Changes In Arch Dimensions Research Articles

Dental Arch Dimension Changes Following Prematurely Extracted Deciduous Molars

The aim was to assess the vertical and horizontal dimensional changes in themaxillary and mandibular dental arches after the unilateral premature loss ofdeciduous molars. Methods: The sample consist of 100 child between 8-9 years of agewith unilateral loss of first or second deciduous molars, either in the maxillary ormandibular arches, Study casts were made and measurements conducted on the Autosketch program on the computer , The data obtained was subjected to statisticalanalysis. The Results of the study showed that when comparing the mean values ofthe loss groups with the control group a statistically significant difference in themaxillary (A) distance after the premature loss of first or second deciduous molars,however a high significant difference statistically in the (ML) distance recorded afterthe premature loss of maxillary second deciduous molar ,while in the mandibular archa statistically high significant difference observed in most of the vertical andhorizontal distances following premature loss of second deciduous molar.Conclusions: The major effect on the dental arch length and width following thepremature loss of the deciduous molars, indicating the need for fitting the spacemaintainers' appliances as soon as the extraction is the final decision to the dentist.

Comparison of arch width and depth changes and pain/discomfort with conventional and copper Ni-Ti archwires for mandibular arch alignment

ObjectiveThe aim of this study was to compare conventional nickel-titanium (Ni-Ti) and copper Ni-Ti archwires in the leveling of mandibular anterior teeth. Materials and MethodsStudy models of 32 patients who received full fixed appliance treatment with 0.022 × 0.028-inch slot self-ligating brackets were analyzed. The copper Ni-Ti group had ligated 0.014-inch Cu-Ni-Ti at T0 (pretreatment) followed by 0.016-inch Cu-Ni-Ti at T1 (2-month interval). In the conventional Ni-Ti group, the archwire sequence involved a conventional 0.014-inch Ni-Ti at T0 and 0.016-inch Ni-Ti at T1. Pretreatment (T0) and posttreatment (4 months after initial treatment) characteristics were recorded from dental casts and included irregularity index, intercanine width, interpremolar width, intermolar width, and canine depth, premolar depth, and molar depth. Each subject was given a specially designed visual analog scale diary, and was asked to complete it over the first month following the first and second arch wires. ResultsThere were no significant differences between the copper Ni-Ti and conventional Ni-Ti groups at 16 weeks in Little's irregularity score changes (P > 0.05). Also, there were no significant differences in intercanine widths, interpremolar width, intermolar width, and depth changes between the copper Ni-Ti and Ni-Ti groups (P > 0.05). Pain score changes between different treatment periods were the same between the copper Ni-Ti and Ni-Ti groups (P > 0.05). ConclusionsCopper Ni-Ti archwires were no more efficient than Ni-Ti archwires in leveling of the mandibular anterior teeth changes in arch dimensions in patients with moderate dental irregularity. Changes in mandibular arch dimensions were similar in the copper Ni-Ti and Ni-Ti groups.

Evaluation of the alignment efficiency of nickel-titanium and copper-nickel-titanium archwires in patients undergoing orthodontic treatment over a 12-week period: A single-center, randomized controlled clinical trial.

ObjectiveThe aim of this trial was to compare the alignment efficiency and intermaxillary arch dimension changes of nickel-titanium (NiTi) or copper-nickel-titanium (CuNiTi) round archwires with increasing diameters applied sequentially to the mandibular arch.MethodsThe initial alignment phase of fixed orthodontic treatment with NiTi or CuNiTi round archwires was studied in a randomly allocated sample of 66 patients. The NiTi group comprised 26 women, 10 men, and the CuNiTi (27℃) group comprised 20 women, 10 men. The eligibility criteria were as follows: anterior mandibular crowding of minimum 6 mm according to Little's Irregularity Index (LII), treatment requiring no extraction of premolars, 12 to 18 years of age, permanent dentition, skeletal and dental Class I malocclusion. The main outcome measure was the alignment of the mandibular anterior dentition; the secondary outcome measure was the change in mandibular dental arch dimensions during 12 weeks. Simple randomization (allocation ratio 1:1) was used in this single-blind study. LII and mandibular arch dimensions were measured on three-dimensional digital dental models at 2-week intervals.ResultsNo statistically significant difference was observed between NiTi and CuNiTi according to LII (p > 0.05). Intercanine and intermolar arch perimeters increased in the CuNiTi group (p < 0.001). Inter-first premolar width showed a statistically significant interaction in week × diameter × application (p < 0.05).ConclusionsThe effects of NiTi and CuNiTi round archwires were similar in terms of their alignment efficiency. However, the intercanine and intermolar arch perimeters, and the inter-first premolar width changes differed between groups.

