3D Facial Changes Between Maximal Intercuspal Position and Physiologic Rest Position.

PURPOSE: To evaluate the soft tissue changes of the face between two positions of occlusion: maximal intercuspal position (MIP) and physiologic rest position (RP). MATERIALS AND METHODS: In this study, facial surface scans of 83 volunteers in two mandibular positions (MIP and RP) were obtained using a 3D optical scanner. On each 3D image, 21 cephalometric soft tissue landmarks were identified and then compared using t test for various facial parameters (widths, heights, depths, angles, and ratio). Additionally, a regional analysis of the facial surface differences in each patient between the two mandibular positions was performed using a whole scan shell best-fit method and the regional forehead best-fit method. RESULTS: In MIP, facial heights with the nasion-gnathion distance shortened by approximately 1.2 mm (due to the vertical shrinkage of both lips together by 0.8 mm), and the mouth width was significantly widened, while other facial widths displayed no change. The labiomental angle and the upper vermilion arch were altered correspondingly, and regional analysis confirmed the findings with evident changes in the mandibular and subnasal areas with deviations amplified toward the facial midline. CONCLUSIONS: By applying 3D facial-scanning technology, this study displayed changes of facial appearance in different mandibular positions (MIP and RP), highlighting the need to instruct and monitor the patient's mandibular position more consistently to achieve accurate and repeatable data in a 3D facial analysis.

Older adults' facial characteristics compared to young adults' in correlation with edentulism: a cross sectional study.

BACKGROUND: Facial ageing is a result of superficial wrinkling combined with changes to the underlying soft tissues and skeleton. The influence of tooth loss, as a geriatric characteristic, on facial appearance is still poorly explained. The aim was to evaluate the facial characteristics of older adults, correlate these characteristics with the dentition and make comparisons with young adults using a non-invasive 3D methodology. METHODS: 90 participants older than 65 years, classified into 3 subgroups (edentulous, partially edentulous, toothed) and 30 young adults were evaluated. Their faces were scanned with an optical Artec 3D-scanner. Cephalometric analyses were made using the RapidForm computer program. An independent t-test and ANOVA were used for the comparisons. Pairwise, post-hoc tests were applied with respect to the significant differences (P < 0.05). RESULTS: The faces of older adults are wider and longer because of the longer middle facial height. Older adults also have a longer upper lip, a larger nose, a smaller nasolabial angle (due to the nasal ptosis), narrower upper- and lower-lip vermilions and larger facial and lower-facial-height angles, resulting in a flat facial profile. The facial changes due to ageing are the most pronounced in the edentulous. In comparison with the toothed, they have a smaller facial height due to the smaller lower facial height, larger nasolabial angle, smaller mouth width, shorter upper lip and narrower lip vermilions. Their profile is flatter and their lips are more retruded. CONCLUSIONS: The proportions of the whole face are changed in older adults and they are the most expressed when this is combined with tooth loss.

Effect of aging and body characteristics on facial sexual dimorphism in the Caucasian Population.

AIM: The aim of this study was to quantify gender-specific facial characteristics in younger and older adults and to determine how aging and body characteristics, such as height and body-mass index (BMI), influence facial sexual dimorphism. METHODS: The cohort study included 90 younger adults of Caucasian origin (average age of 45 females 23.2 ± 1.9 and 45 males 23.7 ± 2.4 years) and 90 older adults (average age of 49 females 78.1 ± 8.1 and 41 males 74.5 ± 7.7 years). Three-dimensional facial scans were performed with an Artec MHT 3D scanner. The data were analyzed using the software package Rapidform®. The parameters to evaluate facial symmetry, height, width, profile, facial shape, nose, eyes and mouth characteristics were determined based on 39 facial landmarks. Student's t-test was used to calculate the statistical differences between the genders in the younger and older adults and a multiple-linear-regression analysis was used to evaluate the impact of gender, age, body-mass index and body height. RESULTS: We found that the female faces were more symmetrical than the male faces, and this was statistically significant in the older adults. The female facial shape was more rounded and their faces were smaller, after normalizing for body size. The males had wider mouths, longer upper lips, larger noses and more prominent lower foreheads. Surprisingly, we found that all the gender-dependent characteristics were even more pronounced in the older adults. Increased facial asymmetry, decreased facial convexity, increased forehead angle, narrower vermilions and longer inter-eye distances occurred in both genders during aging. An increased BMI was associated with wider faces, more concave facial profiles and wider noses, while greater body height correlated with increased facial heights and wider mouths. CONCLUSION: Facial sexual dimorphism was confirmed by multiple parameters in our study, while the differences between the genders were more pronounced in the older adults.

Effect of surgery and radiotherapy on complete blood count, lymphocyte subsets and inflammatory response in patients with advanced oral cancer.

