Comparison of transverse maxillary dental arch width changes with self-ligating and conventional brackets in patients requiring premolar extraction - A randomised clinical trial.

OBJECTIVE: The purpose of this study was to evaluate, the change in the transverse maxillary arch dimensions, in patients requiring all first premolar extractions when using Active and Passive Self-ligating brackets, and comparing them with Conventional brackets. MATERIALS AND METHODS: This study was a non-blinded randomised clinical trial, which consisted of 42 patients (21 males and 21 females) within the age group of 16-25 years, having bimaxillary protrusion. They were divided into three groups with 14 patients each. In Group 1 - Conventional brackets (3M Unitek), in Group 2 - Passive Self-ligation brackets: Smart Clip (3M Unitek), and in Group 3 - Active Self-ligation brackets: Empower AO (American Orthodontics) were bonded. All brackets had MBT prescription and 0.02" slot size. Dental study models were taken before the start of treatment and after six months of retraction. Inter-canine and intermolar widths were measured in all the three groups in the above mentioned stages. RESULTS: As compared to Conventional brackets, Self-ligating brackets (Passive and Active) showed greater increase in the transverse arch widths. Furthermore, between Passive and Active Self-ligating brackets, Passive Self-ligating brackets - Smart Clip (Group 2) showed a greater increment in the transverse arch dimensions, with an increase of 4.89mm in the inter-canine width and 3.4mm in intermolar width. CONCLUSION: Significant difference was found between Self-ligating brackets and the Conventional bracket system regarding maxillary arch width dimensional changes. Passive Self-ligating brackets - Smart Clip (Group 2) showed the highest and inter-molar width increase.

Management of unilaterally impacted multiple posterior teeth: a case report.

INTRODUCTION: The impaction of permanent teeth poses a challenge to orthodontists, especially when posterior teeth are involved. Multiple impacted posterior teeth without associated with systemic conditions/syndromes is an uncommon clinical occurrence which leads to a posterior open bite and severely compromised function. AIM: The present article reports the clinical management of an impacted maxillary second premolar, mandibular premolars and mandibular first and second molars on the right side. METHOD: The premolars were guided into occlusion by orthodontic traction. Disimpaction and uprighting of the mandibular first molar were achieved using a Begg uprighting spring while a T-loop was used to correct the second molar. Absolute anchorage in the form of miniscrews was not required as anchorage demands were minimal. The total treatment time was 24 months. RESULTS: Orthodontic mechanics resolved a demanding clinical problem and eliminated the need for prosthetic replacements. An acceptable occlusion with a Class I molar relationship, normal function and a healthy periodontium were achieved. CONCLUSION: The results indicated the benefits of uprighting multiple impacted teeth through orthodontic treatment.

Skeletal maturation evaluation using mandibular second molar calcification stages.

OBJECTIVE: To investigate (1) the relationships between the stages of mandibular second molar calcification and skeletal maturity; and (2) whether second molar calcification stages can be used as a reliable diagnostic tool to determine skeletal maturity. MATERIALS AND METHODS: Samples were derived from panoramic radiographs and lateral cephalograms of 300 subjects (137 males and 163 females) with ages ranging from 9 to 18 years, and estimates of dental maturity (Demirjian Index [DI]) and skeletal maturity (cervical vertebrae maturation indicators [CVMI]) were made. RESULTS: A highly significant association (C*  =  0.854 for males and 0.866 for females) was found between DI and CVMI. DI stage E corresponded to stage 2 of CVMI (pre-peak of pubertal growth spurt) and DI stages F and G corresponded to stages 3 and 4 of CVMI (peak of pubertal growth spurt). DI stage H was associated with stages 5 and 6 of CVMI (end of pubertal growth spurt). CONCLUSION: A highly significant association exists between DI and CVMI. Mandibular second molar DI stages are reliable indicators of skeletal maturity.

Prevalence of tooth size discrepancy among North Indian orthodontic patients.

OBJECTIVE: To determine the prevalence of tooth size discrepancy (TSD) in a representative orthodontics population, to explore how many millimeters of TSD is clinically significant and to determine the ability of simple visual inspection to detect such a discrepancy. MATERIALS AND METHODS: The sample comprised 150 pretreatment study casts with fully erupted and complete permanent dentitions from first molar to first molar, which were selected randomly from records of the orthodontic patients. The mesiodistal diameters of the teeth were measured at contact points using digital calipers and the Bolton's analysis was carried out on them. Simple visual estimation of Bolton discrepancy was also performed. RESULTS: In the sample group, 24% of the patients had anterior tooth width ratios and 8% had total arch ratios greater than ±2 standard deviation (SD) from Bolton's means. For the anterior analysis, correction greater than ±2 mm was required for 24% of patients in the upper arch or 14% in the lower arch. For the total arch analysis, correction greater than ±2 mm was required for 36% of patients in the upper arch or 32% in the lower arch. CONCLUSION: Bolton's analysis should be routinely performed in all orthodontic patients and the findings should be included in orthodontic treatment planning. 2 mm of the required tooth size correction is an appropriate threshold for clinical significance. Visual estimation of TSD has low sensitivity and specificity. Careful measurement is more frequently required in clinical practice than visual estimation would suggest.