Maximum closing force of mentolabial muscles and type of malocclusion.

OBJECTIVE: To measure the closing force of the upper and lower lips and to ascertain the relationship between the maximum closing force of the mentolabial muscles and types of malocclusion. MATERIALS AND METHODS: Of those who showed the full eruption of a second molar and no permanent tooth loss, 99 subjects were chosen who showed a positive overbite and ANB and no skeletal asymmetry. By using the Y-meter, which can measure the lip force in the vertical direction using a load cell, the closing forces of the upper and lower lips were measured separately. A one-way analysis of variance (ANOVA) test and the Pearson's correlation test were used to evaluate the interrelationship between lip force and dentofacial morphology. RESULTS: The lip closing force was greater in male and Class I subjects. Upper lip force was greater than that of the lower lip in all groups. The values of lip closing forces were related to the variables of upper incisor angulation. In Class II subjects, the values of lip closing forces were also related to the vertical skeletal pattern. CONCLUSIONS: The mentolabial muscle force was highly correlated with dentofacial structure and types of malocclusion.

Differential diagnosis for inappropriate upper incisal display during posed smile: contribution of soft tissue and underlying hard tissue.

The amount of upper incisor display (UID) during smile and conversation is one of the most decisive components in aesthetic judgment. The purpose of this study was to find which soft tissue and underlying hard tissue factors contributed to the amount of UID during posed smile (PS) and at rest posture (RP). The subjects consisted of 76 young adults (33 men and 43 women; mean [SD] age, 24.79 [2.29] y) with skeletal and dental class I relationship, normal overbite/overjet, and minor crowding (<2 mm). After checking reproducibility of the amounts of UID during PS and at RP in lateral cephalograms with facial photographs, 15 hard and soft tissue variables were measured, and statistical analysis was done. There was no significant sex difference in the amount of UID during PS and at RP. The amount of UID during PS significantly increased when anterior maxillary height was longer, lower gonial angle was larger, occlusal plane to sella-to-nasion plane angle was steeper, interlabial gap at RP was larger, upper lip length at RP was shorter and upper lip elevation during PS was larger. Multiple linear regression analysis to predict the degree of UID during PS generated a 4-variable model (adjusted R = 0.607): upper lip elevation (the dynamic soft tissue variable), interlabial gap and upper lip length (the static soft tissue ones), and anterior maxillary height (the hard tissue one). The diverse causes of inappropriate UID according to the soft and hard tissue factors need different treatment approaches such as orthodontic treatment, periodontal treatment, orthognathic surgery, botulinum toxin, or myectomy. The clinician can use these variables as a guideline for differential diagnosis of inappropriate UID.

Analysis of surface roughness and surface free energy characteristics of various orthodontic materials.

INTRODUCTION: The purpose of this study was to analyze the differences in surface characteristics of various orthodontic materials; this might provide valuable information on bacterial adhesion to orthodontic materials. METHODS: Surface roughness (SR) and surface free energy (SFE) characteristics of 5 orthodontic adhesives (2 composites resins, 2 resin-modified glass ionomer cements, and 1 compomer), 5 bracket materials (2 stainless steel, 1 monocrystalline sapphire, 1 polycrystalline alumina, and 1 plastic) and bovine incisors were investigated by using confocal laser scanning microscopy and the sessile drop method. RESULTS: There were significant differences in SR and SFE characteristics among orthodontic materials. Bovine incisors showed the roughest surface, and monocrystalline sapphire showed the smoothest surface. However, there were only small variations in SR (less than 0.3 mum) among the materials, except for bovine incisors. In contrast to SR, there were big differences in SFE characteristics among materials. Generally, bracket materials showed lower SFE--specifically, dispersive and polar components on their surfaces--than orthodontic adhesives. Resin-modified glass ionomer cements had the highest SFE, dispersive component, and polarity; these conditions are more favorable for bacterial adhesion. CONCLUSIONS: This study suggests that SFE characteristics can influence bacterial adhesion to orthodontic materials more than SR, and bracket materials might have less favorable SFE characteristics for bacterial adhesion than orthodontic adhesives.

