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2.
Oncogene ; 33(7): 823-31, 2014 Feb 13.
Article in English | MEDLINE | ID: mdl-23376846

ABSTRACT

Pancreatic cancer remains as one of the most deadly cancers with few treatment options at late stages and little information about how it develops through earlier stages. Activating mutation of the Kras gene has been implicated in, but is not sufficient for, tumorigenesis. In mouse models of pancreatic cancer, loss of tumor suppressor genes in conjunction with Kras mutation leads to gradual stochastic acquisition of neoplastic precursors and carcinomas, whereas many cells remain phenotypically unaltered in younger mice. Here, we demonstrate that two oncogenic events, mutation of Kras and production of the growth factor heparin-binding epidermal growth factor-like growth factor (HB-EGF), are sufficient for rapid and complete neoplastic transformation of the exocrine pancreas. We found that macrophages are the major source of HB-EGF production in pancreatic cancer tissue samples, and that macrophages are present in high density and in close association with human pancreatic cancer lesions. In a mouse model, high macrophage density was observed at the earliest stages of neoplastic transformation. The consequence of elevated HB-EGF signaling was investigated without the confounding effects of other macrophage-produced factors via transgenic overexpression of the active form of HB-EGF. In this model, HB-EGF was sufficient to promote Kras-initiated tumorigenesis, inducing rapid and complete neoplastic transformation of the entire exocrine pancreas shortly after birth. HB-EGF overexpression and Kras(G12D) together, but neither alone, increased proliferation with increased cyclinD1 and decreased Cdkn2a/2d (p16/p19(Ink4A/Arf)). These findings establish the importance of oncogenic synergy in cancer initiation and promotion, and establish a molecular link between inflammation and the earliest stages of tumor induction.


Subject(s)
Carcinoma, Pancreatic Ductal/metabolism , Intercellular Signaling Peptides and Proteins/physiology , Pancreatic Neoplasms/metabolism , Proto-Oncogene Proteins/genetics , ras Proteins/genetics , Animals , Carcinogenesis/genetics , Carcinogenesis/metabolism , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Cell Proliferation , Cells, Cultured , Heparin-binding EGF-like Growth Factor , Humans , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mutation, Missense , Pancreas/pathology , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Phosphorylation , Protein Processing, Post-Translational , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins p21(ras) , ras Proteins/metabolism
3.
Caries Res ; 39(6): 505-8, 2005.
Article in English | MEDLINE | ID: mdl-16251796

ABSTRACT

The aim of this study was to determine any existing difference in the amount of fluoride incorporated in the surface, body enamel and dentin of two groups of deciduous teeth, either exposed to pre- and postnatal fluoride supplements or to postnatal fluoride only. One hundred and eighty five subjects with intact deciduous incisors were selected from a randomized, double blind study of the caries preventive efficacy of prenatal fluoride (F) supplementation. Surface and body enamel samples were obtained by the acid etch biopsy technique. Dentin microsamples were obtained by drilling to a depth of 100 microm using the microdrill biopsy technique. It was concluded that fluoride exposure during the prenatal period offered no additional measurable fluoride uptake by dental tissues other than that attributable to postnatal fluoride alone.


Subject(s)
Cariostatic Agents/analysis , Dental Enamel/chemistry , Dentin/chemistry , Dietary Supplements , Fluorides/analysis , Child, Preschool , Double-Blind Method , Female , Humans , Infant , Infant, Newborn , Pregnancy , Prenatal Exposure Delayed Effects , Prenatal Nutritional Physiological Phenomena , Tooth, Deciduous/chemistry
4.
Clin Orthod Res ; 4(2): 72-78, 2001 May.
Article in English | MEDLINE | ID: mdl-11553088

ABSTRACT

Sound analysis to diagnose internal derangement has received much attention as an alternative to radiographic examination. The purpose of this study was to compare findings with an electronic device (sonography) and clinical examination to magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). Twenty-three symptomatic patients (46 joints) were evaluated for this study. All patients had jaw joint pain and one or more of the following findings; limitation of jaw opening, painful mandibular movement with or without clicking or crepitation. The presence or absence of joint sounds was evaluated clinically by palpation and auscultation and with sonography. If sounds were present (clicking or crepitation) on either examination the patient was considered positive for disc displacement for that examination. Two by two tables were constructed comparing sonography and clinical examination with MRI findings. The sensitivity of the sonogram was 84% and the specificity was 33% when compared with MRI findings. The sensitivity of the clinical examination was 70% and the specificity was 40% when compared with MRI findings. This study suggests that clinical and sonographic examination has a high sensitivity (low false negative examinations) but low specificity (high false positive examinations).

