Guided bone regeneration of large mandibular defects in a primate model

BACKGROUND: An earlier publication from our laboratory described the use of guided bone regeneration to fill large bone voids in the mandible created through en bloc resection in primates. The present report is an embellishment of this paper and describes bone regeneration experiments in 18 adult male Macaca mulatta monkeys to determine how long membranes must be in position to promote guided bone regeneration. METHODS: Thirty-six lesions were created in the mandibles of 18 monkeys in a standardized mandibular defect of 8 x 19 mm. Reinforced ePTFE membranes were placed in the animals and held in place with mini screws and sutures for anywhere from 1 to 12 months. No material was added to the defect. In addition to clinical studies, digital subtraction radiology and fluorescent labeling with tetracycline and histomorphometry are described. RESULTS: The results indicate that no bone gain was observed in membranes exposed for 1 month or less, but bone gain (approximately well over 90% of defects) was observed at 12 months when membranes were left in situ for 2 to 12 months (P <0.0001). No significant difference in the amount of bone gained at 12 months was observed for membranes left in place for intervals ranging from 2 to 12 months. A significant correlation between the amount of bone gain observed at 3 and 12 months was observed (P <0.0001). CONCLUSIONS: Data therefore suggest that membranes left in situ for 1 month or less result in minimal bone gain compared with membranes left in place from 2 to 12 months. In addition, labeling and stained sections clearly showed that the bone produced after 2 months of membrane placement is mature.     

Effect of antiasthmatic medication on dental disease: dental caries and periodontal disease

The prevalence of asthma has been increasing since the 1980s. Asthma and tooth decay are the two major causes of school absenteeism. There are few studies present in the literature. The objectives of the present study were to know the severity of dental caries and periodontal problems in children before and after taking antiasthmatic medication. The present study was conducted on 105, six- to fourteen-year-old asthmatic children to determine the condition of their dental caries and their periodontal status before and after taking antiasthmatic medication, for a period of 1 year and these were matched with their controls. The results showed that salbutamol inhaler shows increased caries rate with high significance over other groups, which was followed by salbutamol tablets and beclamethasone inhaler respectively. It has been concluded that antiasthmatic medication has its effects on dental caries and periodontal disease and asthmatic patients are recommended to adopt more precautionary oral hygiene practices and keep their caries activity and periodontal health under constant check.     

Periodontal infection and preterm birth: results of a prospective study

BACKGROUND: Previous studies have suggested that chronic periodontal infection may be associated with preterm births. The authors conducted a prospective study to test for this association. METHODS: A total of 1,313 pregnant women were recruited from the Perinatal Emphasis Research Center at the University of Alabama at Birmingham. Complete periodontal, medical and behavioral assessments were made between 21 and 24 weeks gestation. After delivery, medical records were consulted to determine each infant's gestational age at birth. From these data, the authors calculated relationships between periodontal disease and preterm birth, while adjusting for smoking, parity (the state or fact of having born offspring), race and maternal age. Results were expressed as odds ratios and 95 percent confidence intervals, or CIs. RESULTS: Patients with severe or generalized periodontal disease had adjusted odds ratios (95 percent CI) of 4.45 (2.16-9.18) for preterm delivery (that is, before 37 weeks gestational age). The adjusted odds ratio increased with increasing prematurity to 5.28 (2.05-13.60) before 35 weeks' gestational age and to 7.07 (1.70-27.4) before 32 weeks' gestational age. CONCLUSIONS: The authors' data show an association between the presence of periodontitis at 21 to 24 weeks' gestation and subsequent preterm birth. Further studies are needed to determine whether periodontitis is the cause. CLINICAL IMPLICATIONS: While this large prospective study has shown a significant association between preterm birth and periodontitis at 21 to 24 weeks' gestation, neither it nor other studies to date were designed to determine whether treatment of periodontitis will reduce the risk of preterm birth. Pending an answer to this important question, it remains appropriate to advise expectant mothers about the importance of good oral health.     

