Posttreatment Lateral Cephalometric Radiographs Research Articles

Comparing the efficiency of maxillary protraction using digital cooperation monitoring in ages 4–7 and 8–11: a prospective study

Abstract Objectives This study compares the effectiveness of face mask therapy applied after rapid maxillary expansion (RME) in 4- to 11-year-old patients with objective co-operation data collected using thermal sensors. The null hypothesis was that there would be no difference in the effectiveness of the maxillary protraction. Materials and method Initial and post-treatment lateral cephalometric radiographs were taken of patients with maxillary retrognathia, aged between 4 to 7 years (6.1 ± 1.88, n = 13) and 8 to 11 years (9.4 ± 1, n = 12) of age. An RME was performed for at least 10 days. The face mask protraction force was set to 450 g per side, and the recommended usage was 10 hr per day. TheraMon® microsensors were integrated into the face mask. Results The daily usage was significantly higher in the younger age group (8.9 ± 1.8 hr) compared to the older group (7.1 ± 0.9 hr). The SNA angle, A-Nasionperp (mm), ANB angle, Wits (mm), maxillary depth, ANS-Me (mm), the molar relationship (mm) and overjet (mm) significantly increased in both groups. Co-A (mm), the saddle angle, articular angle and UL-E Line (mm) showed a significant increase only in the older group, while the L1-A/Pg decreased significantly. The SNB angle decreased significantly only in the younger group. There was no statistically significant difference in the delta values between the two groups. Conclusion The null hypothesis was partly rejected since no difference was observed in the examined skeletal and soft tissue parameters.

Evaluation of natural head position changes in the treatment of class II malocclusions with functional appliance

Objectives: The position of the head to the neck is affected by various factors, including respiratory tract features, temporomandibular joint disorders, type of occlusion, and physical aspects. In addition, malocclusion can negatively affect the head-neck position. The present study aimed to evaluate changes in natural head position following treatment of Class II malocclusions with Farmand II functional appliance. Material and Methods: The present study was implemented as a historical cohort with the before and after design. Pre- and post-treatment lateral cephalometric radiographs of 33 skeletal Class II patients treated with the Farmand II functional appliance were included in the present study. The cephalometric analysis was done by tracing the related lines and landmarks. Facial angles and angles determining the natural head and neck position including craniohorizontal, craniocervical, craniovertical (CCV), and cervical curvature (CCI) were measured. Collected data were entered in Statistical Package for the Social Sciences (SPSS)-version 17 software. Paired t-test was used to evaluate the changes in cephalometric indices before and after treatment. P < 0.05 was defined to be statistically significant for all the tests. Results: The results of the present study, showed a significant reduction in the mean values of A point, nasion, B point (ANB) angle and angle of convexity following treatment (P < 0.001); also, Sella-nasion/Odontoid process tangent (SN/OPT) angle showed a substantial decrease in treated patients (P = 0.033), which is indicative of head flexion following treatment. Moreover, the decrease in the mean values of the craniocervical angles, including True vertical line (NL/VER) and Sella-nasion/true vertical line (SN/VER), suggests downward bending of the head in patients treated with this appliance (P-values of 0.029 and 0.012, respectively). The odontoid process tangent/ cervical vertebra tangent (OPT/CVT) angle showed an insignificant increase (P = 0.260). Conclusion: The present study showed that patients treated with the Farmand II functional appliance tend to flex their heads and maintain their cervical vertebra in a more upright and straight position.

Effect of SEC III protocol on upper airway dimensions in growing class III patients: a retrospective study