Dentoalveolar and arch dimension changes in patients treated with miniplate-anchored maxillary protraction.

The aim of this study was to evaluate dentoalveolar and arch dimension changes in 2 miniplate-anchored maxillary protraction protocols in relation to an untreated control group using 3-dimensional digital models. Thirty growing Class III subjects with maxillary deficiency in the late mixed or early permanent dentition phase were randomly divided into 3 groups. In group 1 (n=10), patients were treated with skeletally anchored facemasks anchored with miniplates placed at the zygomatic buttress. In group 2 (n=10), patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. Group 3 (n=10) was an untreated control group. The decision to discontinue orthopedic treatment was made when the patients had 3 to 4mm of positive anterior overjet. Pretreatment, posttreatment, and observation 3-dimensional digital models were analyzed, superimposed, 3 dimensionally mapped, and sectioned. In this study, there were no significant changes in maxillary arch depth and maxillary or mandibular intermolar width before and after maxillary protraction or after the observation period in the control group. The mandibular arch depth decreased by a small but statistically significant amount only in groups 1and 3. Superimposition of the pretreatment and posttreatment or observation maxillary 3-dimensional digital models showed minimal clinically significant dentoalveolar changes. Miniplate-anchored maxillary protraction protocols can accomplish maxillary advancement by eliminating movements of teeth and dentoalveolarchanges. No spontaneous improvement in transverse deficiency was detected after correction of the anteroposterior deficiency at this age. Consequently, patients with transverse maxillary deficiency should have rapid maxillary expansion before or during the miniplate-anchored protraction period to improve the transverse deficiency.

MAXILLARY ARCH DIMENSIONS CHANGES AFTER CORTICOTOMY ASSISTED SLOW MAXILLARY EXPANSION

Objectives: To evaluate the maxillary arch dimensions changes occurring with corticotomy assisted Slow Maxillary Expansion (SME). Materials and Methods: Sixteen patients (4 males and 12 females) requiring maxillary expansion (mean age:19 years; range: 14-24 years) were divided into two groups: Group A: included 10 patients subjected to buccal alveolar corticotomy before SME and Group B:included 6 patients who had only SME.CBCT images were taken at T1(before) and T2 (after). Arch perimeter (AP) and Arch depth (AD) as well as palatal vault height (PVH) were recorded. T-tests (paired, student) determined the significance performed to evaluate the effect of treatment within and between each group. Results: The significant increase in AP by 2.26 mm in corticotomy group and 1.19 mm in control group, significant decrease in AD -0.6 mm and PVH -0.92 mm immediatly post expansion in corticotomy group only. Conclusions: Corticotomy assisted expansion produced a significant changes in arch dimensions

Mandibular arch orthodontic treatment stability using passive self-ligating and conventional systems in adults: A randomized controlled trial

ObjectiveThis randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention.MethodsFortyseven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age 21.58 ± 2.94 years) were randomized into two groups to receive either passive self-ligating (Damon® 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis.ResultsA significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant.ConclusionsThe stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention.

Dental arch dimensional changes after adenoidectomy or tonsillectomy in children with airway obstruction: A meta-analysis and systematic review under PRISMA guidelines.