Cystatins and cathepsin B during orthodontic tooth movement.

INTRODUCTION: The lysosomal cysteine protease cathepsin B is known to play an important role in the resolution of organic matrix, a final step in bone resorption. Cystatins function as an inhibitor of cathepsin B. Determining the correlation between cathepsin B and cystatin levels in gingival crevicular fluid at various times might provide a better understanding of both the dynamics and the metabolic stages of orthodontic tooth movement. METHODS: Human gingival crevicular fluid was collected at the distal sulcus from the canines of persons not in orthodontic treatment, in retention, and in retraction at various times (initial, 1 day, 1 week, and 1 month postretraction). Cathepsin B and its inhibitor, cystatin, were found with fluorometry. RESULTS: The level of cathepsin B was varied in the retraction group; this was different from the retention and the nonorthodontic groups. Significant initial decreases after force application and subsequent increases by 1 month posttreatment were observed in the retraction group. The variations and differences among groups were negatively correlated with cystatin. CONCLUSIONS: The balance between enzyme and inhibitor might reflect the clinical status of orthodontic tooth movement and provide valuable information for the assessment of recall intervals and retention procedures.

Reliability of landmark identification on monitor-displayed lateral cephalometric images.

INTRODUCTION: Our objective was to compare the reliability of landmark identification with hard-copied film images vs monitor-displayed images from digital lateral cephalograms. METHODS: We randomly selected 50 orthodontic patients. Identification and digitization of the cephalometric landmarks were performed 3 times at 2-week intervals by 2 observers. The 2 methods of landmark identification were the hard-copied film-based method (HFM) and the monitor-displayed method (MDM). Each landmark was expressed as Cartesian coordinates (x and y). Two-factorial repeated measures analysis of variance was used to analyze differences in landmark identification and to estimate the characteristics of the landmarks with high errors. Intraclass correlation coefficients (ICC) were computed to assess interobserver reliability and intraobserver reliability between the methods. RESULTS: There were no statistically significant differences in landmark identification between the 2 methods. The only significant differences between the observers were for porion, pogonion, and the most concave point of the anterior border of the ramus of both sides (R1).The interaction between method and observer did not show a significant difference. A test for intraobserver reliability showed excellent ICC of more than 0.910 except for basion and R1 with HFM. However, with MDM, all landmarks had excellent ICC scores of more than 0.98. MDM is better than HFM in situations of higher radiopacity or radiolucency. Assessment of interobserver reliability showed excellent ICC. However, MDM had better reliability than HFM for basion and R1. CONCLUSIONS: There was no significant difference in landmark identification between MDM and HFM.

Which hard and soft tissue factors relate with the amount of buccal corridor space during smiling?

OBJECTIVE: To investigate which hard and soft tissue factors relate with the amount of buccal corridor area (BCA) during posed smiling. MATERIALS AND METHODS: The samples consisted of 92 adult patients (19 men and 73 women; 56 four first bicuspids extraction and 36 nonextraction treatment cases; mean age = 23.5 years), who were treated only with a fixed appliance and finished with Angle Class I canine and molar relationships. To eliminate the crowding effect on the buccal corridor area, lateral cephalograms, dental casts, and standardized frontal posed smile photographs were obtained at debonding stage and 28 variables were measured. Pearson correlation analysis, multiple linear regression analysis, and independent t-test were used to find variables that were related with buccal corridor area ratio (BCAR). RESULTS: Among the lateral cephalometric and dental cast variables, FMA, lower anterior facial height, upper incisor (U1) exposure, U1 to facial plane, lower incisor (L1) to mandibular plane, L1 to N-B, Sn (subnasale) to soft tissue menton (Me'), Sn to stomodium superius (stms), stms to Me', and interpremolar width were significantly negatively correlated with BCAR. Occlusal plane inclination and buccal corridor linear ratio did not show any significant correlation with BCAR. Multiple linear regression analysis generated a three-variable model: Sn to Me', U1 exposure, and sum of tooth material (STM) (R(2) = 0.324). There was no significant difference in BCAR between extraction and nonextraction groups. CONCLUSIONS: To control the amount of BCA for achieving a better esthetic smile, it is necessary to observe the vertical pattern of the face, amount of upper incisor exposure, and sum of the tooth material.