BACKGROUND: The immune system has a known role in the aetiology, progression and final treatment outcome of oral squamous cell cancers. The aim of this study was to evaluate the influence of radical surgery and radiotherapy on advanced oral squamous cell carcinoma blood counts, lymphocyte subsets and levels of acute inflammatory response markers. METHODS: Blood samples were obtained from 56 patients 5 days before and 10 days after surgery, 30 days and 1 year after radiotherapy. The whole blood count, lymphocyte subsets and inflammatory response markers (C-reactive protein, erythrocyte sedimentation rate, leukocyte count, expression of index CD64 and index CD163 on neutrophils and monocytes) were measured, statistically analysed and correlated with clinical treatment outcomes. RESULTS: The post-operative period was characterised by the onset of anaemia, thrombocytosis, lymphopenia with reduced B lymphocyte, T helper cell and NK cell counts, and a rise in acute phase reactants. Immediately after radiotherapy, the anaemia improved, the lymphopenia worsened, and thrombocyte levels returned to pre-treatment values. There was a drop in counts across the T and B cell lines, including a reduction in B lymphocytes, naïve and memory T cells with reduced CD4+ and CD8+ counts and a decreased CD4/CD8 ratio. One year after radiotherapy all the lymphocyte subsets remained depressed, the only exception being NK cells, whose levels returned to pre-treatment values. CONCLUSIONS: We concluded that surgery resulted in a stronger acute phase response than radiotherapy, while radiotherapy caused a long-lasting reduction in lymphocyte counts. There was no correlation between any of the pre-treatment parameters and the clinical outcome.

Evaluation of an Accelerated Chemoradiotherapy Protocol for Oropharyngeal Squamous Cell Carcinoma in 5 Cats and 3 Dogs.

Accelerated radiation therapy protocols address the specific biology of aggressive oropharyngeal squamous cell carcinoma and this approach was applied in 5 feline and 3 canine oropharyngeal squamous cell carcinoma patients where surgery was not possible (4/5 feline and 2/3 canine cases) or was declined (1/5 feline and 1/3 canine cases). A protocol using 14 fractions of 3.5 Gy over 9-days, combined with carboplatin chemotherapy as a radiosensitiser (total dose 180 mg/m2 in feline and 300 mg/m2 in canine cases) resulted in a complete tumor response in most cases (4/5 feline and 3/3 canine cases) with acceptable acute and long-term side effects. Results achieved in feline cases correspond with published data where these specific radiotherapy protocols were employed. A complete response and long-term survival (> 2-years) was achieved in all canine patients. Although no standardized chemoradiotherapy protocols currently exist, this therapeutic approach can be a useful addition for the management of oropharyngeal squamous cell carcinoma of cats and dogs when the goals of treatment include maximizing tumor control while maintaining function and quality of life.

Modified bone density-dependent orthotropic material model of human mandibular bone.

The prediction accuracy of computational simulations of various biomechanical problems of human bones depends on proper modelling of the problem geometry and boundary conditions but it is also essentially dependent on proper description of the mechanical properties of the all constitutive elements. As the human mandibular bone is a very important load-carrying element in biomechanics, the main aim of this research was to develop an innovative, not yet described in literature, spatial and bone density-dependent orthotropic material model of the human mandibular bone for use in the computational simulations. We compared it with the most used constitutive material models in the computational simulations of the human mandibular bone behaviour with inserted dental implant. The results show that the von Mises equivalent stress distribution values in the bone density-dependent orthotropic model are higher in comparison with other models but the highest are on the top of the alveolar ridge and higher in the lingual than in the buccal part of the lower jaw.

Novel method of 3-dimensional soft-tissue analysis for Class III patients.

INTRODUCTION: The aim of this study was to evaluate 3-dimensional facial shells by incorporating a population-specific average template with a group of Class III subjects preparing to have orthognathic surgery. METHODS: The Class III group included 14 male (MCIII) and 15 female (FCIII) subjects. We used 43 male and 44 female Class I subjects to construct average male (AvM) and female (AvF) faces. Coordinates of 3 points on the facial templates of groups MCIII and FCIII and the templates AvM and AvF were compared. MCIII-AvM and FCIII-AvF superimpositions were evaluated for differences. RESULTS: Vertical distances (sella to soft-tissue pogonion) were statistically significantly higher for the AvM (9.1%) and MCIII (10.1%) than for the AvF and FCIII, respectively (P < 0.05). The distances of soft-tissue pogonion in the horizontal x-axis were positive in 80% of the FCIII group and 85.7% of the MCIII group. The Class III subjects differed from the average face in the lower two thirds, but, in 50% (MCIII) and 60% (FCIII), they differed also in the upper facial third. CONCLUSIONS: (1) The average and Class III Slovenian male morphologic face heights are statistically significantly higher than those of the female subjects. (2) The Slovenian Class III male and female subjects tend toward a left-sided chin deviation. (3) Differences between Class III patients and a normative data set were determined.

Characterization of the normal bacterial flora in peri-implant sulci of partially and completely edentulous patients.