Children with severe airway obstruction tend to have a vertical direction of growth, class II malocclusion, and narrow arches. Adenoidectomy and tonsillectomy were recommended for the promotion of balanced dentition growth in these children.The aim of this study was to determine the effect of adenoidectomy and tonsillectomy on the growth of dental morphology in children with airway obstruction. A comprehensive search of the Medline, Embase, Web of science, and OVID databases for studies published through to January 17, 2016 was conducted. Prospective, comparative, clinical studies assessing the efficacy of adenoidectomy, or tonsillectomy in children with airway obstruction were included. The weighted mean difference (WMD) and 95% confidence interval (CI) were used for continuous variables. Forest plots were drawn to demonstrate effects in the meta-analyses. Eight papers were included in our study. We found that adenoidectomy and tonsillectomy led to a significant change in nasal-breathing in children with airway obstruction. Children with airway obstruction had a significantly narrower posterior maxillary dental arch than children without airway obstruction (WMD = -0.94, 95% CI [-1.13, -0.76]; P < 0.001). After surgery, these children still had a significantly narrower dental arch than the nasal-breathing children (WMD = -0.60, 95% CI [-0.79, -0.42]; P < 0.001). In terms of dental arch width, malocclusion, palatal height, overjet, overbite, dental arch perimeter, and arch length, a tendency toward normalization was evident following adenoidectomy or tonsillectomy, with no significant differences evident between the surgical group and the normal group. The small number of studies and lack of randomized controlled trials were the main limitations of this meta-analysis. Following adenoidectomy and tonsillectomy, the malocclusion and narrow arch width of children with airway obstruction could not be completely reversed. Therefore, other treatments such as functional training or orthodontic maxillary widening should be considered after removing the obstruction in the airway.

Short- and long-term evaluation of mandibular dental arch dimensional changes in patients treated with a lip bumper during mixed dentition followed by fixed appliances.

To evaluate short- and long-term mandibular dental arch changes in patients treated with a lip bumper during the mixed dentition followed by fixed appliances, compared with a matched control sample. Dental casts and lateral cephalograms obtained from 31 consecutively treated patients before (T0) and after (T1) lip bumper, after fixed appliances (T2), and a minimum of 3 years after fixed appliances (T3) were analyzed. The control group was matched as closely as possible. Arch width, arch perimeter, arch length, and incisor proclination were evaluated. Repeated measures ANOVA was used to analyze changes in measurements over all four time points between treatment and control groups. Arch widths and crowding were always significantly different except at T2-T1. At T1-T0, only crowding decreased 3.2 mm while intercanine, interpremolar, and intermolar widths increased by 3.8, 3.3, and 3.9 mm, respectively. Changes at T3-T2 showed a significant decrease of 2.1 mm for crowding and an increase of 3.5, 2.9, 2.7, and 0.8 mm for intercanine, interpremolar, and intermolar widths and arch perimeter, respectively. Finally, at T3-T0, the reduction in crowding of 5.03 mm was significant and clinically important in the treated group. The differences between intercanine, interpremolar, and intermolar widths were also significant (2.1, 3.8, and 3.6 mm, respectively). All those differences favored the treated group. Mandibular dental arch dimensions were significantly changed after lip bumper treatment. At follow-up, all arch widths were slightly decreased, generating an increase of 0.4 mm in crowding, considered clinically irrelevant. Overall changes remained stable after an average 6.3-year follow-up.

Retrospective investigation of the effects and efficiency of self-ligating and conventional brackets.

The purpose of this retrospective cohort study was to assess the effects and efficiency of self-ligating brackets compared with conventional brackets. A secondary purpose was to identify the pretreatment factors associated with the choice of self-ligating or conventional brackets. The subjects were treated by 2 private practitioners who used both self-ligating and conventional brackets in their practices. The self-ligating subjects were consecutively identified (treatment completed between January 2011 and April 2012), and then an age- and sex-matched control group was chosen from the same office. The outcome measures were changes in arch dimensions, changes in mandibular incisor inclinations, final peer assessment rating (PAR) scores, percentages of PAR reduction, overall treatment times, total number of visits, and number of emergency visits. All cast and cephalometric measurements were performed on digital records in a blinded manner. Two calibrated assessors measured the PAR scores. The final sample comprised 74 patients from clinician 1 and 34 patients from clinician 2. The practitioners had significant differences for several treatment parameters; therefore, the data from the 2 clinicians were analyzed separately. For clinician 1, no significant differences were observed between the self-ligating and conventional groups, other than increased arch length in the self-ligating group. The self-ligation patients treated by clinician 2 demonstrated significant increases in transverse dimensions, lower percentages of reduction in PAR scores, shorter treatment times, fewer visits, and more wire-sliding emergencies than the conventional bracket group. Although some significant findings were observed, the small sample and the lack of consistent findings between the 2 clinicians made it difficult to draw strong conclusions.