Quantitative determination of adhesion patterns of cariogenic streptococci to various orthodontic brackets.

INTRODUCTION: Information about the adhesion of cariogenic streptococci to orthodontic brackets can help to determine a means for preventing enamel demineralization. The purpose of this study was to investigate the adhesion levels of 4 cariogenic streptococci strains to various orthodontic brackets with respect to bracket type, bacterial strain, incubation time, and saliva coating. METHODS: Five bracket types (monocrystalline sapphire, polycrystalline alumina, stainless steel, plastic, and titanium) were incubated with unstimulated whole saliva or phosphate-buffered saline solution for 2 hours. Binding assays were then performed by incubating tritium-labeled streptococci with the brackets for 3 or 6 hours. RESULTS: Each cariogenic streptococci strain showed a characteristic adhesion pattern. The adhesion amounts were highest in the plastic brackets and lowest in the monocrystalline sapphire brackets. Longer incubation time generally increased bacterial adhesion. Saliva coating did not significantly influence the adhesion of S mutans strains, but it had a significant effect on the adhesion of S sobrinus strains. However, saliva coating tended to decrease the adhesion of cariogenic streptococci with the longer incubation time compared with the noncoated control. CONCLUSIONS: This study suggests that cariogenic streptococci have various patterns of adhesion according to the bracket type.

En masse retraction and two-step retraction of maxillary anterior teeth in adult Class I women. A comparison of anchorage loss.

OBJECTIVE: To compare the amount of anchorage loss of the maxillary posterior teeth and amount of retraction of the maxillary anterior teeth between en masse retraction and two-step retraction of the anterior teeth. MATERIALS AND METHODS: The sample consisted of 30 female adult patients with Class I malocclusion and lip protrusion who needed maximum posterior anchorage. The sample was subdivided into group 1 (n = 15, mean age = 21.4 years, en masse retraction) and group 2 (n = 15, mean age = 24.6 years, two-step retraction). Lateral cephalograms were taken before (T1) and after treatment (T2). Nine skeletal and 10 anchorage variables were measured, and independent t-test was used for statistical analysis. RESULTS: Although the amount of horizontal retraction of the maxillary anterior teeth was not different between the two groups, there was mild labial movement of the root apices of the upper incisors in group 2 at T2. There were no significant differences in the degree of anchorage loss of the maxillary posterior teeth between the two groups. Bodily and mesial movements of the upper molars occurred in both groups. Approximately 4 mm of the retraction of the upper incisal edges resulted from 1 mm of anchorage loss in the upper molars in both groups. CONCLUSION: No significant differences existed in the degree of anchorage loss of the upper posterior teeth and the amount of retraction of the upper anterior teeth associated with en masse retraction and two-step retraction of the anterior teeth.

Correction of Class II deep overbite and dental and skeletal asymmetry with 2 types of palatal miniscrews.

This case report describes the orthodontic treatment of a 31-year-old woman who had a Class II molar relationship, anterior crowding, deep overbite, maxillary dental midline deviation, vertical maxillary asymmetry, and a hyperdivergent facial pattern. The maxillary right first premolar and the left second premolar were extracted asymmetrically to correct the anterior crowding and the maxillary dental midline deviation. The maxillary molars were intruded with a midpalatal miniscrew, which helped to correct the vertical molar asymmetry and close the mandibular plane. The palatal miniscrew in the maxillary tuberosity was also used to provide anchorage reinforcement for retraction of the anterior teeth. After orthodontic treatment, dental and facial esthetics were greatly improved by treatment of anterior crowding and deep overbite, correction of the dental and skeletal asymmetry, and closure of the mandibular plane. At the 3-year follow-up, most of the treatment results had been maintained.