BackgroundThe primary objective of the study was to evaluate the effects of SEC III (Splints, Class III Elastics, and Chin cup) protocol on the upper airway dimensions using lateral cephalometric radiographs. The secondary objectives were to evaluate the skeletal and dental effects of the SEC III protocol using lateral cephalometric radiographs.MethodsThe pre- and post-treatment lateral cephalometric radiographs of 24 patients treated using the SEC III protocol were used to address the aim of the study. Children in the pre-pubertal (CS-1 or CS-2) or circumpubertal (CS-3 or CS-4) skeletal maturation stage and having class III dentoskeletal malocclusion were included in the study. Patients with a history of previous orthodontic treatment, maxillofacial surgery or trauma, tonsillectomy, adenoidectomy, or craniofacial malformations were excluded. The pre-treatment and post-treatment lateral cephalometric radiographs were traced, then airway measurements, skeletal measurements, and dental measurements were performed. The results were analysed using paired samples t-test or Wilcoxon signed rank test according to the data normality.ResultsData of 6 males and 18 females were analysed (Mean age = 11.21 ± 1.02 years). Duration of active treatment was 5.75 ± 1.03 months. Treatment using SEC III protocol resulted in a significant increase in ANB angle (2.92 ± 1.50 degrees, p < 0.001) and Wits appraisal (3.31 ± 1.99 mm) (p < 0.001). The increase in the mandibular plane angle (0.75 ± 1.42 degrees, p = 0.02) and the maxillary length (2.29 ± 2.69 mm, p < 0.001) was statistically significant. Contrarily, the mandibular length did not change significantly (p = 0.10). The maxillary incisors were significantly proclined (4.38 ± 4.28 degrees; p < 0.001), while the mandibular incisors were significantly retroclined (-5.79 ± 6.21 degrees; p < 0.001) following treatment. The change in the nasopharyngeal airway and the retropalatal airway was not statistically significant. The middle and inferior pharyngeal space (retroglossal airway) significantly decreased by 1.33 ± 1.97 mm (p = 0.003) and 1.96 ± 2.48 mm (p = 0.001), respectively.ConclusionsEarly class III correction using SEC III protocol reduced the retroglossal airway dimensions but did not affect the nasopharyngeal and retropalatal airway dimensions. Correction of the class III dentoskeletal relationship was obtained through both skeletal and dental changes.

Changes in Soft Tissue Variable of Lips Following Retraction of Anterioir Teeth- A Cephalometric Study.

The purpose of this study was to assess the short-term perioral soft tissue variations of the lips before and after treatment cases in 15 patients with bi-maxillary protrusion using treated lateral cephalograms who had already achieved active growth. Fifteen pre-treatment and post-treatment lateral cephalometric radiographs of 18-25-year-old individuals with bimaxillary protrusion treated with all four 1st premolar extractions were accessed from the records. From the reference planes and landmarks, 13 horizontal, 10 vertical, and 2 angular measurements were noted. Statistical comparisons between pre-treatment and post-treatment measurements were measured by a paired t-test to assess the importance of the mean variations at the predetermined significance level. Pearson's correlation coefficient (R) was utilized to assess the strength and significance of the linear relationship between the mean differences for paired (dependent and independent) variables. Pearson's correlation exhibited a noteworthy positive association between the horizontal changes in upper lip position and the horizontal changes of the upper incisor tip point (H-tU1) (R = 0.748), the upper incisor cervical point (H-cU1) (R = 0.707), the lower incisor tip point (H-tL1) (R = 0.839), and the lower incisor cervical point (H-cL1) (R = 0.767). This indicated that upper lip changes are the aftermath of the retraction of the upper and lower incisors in class I bi-maxillary protrusion malocclusion. Thick upper lips showed more retraction of the upper lip in correlation with retraction of the incisors as compared with thin lips. The lower incisor cervical point displayed the strongest association with lower lip retraction.

Effects of Class II elastics during growth on the functional occlusal plane according to skeletal pattern and extraction vs nonextraction.

To investigate the effect of Class II intermaxillary elastics on the functional occlusal plane (FOP) of growing patients. A total of 50 participants aged 11 to 16 years were selected from a university clinic archive >1-year after treatment and after undergoing 6 months of Class II elastic wear, taking pretreatment (T0) and posttreatment (T1) lateral cephalometric radiographs, and consenting to participate at recall (T2). Participants were divided into 3 groups according to skeletal pattern or into 2 groups according to treatment with extraction (E) or nonextraction (NE). Angular changes of FOP relative to the Sella-Nasion (SN), mandibular plane (MP), and Frankfort horizontal (FH) were compared within and between groups. A statistically significant reduction of FOP-SN/FH, but not of FOP-MP, was found from T0-T1-T2 when all patients were grouped together. FOP-SN/MP/FH was significantly the largest in the patients with a hyperdivergent skeletal pattern, but lowest in the patients with a hypodivergent skeletal pattern at T0, T1, and T2 (P < .032). FOP-MP at T0-T2 was statistically larger in group E than in group NE (P < .02). No differences were found for FOP changes (change before treatment minus after treatment and change after treatment minus 1 year after treatment) between different skeletal patterns (P > .433) and treatment groups (P > .193). Use of Class II elastics during the growth period was not found to show adverse effects on FOP rotation. Neither skeletal pattern nor treatment modality differed in the response to Class II elastics with regard to FOP changes. Individual patient growth pattern must be taken into consideration when treatment planning the use of Class II elastics. Orthodontists should take into account individual skeletal and growth patterns while using Class II elastics.

Alveolar cortical plate changes associated with incisor retraction and its influence on the limits of orthodontic tooth movement.

