Three-dimensional facial changes correlated with sagittal jaw movements in patients with class III skeletal deformities.

The aim of this prospective study was to correlate the postoperative 3-dimensional facial changes in skeletal class III deformity with sagittal jaw movements in 84 patients who had been treated by one piece Le Fort I maxillary advancement only (n=18), mandibular setback only (n=38), or both procedures (n=28). At the times of evaluation before and six months after operation all patients had fixed orthodontic appliances. Soft tissue changes were evaluated on optical 3-dimensional scans, while lateral cephalograms were superimposed to assess sagittal jaw movements. Three-dimensional surface facial scans were divided into 11 regions. We modelled soft tissue changes in each region by linear regression with maxillary (point A) and mandibular (point B) sagittal movements as predictors, and adjusted for sex, age, body mass index, type of operation, and interincisal angle. We found the highest values of regression coefficients (around 0.5) for the sagittal movements of the variables points A and B within the regions of the upper and lower lips. This meant that for each mm of maxillary advancement and mandibular setback, the soft tissue moved 0.5mm. In the sides of the face the regression coefficients were between 0.1 and 0.3, as were those within regions indirectly affected by the operations.

Tongue volume in adults with skeletal Class III dentofacial deformities.

BACKGROUND: The size of the tongue is implicated as an essential etiological factor in the development of malocclusions. The aim of our study was to assess tongue size in skeletal Class III (SCIII) patients in comparison to adults with normal occlusion, using three-dimensional (3D) ultrasound. METHODS: The SCIII group consisted of 54 subjects; 34 females and 20 males and the control group contained 36 subjects, 18 from each gender with Class I relationship. 3D ultrasound images of the tongues were acquired, and then the tongues' volumes were assessed. RESULTS: The males in both the SCIII and control groups had significantly larger tongue volumes than the female subjects (mean SCIII 100.8 ± 6.3 and control 92.4 ± 9.8 cm(3) in males vs. SCIII 77.4 ± 10.2 and control 67.2 ± 5.6 cm(3) in females). The highly significantly larger tongue volumes were in SCIII patients of both genders (p were less than 0.01 for female and 0.03 for male). The tongue volumes within the whole SCIII group were significantly larger with more negative Wits values. CONCLUSION: The tongue volumes are significantly bigger in SCIII subjects than normal. Larger tongues correlate with more severe SCIII. The clinical importance of this data is that limited mandibular setback planning is necessary to prevent narrowing of respiratory airways.

Differences in three-dimensional soft tissue changes after upper, lower, or both jaw orthognathic surgery in skeletal class III patients.

The decision is not always straightforward as to which orthognathic procedure is best for a good aesthetic result; three-dimensional imaging has brought new insight into this topic. The aim of this prospective study was to verify objectively whether postoperative changes occur within those regions not directly affected by surgical movements of the underlying jaw bones. The study included 83 young adults with skeletal class III deformities. They were classified into three groups according to the type of surgery: bilateral sagittal split osteotomy set-back of the mandible (BSSO), Le Fort I advancement of the maxilla, or a combination of both. Pre- and postoperative optical scans were registered as regional best-fits on the areas of the foreheads and both orbits. The shell to shell differences were measured and the average distances between the observed regions were calculated. As expected, changes were greatest in the regions where the underlying bones had been moved, but regardless of the operation performed, changes were found over the whole face. Changes in the nose, cheek, and upper lip regions in the BSSO group and in the lower lip and chin region in the Le Fort I group confirmed the concept of the facial soft tissue mask acting as one unit.

T lymphocyte activation and cytokine expression in periapical granulomas and radicular cysts.

INTRODUCTION: Radicular cysts (RCs) are periapical lesions resulting in jaw bone destruction. The inflammatory dental periapical granuloma (PG) is considered to be the origin of RC formation; however the mechanism of RC development remains unclear. METHODS: Cell suspension from the surgically extirpated tissue of 27 RCs and 25 PGs was obtained. Bacteriological analysis of the PG tissue samples was performed in order to define two major groups of PG according to the prevailing causative bacterial infection: the streptococcal PG (PG-S, n=10) and the anaerobe PG (PG-A, n=9) group. The inflammatory response of tissue infiltrating lymphocytes was assessed by following T lymphocyte activation (HLA-DR expression) as well as interferon gamma (IFN-gamma) and interleukin 4 (IL-4) production which were evaluated by the flow cytometry. RESULTS: In comparison to RC both types of PG contained a higher proportion of activated T cells (HLA-DR) and lower proportion of IL-4 producing cells. PG-A tissue contained increased percentage of CD3 cells and increased percentage of T helper 1 (Th1) cells in comparison with PG-S. In RC the IFN-gamma production is higher than in streptococcal PG-S but similar as in PG-A. DISCUSSION: Tissue infiltration by Th2 cells and IL-4 production is likely to play an etiopathogenic role in RC formation.

Spontaneous bone healing of the large bone defects in the mandible.

