statement of problem: the extraction versus non-extraction debate is almost as old as the advent of orthodontic practice and up to now, this dilemma remains. recently, the american board of orthodontics (abo) has developed a method by the name of objective grading system (ogs) in order to evaluate the results of orthodontic treatment. aim: the aim of the present study was to evaluate and compar...

objective: for the assessment of primary arch form, different methods have been used including qualitative classifications, inter-canine and inter-molar widths and quantitative and numerical methods using mathematical models. the purpose of this study was to compare the validity and reliability of cast analyzer x iranian software with those of curve expert professional version 1.1 for arch form...

Aberrant origin of vertebral artery is rare. The anatomical features and clinical significance of this lesion remain to be clarified. A comprehensive collection of the pertinent literature resulted in a cohort of 1286 cases involving 955 patients and 331 cadavers. There were more left than right and more unilateral than bilateral aberrant vertebral arteries. Patients with aberrant origin of ver...

I read with great interest this article describing a total aortic root and arch replacement in a patient with Loeys–Dietz syndrome (LDS) [1]. There is no doubt that this case was a monumental effort and a tribute to their cardiac surgical programme. There is already a sufficient body of literature validating valvesparing root replacements in children with connective tissue disorders [2–4], so t...

BACKGROUND A clinically driven transition in perfusion technique occurred at Children's Hospital and Medical Center, Omaha, Nebraska, from primarily selective cerebral perfusion bracketed by brief periods of deep hypothermic circulatory arrest to a technique of dual arterial perfusion including innominate artery and descending aortic cannulation (DAC), with continuous mildly hypothermic (>30 °C...

A mathematic-geometric model was used to evaluate the variation of mandibular dental arch length with respect to the incisor inclination, but without modifying the intercanine width. In analytical terms, the equations of the curves representing the lower dental arch, before and after incisor inclination of 1 mm and of 1 degree, with controlled and uncontrolled tipping, were studied. The length ...

Crowding is one of the causes of class I malocclusion. The purpose of the present study was to examine the relationship between arch length, arch width and arch perimeter in crowded and non-crowded arches, as well as to made comparison of the right and left sides between them and to find out the contributing factor in lower arch crowding. The study groups consisted of 60 subjects aged 16 to 21 ...

BACKGROUND AND AIM: Tooth extraction as a part of orthodontic treatment plan to create space for leveling and aligning teeth or causing tooth movement leads to changes in arch width and length. The outcome of these changes is important for the clinicians and affects the treatment and retention plans. Despite some previous studies, data in this regard are still scarce and further investigation i...