Longitudinal study of bone density and periodontal disease in men

Bone loss is a feature of both periodontitis and osteoporosis, and periodontal destruction may be influenced by systemic bone loss. This study evaluated the association between periodontal disease and bone mineral density (BMD) in a cohort of 1347 (137 edentulous) older men followed for an average of 2.7 years. Participants were recruited from the Osteoporotic Fractures in Men Study. Random half-mouth dental measures included clinical attachment loss (CAL), pocket depth (PD), calculus, plaque, and bleeding. BMD was measured at the hip, spine, and whole-body, by dual-energy x-ray absorptiometry, and at the heel by ultrasound. After adjustment for age, smoking, race, education, body mass index, and calculus, there was no association between number of teeth, periodontitis, periodontal disease progression, and either BMD or annualized rate of BMD change. We found little evidence of an association between periodontitis and skeletal BMD among older men.     

Congenital muscular dystrophy--a case report

A rare case of congenital muscular dystrophy with unique oro-facial manifestations is presented. Dental considerations and successful management techniques are discussed.     

Inhibition of human embryonic palatal mesenchymal cell cycle by secalonic acid D: a probable mechanism of its cleft palate induction

OBJECTIVE: To assess the mechanism(s) of cleft palate induction by secalonic acid D (SAD) in human embryonic palatal mesenchymal (HEPM) cells and compare them with those evaluated in the murine embryonic palate. DESIGN: Effect of SAD on HEPM cell proliferation was studied by obtaining dose response curves for cell numbers, uptake of 3H-thymidine and the expression of proliferating cell nuclear antigen (PCNA). Effects of SAD on cell cycle were assessed by flowcytometry. Cell-labeling with 3H-glucosamine and immunoblot analysis were conducted to study SAD effects on the synthesis of glycosaminogycans (GAG) and the expression of fibronectin and tenascin, respectively. RESULTS: SAD induced a concentration-dependent decrease in HEPM cell number and 3H-thymidine uptake beginning at 0.1 microg of SAD/ml. Expression of PCNA and progression of cell cycle from G1 to S phase were inhibited following SAD exposure. Cell viability was significantly reduced only at 7.5 microg/ml of SAD or higher indicating that the reduction in cell numbers by SAD at lower concentrations is likely due to reduced proliferation and at higher concentrations due to both reduced proliferation and cell death. Synthesis of extra cellular matrix components (GAGs, fibronectin or tenascin) by HEPM cells, however, was not inhibited by SAD. CONCLUSION: The results of these studies confirmed those of our previous studies with mice and the MEPM cells that SAD may induce cleft palate by reducing numbers of palatal mesenchymal cells by inhibition of their proliferation thereby leading to a reduction in the size of the developing palate shelves.     

Oral ulceration in HIV infection: Investigation and pathogenesis

Oral ulcerations associated with HIV infection include recurrent aphthous ulcers (RAU). Whereas RAU prevalence is not increased, lesion severity is: among a group of HIV⁺ patients, 66% had the more severe herpetiform or major RAU. This increased severity suggests that HIV disease-related changes in the immune system may exacerbate RAU. In the peripheral blood of healthy subjects with RAU, CD4:CD8 cell ratios may be reversed and the proportion of T cell receptor-γδ⁺ cells increased. HIV disease-related immune system changes are characterized by reversed CD4:CD8, lowered CD4 cell counts and an inverse correlation between CD4 cell counts and per cent activated γδ lymphocytes. Adhesion molecules and cytokines involved in lymphocyte homing may be important in RAU pathogenesis: ICAM-I and ELAM are strongly expressed, and TNFα production is increased in peripheral blood lymphocytes of healthy patients with RAU. In patients with active HIV disease/AIDS, serum TNFα levels are increased. Thalidomide, which inhibits TNFα production, is effective treatment for RAU. Some RAU patients have vitamin B12 or folate deficiencies, levels of which are commonly low in HIV⁺/AIDS patients. However, in a case control study of HIV⁺ patients, vitamin B12- or folate-deficiencies were not found to be significant risk factors for RAU.     

"Moebius syndrome": a case report

Moebius syndrome is an extremely rare disorder characterized by a lifetime facial paralysis, involving sixth and seventh cranial nerves with malformations of orofacial structures and the limbs. In this case, an 8 year old girl with Moebius syndrome is presented, clinical findings are described and management aspects are discussed. Early dental evaluation and parental counselling as a part of preventive dental regimen can go a long way in providing complete psychosocial rehabilitation for such physically disabled children.