comparative study of dentoskeletal changes following orthodontic treatment with first premolar extraction in long face and normal patients

The purpose of this study was to evaluate vertical facial and dental changes after orthodontic treatment with extraction of first four premolars, and to find whether long facial height could influence the treatment result. Fifty-six orthodontic patients with the minimum age of 15, whose treatment plan involved extracting four first premolars, participated in the study. The patients included 30 females and 27 males. Cephalometric measurements before and after treatment were compared using a paired T-test. Independent T-test was employed to compare post treatment changes for each parameter between normal and long face groups. The same analysis performed between male and female subjectsTreatment changes revealed a significant increase in the vertical distance from the upper molar to palatal plane, the lower molar to mandibular plane and Menton to palatal plane in all groups. There was significantly more increase in most post-treatment linear measurements in males than in females, with the same direction in both genders. There were no significant differences between normal and long face in any measurement. All patients showed some extrusion of the molar teeth after extraction of the premolars. The difference between normal and long face groups was not significant

Smile analyzer: a software package for analyzing the characteristics of the speech and smile

Taking into account the factors related to lip-tooth relationships in orthodontic diagnosis and treatment planning is of prime importance. Manual quantitative analysis of facial parameters on photographs during smile and speech is a difficult and time-consuming job. Since there is no comprehensive and user-friendly software package, we developed a software program called [Smile Analyze] in the Department of Orthodontics of Mashhad Faculty of Dentistry for measuring the parameters related to lip-tooth relationships and other facial landmarks on the photographs taken during various facial expressions. The software was designed using visual basic. NET and the ADO. NET was used for developing its Microsoft Access database. The program runs on Microsoft Windows. It is capable of analyzing many parameters or variables in many patients' photographs, although 19 more common variables are previously defined as a default list of variables. When all variables are measured or calculated, a report can be generated and saved in either PDF or MS Excel format. Data are readily transferable to statistical software like SPSS for Windows

Mixed dentition analysis in Iranian population

Tanaka and Johnston have offered a very simple method for estimating mesio-distal width of unerupted canines and premolars; But it seems that these estimations are not appropriate for Iranian population. In this investigation we've tried to offer a new formula to estimate the width of unerupted teeth in Iranians. In this study we measured the size of premolars and canins on 400 dental casts and did a regression analysis to find any correlation between the size of these teeth and four lower incisors. We found that using Tanaka and Johnston analysis in Iranian children, unerupted teeth estimated wider than actual size. This study showed that there was a strong correlation between the width of lower incisors and unerupted canine and premolars of both jaws in Iranian population. As we found Tanaka and Johnson's formula will estimate canines and premolars wider and a new formula is offered for Iranian population

Lateral incisors ratio as a substitute for Bolton index

An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure 24 teeth for each patient routinely. In this research our aim was to find an appropriate substitute for the Bolton ratio. One hundred pairs of dental casts were selected and the mesiodistal width of each tooth was measured by a sharpened gauge. Then correlation between lateral ratio [mesiodestal width of lower lateral incisors/ upper lateral incisors] and Bolton's anterior ratio [AR] and overall ratio [OR] was evaluated by paired T test and regression models. Mean overall ratio was 91:3%, anterior ratio 79.0% and lateral ratio 88.4%correspondingly. No significant difference was found between males and females. A well correlation was found between LR and AR [r=0.70] and OR. Strong correlation between LR and AR and OR was established. Mean value of 88.4% for LR was correspondent to normal Bolton ratios