PURPOSE: To characterize the normal bacterial flora and evaluate the presence of periodontopathogenic bacteria around dental implants and to correlate them with the periodontal flora or, in completely edentulous patients, the alveolar gingival flora. MATERIALS AND METHODS: Clinical and radiographic parameters were recorded to exclude peri-implantitis in 34 partially edentulous and 19 completely edentulous patients. Partially edentulous patients were subdivided into two subgroups based on the depth of the periodontal pocket: ≤ 4 mm (n = 19) and > 4 mm (n = 15). Microbial samples were collected from peri-implant sulci, the deepest periodontal sulci, and, for completely edentulous patients, from the alveolar gingiva. Predominant aerobic bacteria were determined by microbiologic culturing, and multiplex polymerase chain reaction was used to detect five periodontopathogenic bacteria: Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. RESULTS: In all the examined patients, oral streptococci were the most frequent aerobic peri-implant bacteria. The frequency of four periodontopathogenic bacteria in tooth sulci (A actino?mycetemcomitans, P gingivalis, T forsythensis, T denticola) was significantly higher around natural teeth with deeper periodontal pockets, but there was no significant difference in the frequency of the same bacteria in peri-implant sulci in the two partially edentulous subgroups. In contrast, there were no such bacteria in the peri-implant sulci or the alveolar gingiva of completely edentulous patients. CONCLUSIONS: In healthy peri-implant sulci, oral streptococci constitute the predominant bacterial flora. In partially edentulous patients four periodontopathogenic bacteria were detected around implants, and none of these bacteria were found around implants in completely edentulous patients.

Facial morphology of Slovenian and Welsh white populations using 3-dimensional imaging.

OBJECTIVE: To use 3-dimensional (3D) facial averages to test the hypothesis that the facial morphologies of 2 European white groups (Slovenia and Wales) have no differences. METHODS: Fifty males and 50 females from Wales and 43 males and 44 females from Slovenia were included in the study. Subjects ranged from 18 to 30 years of age. Four subgroups were formed: Slovenian males (SM), Slovenian females (SF), Welsh males (WM), and Welsh females (WF). 3D data were acquired using a laser scanning system. An average face for each subgroup was obtained using a previously validated mathematical algorithm. Facial differences were quantified after average faces had been superimposed using a previously validated method. RESULTS: A total of 187 subjects from Slovenia and Wales formed 4 gender-specific subgroups. Absolute differences between subgroups ranged from 0.36 mm to 1.51 mm. The mean linear facial difference between SF and WF was 0.64 +/- 0.51 mm, and between SM and WM was 0.36 +/- 0.41 mm. Similarities between subgroups ranged from 13.43% (SF, WF) to 70.23% (SM, WM). Slovenian males and females tend to express Class III facial morphology when compared with the Welsh gender-specific subgroups. Male faces, in general, have more pronounced nasal, brow, and frontal regions and mandibles when compared with females. Female faces have more prominent malar and periocular areas. CONCLUSION: The hypothesis is rejected. Morphologic differences exist between Slovenian and Welsh faces.

Immune response in lymphocyte cultures stimulated by oral bacteria preparations.

Lymphocyte cultures were used as an in vitro experimental model to get a deeper insight into immune response to oral bacteria in periapical granulomas. Lymphocytes isolated from leucocyte concentrate were in lymphocyte cultures stimulated by antigen preparations of oral bacteria. Lymphocyte subsets that have developed in lymphocyte cultures after a week of stimulation were analysed by flow cytometry. A significant increase in expression of INF-γ molecules in CD3+ cells stimulated by antigen preparations of oral streptococci was found, compared with negative control. On the other hand we observed a significant increase in expression of IL-4 in CD3+ cells stimulated by antigens of anaerobic bacteria, compared with negative control. Our results show that antigens of oral streptococci in in vitro lymphocyte cultures induce the differentiation of T helper cells into Th2 cells and that antigen preparations of anaerobic bacteria induce the differentiation of T helper cells into Th1 cells. Furthermore, an increased expression of HLA-DR molecules on CD8+ T cells stimulated by antigens of oral streptococci was found, compared with negative control.

Immune response in chronic periapical parodonititis.

The purpose of our study was to investigate the immune response in chronical periapical parodontitis (CPP) by using multidisciplinary approach. 30 CPP samples were obtained after surgical removal - apicoectomy. Each CPP sample was examined by histological, bacteriological and flow cytometrical (FC) analysis of lymphocytes infiltrating CPP samples. Ten percent of bacteriological samples were sterile, others had significant aerobic and anaerobic growth. We used patohistologic and microbiologic findings and compare them to the results of imunological analysis. By FC we found a significant increase in proportions of T lymphocytes expressing interleukin-2 receptors and ICAM-1 compared to peripheral blood lymphocytes. Proportions of T helper cells that produce interferon-gama (IFN-gamma) was higher in CPP samples predominantly colonized by anaerobic bacteria. There were no differences in IL-4 expression by T cells in both groups (anaerobic and streptoccoccal). Among anaerobic CPP samples differences in proportion of T cells that express IL-2 receptors expression was also found between samples colonised by P. acnes and Bacteroides sp. Oral streptococci cause relatively limited tissue destruction and induce Th2 type of immune response accompanied by non-cytotoxic inflammatory reaction. On the contrary, anaerobic bacteria induce Th1 type of immune response that cause more severe inflammatory reaction (type 4 of hypersensitivity that damage the tissue by the action of cytotoxic T cell activation.

A mouse model of chronic bacterial lesions (a cotton trap) for studying oral bacteria - lymphocyte interactions.

We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.