The extent to which the modelling behaviour of the anterior alveolus limits tooth movement remains unclear. Will the labial and lingual cortical plates model as incisors retract, or will they remain unchanged, therefore limiting the extent of possible tooth movement? Pre- and post-treatment lateral cephalometric radiographs of 29 bimaxillary protrusive patients of South Korean descent were examined. Treatment consisted of two premolar extractions in one or both arches with en masse retraction of the incisors using miniscrew anchorage. Pre- and post-treatment measurements of both tooth and cortical plate position were made at various increments along the length of the root and then compared using paired t tests. Despite the use of miniscrew anchorage, the incisors were retracted by controlled tipping. The labial cortical plates in both arches modelled to follow tooth movement. Following retraction of the incisors in the maxilla, the incisor root approached the lingual cortical plate, which remained unchanged. In the mandible, the lingual cortical plate position was unchanged except at the level closest to the cementoenamel junction. The maxillary and mandibular lingual cortical plates did not model to follow the incisor movement while the labial cortical plates did. These findings suggest that lingual cortical plates may act as limitations to planned orthodontic tooth movement.

Cephalometric evaluation of changes in vertical dimension and molar position in adult non-extraction treatment with clear aligners and traditional fixed appliances.

ABSTRACTIntroduction: Orthodontists have been using clear aligners to treat malocclusions, and one potential effect of treatment with orthodontic aligners is the intrusion and/or resists extrusion of the posterior teeth. This “bite-block effect” is primarily anecdotal due to the frequent occurrence of posterior open bites in patients after clear aligner therapy. Objective: The purpose of this study was to compare changes promoted by clear aligners and traditional fixed appliances in cephalometric measurements of the vertical dimension and molar position in adult patients with Class I malocclusion treated with non-extraction. Methods: Pre- and post-treatment lateral cephalometric radiographs of adult patients treated with either clear aligners (n=44) or traditional fixed appliances (n=22) were selected for retrospective analysis. Eight interval measurements and one nominal measurement were evaluated: anterior overbite (OB), mandibular plane angle related to cranial base (SN_MP) and related to Frankfort (FMA), lower molar height (L6H) and upper molar height (U6H), palatal plane to mandibular plane angle (PP_MP), lower facial height (LFH), total facial height (TFH), and posterior open bite (Posterior_OB). A single evaluator traced all cephalographs, and changes in select measures of the vertical dimension were compared within and between groups. Results: OB decreased (1.15 mm) and L6H increased (0.63 mm) in the traditional fixed appliance group. Mandibular plane angles (related to cranial base and to Frankfort) increased (0.43° and 0.53°, respectively) in the clear aligner group, but just FMA showed significant difference between groups (difference of 0.53°). LFH and TFH increased (ranging from 0.52 mm to 0.80 mm) in both groups, with no differences between treatment modality. Presence of visible posterior open bite significantly increased over the course of treatment. OB, FMA and L6H exhibited an interaction between treatment stage (pre- and post-treatment) and modality (clear aligner therapy and traditional fixed appliances), but no interaction among these three variables was found. Conclusions: The evidence does not support the theory that clear aligner therapy produces better vertical dimension control than traditional fixed appliances. Traditional fixed appliance therapy slightly extruded the lower molar, and clear aligner therapy produced a slightly mandibular backward rotation.

Comparison of Ricketts, Pancherz and Centrographic Superimposition Methods in Post-Treatment Assessment of the Effects of Twin Block-Appliance Therapy

Objectives: Aim of this study was to do a comparative post-treatment assessment, using three superimposition methods (Ricketts, Pancherz and Centrographic), in patients with Angle’s Class II Division 1 malocclusion and functional retrusion of mandible following twin block appliance therapy. Methods: In this retrospective cross sectional study, pre and post-treatment lateral cephalometric radiographs of 33 cases were analyzed and compared using Ricketts, Pancherz and Centrographic superimposition methods. Changes were evaluated quantitatively for all three methods using a reference grid. The anteroposterior position of upper and lower centroids with respect to the centroid plane was evaluated. Results: Paired samples t-tests and intraclass correlation coefficient revealed excellent reliability of Ricketts, Pancherz and Centrographic superimposition techniques for all parameters. An advancement of 4.14 + 2.24 and 4.18 + 2.26 in Pancherz, 4.30 + 2.14 and 4.38 + 2.18 in Ricketts and 4.36 + 2.19 and 4.50 + 2.19 in Centrographic superimposition methods was shown by point B and pogonion respectively. The observed advancement of Point B and restriction of mesial movement of upper first molar (U6) was statistically significant for Centrographic method as compared to Pancherz. Advancement of lower centroid was seen in all cases with 72.7% in level with centroid plane and 24.2% within 1mm of it. Conclusions: All three superimposition methods (Ricketts, Pancherz and Centrographic) proved equally reliable in assessing treatment changes following twin block therapy. Forward movement of lower centroid was observed in 100% of the cases indicating true mandibular advancement following twin block appliance therapy in Skeletal Class II Division 1 malocclusions.

