Junichiro Iida

Interleukin-1β levels, pain intensity, and tooth movement using two different magnitudes of continuous orthodontic force

This study aimed to determine the optimum orthodontic force from a broader perspective. Interleukin (IL)-1β levels in human gingival crevicular fluid (GCF), pain intensity, and the amount of tooth movement were measured during canine retraction using different magnitudes of continuous orthodontic force. Sixteen subjects (two males and 14 females), aged 18-24 years, diagnosed with Class I bimaxillary protrusion and treated with first premolar extractions participated in this study. The upper canines were retracted with continuous forces of 50 or 150 g using nickel-titanium coil springs on segmented archwires. One of the lower canines was used as a control. GCF was collected from the distal site of each tooth at specific time points. IL-1β concentrations, pain intensity, using the visual analogue scale (VAS), and the amount of tooth movement were evaluated. One-way analysis of variance, Friedman, and paired t-tests were used for comparisons of IL-1β in GCF, the plaque and gingival indices, and the efficiency of tooth movement on pain perception, respectively. IL-1β concentration in the 150 g group showed the highest level at 24 hours and 2 months with significant differences compared with the control group (P < 0.05). The mean VAS score of pain intensity from the 150 g force was significantly greater than from the 50 g force at 24 hours (P < 0.01). However, no significant difference in the amount of tooth movement was found between these two different magnitudes of continuous force at 2 months. A 50 g force could effectively induce tooth movement similar to 150 g with less pain and less inflammation.

Spectrum of Factors Affecting Dental Arch Relationships in Japanese Unilateral Cleft Lip and Palate Patients

Cleft lip and palate care involves multidisciplinary management of affected anatomical structures and functions. These include speech, hearing, and social integration. Maxillary growth retardation and high incidence of Class III malocclusion are the major problems in patients with cleft lip and palate (Ross and Johnston, 1972; Ross, 1987c; Mars and Houston, 1990; Mars et al., 1992; Ishikawa et al., 2002). Orthodontic anomalies such as crowding, rotation and malposition of the teeth are also common in cleft lip and palate patients. In children with cleft lip and palate, abnormalities in number, size, shape and timing of tooth formation are more frequent than in the general population (Ranta R, 1986). The development of methods to detect levels of treatment outcomes is necessary if surgeons are to have a sound basis on which they can justify modifications of their timing or techniques (Atack et al., 1997). Dental arch relationships are important parameters for facial growth and are thus an important indicator for the quality of cleft treatment outcome (Hathorn et al., 1996). This Cleft lip and palate is a congenital anomaly. The etiology has been thought to be multifactorial in nature with genetic and environmental factors contributing to its presence (Berkowitz, 2006). This congenital anomaly affects approximately 1.41 per 1000 live births in Japanese (nonsyndromic clefts) and 1.25 in the other Asian populations (Cooper et al., 2006).