Lower facial height treatment changes in bi-maxillary protrusion orthodontic cases

Aim of the study was to investigate the change in lower anterior facial height [LAFH] following 1[st] premolar extraction and incisor retraction in bimaxillary proclination orthodontic cases. 35 patients [M:F ratio 18:17] with bimaxillary protrusion with age ranging from 14-17 years [mean calculated age 15.6 years] were treated with 1[st] premolar extractions followed by retraction of the upper and lower labial segments with fixed orthodontic appliances. Pre and post cephalometric values were recorded for each patient. The skeletal parameters measured were SNA, SNB, ANB, MMA, SN-MP and the facial height ratio. The angular soft tissue parameters measured were the naso-labial and the labio-mental angle to investigate the soft tissue changes compared with lower facial height. Pre and post cephalometric values were calculated separately for each patient and the mean value was calculated. The lower anterior facial height decreased by 3 percent following 1[st] premolar extraction space closure and retraction of the upper and lower labial segments. The naso-labial angle showed 4 degrees mean value change following upper incisor retraction, while the labio-mental angle demonstrated a mean value change of 2 degrees post-treatment. Lower facial height can be altered following 1[st] premolar extractions and incisor retraction in bimaxillary proclination patients with increased anterior vertical discrepancies. Skeletal effects were more pronounced as compared to the overall soft tissue profile changes

Soft tissue changes with retraction in bi-maxillary protrusion orthodontic cases

To investigate the profile soft tissue changes, and associated dental and skeletal effects, in upper and lower incisors following 1[st] premolar extraction and incisor retraction in bimaxillary proclination orthodontic cases. Thirty-five patients [M:F ratio 18:17] with bimaxillary protrusion with age ranging from 14-17 years [mean calculated age 15.6 years] were treated with 1[st] premolar extractions followed by retraction of the upper and lower labial segments with fixed orthodontic appliances. Pre and post cephalometric values were recorded for each patient. The angular and linear soft tissue parameters measured were the naso-labial angle, labio-mental angle and the upper and lower lips distance to Ricketts esthetic plane to investigate the soft tissue changes compared with incisor retraction following treatment. The skeletal parameters measured were SNA, SNB, ANB, MMA, SN-MP and the facial height ratio, while the dental parameters measured were upper incisors to maxillary and SN plane, lower incisors to mandibular plane and the inter-incisal angle. Pre and post cephalometric values were calculated separately for each patient and the mean value was calculated. The upper lip prominence decreased by 3mm while the lower lip retracted by 5 mm following 1[st] premolar extraction space closure and retraction of the upper and lower labial segments. The naso-labial angle showed 4 degrees mean value change following upper incisor retraction, while the labio-mental angle demonstrated a mean value change of 2 degrees post-treatment. The facial soft tissue profile demonstrated both angular and linear changes post-treatment following 1st premolar extractions and incisor retraction in bi-maxillary proclination patients, followed by dental changes while skeletally the lower facial height dimension reduced post-treatment

Bracket de-bonding and breakage prevalence in orthodontic patients

The aim of this study was to investigate the prevalence of orthodontic bracket breakage and de-bonding amongst orthodontic patients at Jinnah Medical and Dental College, Karachi. The study stretched over a 13-month period from April 2008 to May 2009. For this cross sectional study 470 routine patients undergoing fixed orthodontic treatment at the Department of Orthodontics were examined. The male to female ratio was 225:245 with a mean age of 16.4 years. The patients were divided into 4 age groups namely A [8-10 years], B [11-13 years], C [14-16 years] and D [>18 years] respectively. In this study, 150 patients had skeletal class 1, 265 had skeletal class II division one and 55 had skeletal class II division two malocclusions, respectively. All patients were bonded with 3M Transbond XT[TM] light cure orthodontic syringe adhesive system. Prior to bonding, the enamel was polished with 10-15 seconds slurry of pumice paste on slow-speed rotation rubber cup. The teeth were washed and dried, followed by 15-30 seconds enamel etch time per tooth with Coltene Whaledent Swiss-Tec_ 35% ortho-phosphoric acid gel. The results of the present study demonstrated more mandibular dentition bracket de-bonding as compared to the maxillary dentition. Both sexes demonstrated greater lower buccal segment bracket breakage followed by the lower anterior segment, with males having slightly higher de-bonding rate as compared to their female counterparts. Furthermore, the lower age groups demonstrated greater breakage compared to older age groups. It was concluded that both sexes had affinity for bracket de-bonding during active orthodontic treatment especially in the mandibular buccal segments. Teenage subjects had more bracket breakage compared to adults. This could be due to greater self-awareness self-motivation and proper oral care in adults during treatment. However, further studies are required to investigate the reasons for bracket breakage and to compare chemically and light-cured composite systems in orthodontics

Dental maturity amongst various vertical and sagittal facial patterns

To compare the mean dental maturity amongst three vertical facial patterns [short, average and long anterior facial heights] and also amongst two sagittal facial patterns [skeletal class I and II] in orthodontic patients. Cross-sectional analytical study. The Aga Khan University Hospital, Karachi, from August to October 2008. Data was retrospectively retrieved from pretreatment orthodontic records of patients who visited the orthodontic clinic. The sample was divided into three vertical groups, namely short, average and long anterior facial types, and two sagittal groups, namely skeletal class I and II. Dental development was assessed using the Demirjian's system. One way ANOVA and independent sample t-test were used to find any difference in dental maturity amongst vertical and sagittal facial patterns, respectively. There was no statistically significant difference in dental maturity amongst the three vertical facial patterns [p=0.111] and also amongst the two sagittal groups [p=0.975]. Statistically significant gender dimorphism [p < 0.001] was seen amongst boys and girls for dental maturity with girls being more advanced than boys in their dental development. Dental maturation in the three vertical and the two sagittal groups showed no statistically significant difference in our studied population sample and thus need no variations in treatment initiation timings. However, girls should be treated earlier as they are dentally more advanced than boys