Arch-dimensional changes in non-extraction cases with finishing wires of a particular material, size and arch form

Abstract Aim This study was undertaken to assess pre- and post-treatment upper and lower arch dimensions, and changes occurring in those dimensions, during orthodontic treatment without premolar extractions, when finishing wires of a particular material, size and arch form had been used. Methods The records of 58 patients (31 male and 27 female) with a mean age of 13.52 (±1.60) years were selected for this study, with ethics approval gained from the Departmental Human Ethics Advisory Group of the University of Melbourne (DHEAG no: 1033997.1). All patients had been treated with fixed appliances (0.018 inch, pre-adjusted edgewise) in the early permanent dentition, without premolar extractions, by one experienced orthodontist. Pre- and post-treatment upper and lower arch dimensions were measured from study casts. Correlation coefficients were calculated between these measurements as well as pretreatment cast and vertical cephalometric measurements, gender and the amount of crowding that had been relieved. Results Despite the use of finishing archwires of the same material, size and arch form (0.016 × 0.022 inch, heat-treated cobalt-chromium), there was considerable variation in dimensional changes that occurred during treatment within the total sample and its various subgroups, and in the final arch dimensions. All arch width changes were found to be strongly correlated with the amount of pretreatment crowding. Post-treatment arch dimensions and changes in those dimensions were also strongly correlated with pretreatment dimensions, suggesting that the final post-treatment arch dimensions were significantly influenced by other factors rather than simply the material, size and arch form of the finishing wires. In this treated sample, no statistically significant differences were found in the resultant arch widths and arch width changes occurring in the different vertical pattern sub-groups. Conclusion The placement of finishing wires of a particular material, size and arch form is unlikely to result in exactly matching end-of-treatment arch forms and dimensions in all orthodontic patients. Instead, whether using a 0.018 or a 0.022 inch slot system, the clinician should expect considerable individual variation in final arch form and dimension, despite the placement of apparently very similar wires. The main determinants of final arch form and dimension appear to be the original muscular and occlusally-related arch form and dimension and the amount of crowding to be relieved. Final arch forms and dimensional changes with treatment are unlikely to be directly related to patient gender, age or underlying vertical pattern. The findings indicate that clinicians must decide whether they will accept the considerable lateral and antero-posterior expansion that is likely to occur when crowding is to be relieved in the permanent dentition without premolar extractions.

Maxillary Arch Dimension Changes of 3-5 Years Old Filipino Children

Background: The purpose of this study was to assess the dental arch dimensions in primary dentition of 3-5 years old Filipino children and determining the existence of sexual dimorphism. Materials and Methods: In this descriptive study, 60 Filipino preschool children aged 3-5 years old were selected from Manila city. Study casts were used for measurements of 3 arch dimensions: bicanine width, bimolar width, and arch length. The analyses were performed to compare values within age-groups and within gender-groups, besides reporting mean and standard deviations. The data were subjected to One-way ANOVA and Student t-test. Results: Significant differences were observed regarding dental arch dimensions among different ages and genders (p<0.05). Comparison between genders showed a statistically significant difference in bicanine width at the age of 4 (p=0.04), in bimolar width at age of 5 (p=0.006), and in arch length at age of 4 (p=0.03) and 5 (p=0.02). Differences within male group for different ages showed only arch length dimension was statistically significant (p=0.021). In females, however the comparison between age-groups also revealed a statistically significant difference in bicanine (p= 0.016) and bimolar widths (p=0.027) dimensions. Conclusion: The present study showed that dental arch dimensions, vary among different ages and genders of children. It also showed that a sexual dimorphism does exist between the gender groups.

Mandibular arch dimensions following bonded and banded rapid maxillary expansion

BackgroundThe purpose of this study was to examine changes in mandibular arch dimensions of subjects submitted to either bonded or banded maxillary expansion. MethodsThe sample comprised of two groups, one with patients who underwent maxillary expansion with banded, Haas-type expanders, retrospectively selected (banded group), and the other patients carefully matched in sex, age, and malocclusion, prospectively observed with bonded, Hyrax-type expanders (bonded group). Each group was composed of 29 subjects evaluated at T1, before maxillary expansion, and T2, after expansion and stabilization. The mandibular arches were evaluated for changes in arch width, depth, and perimeter. Paired and independent Student's t tests were used to compare groups. ResultsPatients in the banded group experienced significantly more mandibular arch width expansion in the molar region. Both groups experienced a decrease in arch depth; however, the bonded group showed significantly greater loss. ConclusionRapid maxillary expansion is an effective method for achieving a gain in arch width and space in the maxillary arch and, depending on the type of expander, banded or bonded, it produces a different response on an untreated mandibular arch.

