Biomedical subjects

H M Proskin

Publications and source records attributed to H M Proskin.

97 records · Page 6Linked to original sources

PubMedDate not supplied

MR fat suppression technique in the evaluation of normal structures of the knee.

The chopper fat suppression (CFS) pulse sequence, which is a phase sensitive implementation of the Dixon fat suppression method and the spin echo (SE) pulse sequence, was used in the evaluation of anatomic structures of the normal knee using 48 sets of imaging sequences in six volunteers using a repetition time/echo time combination of 1,500/30, 60 ms. A demonstration of the CFS technique in 10 patients with suspected knee pathology is also presented. A semiquantitative grading scale was established to rate anatomic visualization and used to compare CFS and SE pulse sequence techniques. The results in normal subjects demonstrate that hyaline cartilage is significantly better visualized by fat suppression pulse sequence than by conventional SE pulse sequence in the coronal and sagittal planes of imaging (p less than 0.001). The preliminary results from patients studies suggest that CFS imaging may be useful in the evaluation of meniscal tears, in the differentiation of hyaline cartilage from joint fluid, and in the detection of both soft tissue and bone injuries.

Adipose Tissue↗

PubMedDate not supplied

Fluoride in plaque fluid, plaque, and saliva measured for 2 hours after a sodium fluoride monofluorophosphate rinse.

Sodium monofluorophosphate (NaMFP) and sodium fluoride (NaF) are the two most common sources of fluoride used in currently marketed fluoride dentifrices. The purpose of this study was to investigate the effect of mouth rinses containing NaF or NaMFP on the concentrations of fluoride, or the MFP ion, in saliva, whole plaque, and plaque fluid. Twelve subjects abstained from tooth brushing for 48 h, fasted overnight, and then rinsed 1 min with 12 mmol/l (228 ppm [microg/g] F) NaF or NaMFP in the morning. Before the rinse and at 30, 60 and 120 min afterwards, upper and lower molar and premolar plaque samples and whole saliva samples were collected. Aliquots of plaque fluid and centrifuged saliva were obtained from these samples, and the whole plaque residue acid extracted. The F and MFP concentrations were then measured in these samples using ultramicro methods. For both rinses, a higher concentration of plaque fluid fluoride was found at lower molar sites while the reverse was true for the whole plaque fluoride. Furthermore, for both rinses, plaque fluid, whole plaque, but not salivary, fluoride concentrations were above baseline at 120 min. Following the NaMFP rinse, a substantial amount of unhydrolyzed MFP was found in plaque fluid and saliva. Although there was a very large range in these measurements, fluoride in plaque fluid (excluding fluoride in unhydrolyzed MFP) and whole plaque were significantly (p<0.05) greater after the NaF rinse at all time periods. In saliva, the NaF rinse produced a statistically significant greater salivary fluoride (excluding fluoride in unhydrolyzed MFP) only at 60 min. The lack of a clear correlation between these measurements and clinical studies suggest a novel mechanism may enhance the effectiveness of NaMFP dentifrices.

Adult↗

PubMedDate not supplied

Clinical outcomes for early childhood caries: influence of aggressive dental surgery.

PURPOSE: The objective of this study was to assess the relationship between the number of stainless steel crowns (SSCs) placed, number of surfaces at risk (SAR) post dental surgery, and the risk for relapse in patients treated for Early Childhood Caries (ECC). METHODS: The study population consisted of 57 children treated for ECC under general anesthesia, ranging in age from 2.3 to 7.3 years old at the time of entry. Dental surgery utilized an aggressive approach: teeth that had necrotic pulps or were nonrestorable were extracted; decayed primary mandibular incisors that could not be treated by stripping were extracted; primary maxillary incisors with 3 or more carious surfaces were extracted; single-surface lesions of primary molars that did not compromise cusp integrity were restored with intracoronal amalgam restorations; primary maxillary, incisors and canines with smooth-surface lesions affecting 2 or less surfaces were treated with intracoronal composites; primary molars and canines requiring vital pulp therapy were restored with SSCs; primary molars with caries lesions affecting 2 or more surfaces (including smooth-surface, white-spot lesions) were restored with SSCs; primary canines with caries affecting 3 or more surfaces were restored with stainless steel crowns; topical fluoride was applied after all restorative therapy was completed. The cohort was examined for new caries lesions 6 months post dental surgery. Relapse was defined as the presence of new smooth-surface caries lesions as defined by Radike. Comparisons between relapse (R) and nonrelapse (NR) groups, with respect to the number of SSCs placed and the number of SAR, were performed using t tests and Wilcoxon tests. A 0.05 level of significance was employed in all statistical tests. RESULTS: Twenty-one of the 57 (37%) patients relapsed. No statistically significant difference for the number of SSCs placed or SAR existed between the R group (SSCs: mean = 4.57, median = 4 +/- 2.18; SAR: mean = 39.76, median = 40 +/- 13.62) and NR group (SSCs: mean=5.44, median = 5.5 +/- 2.62; SAR: mean = 39.98, median = 39.5 +/- 15.19). CONCLUSIONS: The risk for relapse in children treated for ECC is not associated with the number of SSCs placed or SAR; aggressive dental surgery for ECC does not result in acceptable clinical outcomes.

