The role of the orthodontist in the treatment of adolescents with orofacial clefts

In the orthodontic treatment of patients with clefts the main aim is to maximize the growth and development of the maxillary complex and, at the same time, to improve functional efficiency and facial aesthetics. The commonest malocclusions found in adolescents with lip and palate clefts are: frontal or anterior crossbite; posterior or buccal crossbite which is either unilateral or bilateral; retrusion of the middle third of the face to a greater or a lesser degree; open bite; and finally malformation and displacement of the teeth adjacent to the cleft. Treatment may be divided into: correction of malocclusions in the transverse plane; correction in the antero-posterior plane; vertical corrections; and correction of misplaced individual teeth. Posterior (lateral) crossbite can be corrected by both gradual and rapid (forced) expansion using various removable appliances. Following this, correction of anterior crossbite and restoration of vertical occlusal relationships will be necessary. Finally, misplaced individual teeth will need to be repositioned. Traumatic surgery and consequent scar tissue affects the growth of the maxillary arch and the development of the occlusion. This was demonstrated in a comparative analysis of monozygotic and dizygotic twins discordant for clefts as well as in twin pairs whose clefts were non-identical in type and extent. The adolescents who still have unoperated clefts have special problems.

Microbial growth comparisons of five commercial parenteral lipid emulsions

The ability of parenteral lipid emulsions to support microbial growth was compared using commercially available brands of lipid emulsion. Both 10 and 20% concentrations of soybean and safflower oil emulsions were used. Washed cultures of six gram-negative, three gram-positive, and one yeast, in concentrations of 1 x 10(4) to 2 x 10(4) colony-forming units/ml, were inoculated into lipid emulsion aliquots and stored at room temperature. There were than subcultured at 0, 6, 12, 24 and 48 hr. After 48 hr at 37 degrees C, growth was recorded as colony-forming units/ml. Normalized growth curves were expressed as mean +/- SEM. ANOVA demonstrated no difference in growth patterns due to the nature of the oil or its concentration. Gram-negative organisms multiplied faster when compared to gram-positive (p less than 0.05 at 12 hr, p less than 0.01 at 24 hr, and p less than 0.005 at 48 hr). Yeast grew as well as bacteria. The Center for Disease Control's recommendation of a 12-hr hang time for parenteral lipid emulsions should be observed until correlation of laboratory microbial growth patterns and clinical use are studied further.

A comparative occlusal and cephalometric study of dental and skeletal anteroposterior relationships

Anteroposterior dental relationships (Class I, II or III) were assessed from study plaster models and skeletal relationships were determined on the basis of the ANB angle of 585 orthodontic patients. It was found that there was no agreement between dental and skeletal anteroposterior relationships in about 25 per cent of the cases investigated.

Twins with clefts

The concurrence of two experiments of nature, twins and congenital birth defects, provides a unique population for the elucidation of nature-nurture questions. Although the concurrence of twins with clefts is not common, their frequency in the aggregate of international reporting is sufficient to allow for meaningful studies.

In a recent conference on the genetics of cleft lip and palate, Fraser (1968) summarized the state of knowledge regarding etiology. The following quotation from his report is pertinent to the present paper:

1) In the majority of cases, cleft lip or cleft lip and palate [CL(P)] represents a quasi-continuous variant, or threshold character of multifactorial etiology. For cleft palate [CP] there is less convincing information;

2) Observations on arch form, face shape, body asymmetries and developmental variables suggest that such variants may underly the predisposition to clefts;

3) Twin studies may be useful in identifying the physiognomic factors predisposing to facial clefts.

With these concepts in mind, we initiated an analysis of 19 twin pairs selected from the continuing longitudinal growth study which began at our Center in 1949 (Pruzansky and Lis, 1958).