Dental Crowding Research Paper

Introduction

Crowding within the dental arch is a common symptom found in most orthodontically treated patients. Therapy options include conservative methods such as the distalisation of molars or the transversal expansion of the dental arch as well as the extraction of permanent teeth [1]. Whereas the extraction of carious teeth to solve space problems within the dental arch was proposed as early as 1771 by John Hunter [2], the benefits and necessity of systematic extractions of healthy and sound premolars as enforced by Begg, Jarabak and Tweed [3] are still a matter of controversy. Within the last decades, the indication of extraction treatment has come to be based on the individual situation of the patients [4]. The decisive criteria are

In 80 % of orthodontic patients, this occurs predominantly in the canine region [9] and is mainly treated by a symmetric extraction of the first or second premolars in all four quadrants [10]. Additional indications are a distinct sagittal overbite due to severe proclination of the upper incisors, which can be reduced by the space gained after premolar extraction [8], as well as a severe open bite situation.The relative contraindications of extraction treatment are considered to be deep bite, horizontal growth type as well as a concave lip profile and a prominence of the nose. This consensus is founded on the general belief that loss of vertical dimension and a negative impact on facial profile have to be expected after premolar extractions

All the subjects have had labial orthodontics with 0.022” slot. Space closure was performed throughout with sliding mechanics using the MBT system (buccal braces, 0.022″ slot) in combination with a rectangular archwire of 0.019″ × 0.025″. At the end of orthodontic treatment, the vertical overbite was measured from the models to compare the effects of extraction/non-extraction treatment and to evaluate the changes that transpired from baseline to follow-up exam for both groups. Vertical overbite was measured as the Vertical distance between the incisal ridges of the most anteriorly positioned maxillary and mandibular incisors.( Fig 1 and 2)

STATISTICS

All analyses were carried out using the Statistical Package for Social Sciences 19.0 (IBM Corporation, Armonk, NY, USA). Descriptive statistics were calculated as mean and standard deviation. Two-sided, independent t tests were carried out to compare thevalues of parameterat the beginning and end of orthodontic treatment