5.
Pediatr Dent ; 23(3): 260-2, 2001.
Article in English | MEDLINE | ID: mdl-11447961

ABSTRACT

PURPOSE: HIV status is monitored by expression of clinical symptoms as well as CD4 lymphocyte counts. The purpose of this study is to assess the relationship between delayed dental eruption (DDE) and the progression of pediatric HIV infection to AIDS. METHODS: A population of 70 perinatally HIV-infected children, aged 5 months to 13 years at their time of entry into the study, received dental examinations. Regression analysis between dental age and chronological age was performed. Subject CDC classification, adjusted for age, was used to determine an association between eruptive delay and severity of disease progression. RESULTS: Data revealed no significant difference in timing of eruption based on severity of CD4 depletion alone (P = 0.09). However, clinical symptom status was strongly associated with DDE (P = 0.003). The relationship between symptoms and DDE persisted after controlling for CD4 depletion. CONCLUSIONS: Our study indicates that there is a correlation between the progression from HIV infection to Pediatric AIDS and DDE and that this delay is most closely linked to severity of symptoms and not CD4 depletion.


Subject(s)
HIV Infections/complications , Tooth Diseases/complications , Tooth Eruption/physiology , Acquired Immunodeficiency Syndrome/physiopathology , Adolescent , Age Determination by Teeth , Age Factors , CD4 Lymphocyte Count , Child , Child, Preschool , Cohort Studies , Disease Progression , Female , HIV Infections/classification , HIV Infections/physiopathology , Humans , Infant , Logistic Models , Male , Multivariate Analysis , Odds Ratio , Racial Groups , Sex Factors
6.
Int J Oral Maxillofac Surg ; 30(2): 113-7, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11405445

ABSTRACT

The purpose of this study was to estimate the frequency and amount of temporomandibular joint (TMJ) fluid, as well as the frequency and type of condyle marrow alterations in asymptomatic volunteers and compare to patients with TMJ pain and dysfunction. Proton-density and T2 weighted magnetic resonance (MR) images of the TMJs of 62 asymptomatic volunteers and 58 symptomatic patients were analysed for fluid and condyle marrow alterations as well as disk position. The amount of fluid (increased T2 signal) was characterized as none, minimal, moderate or marked and related to the disk position. The differentiation between moderate and marked fluid was based on the maximum amount of fluid seen in the volunteers; more than this amount was categorized as marked fluid. The marrow of the mandibular condyle was categorized as normal, edema (increased T2 signal) or sclerosis (decreased proton-density and T2 signal) and related to fluid and disk position. In the 62 asymptomatic volunteers, 50 (81%) had none or minimal and 12 (19%) had moderate TMJ fluid. In the 58 symptomatic patients, 40 (69%) had none or minimal and 18 (31%) had moderate or marked fluid. Both in volunteers and patients, moderate fluid could be seen in joints with normal disk position, but was significantly associated with disk displacement. In the 62 volunteers, no signal abnormalities in the condyle marrow were found. In the 58 patients, six (10%) had abnormal bone marrow. These six patients had disk displacement and two had moderate or marked fluid. Marked fluid and condyle marrow abnormalities were therefore not encountered in any of the asymptomatic volunteers but in about 10% of the patients.


Subject(s)
Bone Marrow Diseases/diagnosis , Magnetic Resonance Imaging , Mandibular Condyle/pathology , Mandibular Diseases/diagnosis , Synovial Fluid , Temporomandibular Joint Disorders/diagnosis , Temporomandibular Joint/pathology , Adolescent , Adult , Child , Edema/diagnosis , Facial Pain/diagnosis , Female , Humans , Image Processing, Computer-Assisted/methods , Joint Dislocations/classification , Joint Dislocations/diagnosis , Magnetic Resonance Imaging/methods , Male , Middle Aged , Osteosclerosis/diagnosis , Temporomandibular Joint Disc/pathology
7.
J Prosthet Dent ; 85(1): 88-94, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11174684