Differential gene expression of periodontal ligament cells after loading of static compressive force.

BACKGROUND: Compressive force is an important mechanical stimulus on the periodontal ligament (PDL) and is closely related to therapeutic tooth movement. In this study, early or late response genes related to the compressive stress in PDL cells were evaluated. Particularly, the expression of interleukin (IL)-6, IL-8, and alkaline phosphatase (ALP) was studied. METHODS: The primary cultured cells from PDL were grown in a three-dimensional collagen gel, and received a continuous static compressive force (1.76 g/cm(2)). The expressed genes were screened by cDNA microarray assays for 2 or 12 hours after the initiation of the mechanical force application. The genes of interest that showed significant changes in expression in the cDNA microarray assay were analyzed further by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), enzyme-linked immunoabsorbent assays (ELISA), and ALP assays. RESULTS: ALP, IL-6, and IL-8 were selected among the genes that significantly changed expression (/M/ >0.7) and subsequently were confirmed by quantitative RT-PCR. The secreted protein concentrations for IL-6, IL-8, and ALP activity were measured at 72 hours after application of continuous static compressive force. The protein level of IL-6 was significantly increased at 72 hours (P <0.001), but there was no significant change in IL-8 (P >0.05). ALP activity was decreased approximately 41.5% compared to the control (P = 0.015). CONCLUSIONS: Considering that IL-6 is a potent osteoclast activator and the compressive side of PDL during orthodontic tooth movement shows the resorption of calcified tissue, the changed expression of IL-6 and ALP in response to the static compressive force in PDL cells may contribute to the orthodontic tooth movement or alveolar bone remodeling.

Quantitative determination of adhesion patterns of cariogenic streptococci to various orthodontic adhesives.

OBJECTIVE: To investigate the adhesion of various cariogenic streptococci to orthodontic adhesives. MATERIALS AND METHODS: Five light-cure orthodontic adhesives (one fluoride-releasing composite, three non-fluoride-releasing composites, and one resin-modified glass ionomer cement) were used. The adhesive type, bacterial strain, incubation time, and saliva coating were studied. Thirty specimens of each adhesive were incubated with unstimulated whole saliva or phosphate-buffered saline for 2 hours. Binding assays were then performed by incubating tritium-labeled streptococci with the adhesives for 3 or 6 hours. RESULTS: The results showed a characteristic adhesion pattern according to the type of bacterial strains used. Streptococcus mutans LM7 showed the highest amount of adhesion, whereas S sobrinus B13 showed the lowest amount of adhesion. The cariogenic streptococci adhered to the glass ionomer significantly more than to the composites, whereas there was no significant difference in the adhesion amount among the four composites. The extended incubation time significantly increased bacterial adhesion. However, saliva coating did not significantly alter adhesion patterns of cariogenic streptococci. CONCLUSIONS: This study suggests that cariogenic streptococci can adhere diversely according to adhesive type and that the adhesion of the cariogenic streptococci is not influenced by its fluoride-releasing properties.

Discrimination of internal derangement of temporomandibular joint by lateral cephalometric analysis.