Child↗

PubMedDate not supplied

Monitoring of sedated pediatric dental patients.

The results of this study showed that children sedated with 50 mg/kg chloral hydrate and 25 mg hydroxyzine in conjunction with 40 percent nitrous oxide and 60 percent oxygen may have respiratory difficulties which are not detected by the traditional monitoring of blood pressure, pulse, respiratory rate and skin color. The use of a pulse oximeter that noninvasively measures oxygen saturation of hemoglobin (SaO2) allowed earlier detection of respiratory distress, when correction was a relatively simple matter of readjusting head position. This combination of sedative agents was effective in managing two-thirds of the patients originally classified in a behavioral category of definitely negative. No children sedated with only 40 percent nitrous oxide and 60 percent oxygen exhibited respiratory problems, and over 80 percent of the patients classified in behavioral category of negative were managed effectively with this technique.

Anesthesia, Dental↗

PubMedDate not supplied

Comparison of the sedative effectiveness of two pharmacological regimens.

This study was designed to evaluate the effectiveness of two orally administered pharmacological regimens. The subjects were twenty-six patients requiring a sedative premedication for dental treatment, due to difficult behavior. A randomized, double-blind, cross-over design was employed using chloral hydrate syrup, 30 mg/Kg; and diphenhydramine HCl, 1.5 mg/Kg orally, not to exceed 2,000mg and 75mg, respectively; and chloral hydrate syrup, 30 mg/Kg; and diazepam solution, 0.2 mg/Kg orally, not to exceed 2000mg and 10mg, respectively. The level of conscious sedation was assessed, utilizing two scales employed previously in other studies. It was demonstrated that it is possible to maintain a low-dose range of sedative medication with satisfactory results. The combination of diazepam and chloral hydrate was found to be more effective than the diphenhydramine, chloral hydrate combination.

Adult↗

PubMedDate not supplied

Immediate implantation of pure titanium implants into extraction sockets of Macaca fascicularis. Part I: Clinical and radiographic assessment.

Immediate implants have the advantages of few surgical exposures, short treatment time, and maintenance of alveolar bone height and width. The purpose of this study was to compare immediate implants with conventional implants (implants placed into ossified extraction sites) in adult monkeys. Forty-eight implants were placed and allowed to heal for a 6-month period. Following a 7-month loading period, the monkeys were sacrificed, and implant sections were evaluated histologically. Clinical and radiographic measurements showed few significant differences between immediate and control implants.

Alveolar Process↗

PubMedDate not supplied

Immediate implantation of pure titanium implants into extraction sockets of Macaca fascicularis. Part II: Histologic observations.

The purpose of this study was to evaluate immediate implants with implants placed in ossified extraction (control) sites. Histologic observation of immediate and control implants showed similar levels of bone integration at the light microscopic level using ground-section and decalcified thin-section histologic methods. Both histologic methods provided similar information in relation to determination of hard and soft tissue components measured at the interface. The percentage of bone integration was similar in different anatomic regions of the oral cavity. Bone patterns peripheral to the interface region differed, suggesting that special consideration be given to implants placed in the posterior regions of the maxilla and mandible.

Alveolar Process↗