ABSTRACT

STATEMENT OF PROBLEM: Chemical bonding plays a major role in the adherence between metal and porcelain. The formation of an oxide layer on solder material has not been described in the literature. It is unknown whether the application of solder negatively affects the bond strength between porcelain and metal. PURPOSE: This in vitro study assessed the effect of solder on the bond strength between metal and porcelain. MATERIAL AND METHODS: Forty 20 x 6 x 0.5 mm patterns were divided into test (20) and control (20) groups. Test samples were perforated and repaired with solder, and 2 layers of opaque and dentin porcelain subsequently were applied on all samples. The samples were subjected to a 3-point flexural test on a screw-driven mechanical testing machine at a crosshead speed of 0.5 mm/min. Failure type (adhesive vs cohesive) was quantified by digitizing photographs of test and control samples. Three samples in each group also were examined with an SEM coupled with an x-ray energy-dispersive spectroscopy apparatus (SEM/EDS). Means and standard deviations of loads at failure, sample thickness, and surface area covered with porcelain were calculated, and data were analyzed with Student t test (P < or = 0.05). RESULTS: The mean fracture load for test samples was significantly greater than for control samples (P = 0.0038). Test samples also were significantly thicker (mean thickness difference 0.14 mm) (P = 0.0001). When the data were controlled for thickness by using a multiple linear regression analysis, no significant difference was found (P = 0.68). Test samples had a greater surface area covered with opaque porcelain (P = 0.0006) as determined by visual inspection. CONCLUSION: In this study, soldered and nonsoldered samples did not show any significant difference in porcelain-to-metal bond strength. Visual analysis revealed a significant difference in the amount of porcelain remaining on the fracture surface of the test and control samples; a complete quantitative elemental analysis with SEM/EDS is in progress.


Subject(s)
Dental Prosthesis Repair/methods , Dental Soldering , Metal Ceramic Alloys/chemistry , Dental Porcelain/chemistry , Dental Restoration Failure , Electron Probe Microanalysis , Linear Models , Materials Testing , Microscopy, Electron, Scanning , Oxides , Pliability , Stress, Mechanical , Surface Properties
8.
Ambul Pediatr ; 1(3): 162-6, 2001.
Article in English | MEDLINE | ID: mdl-11888393

ABSTRACT

Disparities in children's oral health are an important and solvable health problem in the United States today. Many parts of the dental and public health communities are actively engaged in efforts aimed at addressing these disparities. Much progress has been made in explicating the issues, developing the scientific and clinical knowledge base needed for primary prevention and treatment, and beginning the development of new training and community-based approaches. But much more is still needed, and there is a great deal that the pediatric community can do to help.


Subject(s)
Dental Care for Children/organization & administration , Dental Health Services/organization & administration , Health Services Needs and Demand , Oral Health , Child , Community Participation , Cost of Illness , Dental Caries/economics , Dental Caries/prevention & control , Humans , Primary Prevention , Socioeconomic Factors , United States
9.
Environ Health Perspect ; 108(11): 1099-102, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11102303

ABSTRACT

Epidemiologic studies suggest an association between lead exposure and caries. Our objective was to establish whether children with a higher lead exposure as toddlers had more caries at school age than children with a lower lead exposure. We used a retrospective cohort design. A sample of children who attended second and fifth grades in the Rochester, New York, public schools during the 1995-1996 and 1996-1997 school years were examined for caries through a dental screening program. For each child we assessed the number of decayed, missing, or filled surfaces on permanent teeth (DMFS), and the number of decayed or filled surfaces on deciduous teeth (dfs); the number of surfaces at risk (SAR) was also recorded. Lead exposure was defined as the mean of all blood lead levels collected between 18 and 37 months of age by fingerstick [provided the blood lead level was [less than/equal to] 10 microg/dL)] or venipuncture. A total of 248 children (197 second graders and 51 fifth graders) were examined for caries and had a record of blood lead levels to define lead exposure. The mean dfs was 3.4 (range 0-29); the mean DMFS was 0.5 (range 0-8). Logistic regression was used to examine the association between the proportion of children with DMFS [Greater/equal to] 1, and the proportion with dfs [Greater/equal to] 1, and lead exposure [< 0.48 micromol/L vs. [Greater/equal to] 0.48 micromol/L (< 10 microg/dL vs. [Greater/equal to] 10 microg/dL)] while controlling for SAR, age at examination, and grade in school. For DMFS, the adjusted odds ratio was 0.95 [95% confidence interval (CI), 0.43-2.09; p = 0.89); for dfs, the odds ratio was 1.77 (95% CI, 0.97-3.24; p = 0.07). This study did not demonstrate that lead exposure > 10 microg/dL as a toddler was a strong predictor of caries among school-age children. However, the results should be interpreted cautiously because of limitations in the assessment of lead exposure and limited statistical power.


