An evaluation of factors affecting duration of orthodontic treatment.

One of the first questions asked by new orthodontic patients is: How long will I need to wear my braces? A multitude of factors have the potential to influence the answer to this question. The purpose of this retrospective study was to identify some of the primary factors that influence orthodontic treatment duration. Few studies have attempted to evaluate these factors. Data were gathered from 140 consecutively completed, comprehensive treatment patient records in five orthodontic offices. Thirty-one variables related to patient characteristics, diagnostic factors, modality of treatment, and patient cooperation were evaluated. Average treatment time was 28.6 months with a range of 23.4 to 33.4 months among the five offices. Nearly half (46.9%) of the variation in treatment duration was explained by a five-step multiple regression analysis. Included in the regression equation were the number of missed appointments, the number of replaced brackets and bands, the number of treatment phases, the number of negative chart entries regarding oral hygiene, and the prescription of headgear wear during treatment. An additional 6.7% of the variance was explained by variation among the five offices. Six of the 31 variables examined made a statistically significant (alpha =.01) contribution to the explanation of variation in treatment time. The quality of the finished cases and the appropriateness of the original diagnosis and treatment plan were not evaluated. Developing an objective assessment to evaluate these areas may be important for increasing our understanding of treatment time variation.

One-stage repair of interrupted aortic arch, ventricular septal defect, and subaortic obstruction in the neonate: a novel approach.

BACKGROUND: One-stage repair of interrupted aortic arch, ventricular septal defect, and severe subaortic stenosis represents a surgical challenge. Techniques that use extracardiac conduits to bypass the subaortic area or involve transaortic or transatrial resection of the conal septum have shown limitations and have failed to reduce the high mortality rate associated with subaortic obstruction. METHODS AND RESULTS: A new operative approach was used in nine neonates (2.1 to 3.9 kg) who underwent one-stage repair of interrupted aortic arch (type B, eight patients; type C, one patient), ventricular septal defect, and severe subaortic stenosis. All patients had severe subaortic stenosis according to preoperative echocardiography (mean ratio of subaortic to descending aortic diameter, 0.63 +/- 0.08). With a transpulmonary (seven patients) or transatrial (two patients) approach and without resection of the conal septum, the ventricular septal patch was placed on the left side of the septum to deflect the conal septum anteriorly and away from the subaortic area. There were no early or late deaths. Median intensive care unit and hospital stays were 17 days (6 to 47 days) and 21 days (10 to 55 days), respectively. On follow-up echocardiography (1 to 29 months, median 12 months), no patients had significant residual subaortic obstruction and one patient had mild residual arch obstruction (20 mm Hg). Growth of the subaortic region was demonstrated in all patients (mean ratio of subaortic to descending aortic diameter, 1.20 +/- 0.10; < 0.001). CONCLUSIONS: Relief of severe subaortic stenosis during one-stage neonatal repair of aortic arch interruption and ventricular septal defect can be accomplished successfully without resection of the conal septum.

Shear strength of ceramic brackets bonded to porcelain.

The purpose of this study was to compare the bond strengths of three different adhesive systems when used alone and combined with a porcelain priming agent to bond ceramic brackets to porcelain surfaces. Sixty porcelain specimens were randomly assigned to the six different treatment groups. Half were bonded with the porcelain priming agent and one of the adhesive systems and the other half with one of the adhesive systems alone. The shear bond strengths of all specimens were tested, with an Instron testing machine, 10 minutes after being bonded. The surface of the porcelain and the bracket base were examined, with scanning electron microscopy (SEM) and qualitative energy dispersive x-ray analysis (EDS), to determine the bond failure patterns and to check the porcelain surface for the presence of cracks and fractures. There was a statistically significant difference within each adhesive between those samples with the priming agent and those without the priming agent. Differences between the three adhesives were not statistically significant (p < or = 0.05).

Validity and reliability of an "Adult Children of Alcoholics" Index.

A 21-item Adult Children Of Alcoholics (ACOA) Index was statistically analyzed in an effort to develop a measure of identifying and assessing ACOAs. The ACOA Index, administered to a conference sample (n = 328), produced four factors suggesting rejection, impulsiveness, inconsistency, and deliberation. The ACOA Index was most highly correlated with indexes for mild depression and low self-esteem. ACOAs scored significantly higher on the ACOA Index than non-ACOAs with an overall correct classification of 67%. Test-retest procedure produced a Pearson r = .80 using a college student sample (n = 134), but only r = .40 for a sample of alcohol inpatients (n = 34). The alpha coefficient for the ACOA Index is .85.

Impact of overbite on indicators of temporomandibular joint dysfunction.

