Relaxation of orthodontic elastomeric chain [in vitro comparative study]

This in vitro study was designed to determine the force relaxation of the elastomeric chains for Orthoorganizer and Orthomatrix companies under different time intervals [zero, 1, 4, 24 hours and 1, 2, 3, 4, 5, and 6 weeks] in artificial saliva; and to evaluate the effect of time and extension on the load relaxation behavior of these chains. Specifically constructed frameworks were used and in addition to electronic balance for load measurements. The results of this study showed a greatest loss of force at the first hour with a subsequent slower rate. The greater the extension length, the greater the initial force but the lesser the percent of force remaining within the same company

Effect of the rapid maxillary expansion on the treatment of primary nocturnal enuresis [clinical study]

The present study was conducted to evaluate the effect of rapid maxillary expansion [RME] the primary nocturnal enuresis [NE]. A sample consists of 19 patients, with resistant primary nocturnal enuresis, aged 6-15 years, treated by banded Hyrax expander in the College of Dentistry University Baghdad, 7 patients out of study group considered as control group at first to exclude placebo effect of the appliance. CT scan was used to evaluate the increase in the nasal cavity width at the level of inferior choncha, rhinomanometry used to assess nasal airflow and nasal resistance, osmolality measured to evaluate plasma antidiuretic hormone [ADH] all these parameters done before and 2-3 months at expansion in Al-Kadhymia Teaching Hospital. Patients in the study group underwent rapid maxilla expansion in 10-15 days, after 2 to 3 months of expansion most of the patients show complete dryness and others show notable improvement in nocturnal enuresis. The improvement in nocturnal enuresis following rapid maxillary expansion may be due to: -1-Restoration of normal sleep patterns, that make the patient wake easily, this caused by improvement nasal breathing, snoring, deep sleep, and treatment of mouth breathing following rapid maxilla expansion. -2-Increase in the antidiuretic hormone secretion, that causes decrease in the plasma osmolality and urine production following rapid maxillary expansion

Skeletodental modulation for horizontal activator treatment for sheletal II and dental class II division 1 [Clinical and cephalometric study]

The present study was conducted to evaluate the effect of horizontal activator on patients suffering from skeletal and dental class II division 1 malocclusion. The sample consist of 13 Iraqi patients of both genders at early adolescent period, 1 year before maximum growth spurt [12 years for females and 14 years for males]. The study aimed to evaluate the skeletal effect of horizontal activator treatment, examine the dental treatment modulation due to activator therapy, and determine the mode of activator treatment whether it is a skeletodental or a change in the glenoid fossa position. The main findings were that H-Activator treatment has orthopedic and orthodontic effect and its orthopedic effect is observed more on the mandible than the maxilla by increasing the length of the mandible with remodeling of the glenoid fossa. Moreover, its dental effect is more on the upper dentition than the lower dentition. This is mostly on the upper incisors by biomechanical forces applied by the appliance which is originally gained from the muscles of mastication, however, dental changes were insignificant