Subject(s)
Dental Caries/etiology , Lead/adverse effects , Child , Child, Preschool , Cohort Studies , DMF Index , Dental Caries/epidemiology , Environmental Exposure , Female , Humans , Infant , Lead/blood , Male , New York/epidemiology , Retrospective Studies , Tooth, Deciduous
10.
J Prosthet Dent ; 84(3): 309-17, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11005904

ABSTRACT

STATEMENT OF THE PROBLEM: Investigators suggest that metals should be finished in 1 direction before porcelain application to minimize metal irregularities and trapped contaminants. These irregularities are thought to be focal points for porosity and crack propagation. PURPOSE: This study investigated the influence of metal finishing and sandblasting on (1) porosity production at the porcelain-metal interface, and (2) porcelain-metal beam failure load. MATERIAL AND METHODS: Eighty cast metal samples were divided into 4 test groups: (A) bidirectional finish/sandblasting; (B) unidirectional finish/sandblasting (C) bidirectional finish only; and (D) unidirectional finish only. The porcelain applied was 1.5 mm thick. Samples were sectioned longitudinally. Half of the samples were subjected to a 3-point flexural test. The remaining samples were sectioned into 4 slices and were examined with a light microscope (x500). Number and diameter of porosities at the metal-porcelain interface were recorded. RESULTS: Mean loads at failure (lbs) were as follows: A, 11.1 +/- 1.3 (5.03 +/- 0.58 Kg); B, 11.2 +/- 1.7 (5. 08 +/- 0.77 Kg); C, 4.0 +/- 1.8 (1.81 +/- 0.81 Kg); and D, 5.0 +/- 2. 1 (2.26 +/- 0.95 Kg). Groups A and B were significantly different from groups C and D (P<.0001). Nonsandblasted samples (C and D) exhibited a separation at the ceramometal interface, which prevented quantification of porosity size and number. Average interface porosity sizes (microm) (A, 8.99 +/- 1.92; B, 10.03 +/- 1.86) showed no significant difference. The mean interface porosity number (A, 62. 3 +/- 16.02; B, 67.4 +/- 10.01) showed no significant difference. CONCLUSION: Direction of metal finishing did not affect the porosity number and size at the ceramometal interface or the beam failure loads. Sandblasting increased the beam failure loads. Nonsandblasted samples showed detachment of the porcelain from the metal.


Subject(s)
Dental Polishing/methods , Dental Porcelain/chemistry , Metal Ceramic Alloys/chemistry , Aluminum Oxide , Analysis of Variance , Equipment Failure Analysis , Materials Testing , Microscopy, Electron, Scanning , Porosity , Statistics, Nonparametric , Surface Properties
11.
Pediatr Dent ; 22(4): 299-301, 2000.
Article in English | MEDLINE | ID: mdl-10969436

