Change in arch width after extraction and non extraction treatment

The aim of this study was to compare the arch width dimension after extraction and non extraction in pre and post orthodontic treatment. Comparative cross sectional study was carried out in the Orthodontics Department of Alvi Dental Hospital, Karachi, from June to December 2010. Non probability, purposive type of sampling technique was used for data collection. Our sample consists of sixty patients, of which the extraction group was n= 30 [50%] and non extraction group n=30 [50%]. Pre treatment and post treatment intercanine [Anterior] and intermolar [Posterior] arch widths of maxillary and mandibular arch was calculated on cast and compared statistically. In extraction group maxillary intercanine width was 0.70 mm and mandibular intercanine arch width was 0.18 mm larger than non extraction group. In extraction group maxillary intermolar width was 1.65 mm and mandibular intermolar width was 1.3 mm smaller than non extraction group. Extraction treatment did not result in narrower dental arches as compared to non extraction Treatment

Apical gingival margin movement in response to maxillary incisor intrusion with fixed orthodontic therapy

To determine the proportion of apical gingival margin movement in response to maxillary incisor intrusion, with fixed orthodontic therapy, in patients requiring maxillary incisor intrusion. Descriptive study was carried out in the Orthodontics department of Alvi Dental Hospital, Karachi, from June to December 2009. Forty five subjects requiring maxillary incisor intrusion were included in the study, who received 2x2 segmental 17x25 stainless steel archwire therapy, for 3 months. Maxillary incisor intrusion measured on cephalogram, and crown length, measured on cast and clinically, were used to compute the proportion of apical gingival margin movement in response to maxillary incisor intrusion. Out of 45 patients, 20 subjects showed proportion of gingival margin movement in apical direction to be 71 to 80% in response to maxillary incisor intrusion, 18 subjects showed 61 to 70% and 12 patients demonstrated 81 to 90%. The mean reduction in clinical crown length was found to be 0.45 +/- 0.21 mm which was statistically significant [p <0.05]. With maxillary incisor intrusion, the gingiva moves in the same direction as the tooth, yet considerably less. Hence incisor clinical crown reduces in length, resulting in unsatisfactory appearance of anterior teeth. This may indicate the need for gingival correction after intrusion therapy

Changes in skeletal and dental structures after leveling the curve of spee with continuous archwire

To determine the changes in skeletal and dental structures after leveling the curve of Spee with continuous archwire. Descriptive study was carried out in the orthodontics department of Alvi Dental Hospital, Karachi, from June to December 2011. Thirty one subjects requiring orthodontic treatment were included in this study. All patients received fixed appliance therapy and reverse curve continuous archwire for six months. Change in the mean values of L4-MP [measured from cusp tip of the first premolar perpendicular to mandibular plane], L6-MP [measured from cusp tip of the lower first molar perpendicular to mandibular plane], overjet, overbite, L1-APog [measured as the distance of mandibular incisor to the line drawn from point A to pogonion], IMPA [Incisor Mandibular Plane Angle], FOP-MP [measured as Functional Occlusal Plane angle to the Mandibular Plane] and LAFH [Lower Anterior Face Height] were measured on cephalogram and compared to pretreatment values. Mean change in dental variables; L4-MP, overjet, overbite, IMPA, L1-A-pog was significant whereas L6-MP was not significant. Mean change in both the skeletal variables FOP-MP and LAFH was found to be significant. Continuous archwire technique effectively leveled curve of Spee in this sample of Class II Division 1 deep bite patients treated without extraction. Leveling of curve of Spee occurred mainly due to premolar extrusion, mandibular incisor protrusion and raised IMPA to a slightly higher limit from the normal range. In this study leveling curve of Spee with continuous archwire significantly increased functional occlusal plane to mandibular plane and lower anterior face height. Highly significant decreases in overjet and overbite were observed which can also be contributed to leveling of curve of Spee