Association between facial measurements and polymorphisms in human epidermal growth factor and transforming growth factor β1

The aim of the study was to evaluate the association between genetic polymorphisms in human epidermal growth factor (EGF) (rs4444903) and transforming growth factor β1 – (TGF-β1) (rs1800470) with facial measurements in patients with dentofacial deformities. A total of 144 adult patients with dentofacial deformities were included. Facial linear and angular measurements were traced in lateral cephalometric radiographs used Dolphin 2D software. Cells from oral mucosa were collected for DNA to be extracted. The polymorphisms were genotyped using real-time polymerase chain reaction (PCR). Probabilites of less than 0.05 were accepted as significant. The rs4444903 heterozygous patients had a decrease in the mandibular length (p = 0.043) and the length of the mandibular base (p = 0.008), and homozygous A patients also had a reduction in the length of the mandibular base (p = 0.013) compared with homozygous G patients. Patients AG had an increase in measurement of the anterior facial height (p = 0.032) and in ANS-Me distance (p = 0.022) when compared with homozygous A. To the rs1800470, heterozygous patients had an increase in the length of the mandibular base (p = 0.043) when compared with homozygous A. Heterozygous AG patients had an increase in angular measurements in TGF-β1 polymorphism for the upper gonial angle, when compared with the homozygous AA (p = 0.032). Genetic polymorphisms in EGF and TGF-β1 are associated with facial measurements in a Brazilian population of patients with dentofacial deformities.     

Cervical vertebrae: Mandibular growth dynamism indicators?

A study of mandibular growth maturation was performed on a population of 103 patients during orthodontic treatment (69 girls and 34 boys) from 11 to 16 years, having initially a Class II skeletal discrepancy. The relationship between wrist maturation indices and the cervical vertebrae maturation was studied by Lamparski classification. Significant correlations were found between Bj?rk stages, MP3=, MP3 cap and MP3 U and respectively Lamparski stages as CVS 2, CVS 3-4 and CVS 5-6. This retrospective longitudinal study identified three mandibular variables at three different maturation stages according to Bj?rk classification and to the six stages of Lamparski classification. The relationships between these different maturation stages and a quantitative mandibular response permit to estimate optimal time for our orthodontic therapy. The results indicate a significant increase in mandibular length between CVS 4 and CVS 5, suggesting the persistence of a condylar response to a stimulation therapy after CVS3 or CVS 4 stages (MP3 cap). Mandibular growth seems to continue after MP3 U stage or CVS 5 stage.     

Is radius-union an indicator for completed facial growth?

The purpose of this study was to determine if facial or dentoalveolar growth takes place after the occurrence of the radiographic handwrist stage R-J (completed fusion of the proximal epiphysis and diaphysis of the radius), which generally defines the completion of facial growth. Handwrist roentgenograms and lateral head films (LHFs) from 56 subjects (31 male and 25 female) aged 14 to 21 years were examined. Eight cephalometric distances (3 sagittal, 4 vertical, and 1 diagonal) and their changes during 2 different examination periods (from 1 year before to 2 years after the occurrence of R-J) were assessed. The investigation revealed that after the occurrence of R-J vertical dentoalveolar growth changes between 0.5 and 1.75 mm took place in the mandible and in the maxilla in 20% and 10% of the subjects, respectively. Comparing the 2 periods the frequency of the measured growth changes before and after R-J was, on average, almost equal. Because chronological age cannot be used for the assessment of facial growth termination, a reliable indicator for the assessment of facial growth termination is of major importance. After the occurrence of the handwrist stage R-J, most subjects revealed growth changes of less than 1 mm. Especially in the field of tooth implantology, it is important to forecast even small vertical dentoalveolar growth changes. The detected amount of growth after the insertion of an implant can cause esthetic and functional problems.     

Smad7 blocks transforming growth factor-β1-induced gingival fibroblast-myofibroblast transition via inhibitory regulation of Smad2 and connective tissue growth factor

