Professor

<strong>Targeted Chemometrics Investigations of Source-, Age- and Gender-Dependencies of Oral Cavity Malodorous Volatile Sulphur Compounds</strong> Halitosis is a highly distressing, socially-unaesthetic condition, with a very high incidence amongst the adult population. It predominantly arises from excessive oral cavity volatile sulphur compound (VSC) concentrations, which have either oral or extra-oral etiologies (90-95 and 5-10% of cases, respectively). However, reports concerning age- and gender-related influences on the patterns and concentrations of these malodorous agents remain sparse; therefore, this study’s first objective was to explore the significance and impact of these potential predictor variables. Moreover, because non-oral etiologies for halitosis may represent avatars of serious extra-oral diseases, the second objective was to distinguish between etiology- (source-) dependent patterns of oral cavity VSCs. Oral cavity VSC determinations were performed on 116 healthy human participants using a non-stationary gas chromatographic facility, and following a 4 hr. period of abstention from all non-respiratory oral activities. Participants were grouped according to age band and gender. Statistical analyses of VSC level data acquired featured both univariate/correlation and multivariate (MV) approaches. Factorial analysis-of-variance and MV analyses revealed that the levels of all VSCs monitored were independent of both age and gender. Principal component analysis (PCA) and an agglomerative hierarchal clustering strategy demonstrated that VSC predictor variables were partitioned into two components, the first arising from orally-sourced H₂S and CH₃SH, the second from extra-orally-sourced (CH₃)₂S alone (58 and 35% of total PCA variance respectively). In conclusion, oral cavity VSC concentrations appear not to be significantly influenced by age band and gender. Furthermore, (CH₃)₂S may serve as a valuable biomarker for selected extra-oral conditions.靶向化学计量学研究口腔异味挥发性硫化物的来源、年龄与性别依赖性 口臭（halitosis）是一种极具困扰性且影响社交美观的病症，在成年人群中发病率极高。其主要病因是口腔内挥发性硫化物（volatile sulphur compounds, VSC）浓度过高，此类病因可分为口源性与外源性两类，分别占总病例的90%~95%与5%~10%。然而，目前关于年龄与性别对这类异味物质的组成模式与浓度水平的影响相关研究仍较为匮乏；因此本研究的首要目标是探究这两类潜在预测变量的重要性与影响效应。此外，由于口臭的非口源性病因可能是各类严重口外疾病的临床表征，本研究的第二项目标是区分基于病因（即来源）的口腔VSC组成模式。 本研究针对116名健康受试者开展口腔VSC检测，检测采用非固定式气相色谱设备，且所有受试者在检测前4小时均需暂停所有非呼吸类口腔活动。研究人员按年龄区间与性别对受试者进行分组。对获取的VSC浓度数据开展的统计分析涵盖单变量/相关性分析与多变量分析（multivariate, MV）两类方法。析因方差分析与多变量分析结果显示，所有被监测的VSC浓度水平均与年龄及性别无显著相关性。主成分分析（principal component analysis, PCA）与凝聚层次聚类分析策略结果表明，VSC预测变量可划分为两个组分：第一组分为口源性硫化氢（H₂S）与甲硫醇（CH₃SH），第二组分为仅外源性二甲基硫醚（(CH₃)₂S），二者分别占PCA总方差的58%与35%。 综上，口腔VSC浓度水平似乎并未受到年龄区间与性别的显著影响。此外，二甲基硫醚（(CH₃)₂S）可作为特定口外疾病的潜在有效生物标志物。