A cephalometric comparison of treatment effects and predictors of chin prominence in Class II Division 1 and 2 malocclusions with Forsus fatigue-resistant fixed functional appliance

BackgroundThe aim of this study was to cephalometrically evaluate and compare a treatment protocol in patients with Class II Division 1 (II/1) and Class II Division 2 (II/2), and to pursue predictors of the change in chin prominence. MethodsThis retrospective study included 30 patients with Class II/1 and 25 patients with Class II/2 treated with the Forsus appliance, in combination with fixed appliances. Pre- and posttreatment lateral cephalometric radiographs were collected, and 28 measurements were recorded. A two-sample t test was used for the pretreatment comparison among the two Divisions. Paired t tests were used to evaluate the treatment changes within each group. Analysis of covariance was used to compare the treatment changes between the Divisions after adjusting for the baseline value, age, gender, treatment duration, and time with the Forsus appliance. The Simes multiple testing procedure permitted adjustment for multiple comparisons. Regression analysis was performed to identify predictors explaining the change in chin prominence. ResultsClass II correction occurred in both Divisions, mainly through dentoalveolar effects. There were no significant cephalometric differences found in the mean treatment changes between the Divisions. The pretreatment Gonial angle, molar eruption, lower incisor inclination, mandibular body length, and soft tissue chin thickness had a significant impact on the treatment changes in chin prominence. ConclusionsTreatment with the Forsus in combination with preadjusted fixed appliances leads to a favorable treatment outcome and produces similar treatment changes in both Class II Divisions.

Pharyngeal airway dimensional changes after premolar extraction in skeletal class II and class III orthodontic patients.

OBJECTIVE:To assess and compare the changes in pharyngeal airway space dimensions following orthodontic treatment of skeletal class II and class III facial deformities with premolar extraction.MATERIALS AND METHODS:Sixty pre and posttreatment lateral cephalometric radiographs of patients who underwent fixed orthodontic treatment with premolar extraction were collected. The sample was divided into two groups – 32 patients with skeletal class II and 28 patients with skeletal class III malocclusion. Both groups were subdivided into growing patients (<16 years old) and adults (>16 years old). Nasopharyngeal, palatopharyngeal, and glossopharyngeal airway space dimensions were measured in the pretreatment (T0) and posttreatment (T1) cephalometric radiographs using Dolphin Imaging 11.7 software. Two-way, repeated-measures analysis of variance was used to assess the in-treatment changes.RESULTS:Nasopharyngeal airway dimension showed similar significant increase in class II (P = 0.042) and class III (P = 0.049) patients from T0 to T1, whereas palatopharyngeal and glossopharyngeal dimensions were insignificantly decreased in both groups. However, both malocclusions followed the same pattern of changes in relation to airway dimensions. In addition, no significant statistical difference was found in the airway spaces between growing and adult patients.CONCLUSIONS:Extraction of premolars did not affect the pharyngeal dimensions except those of the nasopharynx, which showed a significant increase after extraction in both groups.

Mandibular Incisor Position Changes do not Explain Increase in Keratinized Gingiva Height after Periodontally Accelerated Osteogenic Orthodontics

Purpose This study aimed to reexamine the relationship between mandibular incisor inclination, prominence and vertical changes in position, and keratinized gingival tissue (KT) height changes labial to the mandibular incisors after orthodontic treatment with and without augmented corticotomy (Cort). Materials and Methods Two orthodontically treated groups of 35 individuals each, with (Cort) and without (conventional [Conv]) alveolar decortication and augmentation bone grafting (periodontally accelerated osteogenic orthodontics [PAOO]), were matched for sample size, gender, mandibular premolar extractions, pretreatment age, posttreatment observation period, and pretreatment KT height in this case–controlled retrospective study. Pre- and post-treatment lateral cephalometric radiographs were evaluated for mandibular incisor vertical, inclination, and prominence changes. Results As reported previously (Wilcko 2015), KT height had significantly increased by 0.78 mm (P = 0.001) in the Cort group and decreased by 0.38 mm (P = 0.002) in Conv on an average of 1.5 years after completion of active orthodontic therapy. In this study, Cort mandibular incisors proclined and protruded significantly during therapy while Conv incisors did not. Changes in mandibular incisor inclination and prominence explained neither the decrease in keratinized gingiva height in Conv nor the KT height gain in Cort. Conclusions In spite of mandibular incisor proclination and protrusion, orthodontic therapy combined with alveolar decortication and augmentation bone grafting resulted in a clinically significant increase in keratinized gingiva height 1.5 years’ posttreatment.