Background: Transforming growth factor‐β1 (TGF‐β1), its downstream signaling mediators (Smad proteins), and specific targets, including connective tissue growth factor (CTGF), play important roles in tissue remodeling and fibrosis via myofibroblast activation. We investigated the effect of overexpression of Smad7, a TGF‐β1 signaling inhibitor, on transition of gingival fibroblast to myofibroblast. Moreover, we analyzed the participation of CTGF on TGF‐β1–mediated myofibroblast transformation. Methods: To study the inhibitory effect of Smad7 on TGF‐β1/CTGF‐mediating gingival fibroblast transition into myofibroblasts, we stably overexpressed Smad7 in normal gingival fibroblasts and in myofibroblasts from hereditary gingival fibromatosis (HGF). Myofibroblasts were characterized by the expression of the specific marker isoform α of the smooth muscle actin (α‐SMA) by Western blot, flow cytometry, and immunofluorescence. Enzyme‐linked immunosorbent assay for type I collagen was performed to measure myofibroblast activity. CTGF's role on myofibroblast transformation was examined by enzyme‐linked immunosorbent assay and small interference RNA. Results: TGF‐β1 induced the expression of α‐SMA and CTGF, and small interference RNA–mediating CTGF silencing prevented fibroblast‐myofibroblast switch induced by TGF‐β1. In Smad7‐overexpressing fibroblasts, ablation of TGF‐β1–induced Smad2 phosphorylation marked decreased α‐SMA, CTGF, and type I collagen expression. Similarly, HGF transfectants overexpressing Smad7 demonstrated low levels of α‐SMA and phospho‐Smad2 and significant reduction on CTGF and type I collagen production. Conclusions: CTGF is critical for TGF‐β1–induced gingival fibroblast‐myofibroblast transition, and Smad7 overexpression is effective in the blockage of myofibroblast transformation and activation, suggesting that treatments targeting myofibroblasts by Smad7 overexpression may be clinically effective in gingival fibrotic diseases, such as HGF.     

Bone-specific alkaline phosphatase – a potential biomarker for skeletal growth assessment

Objective: The present study was aimed to assess levels of serum Bone-specific alkaline phosphatase (BALP) and serum Insulin-like growth factor-1 (IGF-1) and comparing with cervical vertebral maturation index (CVMI) stages.

Design: Cross-sectional study.

Setting: Maulana Azad Institute of Dental Sciences, New Delhi, India.

Participants: 150 subjects (75 males and 75 females) in the age group of 8–20 years.

Methods: Subjects were divided into six CVMI stages. Enzyme-linked immunosorbant assay was performed for the estimation of serum BALP and serum IGF-1 levels. Mann–Whitney U test was performed to compare mean ranks of serum BALP and serum IGF-1 with different CVMI stages. Spearman correlation between serum BALP and serum IGF-1 was done across 6 CVMI stages.

Results: Peak serum IGF-1 levels were found at CVMI stages 4 and 3 for males and females respectively. Peak levels for serum BALP were found at stage 3 for both genders with significant differences from other stages. A statistically significant correlation was seen between serum IGF-1 and serum BALP from CVMI stages 1 to 3 and 4 to 6 (p?Conclusions: BALP showed promising results and can be employed as a potential biomarker for the estimation of growth status.     

Plasma rich in growth factors promote gingival tissue regeneration by stimulating fibroblast proliferation and migration and by blocking transforming growth factor-β1-induced myodifferentiation

Background: Periodontitis involves inflammation and infection of the ligaments and bones that support the teeth. Gingival fibroblasts are the most abundant cells in periodontal tissue, and they play a role in maintaining the structural integrity of the tissue. Plasma rich in growth factors contain a pool of proteins and growth factors that promote wound healing and tissue regeneration. In the present study, we evaluate the potential of different formulations obtained with this approach to stimulate several biologic processes involved in wound healing, including fibroblast proliferation, migration, adhesion, and the autocrine release of some angiogenic factors and extracellular matrix components. Furthermore, the ability of this technology to prevent and inhibit transforming growth factor β1‐induced myodifferentiation was also determined. Methods: Cell proliferation was evaluated through a colorimetric assay, cell migration was performed on culture inserts, and cell adhesion was studied through a fluorescence‐based method. Enzyme‐linked immunosorbent assay was used to determine some of the biomolecules released by gingival fibroblasts. Smooth muscle actin expression was assessed through immunofluorescence microscopy. Results: Results showed that plasma rich in growth factors significantly increased gingival fibroblast proliferation, migration, and cell adhesion on type I collagen matrix. In addition, it stimulated the autocrine expression of vascular endothelial growth factor, hepatocyte growth factor, and hyaluronic acid. The myofibroblast phenotype, which is characterized by expressing α‐smooth muscle actin, was inhibited and reverted by treating with this technology. Conclusion: These findings suggest that plasma rich in growth factors is capable of promoting regeneration of gingival connective tissue by stimulating some of the main processes involved in wound regeneration.     

Are intrauterine growth restriction and preterm birth associated with dental caries?

