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...

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...

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...

BACKGROUND In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossiliz...

The conventional lingual arch is a nonfunctional fixed space maintainer used in the mandibular arch to maintain arch length by the prevention of mesial movement of the permanent first molars. This study highlights a functional lingual arch with a hinge-type lockable dentulous component that incorporates molar tubes, with various advantages over the conventional lingual arch. How to cite this ...

In this paper the class of ARCH(∞) models is generalized to the nonstationary class of ARCH(∞) models with time-varying coefficients. For fixed time points, a stationary approximation is given leading to the notation “locally stationary ARCH(∞) process.” The asymptotic properties of weighted quasi-likelihood estimators of time-varying ARCH(p) processes (p < ∞) are studied, including asymptotic ...