No abstract

This study indicates that increasing the construction bite height might give more favorable stress patterns in the TMJ, thereby improving the condylar response to functional appliances. The findings of this preliminary study need to be investigated in an animal model and in humans before deriving clinical implications.

Introduction:To assess the positional variations of maxillary horizontal and vertical plane with respect to infrazygomatic crest (key ridge) in skeletal class I, II and III cases.

Objective: To evaluate the stress patterns in temporomandibular joint (TMJ) during mandibular protraction at different horizontal advancements with constant vertical height in a construction bite using a three-dimensional finite element method. Materials and Methods: A three-dimensional computer-aided model was developed from the magnetic resonance imaging (MRI) of a growing boy (age 12 years) using MIMICS software (version 7.0, Materialise, Leuven, Belgium). Stresses with constant vertical opening of 5 mm changing the sagittal advancements from 0 mm to 5 mm and 7.5 mm were recorded. Differences in magnitude and pattern of stresses were compared. Results: The tensile stresses in the posterosuperior aspect of the condylar head and on the posterior aspect of the glenoid fossa migrated posteriorly with increased bite advancements. The location of tensile stresses changed in the condylar head and fossa on mandibular protraction of 5 mm to 7 mm. Conclusion: This study indicates that larger horizontal advancements of construction bites may not be favorable for tissues of TMJ. Clinical application necessitates study on an animal model.

Unlike amalgam, the difficulty of condensing composite presents us with the challenge, recreating a tight interproximal contact. May be more importantly, trimming composite that has been extruded beyond the preparation margin around an interproximal box is difficult, frustrating and unpredictable. So in a quest to minimize the amount of trimming we need to do with high-speed instrumentation after the composite is cured. Recreating the natural tooth shape and sealing the walls begins with the matrix. A matrix system must do the following three things: Recreate the natural tooth shape and interproximal contact Seal the proximal and gingival walls of the prep Overcome the thickness of the band. On the market today are both plastic and metal matrix bands. They are available in a variety of thicknesses and delivery systems that include sectional matrix bands, circumferential systems and bands that require a holder. Here, we present the NS matrix system which is a highly effective and economical matrix system that can be used for a variety of clinical applications, including posterior and anterior restorations. How to cite this article Sharma NS, Shrivastav SS, Hazarey PV, Kamble RH, Sharma PN. The NS Matrix System. World J Dent 2013;4(1):4-5.