INTRODUCTION: The purposes of this study were to analyze the progress of internal derangement (ID) of the temporomandibular joint (TMJ) and to find critical yardsticks that can be used during lateral cephalometric analysis to identify subjects with potential ID. METHODS: The sample consisted of 134 women whose primary complaints were malocclusions. They were divided into 5 groups based on the results of magnetic resonance imaging of bilateral TMJs: bilateral normal disc position, unilateral disc displacement with reduction (DDR) and contralateral normal disc position, bilateral DDR, unilateral DDR and contralateral disc displacement without reduction (DDNR), and bilateral DDNR. Thirty-six cephalometric variables from their lateral cephalograms were analyzed with 1-way ANOVA and discriminant analysis to determine the key factors in identifying subjects with TMJ ID. RESULTS: Backward positioning of the mandible, clockwise rotation of the mandible, proclination of the mandibular incisors, and increase in overjet intensified gradually with the progression of TMJ ID, and the subjects with bilateral DDNR showed the greatest changes in dentofacial morphology. Stepwise variable selection in discriminant analysis identified the following 2 variables: mandibular incisor to Frankfort horizontal plane angle and overjet. Discriminant analysis resulted in the correct classification of 79.1% of the subjects and showed that those with smaller mandibular incisor to Frankfort horizontal plane angles and larger overjets had high possibilities of TMJ ID. CONCLUSIONS: This study suggests that some cephalometric variables can be used as an auxiliary diagnostic tool to help identify patients with potential TMJ ID.

Transverse implications of maxillary premolar extraction in Class III presurgical orthodontic treatment.

INTRODUCTION: Maxillary premolars are often extracted to resolve incisor proclination in presurgical orthodontic treatment for severe skeletal Class III patients. The aim of this article was to compare arch-width changes and orthodontic tooth movements between maxillary premolar extraction and nonextraction modalities, and to provide an additional indication for presurgical maxillary premolar extraction according to the transverse dental arch characteristics of Class III surgical-orthodontic patients. METHODS: Pretreatment and posttreatment dental casts of 55 adult Class III patients (24 nonextraction, 31 extraction) who underwent surgical-orthodontic treatment were collected. The changes in maxillary and mandibular dental arch widths were measured from the canines to the second molars. Orthodontic tooth movement was evaluated with an angulation-and-inclination measuring gauge. RESULTS: Statistical analyses showed that intermaxillary arch congruity was attributed mainly to maxillary arch-width changes. The arch-width changes could be interpreted as the result of inclination changes in both posterior dentitions. For the arch-width change, analysis of covariance (ANCOVA) showed a significant extraction effect: the premolar extraction group's ability to accommodate arch-width change was significantly greater than that of the nonextraction group. CONCLUSIONS: The indications for maxillary premolar extraction in Class III presurgical orthodontic treatment might depend in part on the characteristics of the maxillary arch width and posterior teeth inclinations.

Evaluation of internal derangement of the temporomandibular joint by panoramic radiographs compared with magnetic resonance imaging.

INTRODUCTION: Panoramic radiographs are routinely used in orthodontic diagnosis and treatment planning. It would be useful if these radiographs could also provide information about internal derangement (ID) of the temporomandibular joint (TMJ). METHODS: The sample consisted of 168 condyles in 84 women. They underwent panoramic radiography on 1 of 3 machines and bilateral magnetic resonance imaging of the TMJ on 1 machine. Six panoramic variables were analyzed by 2-factor ANOVA to evaluate differences in condylar morphology with respect to status of the TMJ ID and type of panoramic machine. RESULTS: Decreased condylar heights and distally inclined condyles were found in the patients with TMJ ID, irrespective of the type of panoramic machine used. The change became more severe as ID progressed to disk displacement without reduction. CONCLUSIONS: This study suggests that some panoramic variables can help the clinician identify patients with potential ID.

Relationship between temporomandibular joint internal derangement and facial asymmetry in women.