A clinical comparison of maxillary expansion: TransForce transverse appliance versus NiTi palatal expander

BackgroundTransForce lingual appliances are a new series of expansion appliances introduced to develop arch form in a more physiologic manner. The aim of the present study was to evaluate and compare the effects of the TransForce transverse appliance (TTA) and the nickel-titanium palatal expander (NPE) on arch development. MethodsTwenty patients (mean age 11.8 years) with skeletal class II malocclusion requiring arch expansion as a part of orthodontic treatment were enrolled. Patients were randomly divided into two groups of 10 each. Study models and lateral cephalograms were obtained from the patients at the beginning of the treatment (T1) and at the end of expansion (T2). Transverse interdental width, skeletal expansion, alveolar tipping, molar rotation, ratio of intercanine to intermolar change, and rate of expansion were analyzed by using study models. ResultsBoth appliances produced significant changes in transverse arch dimensions. Rate of expansion with NPE was significantly greater (P = 0.03). Intergroup comparisons of skeletal expansion, alveolar tipping, molar rotation, and the ratio of intercanine to intermolar change showed no significant differences. ConclusionsBoth appliances were efficient for expanding the maxillary dentition and alveolar process. Both appliances have potential for skeletal expansion. Rate of expansion with the NPE was greater than that with the TTA.

Mandibular Dental Arch Dimensional Changes following Prematurely Lost Deciduous Molars

Mandibular Dental Arch Dimensional Changes following Prematurely Lost Deciduous Molars

Space supervision and guidance of eruption in management of lower transitional crowding: A non-extraction approach

Mandibular incisor crowding in the mixed dentition is one of the most common problems presenting to the orthodontist. Asymmetry of alignment, premature loss of primary canine(s), and disruption in arch integrity are all early benchmarks of a tooth size/arch length discrepancy in the transitional dentition that can occur independent of any skeletal discrepancy. Space supervision and guidance of eruption refer to treatment interventions during the early to mid-mixed dentition periods that influence the eruption patterns and positioning of the permanent teeth during their transition. Generally considered applicable to individuals with adequate overall arch dimensions to accommodate a normal complement of permanent teeth with an acceptable esthetic and functioning occlusion, guidance of eruption involves the implementation of directed interventions to optimize the eruption and alignment patterns of the permanent teeth as part of a non-extraction protocol.

The timing of significant arch dimensional changes with fixed orthodontic appliances: Data from a multicenter randomised controlled trial

ObjectivesTo identify the timing of significant arch dimensional increases during orthodontic alignment involving round and rectangular nickel-titanium (NiTi) wires and rectangular stainless steel (SS). A secondary aim was to compare the timing of changes occurring with conventional and self-ligating fixed appliance systems. MethodsIn this non-primary publication, additional data from a multicenter randomised trial initially involving 96 patients, aged 16 years and above, were analysed. The main pre-specified outcome measures were the magnitude and timing of maxillary intercanine, interpremolar, and intermolar dimensions. Each participant underwent alignment with a standard Damon (Ormco, Orange, CA) wire sequence for a minimum of 34 weeks. Blinding of clinicians and patients was not possible; however, outcome assessors and data analysts were kept blind to the appliance type during data analysis. ResultsComplete data were obtained from 71 subjects. Significant arch dimensional changes were observed relatively early in treatment. In particular, changes in maxillary inter-first and second premolar dimensions occurred after alignment with an 0.014in. NiTi wire (P<0.05). No statistical differences in transverse dimensions were found between rectangular NiTi and working SS wires for each transverse dimension (P>0.05). Bracket type had no significant effect on the timing of the transverse dimensional changes. ConclusionsArch dimensional changes were found to occur relatively early in treatment, irrespective of the appliance type. Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed. Clinical significanceOn the basis of this research orthodontic expansion may occur relatively early in treatment. Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed.