OBJECTIVES: To assess the association between two intrauterine growth restriction (IUGR) surrogates - IUGR [small for gestational age birth (SGA) and fetal growth restriction (FGR)] and preterm birth with dental caries. METHODS: Data from the Third National Health and Nutritional Examination Survey (1988-1994) were used, including 2- to 5.9-year-old singletons (n = 3189). Dental caries was defined as presence of any teeth with dental caries (treated or untreated) and also as presence of at least two teeth with dental caries. Exposure variables were preterm birth (<37 gestational weeks), FGR, and SGA. Covariates included were poverty, race/ethnicity, age, sex, sucrose intake, environmental tobacco smoking, dental visits, education of head of household, breastfeeding, and use of baby bottle. Separate statistical analyses were conducted for IUGR and for preterm birth through the estimation of prevalence ratio (PR), taking complex sampling design into consideration and adjusting for confounders. Sensitivity analysis was conducted including and excluding 2-year-old children and also with the two definitions of dental caries. RESULTS: In general, the inclusion of 2-year-old children and the case definition of presence of any teeth with dental caries biased the results toward the null, but with no major changes in the results. In bivariate analysis, SGA and FGR birth were both negatively but not significantly associated with dental caries while a significant positive association was found for preterm birth. Sensitivity analysis showed that the PR for preterm in bivariate analysis varied from 1.65 (95% CI 1.14-2.40) to 1.84 (95% CI 1.19-2.83). After adjusting for confounders, the PR for preterm birth varied from 1.38 (95% CI 1.00-1.89) to 1.64 (95% CI 1.22-2.20). After adjustment, the PR for SGA varied from 0.79 (95% CI 0.56-101) to 0.66 (95% CI 0.33-0.96). For children from 3 to 5.9 years old, the adjusted PR for FGR using the category 'none' as reference were mild (PR 1.10; 95% CI 0.76-1.58), moderate (PR 0.66; 95% CI 0.26-167), and severe (PR 0.59; 95% CI 0.36-0.99). These values for FGR were very similar for the other models using other classifications of case definition or inclusion of 2-year-old children. CONCLUSIONS: Preterm birth was found to be positively associated with dental caries while there is an indication that SGA and FGR are negatively associated with dental caries. Although the negative association is counterintuitive, it is possible that increased antibiotic use and delayed tooth eruption may explain the negative association between IUGR and dental caries.     

Application of bone growth factors—the potential of different carrier systems

Aim

The aim of the present review was to characterize the potential of different biomaterials as carriers for bone growth factors.

Introduction

Beyond mechanical and structural characteristics, one of the features that account for a potential carrier is the possibility to couple growth factor molecules to it. As simple adsorption of the growth factor to the carrier surface by soak loading produces a burst release of growth factors with rapid decrease of biological activity, the ability to accomplish controlled release of functional growth factor molecules is one of the crucial characteristics for an appropriate carrier material.

Conclusion

The variety of carrier materials requires different strategies to either couple growth factors to the material surface or to incorporate them into the carrier matrix. The present review outlines current technical approaches and discusses future trends in the use of carrier materials for bone growth factors.     

Predicting vertical growth of the mandibular ramus via hand–wrist radiographs

Aim

The purpose of this study was to investigate whether growth increments of the mandibular ramus in the vertical direction can be predicted using cephalometric variables in combination with a hand?Cwrist radiograph.

Patients and methods

Our data comprised cephalograms taken at the beginning (T1) and end (T2) of orthodontic treatment, and hand?Cwrist radiographs taken at T1 of 49 adolescent patients with a Class I malocclusion. Cephalograms were scanned and analyzed with the aid of a computer. Relative growth increments (in %) of body height and different cephalometric variables during the observation period were recorded. Growth changes were compared statistically to each other and to the growth prediction assessed with the hand?Cwrist radiograph according to Greulich and Pyle (GPP). Stepwise linear regression (SPSS?) was used to statistically analyze the impact of gender, age, body height, growth prediction as assessed with a hand?Cwrist radiograph, and cephalometric variables at T1 on changes in the increase in the height of the mandibular ramus.

Results

Growth prediction assessed via hand?Cwrist radiographs at the beginning of treatment did not enable a reliable prediction of the remaining vertical growth of the mandibular ramus. Only the patient??s gender and height of the mandibular ramus at the beginning of treatment had a statistical impact on growth changes in the ramus height that occurred during the observation period.

Conclusion

Our results suggest that the vertical growth potential of the mandibular ramus cannot be predicted by analyzing hand?Cwrist radiographs or by evaluating cephalometric variables other than the initial mandibular ramus height.     

Kinetic study of β-oxide growth on Pt-Au alloys in an alkaline medium

Surface oxides on a Pt-Au alloy in 0.05 M KOH are formed potentiostatically at potentials, varying between 2.00 V and 2.50 V for polarization times, t_p, up to 1000 s at temperature values in the range from 293 K to 308 K. This procedure results in the deposition of β-oxide films whose charge densities, q_ox, do not exceed 5.848 mC cm⁻². Cyclic voltammetry reveals three oxide-reduction peaks whose potential values depend on the polarization potential and time but not on the temperature of the electrolyte. The temperature increase leads only to augmentation of the oxide thickness. The linear plots of 1/q_ox versus log t_p obtained for different polarization potential and temperature values show that the oxide growth follows inverse-logarithmic kinetics and hence is limited by the rate of escape of Pt²⁺ and Au²⁺ cations from the metal into the oxide at the inner metal/oxide interface. The experimental data treatment provides to evaluate the potential drop across the oxide and the intensity of the electric field controlling the oxide layer growth. The values obtained are compared to those found for β-oxide films formation on Pt and Au under identical conditions. The electric field values for the oxide growth on the alloy electrode at 2.5 V are within the range from 0.165 × 10⁹ V m⁻¹ to 0.180 × 10⁹ V m⁻¹ which refer to those for the process on Au and Pt, respectively.     