INTRODUCTION: Internal derangement (ID) of the temporomandibular joint (TMJ) can cause facial asymmetry. The purposes of this study were to analyze the relationship between facial asymmetry and TMJ ID by using posteroanterior cephalometric variables, and to compare the findings with the results of magnetic resonance imaging (MRI). METHODS: The sample consisted of women seeking orthodontic treatment at Seoul National University Dental Hospital who had routine posteroanterior cephalograms and bilateral MRIs of the TMJ. To eliminate the influence of condylar hyperplasia on facial asymmetry, only those with SNB angles less then 78 degrees were selected (n = 63). They were classified into 5 groups according to the results of the MRI: bilateral normal disk position, unilateral normal TMJ and contralateral disk displacement with reduction (DDR), bilateral DDR, unilateral DDR and contralateral disk displacement without reduction (DDNR), and bilateral DDNR. Fourteen variables from posteroanterior cephalograms were analyzed with 1-way ANOVA to evaluate differences among the 5 groups. RESULTS: Subjects with TMJ ID of greater severity on the unilateral side had shorter ramal height compared with those with bilateral normal or bilateral DDR or bilateral DDNR. In addition, the mandibular midpoint deviated toward the side where the TMJ ID was more advanced. CONCLUSIONS: Subjects with a more degenerated TMJ on the unilateral side might have facial asymmetry that does not come from condylar or hemi-mandibular hyperplasia.

Classification of the skeletal variation in normal occlusion.

The aims of this study were to classify normal occlusion samples into specific skeletal types and to analyze the dentoalveolar compensation in a normal occlusion in order to provide the clinically applicable differential diagnostic criteria for an individual malocclusion patient. Lateral cephalograms of 294 normal occlusion samples, who were selected from 15,836 adults through a community dental health survey, were measured. Using a principal component analysis, two factors representing the anteroposterior and vertical skeletal relationships were extracted from 18 skeletal variables. Cluster analysis was then used to classify the skeletal patterns into nine types. Nine types of polygonal charts with a profilogram were created. Discriminant analysis with a stepwise entry of variables was designed to identify several potential variables for skeletal typing, which could be linked with computerized cephalometric analysis for an individual malocclusion patient. Discriminant analysis assigned 87.8% classification accuracy to the predictive model. It was concluded that because the range of a normal occlusion includes quite diverse anteroposterior and vertical skeletal relationships, classifying the skeletal pattern and establishing an individual dentoalveolar treatment objective might facilitate clinical practice.

Cephalometric keys to internal derangement of temporomandibular joint in women with Class II malocclusions.

The aim of this study was to find cephalometric keys to provide information on the progression of temporomandibular internal derangement. The sample consisted of 58 women with Class II malocclusions. They were examined with routine lateral cephalograms and magnetic resonance imaging of the temporomandibular joint (TMJ) before orthodontic treatment. They were classified into 3 groups according to the results of the magnetic resonance imaging: normal disk position, disk displacement with reduction, and disk displacement without reduction. Thirty-four cephalometric variables regarding their pretreatment lateral cephalograms were analyzed by 1-way analysis of variance to evaluate the differences in the dentofacial morphology among the 3 groups. The results showed a decrease in posterior facial height, a decrease in ramus height, and backward rotation and retruded position of the mandible in the subjects with internal derangement of the TMJ. These changes were less severe in those with disk displacement with reduction and more severe as internal derangement progressed to disk displacement without reduction. The results suggest that internal derangement of the TMJ might induce dentofacial changes, and that some cephalometric variables can assist in identifying potential patients with internal derangement of the TMJ.

In vitro expression of matrix metalloproteinase-1, tissue inhibitor of metalloproteinase-1 and transforming growth factor-beta1 in human periodontal ligament fibroblasts.