Spontaneous healing of large bone defects in the mandibles of 33 patients was studied. Standard postoperative clinical and radiographic examinations were performed immediately after surgery and after 2, 6 and 12 months. They were analysed using a novel relative bone densitometry method and indexes of relative bone healing were established. Spontaneous bone regeneration occurred in all patients clinically, and the computer analysis of radiographs showed that the mean final bone density in the bone defects was 88% of the bone density of the surrounding healthy bone. In the cases of smaller defects (the greatest diameter on panoramic radiographs was 20-30 mm) the final bone density was 97%, while the larger defects finally healed with 84% of the bone density of the surrounding bone. Increased patient age had a negative influence on healing and the shape of the bone defects was more important for healing than their volume. Spontaneous bone healing occurred even in large bone defects in the mandible, therefore this simple treatment with low economic and biological costs should be the treatment of choice, taking into account the patient's age, surgical principles and time of rehabilitation.

Osteoporosis and mandibles.

OBJECTIVES: The purpose of this study was to find out whether mandibular bone tissues on dental panoramic tomograms (DPTs) are statistically significantly different between osteoporotic and non-osteoporotic women. We wanted to develop a simple method of common DPT analysis that could represent a simple, inexpensive and readily available screening tool for osteoporosis. METHODS: DPT images of 36 women with primary osteoporosis were compared with 20 DPT images of non-osteoporotic women of the same age group. Scanned DPTs were analysed using public computer software. Mandibular atrophy was assessed by six anatomic indexes. Anatomic indexes were divided into subgroups regarding the presence of teeth. Relative bone density (RBD) was assessed using a colour histogram (CH) plugin. Nine RBD indexes were calculated as relations of CH values measured on specific sites of the mandible. RESULTS: The subtractions of average values of anatomic indexes with and without a tooth were 1.5 to 2.5 times higher in the osteoporotic group of women. Average of RBD indexes differed statistically significantly between the groups (P<0.05). Three RBD indexes differed statistically significantly between groups (P<0.05). CONCLUSIONS: Mandibular bone tissues on DPTs are statistically significantly different between osteoporotic and non-osteoporotic women. RBD of the mandible is statistically significantly lower in the osteoporotic group of women. We developed a simple method of common DPT analysis, which could represent a simple, inexpensive and readily available screening tool for osteoporosis.

Commensal oral bacteria antigens prime human dendritic cells to induce Th1, Th2 or Treg differentiation.

In various immunopathologic conditions, bacterial flora induce an immune response which results in inflammatory manifestations, e.g. periapical granuloma. Dendritic cells provide the main orchestration of specific immune responses. The aim of our study was to test the capacity of distinct oral bacterial antigens (prepared from Streptococcus mitis, Propionibacterium acnes, and Bacteroides spp.) to prime human dendritic cells for stimulation of the T-lymphocyte response. To assess the T-lymphocyte response, the expression of CD25, CD69, intracellular interferon gamma (cIFN-gamma), and intracellular interleukin 4 (cIL-4) was determined. Dendritic cells were prepared from leukocyte buffy coat from healthy blood donors. Monocytes were stimulated with IL-4 and GM-CSF and dendritic cells activated with bacterial lysates. Cell suspensions contained up to 90% dendritic cells, which represented 2-12% of the initial number of mononuclear cells. Lymphocyte subsets that developed in lymphocyte cultures after 1 week of stimulation were analyzed by flow cytometry. Dendritic cells, primed with antigens of Bacteroides fragilis have shown significantly higher activation and expression of intercellular IFN-gamma by T lymphocytes compared to negative controls. The dendritic cells primed with antigens of P. acnes had no effect on T-lymphocyte activation or cytokine production; instead they induced differentiation of T lymphocytes into CD25bright cells (regulatory T cells) with a potentially inhibitory effect on immune response. Dendritic cells primed with antigens of S. mitis induced increased expression of cIL-4. We conclude that commensal oral bacteria antigens prepared from B. fragilis, S. mitis, and P. acnes prime human dendritic cells to induce Th1, Th2, and T(reg) differentiation, respectively. This may advance our understanding of immunopathologic manifestations in the oral cavity and offer new possibilities for redirecting immune responses in mucosal vaccination.

Characteristic forms of the upper part of the oral cavity in newborns with isolated cleft palate.

OBJECTIVE: To determine the functional and morphological compensation of the lack of integrity in the upper part of the oral cavity in newborns with isolated cleft palate. Integrity of the upper part of the oral cavity is required for the effective pumping of amniotic fluid, the essential mode of nutrition in intrauterine life. The adaptation could be seen immediately after birth. MATERIALS: Plaster casts of the upper part of the oral cavity in 60 newborns with isolated cleft palate of various extent and plaster casts of the upper part of the oral cavity in 27 newborns without cleft were used. A number of surface points were identified and used for a trigonometric morphological analysis. RESULTS: The parameters of the upper part of the oral cavity in four groups of newborns with various extent of isolated cleft palate were compared with newborns without cleft palate. The results indicate a shift of the functional oral cavity into the nasal cavity and the pharynx, depending on the extent of the cleft. CONCLUSION: The pumping activity of the tongue forms the upper part of the oral cavity and consequently the tongue moves into the nasal cavity and pharynx, depending on the extent of the cleft. In this way, effective pumping of amniotic fluid is possible despite the cleft. This is of vital importance for the fetus during intrauterine life. A poorly passable or even unpassable respiratory way is only of secondary importance during that time.

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-gamma 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 pathohistologic and microbiologic findings and compared them to the results of immunological 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 streptococcal). 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.