Mandibular growth in subjects with infraoccluded deciduous molars: a superimposition study.

The aim of this longitudinal cephalometric study was to analyze the growth characteristics of the mandible in subjects with infraocclusion of the mandibular deciduous molars. A group of 28 subjects with bilateral infraocclusion of mandibular deciduous molars (IG) were enrolled in a prospective longitudinal study on the growth characteristics of the mandible and compared with a control group (CG) of 28 subjects. Lateral cephalograms were collected in both groups at T1 and at T2, after a mean 19-month interval in the IG and after a mean 16-month interval in the CG.

Early predictive variables for upper canine impaction as derived from posteroanterior cephalograms.

The aim of this study was to identify a model of cephalometric variables for early diagnosis of the displacement of upper permanent canine and early prognosis of upper canine impaction. Postero-anterior (PA) cephalograms of 43 subjects (22 males and 21 females) with different types of malocclusions in the mixed dentition were analyzed at the time of first observation (mean age 8 years and 5 +/- 9 months). All subjects were reevaluated at the mean age of 14.

Two interceptive approaches to palatally displaced canines: a prospective longitudinal study.

This study evaluated the effectiveness of two interceptive approaches to palatally displaced canines (PDCs), ie, extraction of the deciduous canines alone and in association with the use of a cervical pull headgear. The prospective longitudinal design of the investigation included 46 subjects with PDC (62 maxillary canines) who were randomly assigned to one of three groups (1) a group that underwent the extraction of the deciduous canine only, (2) a group that received in addition the use of a cervical pull headgear, and (3) an untreated control group. Panoramic radiographs were evaluated at initial observation (T1) and after an average period of 18 months (T2).

OH-initiated oxidation of DMS/DMSO: reaction products at high NOx levels.

Dimethylsulphide (DMS) gas phase oxidation with OH radicals was investigated by long path FT-IR spectroscopy and by ion chromatography (IC) and HPLC-MS2 to quantify the reaction products and evaluate heterogeneous processes. The experiments were performed considering two different NOx (NO2+NO) levels. The initial concentration of NO2 was varied from 24 ppbV (NOx=1 ppmV) to 953 ppbV (NOx=10 ppmV).