Extracellular matrix remodelling is mediated via matrix metalloproteinases (MMPs) and their regulatory factors such as tissue inhibitors of metalloproteinases (TIMPs) and transforming growth factor-beta (TGF-beta). The regulation of MMPs is thought to be associated with cytoskeletal changes. In this study, cytoskeletal changes in human periodontal ligament fibroblasts (PDFs) were induced using cytochalasin B (CB) which reorganizes actin microfilaments reversibly, and colchicine which disrupts microtubules irreversibly. The levels of MMP-1, TIMP-1 and TGF-beta secreted by the CB- or colchicine-treated PDFs were measured using an enzyme-linked immunosorbent assay. Differences between experimental and control groups were tested using analysis of variance (ANOVA) and Scheffé's ad hoc test. Although CB treatment did not significantly increase MMP-1 expression over the controls, colchicine treatment significantly increased the expression of MMP-1 (P < 0.01) in a time-dependent manner compared with the controls. Both CB and colchicine showed a time-dependent increase in TIMP-1 and TGF-beta1 expression and a dose-dependent increase in TIMP-1 and TGF-beta1 expression until threshold compared with the controls (P < 0.05, P < 0.01 and P < 0.001). In addition, CB treatment produced significantly increased TGF-beta1 expression over the controls (P < 0.05 and P < 0.001) from lower doses, with this effect occurring at earlier time points compared with colchicine treatment.

Transforming growth factor-beta3 gene SfaN1 polymorphism in Korean nonsyndromic cleft lip and palate patients.

The nonsyndromic cleft lip and palate (NSCL/P) is a congenital deformity of multifactorial origin with a relatively high incidence in the oriental population. Various etiologic candidate genes have been reported with conflicting results, according to race and analysis methods. Recently, the ablation of the TGF-beta3 gene function induced cleft palates in experimental animals. Also, polymorphisms in the TGF-beta3 gene have been studied in different races; however, they have not been studied in Koreans. A novel A --> G single nucleotide polymorphism (defined by the endonuclease SfaN1) was identified in intron 5 of TGF-beta3 (IVS5+104 A > G). It resulted in different genotypes, AA, AG, and GG. The objective of this study was to investigate the relationship between the SfaN1 polymorphism in TGF-beta3 and the risk of NSCL/P in the Korean population. The population of this study consisted of 28 NSCL/P patients and 41 healthy controls. The distribution of the SfaN1 genotypes was different between the cases and controls. The frequency of the G allele was significantly associated with the increased risk of NSCL/P [odds ratio (OR) = 15.92, 95% confidence interval (CI) = 6.3-41.0]. The risk for the disease increased as the G allele numbers increased (GA genotype: OR = 2.11, 95% CI = 0.38-11.68; GG genotype: OR = 110.2, 95% CI = 10.67 - 2783.29) in NSCL/P. A stratified study in patients revealed that the SfaN1 site IVS5+104A > G substitution was strongly associated with an increased risk of NSCL/P in males (p < 0.001), but not in females. In conclusion, the polymorphism of the SfaN1 site in TGF-beta3 was significantly different between the NSCL/P patients and the control. This may be a good screening marker for NSCL/P patients among Koreans.

Adhesion of oral streptococci to experimental bracket pellicles from glandular saliva.

The aim of this study was to evaluate the functions of bracket pellicles as the binding receptors for Streptococcus mutans and Streptococcus gordonii. Four different types of orthodontic brackets were used: stainless steel, monocrystalline sapphire, polycrystalline alumina, and plastic. The bracket pellicles were formed by incubating orthodontic brackets with fresh submandibular-sublingual saliva or parotid saliva for 2 hours. The pellicles were extracted, and their components were confirmed by gel electrophoresis, immunodetection, and amino acid composition analysis. The roles of the bracket pellicles in the adhesion of oral streptococci were evaluated by incubating tritium-labeled streptococci with pellicle-transfer blots. The results showed that the salivary components adhered selectively according to type of bracket and glandular saliva. The selective adsorption was also proven by the amino acid composition profiles. Among the several salivary proteins, MG2, alpha-amylase, and the acidic proline-rich proteins provided the binding sites for S gordonii. However, none of these proteins in the bracket pellicles contributed to the adhesion of S mutans. These findings suggest that numerous salivary proteins can adhere selectively to the orthodontic brackets, and some of them contribute to the binding of S gordonii.