Epidemiological studies have suggested that deep overbite is associated with symptoms of temporomandibular dysfunction (TMD). This finding was directly tested by deliberately constituted groups of deep and normal overbite subjects matched for age and sex. Eighty-one subjects participated. Dependent measures included the TMJ Scale test; measures of muscle activity in the right and left frontalis, temporalis, and masseter muscles; and pressure threshold meter readings for the same sites. The results showed no differences between deep and normal overbite subjects for all the dependent measures studied. The role of overbite alone in producing TMD symptoms is questioned.

Adult children of alcoholics: the effects of background and treatment on ACOA symptoms.

This research attempts to identify the factors that differentiate adult children of alcoholics (ACOAs). A national purposive sample of ACOAs (n = 500) was administered an ACOA index measuring ACOA symptoms. An ANOVA analysis for the ACOA index scores showed gender, minority race or ethnicity, rating of parents' relationship, receiving help as a child, and seeking treatment as an adult to have significant effects. Notably, minorities scored significantly lower on the ACOA index, and seeking treatment increased the scores, even in interaction with parents' relationship and receiving help as a child. These findings point to the need for differentiating treatment for ACOAs and developing more effective treatment in general. They also confirm the importance of offering even informal support to children in troubled families.

The effectiveness of a counterrotational-action power toothbrush on plaque control in orthodontic patients.

This study compared counterrotational-action power toothbrushing with manual toothbrushing in effectiveness on plaque control and gingival health in 20 randomly selected orthodontic patients at the University of Missouri-Kansas City. A blind two-group crossover design was used. Gingival and plaque scores were recorded, and a prophylaxis was given to bring the plaque score to zero. Ten subjects received counterrotational power brushes, and ten subjects received manual brushes. Instructions appropriate to each brushing method were given by a hygienist. At 30 and 60 days, plaque and gingival scores were recorded and a prophylaxis was given. At 60 days the subjects who were using power brushes were switched to manual brushes, and the subjects who were using manual brushes were switched to power brushes. At 30 and 60 days, plaque and gingival scores were recorded and a prophylaxis was given. Plaque and gingival scores were significantly less (p less than 0.01) after brushing 2 months with the counterrotational power brush than with the manual brush. This finding was irrespective of the sequence in which the brushes were used.

Exposure reduction and image quality in orthodontic radiology: a review of the literature.

This article summarizes the use of rare earth screen technology to achieve high-quality panoramic and cephalometric radiographs with sizable reductions in patient radiation dosage. Collimation, shielding, quality control, and darkroom procedures are reviewed to further reduce patient risk and improve image quality.

Bond strength of thermally recycled metal brackets.

Bracket recycling has emerged concurrently with the practice of direct bonding. This study was undertaken to determine the effect of recycling on the retention of mesh-backed stainless steel brackets. Mesh strand diameter was measured on forty new brackets. These brackets were bonded to recently extracted human premolar teeth, and the tensile force required to fracture each bond was recorded. The brackets were then reconditioned by a thermal process. The mesh strand size was remeasured and the tensile test was repeated. It was found that (1) mesh strand diameter decreased 7 percent during the reconditioning process (93.89 microns +/- 3.17 S.D. compared to 87.07 microns +/- 4.76 S.D., z = 17.62, P less than 1 X 10(-5) ), (2) new bracket bonds were 6 percent stronger than recycled bracket bonds (43.88 pounds +/- 7.98 S.D. bond strength), and (3) reduction in mesh strand diameter during the reconditioning process did not correlate with changes in bond strength between initial and recycled bonding (Pearson r = 0.038).

The Michigan School Study cephalometric norms expressed in template form.

User-calibrated cephalometric templates have been presented for boys and girls at the ages of 6, 8, 10, 12, 14, and 16 years. The templates were derived by geometric triangulation from normative data published in An Atlas of Craniofacial Growth. A technique for using the templates diagnostically has also been presented.

Tooth migration during the transitional dentition.

Posteruptive tooth migration between 6 and 14 years involves both total arch displacement and intra-alveolar tooth movement. Central incisors, canines, and permanent first molars all drift forward within the alveolar bone. The molars, and to a lesser extent the incisors, drift occlusally. With respect to lingual arch contour, lateral movement of molars and canines is negligible.

Testosterone metabolism in male rat epiphysis.

Using radioactive substrate, thin-layer chromatography and recrystallization methods as well as differential centrifugation, gel filtration and electrophoresis, testosterone metabolism was investigated in male rat epiphyseal growth plate. 5alpha-androstane 3alpha-17beta-diol was found to be a major metabolite in vitro; lesser amounts of androstenedione and androstanedione, and a very small amount of 5alpha-dihydrotestosterone were also identified. Radioactivity was recovered in epiphyseal subcellular fractions 30 minutes following in vivo administration of tritiated 5alpha-dihydrotestosterone; within 2 hours radioactivity had fallen to essentially background level in all fractions but the cytosol. A testosterone binding protein could not be identified within epiphyseal cytosol.