAP/SM. Number of peaks, S/N(signal to noise) ratio and approximate range of target peaks were set as main selection criteria to find if these spell out any common regularity in results. Results: Different methods perform differently. DHB/DD performed worst in both samples, with no effective peak detected. For saliva sample, the S/N ratios of other six methods were lower. M/z range distributed differently. DHB/SM and DHAP/DD performed best in number of peaks, m/z distributing in 1000 to 2000 account for the vast majority. For serum sample, S/N ratios and m/z range distribution were different in different methods. S/N ratio of SA/DD and SA/SM were higher, number of peaks and m/z distribution were not irreplaceable. S/N ratios of the other four methods were lower. Conclusion: DHAP/DD and HCCA/SM performed best in number of peaks, m/z in 5000 - 7000 account for the vast majority in HCCA/SM and 1000 - 2000 in DHAP/DD. Further studies should focus on other characteristics of peptide components detected in different matrix methods to increase evidence when selecting matrix type/preparation methods. Keywords: MALDI-TOF MS, matrix preparation, proteomics, peptides, saliva

Objective: To assess the correlation between conventional magnetic resonance (MR) imaging and MR sialography of parotid glands with salivary gland scintigraphy in patients with Sjögren's syndrome. Methods: A retrospective study was conducted on eight patients with Sjögren's syndrome who underwent MR imaging and salivary gland scintigraphy. Conventional MR imaging techniques, such as T1-weighted images (T1WI), T2-weighted images (T2WI), and short TI inversion recovery images (STIR) were used for changes of fat signal in the parotid gland, while the MR sialography were used for ducts dilation of the parotid gland. Regarding scintigraphy, time-activity curves of each parotid gland were analysed. The salivary gland excretion fraction was defined as A (before stimulation test (counts/20 s)) and B (after stimulation test (counts/20 s)). Results: Regarding characteristic appearances of fat signal, the A/B of parotid gland with homogeneous intensity distribution (3.51 ± 0.75) was higher than that with heterogeneous intensity distribution (1.56 ± 0.66, P = 0.001). Regarding MR sialographic stages, the A/B of parotid gland with stage 0 (3.51 ± 0.75) was higher than that with stage 1 (2.03 ± 0.86, P = 0.009) and with stage 2 (1.26 ± 0.25, P = 0.000). Conclusion: The results suggest that MR sialography of the parotid glands is a useful noninvasive tool for evaluating the decrease of salivary gland excretion in patients with Sjögren's syndrome. Keywords: magnetic resonance imaging, parotid gland, sialography, Sjögren's syndrome

Objective: To investigate the psychological condition of Chinese patients with or without a primary complaint of halitosis. Methods: The psychological condition of 196 Chinese patients who visited the Department of Periodontics was evaluated using the Cornell Medical Index (CMI) health questionnaire. The breath malodour of all patients was scored using the organoleptic test (OLT). Results: More than half of patients (53.1%) complaining of halitosis actually demonstrated pseudo-halitosis. The overall scores and scores for emotional symptoms of CMI were significantly higher in patients with a chief complaint of halitosis than in those without such a complaint (P 0.05). Females with a chief complaint of halitosis exhibited significantly higher scores for all parameters relative to females without a complaint (P 0.05), while males with a chief complaint of halitosis exhibited enhanced emotional symptoms, particularly inadequacy, anxiety, and tension (P 0.05) when compared with males without a halitosis complaint. Among patients complaining of halitosis, CMI scores for all parameters showed no difference between genuine halitosis female patients and pseudo-halitosis female patients, while male patients with pseudo-halitosis showed higher scores in the CMI overall score, scores for emotional symptoms and sensitivity, than males with genuine halitosis. Conclusion: There was a marked inconsistency between the complaints of patients and their actual odour status. Patients with a chief complaint of halitosis exhibited a greater level of inadequacy, depression, anxiety, sensitivity, anger, and stress. The psychological status of the patients varied with gender. Keywords: halitosis, malodour, psychological