ABSTRACT

PURPOSE: Previous studies have demonstrated that babies are at higher risk for mutans streptococci (ms) colonization if their mothers have dense salivary ms reservoirs relative to babies who have mothers with negligible salivary reservoirs. This communication provides data that identifies another potential risk factor (use of a nursing bottle at bedtime and/or naptime that contains a substrate other than water) for baby infection by ms. METHODS: The study population consisted of 60 babies (28 males/32 females; mean age 15 mos; age range 12-18 mos) who were all healthy, caries free, and slept with a nursing bottle that contained a substrate other than water (NB+). Pooled maxillary incisor plaque and saliva samples were obtained and immediately placed in Reduced Transparent Fluid (RTF); they were serially diluted and plated onto Mitis Salivarius Agar plus Bacitracin (MSB) and blood agar plates within 4 hours of collection; the plates were incubated in an anaerobic environment for 48 h at 37 C and then placed for 24 h under aerobiosis prior to examination; representative ms colonies were isolated and subjected to mannitol and sorbitol fermentation tests for taxonomic verification. Plates with colony counts between 20 and 300 were utilized to determine the % of ms in each sample. RESULTS: Fifty one of the 60(85%) babies harbored ms in at least 1 of the 2 samples. The 95% confidence interval for the proportion of subjects with detectable levels of ms was 73%-93%. Fisher's exact test showed that babies 16-18 mos age were more likely to have detectable levels of ms than babies 12-15 mos age (p = 0.01). Levels of ms in plaque and saliva were as follows: < 0.1% (plaque 27/51, mean age 15 mos, sd 1.77; saliva 28/51, mean age 15 mos, sd 1.76); 0.1%-1.0% (plaque 4/51, mean age 14 mos, sd 1.5; saliva 6/51, mean age 15 mos, sd 1.46); > 1.0% (plaque 14/51, mean age 16 mos, sd 2.1; saliva 11/51, mean age 16 mos, sd 1.91). The density of infection did not vary by age for plaque (P = 0.32) or saliva (P = 0.64). CONCLUSION: These findings support the concept that NB+ is a strong indicator for ms infection in Puerto Rican babies; that prevalence of infection increases with age; and that density of infection does not vary with age in this population.


Subject(s)
Bottle Feeding/adverse effects , Streptococcal Infections/epidemiology , Streptococcal Infections/etiology , Streptococcus mutans/isolation & purification , Age Factors , Dental Plaque/microbiology , Diet, Cariogenic , Female , Humans , Infant , Male , Prevalence , Puerto Rico/epidemiology , Saliva/microbiology
12.
Article in English | MEDLINE | ID: mdl-10884646

ABSTRACT

OBJECTIVE: To evaluate the effectiveness of the American Academy of Oral and Maxillofacial Radiology-sponsored training packet for identification of carotid artery calcifications on panoramic radiographs. STUDY DESIGN: Two examiners, who completed the training (trainees), examined 778 panoramic radiographs. The sample included 298 men, with a mean age of 66, and 480 women, with a mean age of 68. Findings were compared with those obtained by an oral and maxillofacial radiologist. A kappa statistic was used to determine agreement between the 2 trainees. The positive predictive value (PPV) of the program was estimated by comparing the trainees rating of disease status with an expert in case identification. RESULTS: Examiners 1 and 2 identified 99 and 78 positive cases, respectively. A kappa statistic of 0.87 (95% CI, 0.81-0.92) was obtained, indicating good interexaminer agreement. The expert identified 27 positive cases, resulting in a PPV of 34.6% (95% CI, 24.4-46.3). CONCLUSION: Although the training packet offers valuable training, it does not provide a high PPV, suggesting the need to modify it or to seek an expert opinion before classification of a patient as having calcification on a panoramic radiograph.


Subject(s)
Arteriosclerosis/diagnostic imaging , Calcinosis/diagnostic imaging , Carotid Artery Diseases/diagnostic imaging , Education, Dental, Continuing , Radiology/education , Aged , Aged, 80 and over , Clinical Competence , Diagnosis, Differential , Diagnostic Errors/prevention & control , Female , Humans , Male , Middle Aged , Observer Variation , Program Evaluation , Radiography, Panoramic
13.
J Prosthet Dent ; 84(1): 32-7, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10898839

ABSTRACT

STATEMENT OF PROBLEM: If a post does not fit passively, binding with the radicular tooth structure occurs, possibly increasing the risk for root fracture. Therefore, it is necessary to fabricate slightly undersized cast posts to allow for passive fit and cement placement. Shrinkage of the mold cavity may be a desired effect during the casting of posts. PURPOSE: This study evaluated the influence of: (1) a cellulose ring liner, and (2) a lower casting temperature of the metal ring, on the dimensions of a cast post. MATERIAL AND METHODS: Eighty plastic posts were divided in 4 equal groups (group 1, 815 degrees C, liner; group 2, 815 degrees C, no liner; group 3, 600 degrees C, liner; and group 4, 600 degrees C, no liner), invested in phosphate-bonded investment and cast with a noble alloy. Posts were measured at 2 locations, the tip and base, before and after casting. RESULTS: Investing in a lined metal ring and using a casting ring temperature of 815 degrees C (group 1) resulted in markedly oversized posts (tip: +25.8 microm; base: +20.3 microm). The absence of the cellulose liner in the casting ring (group 2) decreased the expansion of the investment producing slightly oversized castings (tip: +9.75 microm; base: +4.52 microm). Lined rings that were heated to a final temperature of 600 degrees C (group 3) produced posts that were oversized (tip: +16.65 microm; base: +11.05 microm). Final casting ring temperature of 600 degrees C and the absence of a cellulose liner (group 4) resulted in posts slightly undersized (tip: -4.1 microm; base: -2.2 microm). CONCLUSION: The use of 2 casting ring temperatures (815 degrees C or 600 degrees C) and the influence of a ring liner were investigated. Decreasing the casting ring temperature from 815 degrees C to 600 degrees C and the absence of a ring liner significantly decreased the dimensions of a cast post.


