To probe recent trends in transfusion practice and their effect on the adequacy of the national blood resource, transfusions and collections in the United States in 1989 were studied, by using data shared by the American Association of Blood Banks, the American Red Cross, and the Council of Community Blood Centers, together with results from a sample survey of the 3600 hospitals that were not members of the national organizations. Statistical methods were used to estimate national activities. The total US supply of blood in 1989 was 14,229,000 units, an increase of 1.2 percent over the supply in 1987. Red cell transfusions were 12,059,000 units. A total of 3,159,000 patients underwent transfusion with whole blood and/or red cells (mean, 3.8 units/patient). Preoperative autologous deposits of 655,000 units by 310,000 patients represented an increase of 65 percent over the level in 1987. However, only 356,000 units (54%) were transfused to the patients who preoperatively deposited them; of the remainder, 13,000 units were crossed over for transfusion to other patients, while 286,000 units were never used. Directed donations, 350,000 units, were provided for 130,000 intended recipients, but only 97,000 units (28%) were transfused to their intended recipients; of the balance, 59,000 units (17%) were crossed over and 194,000 units (55%) were never transfused. Total platelet transfusions were equivalent to 7,258,000 units in 1989, for an increase of 13.7 percent over totals in 1987.

The brands and shades of the composite resins were shown to have a clear effect on TP, but an inconsistent tendency for ΔE*(ab).

While the US blood supply was adequate for transfusion needs in 1992, blood collections and red cell transfusions had decreased substantially since 1989.

Background Despite the gradual increase in the use of rapid maxillary expansion (RME), specifically RME with the aid of skeletal anchorage in adults, there have been no reports comparing dentoskeletal and soft tissue changes between nonsurgical tooth-borne and tooth-bone-borne RMEs in adults. This study aimed to analyse differences in dentoskeletal and soft tissue changes between tooth-borne and tooth-bone-borne RMEs using a similar appliance design and the same expansion protocol in adult patients. Methods Twenty-one patients with tooth-borne expansion (a conventional expansion screw with two premolars and two molar bands for dental anchorage [T-RME]) and the same number of patients with tooth-bone-borne hybrid expansion (a conventional expansion screw with two premolar and two molar bands for dental anchorage and four mini-implants in the palate for skeletal anchorage [H-RME]) were included. Dentoskeletal and soft tissue variables at pretreatment (T1) and after expansion (T2) were measured using posteroanterior and lateral cephalograms and frontal photographs. The sex distribution of the two groups was analysed using the chi-square test, and the change after RME in each group was evaluated using the Wilcoxon signed-rank test. Differences in pretreatment age, expansion duration, post-expansion duration, and dentoskeletal and soft tissue changes after RME between the two groups were determined using the Mann–Whitney U test. Results There were no significant differences in the expansion protocol, pretreatment conditions, and sex distribution between the two groups. Despite similar degrees of dental expansion at the crown level between the two groups, H-RME induced increased skeletal and parallel expansion of the maxilla compared to T-RME. After expansion, H-RME demonstrated increased forward displacement of the maxilla without significant changes in the vertical dimension, while T-RME exhibited increased backward displacement of the mandible, increased vertical dimension, and decreased overbite. Both groups showed significant retroclination and extrusion of the maxillary incisors without significant intergroup differences. There were no significant soft tissue changes between the two groups. Conclusion This study suggests that using skeletal anchorage in RME may induce increased skeletal and parallel expansion of the maxilla without significant effects on the vertical dimension.

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