Comparison of maxillary arch dimensional changes with passive and active self-ligation and conventional brackets in the permanent dentition: A multicenter, randomized controlled trial

The purpose of this study was to compare maxillary arch dimensional and inclination changes during alignment with conventional brackets and self-ligation. Ninety-six patients, ages 16 years and above, were included in this multicenter, 3-group parallel randomized trial. The main outcome measures were changes in maxillary intercanine, interpremolar, and intermolar dimensions, and molar and incisor inclination changes. The patients were randomly allocated in permuted blocks of 12 subjects into 3 equal groups with the allocations concealed in opaque sealed envelopes. Each participant underwent alignment with a standard Damon Q (Ormco, Orange, Calif) wire sequence for a minimum of 34 weeks. Blinding ofclinicians and patients was not possible. Data were analyzed on a per-protocol basis, since losses to follow-up were minimal. Complete data were obtained from 87 subjects. Bracket type had no significant effect on any of the transverse dimensional changes. No difference in molar inclination was found between passive self-ligation and conventional brackets (0.67°; 95% CI, -2.24, 3.58; P= 0.65) or active self-ligation (0.91°; 95% CI, -1.95, 3.78; P= 0.53). Similarly, incisor inclination changes with the Damon Q could not be differentiated from those developing with either conventional system (0.44°; 95% CI, -1.93, 2.8; P= 0.71) orIn-Ovation C (-0.22°; 95% CI, -2.58, 2.14; P= 0.85). No harms were encountered. No difference in the arch dimensional or inclination changes during alignment can be expected between conventional brackets and either active or passive self-ligation.

Early Dimensional Changes in Maxillary Cleft Size and Arch Dimensions of Children with Cleft Lip and Palate and Cleft Palate

Objective : To study early changes in cleft size and maxillary arch dimensions and to evaluate these changes in relation to performed surgical procedures. Design : Retrospective longitudinal study. Setting : The Cleft Lip and Palate Center, Uppsala University Hospital, Sweden. Patients : Dental study models of 79 consecutive children (28 with unilateral cleft lip and palate, 39 with cleft palate, and 12 with Pierre Robin sequence) were analyzed. Interventions : Lip repair at 3 to 4months, soft palate repair at 6 to 10months, and hard palate repair at 25 to 26months of age. Main Outcome Measures : Cleft size was measured before each surgical intervention up to 2years and arch dimensions were measured before each surgical intervention and at 5years. Results : Cleft widths decreased from infancy up to 2years, but the anteroposterior cleft length in cleft palate was unchanged. Arch widths between cuspid points (C-C1) and tuberosity points (T-T1) and also the change over time in C-C1 and T-T1 differed significantly between the groups from infancy up to 5years. Conclusions : Cleft widths decreased after lip closure and/or soft palate closure. The children with unilateral cleft lip and palate had wider maxillary arch dimensions than the children with cleft palate or Pierre Robin sequence during the first years of life, but after hard palate closure the transverse growth was reduced in the children with unilateral cleft lip and palate. At 5years the children with unilateral cleft lip and palate had similar maxillary widths as the children with cleft palate and/or Pierre Robin sequence.

Residents' journal review

Residents' journal review

Vertical facial and dental arch dimensional changes in extraction vs. non-extraction orthodontic treatment.

To compare the vertical facial and dental arch dimensional changes occurring with extraction and nonextraction orthodontic treatments. Cross-sectional comparative study. The Aga Khan University Hospital, Karachi during the period 2003 to 2005. Data were collected using records of patients who visited the study setting during the study period. Pre- and post-treatment lateral cephalographs and study casts of 81 orthodontic patients (41=non-extraction and 40=premolar extractions) were taken. Variables used for evaluating vertical dimension were Frankfort mandibular plane angle (FMA), facial height (N-Me), facial height ratio (N-ANS/ANS-Me), soft tissue facial height (G' to Me'), soft tissue facial height ratio (G'-Sn'/zn'-Me'), upper first molar to palatal plane and lower first molar to mandibular plane distance, posterior facial height to anterior facial height ratio (PFH/AFH) and Y-axis. Intercanine, interpremolar and intermolar widths and arch depths were also measured. To evaluate the pre-treatment and posttreatment comparison within each group, paired t-tests were used. For pre- and posttreatment comparisons between the extraction and non-extraction groups, independent sample t-tests were used. The mean age was 15.8+/-1.5 years for non-extraction and 15.4+/-1.2 years for the extraction group. There was no significant difference in the vertical dimensional changes between extraction and non-extraction treatments as it increased in both groups. When comparing posttreatment arch dimensions, there was an increase in the maxillary intermolar width in the non-extraction group while the intermolar widths and arch depths decreased in the extraction group in both arches. Vertical dimensional changes showed no significant difference between extraction and non-extraction groups. Intermolar widths and arch depths decreased in both arches in the extraction group while the maxillary intermolar width increased in the non-extraction group.