Subject(s)
Dental Casting Technique/instrumentation , Post and Core Technique , Analysis of Variance , Cellulose , Dental Alloys , Differential Thermal Analysis , Humans , Models, Dental , Temperature
14.
Clin Orthod Res ; 2(3): 124-32, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10534987

ABSTRACT

OBJECTIVE: The purpose of this study is to investigate the effect of unilateral TMJ disc displacement on the midface and cranial base. STUDY DESIGN: Thirteen 10-week-old rabbits, eight controls and five experimental were included in this study. The five experimental rabbits had surgically created unilateral disc displacement. Animals were sacrificed at 22 weeks and frontal, occlusal, and lateral oblique radiographs were made of the skulls. RESULTS: The occlusal radiograph demonstrated that the glenoid fossa on the experimental side was located more anterior. The oblique radiograph demonstrated the root of the zygomatic arch the experimental side was inferior. The anterior aspect of the fossa was more inferior on the frontal radiograph. CONCLUSIONS: A previous study suggested a shortening in the ramal height. This study suggests an alteration of the cranial articular fossa. Thus, it is suggested that disc displacement is capable of producing asymmetry in the developing mandible and cranial base.


Subject(s)
Facial Asymmetry/etiology , Joint Dislocations/complications , Temporomandibular Joint Disc/pathology , Temporomandibular Joint Disorders/complications , Animals , Disease Models, Animal , Facial Bones/diagnostic imaging , Facial Bones/growth & development , Facial Bones/pathology , Mandibular Condyle/pathology , Maxillofacial Development , Rabbits , Radiography , Skull Base/diagnostic imaging , Skull Base/growth & development , Skull Base/pathology , Temporomandibular Joint Disc/injuries
15.
J Prosthet Dent ; 82(2): 205-8, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10424985

ABSTRACT

STATEMENT OF PROBLEM: The significance of the position of the mandibular condyle in the glenoid fossa remains a controversial subject. PURPOSE: This study evaluated the relationship between condyle position and disk displacement. MATERIAL AND METHODS: Fifty-two asymptomatic volunteers and 130 symptomatic patients underwent linear tomography and bilateral temporomandibular joint magnetic resonance scans. RESULTS: There was a higher prevalence of distal condyles in symptomatic patients with disk displacement compared with asymptomatic volunteers (P <.05). Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a sensitivity of 0.64, 0.56, and 0.33, respectively. Distally positioned condyles identified joints with disk displacement with reduction, disk displacement without reduction, or a symptomatic normal joint with a specificity of 0.56, 0.65, and 0.55, respectively. CONCLUSION: There were more distal condyles in symptomatic subjects with disk displacement, but the reliability of a distal condyle to predict the presence or absence of disk displacement was low.


Subject(s)
Joint Dislocations/diagnosis , Mandibular Condyle/pathology , Temporomandibular Joint Disc/pathology , Cephalometry , Female , Forecasting , Humans , Joint Dislocations/pathology , Magnetic Resonance Imaging , Male , Prevalence , Reproducibility of Results , Sensitivity and Specificity , Temporal Bone/pathology , Temporomandibular Joint/pathology , Tomography
16.
JAMA ; 281(24): 2294-8, 1999.
Article in English | MEDLINE | ID: mdl-10386553