Association between Björk's structural signs of mandibular growth rotation and skeletofacial morphology

The aim of this study was to apply Bj?rk's structural signs of mandibular growth rotation to answer the questions: (1) Is a hyperdivergent or hypodivergent skeletofacial growth pattern characterized by a specific mandibular morphology? (2) Are severe skeletofacial hyperor hypodivergencies recognized more easily than mild ones? (3) Are skeletofacial hyper- or hypodivergencies recognized more easily in older than in younger subjects? Mandibular cuttings from lateral head films of 135 Class I or Class II subjects were surveyed twice by nine observers. Of the 135 subjects, 95 subjects exhibited a large (ML/NSL > 38 degrees) and 40 a small (ML/NSL < 26 degrees) mandibular plane angle. Using the structural signs of mandibular growth rotation, the observers had to categorize the subjects as having either a high-angle or low-angle skeletofacial morphology. In 14% (13 of 95) of the subjects with a large ML/NSL angle, the skeletofacial hyperdivergency was recognized in all registrations, but in 19% (18 of 95), the hyperdivergency was identified in less than half of the registrations. In 63% (25 of 40) of the subjects with a small ML/NSL angle, the skeletofacial hypodivergency was recognized in all registrations, whereas in only 2.5% (one of 40), the hypodivergency was identified in less than half of the registrations. There was no association between the degree of hypo- or hyperdivergency or the age of the subjects and the number of correct registrations. Using the structural method of Bj?rk, it was difficult to categorize the subjects as having either a hyperor hypodivergent skeletofacial morphology. However, hypodivergency was recognized more easily than hyperdivergency.     

Cranial growth in infants─A longitudinal three-dimensional analysis of the first months of life

Purpose

In the first months of life, any deviation from a physiological growth pattern can cause skull deformity. As there has not been any longitudinal three-dimensional (3D) study investigating the physiological growth of the infant skull, the aim of the present study was to acquire such data.

Considerations of dentofacial growth in long-term retention and stability: is active retention needed?

It is extremely important to pay attention to the person's growth pattern, and a distinction must be made in the selection of retention devices on the basis of the nature and the extent of dentofacial dysplasia (growth pattern). The nature and duration of retention should depend on the maturation status of the patient and on anticipated future growth. Retention guidance is necessary for adjustment of the dentition to late growth changes and maturation of neuromuscular balance. "Active retention" is a concept we accept as readily as the orthopedic surgeon does for his scoliosis patients. There is some merit in the philosophy of those clinicians who advocate permanent retention guidance. Without always being aware of the biomechanics of growth change, they are in fact carrying the patient through the active stages of growth with their retention appliances. Finally, one may philosophize that nothing about the human morphology is stationary. Aging is a well-documented process of change. Lifetime dentitional adjustment and changing dental relationships are known to all, even in otherwise healthy persons. Then why do we expect long-term stability in every case? The answer to the question of long-term stability is long-term retention--dynamic, not static.     

Mandibular growth following implant restoration: does Wolff's law apply to residual ridge resorption?

This study measured bone height under a fixed detachable cantilever restoration supported by five or six endosseous implants in 60 consecutively treated patients. Panoramic films were made at surgery and 1, 2, 3, and 4 years postrestoration. A computer-enhanced method was used to measure mandibular height 5, 10, 15, and 20 mm distal to the last implant, which was used as a length. standard to correct for variation in film magnification. Implant restoration resulted in a significant growth of the mandible (baseline: 7.25 +/- 0.25 mm, 4 years: 8.18 +/- 0.18 mm; P = .05). The growth in dimension appears to occur during the first year of function.     

Role of vascular endothelial growth factor in reconstructive surgery after surgical excision of malignant tumor

As a key mediator of normal physiological angiogenesis, vascular endothelial growth factor(VEGF) has been regarded as an emancipator to plastic surgeon, and yet a misfortune to oncology surgeon, due to its singular biological effect. Therefore in some clinical cases, especially for some malignant tumor patients having endured radical surgery and being craving for a reconstructive surgery, VEGF plays a role full of paradoxes. To make a clinical balance, we should find a point to inhibit tumor cell from utilizing VEGF and make a permission to normal tissues to employ it.