ABSTRACT

CONTEXT: Experiments show that dental caries rates are higher among lead-exposed animals, but this association has not been established in humans. OBJECTIVE: To examine the relationship between blood lead levels and dental caries. DESIGN: Cross-sectional survey conducted from 1988 to 1994 that included a dental examination and venipuncture blood lead assay. SETTING AND PARTICIPANTS: A total of 24901 persons aged 2 years and older who participated in the Third National Health and Nutrition Examination Survey, which assessed the health and nutritional status of children and adults in the United States. MAIN OUTCOME MEASURES: For children aged 2 to 11 years, the sum of decayed and filled deciduous or primary surfaces; for persons aged 6 years and older, the sum of decayed and filled permanent surfaces; for those 12 years and older, the sum of decayed, missing, and filled surfaces. RESULTS: The log of blood lead level was significantly associated with the number of affected surfaces for both deciduous and permanent teeth in all age groups, even after adjusting for sociodemographic characteristics, diet, and dental care. Among children aged 5 to 17 years, a 0.24-micromol/L (5-microg/dL) change in blood lead level was associated with an elevated risk of dental caries (odds ratio, 1.8; 95% confidence interval, 1.3-2.5). Differences in blood lead level explained some of the differences in caries prevalence in different income levels and regions of the United States. We estimated the population attributable risk of lead exposure to be 13.5% and 9.6% of dental caries occurring in 5- to 17-year-olds exposed to the high and moderate levels, respectively. CONCLUSIONS: Environmental lead exposure is associated with an increased prevalence of dental caries in the US population. Findings may help explain the distribution of caries by income and region of the United States.


Subject(s)
Dental Caries/blood , Dental Caries/epidemiology , Lead/blood , Adolescent , Adult , Child , Child, Preschool , Cross-Sectional Studies , Environmental Exposure , Female , Health Surveys , Humans , Logistic Models , Male , Multivariate Analysis , Risk Factors , Socioeconomic Factors , United States/epidemiology
17.
J Prosthet Dent ; 79(6): 658-62, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9627894

ABSTRACT

STATEMENT OF PROBLEM: It has been suggested that dental occlusion may play a role in the development of intraarticular temporomandibular joint disorders. PURPOSE: This study evaluated the relationship between horizontal and vertical overlap and intraarticular temporomandibular joint disorders. MATERIAL AND METHODS: Vertical and horizontal overlap of the anterior teeth of 82 asymptomatic volunteers and 263 symptomatic patients were examined. RESULTS: Fifty-five (67%) of the asymptomatic volunteers had normal joints and 27 (33%) had disk displacement. Two hundred and twenty-one patients (84%) had disk displacement and 42 (16%) had bilateral symptomatic normal joints. Horizontal overlap equal to or greater than 4 mm was more prevalent in the symptomatic patient group as compared with the asymptomatic volunteer group (p < 0.05). Vertical overlap equal to or greater than 4 mm demonstrated no significant differences. CONCLUSION: Horizontal overlap equal to or greater than 4 mm was greater in symptomatic patients with intraarticular temporomandibular joint disorders.


Subject(s)
Malocclusion/complications , Temporomandibular Joint Disorders/etiology , Adult , Case-Control Studies , Female , Humans , Joint Dislocations/etiology , Male , Risk Factors , Vertical Dimension
18.
Pediatr Dent ; 20(1): 17-24, 1998.
Article in English | MEDLINE | ID: mdl-9524968

ABSTRACT

PURPOSE: Intraoral fluoride-releasing (IFR) devices provide elevated levels of fluoride in the mouth for extended periods of time. However, retention and protection of the devices have posed major challenges for clinical applications. The objectives of this study were to develop new methods for retaining and protecting IFR devices in the mouth and to assess their effects on salivary fluoride levels and distribution in adolescents. METHODS: Four different IFR systems (combinations of an IFR device and its retainer) were evaluated in four groups of 10 adolescents each, 12-15 years of age, for a period of six months. Each child wore two IFR systems of a given type affixed to the buccal surface of each permanent maxillary first molar. Unstimulated saliva samples were collected at each clinical examination and analyzed for fluoride. RESULTS: A significant increase in salivary fluoride concentration from a baseline mean of 0.07-0.69 microgram/mL was observed on day 14 postinsertion. IFR system retention was 85% after 6 months and, of the systems retained, 100% were functional. CONCLUSIONS: These findings suggest that IFR devices can be successfully protected and retained in the mouth for prolonged periods of time.


Subject(s)
Cariostatic Agents/administration & dosage , Drug Delivery Systems/methods , Fluorides, Topical/administration & dosage , Adolescent , Analysis of Variance , Cariostatic Agents/analysis , Cariostatic Agents/pharmacokinetics , Child , Dental Bonding , Drug Delivery Systems/classification , Drug Delivery Systems/instrumentation , Equipment Design , Female , Fluorides, Topical/analysis , Fluorides, Topical/pharmacokinetics , Follow-Up Studies , Humans , Male , Membranes, Artificial , Methacrylates/chemistry , Methylmethacrylate , Methylmethacrylates/chemistry , Mouth/metabolism , Orthodontic Appliance Design , Orthodontic Brackets , Periodontal Index , Saliva/chemistry , Saliva/metabolism , Sodium Fluoride/administration & dosage , Stainless Steel , Surface Properties
19.
Cleft Palate Craniofac J ; 34(5): 410-6, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9345609

ABSTRACT

OBJECTIVE: The purpose of this study was to retrospectively investigate mandibular asymmetry in unilateral cleft lip and palate individuals (UCLP) in relation to chronologic age and in relation to lower facial asymmetry. DESIGN: The longitudinal records of 34 UCLP individuals and 142 controls treated in the Department of Orthodontics, Eastman Dental Center, Rochester, NY, were included in the study. Posteroanterior and oblique cephalometric radiographs were analyzed for lower facial asymmetry and mandibular asymmetry, respectively. Mandibular asymmetry in UCLP was analyzed relative to three age groups (6-10, 11-14, and 15 or greater) and compared to controls. Moreover, mandibular asymmetry was analyzed relative to lower facial asymmetry. RESULTS: UCLP individuals showed no significant differences in mandibular asymmetry compared to controls. In addition, no significant correlation was found between mandibular asymmetry and lower facial asymmetry in UCLP. CONCLUSIONS: The degree of mandibular asymmetry in UCLP appears not to be the major contributing factor to the lower facial asymmetry noted on these individuals. Possible cranial-base/temporal-region anomalies may be involved in unilateral cleft lip and palate and be responsible of the asymmetry noted in the lower facial skeleton.


Subject(s)
Cleft Lip/complications , Cleft Palate/complications , Facial Asymmetry/etiology , Mandible/pathology , Adolescent , Age Factors , Case-Control Studies , Cephalometry , Child , Chin/diagnostic imaging , Chin/pathology , Cleft Lip/diagnostic imaging , Cleft Lip/pathology , Cleft Lip/surgery , Cleft Palate/diagnostic imaging , Cleft Palate/pathology , Cleft Palate/surgery , Facial Asymmetry/diagnostic imaging , Facial Asymmetry/pathology , Female , Humans , Longitudinal Studies , Male , Mandible/diagnostic imaging , Mandibular Condyle/diagnostic imaging , Mandibular Condyle/pathology , Radiography , Retrospective Studies , Skull Base/diagnostic imaging , Skull Base/pathology , Temporal Bone/diagnostic imaging , Temporal Bone/pathology
20.
J Orofac Pain ; 11(3): 215-21, 1997.
Article in English | MEDLINE | ID: mdl-9610311

ABSTRACT

Temporomandibular disorders (TMD) has been suggested to be of multifactorial etiology. One factor that has been suggested is laxity of joint ligaments. The purpose of this study was to evaluate the relationship between generalized joint hypermobility and TMD. Thirty-eight asymptomatic volunteers and 62 symptomatic patients were included in this study. All asymptomatic volunteers did not have temporomandibular joint pain, limited jaw movement, joint sounds, or previous TMD treatment. All subjects had bilateral magnetic resonance imaging scans in the sagittal closed and opened and coronal closed positions. The Beighton test was used to score joint laxity with a laxity score of > or = 4 to define generalized joint laxity. The symptomatic group had an increase in joint laxity as compared to asymptomatic control subjects (odds ratio 4.0 [95% confidence interval = 1.38 to 10.95, P = .01]). There were no differences in laxity between male and female symptomatic subjects (P > .05). This study suggests a positive correlation between generalized joint laxity and TMD.


Subject(s)
Joint Instability/complications , Temporomandibular Joint Disorders/etiology , Adult , Case-Control Studies , Confidence Intervals , Female , Humans , Joint Dislocations/etiology , Magnetic Resonance Imaging , Male , Odds Ratio , Range of Motion, Articular , Temporomandibular Joint Disc/pathology
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