Upper airway changes following single-step or stepwise advancement using the Functional Mandibular Advancer.

Purpose of the present study was to determine and compare possible changes in the dimensions of the pharyngeal airway, morphology of the soft palate, and position of the tongue and hyoid bone after single-step or stepwise mandibular advancement using the Functional Mandibular Advancer (FMA). The sample included 51 peak-pubertal Class II subjects. In all, 34patients were allocated to two groups using matched randomization: a single-step mandibular advancement group (SSG) and a stepwise mandibular advancement group (SWG). Both groups were treated with FMA followed by fixed appliance therapy; the remaining 17 subjects who underwent only fixed appliance therapy constituted the control group (CG). The study was conducted using pre- and posttreatment lateral cephalometric radiographs. Data were analyzed by paired t test, one-way analysis of variance, and Pearson's correlation coefficient. In the SWG and SSG, although increases in nasopharyngeal airway dimensions were not significant compared with those in the CG, enlargements in the oropharyngeal airway dimensions at the level of the soft palate tip and behind the tongue, and decreases in soft palate angulation, were significant. Tongue height increased significantly only in the SWG. Compared with the CG, while forward movement of the hyoid was more prominent in SSG and SWG, the change in the vertical movement of the hyoid was not significant. No significant difference between SWG and SSG was observed in pharyngeal airway, soft palate, tongue or hyoid measurements. The mode of mandibular advancement in FMA treatment did not significantly affect changes in the pharyngeal airway, soft palate, tongue, and hyoid bone.

Skeletal and Dento-Alveolar effects of the Rick-A-Nator Appliance in Early Stage Correction of Class II Malocclusion

Aim: The aim of the present study was to evaluate the skeletal and dento-alveolar effects of the Rick-A-Nator appliance in the treatment of growing patients with skeletal Class II malocclusion due to retrusive mandible.Methods: 13 Class II growing patients with mandibular retrusion and between the ages of 9 years and 12 years were selected to be included in this study. Control group for the treated group was generated from growth data of untreated Class II subjects. Pre-treatment and post-treatment lateral cephalometric radiographs were traced and analyzed. Changes in the treated group were compared to those in the control group.Results: The mandibular length was highly significantly increased by 2.44 mm. The mandibular incisors were proclined by distance of 4.54 mm. The overjet was highly significantly reduced by 4.25 mm. The molar relation was significantly corrected by 3.62 mm. While the overbite was reduced from a mean of 75.43% before treatment to a mean of 21.16% after treatment.Conclusions: The Rick-A-Nator appliance was effective in treatment of Class II malocclusion with deficient mandible. Significant reduction of the overjet and the overbite were associated with the Rick-A-Nator treatment.

Soft tissue to hard tissue advancement ratios for mandibular elongation using distraction osteogenesis in children.

Distraction osteogenesis is extensively used for the elongation of hypoplastic mandibles in children, yet the soft tissue profile response to this is not well understood. The pre- and posttreatment lateral cephalometric radiographs of 27 pediatric patients who underwent bilateral mandibular elongation using distraction osteogenesis were analyzed retrospectively to correlate horizontal soft tissue advancement with horizontal underlying bone advancement at B point and pogonion. Horizontal advancement (in millimeters) of bone and overlying soft tissue at these points was collected from the radiographs of each patient, and linear regression analysis was performed to determine the relationship of hard to soft tissue horizontal advancement at these points. A 1:0.90 mean ratio of bone to soft tissue advancement was observed at B point/labiomental sulcus and at pogonion/soft tissue pogonion (linear regression analysis demonstrated slopes [beta1 values] of 0.94 and 0.92, respectively). These ratios were consistent throughout the sample population and are highly predictive of the soft tissue response that can be anticipated. Magnitude of advancement, age, and sex of the patient had no effect on these ratios in our population. This study assists with our understanding of the soft tissue response that accompanies bony elongation during distraction osteogenesis which will allow us to more effectively treatment plan the orthodontic and surgical intervention that will optimize the patients' functional and esthetic outcome.

Severity and outcome assessments of patients undertaking surgical orthodontic treatment

Abstract Background: Combined orthognathic-orthodontic treatment can be lengthy and expensive. It is therefore important to evaluate the effectiveness of proposed treatment and the likely outcomes. Objectives: To determine the demographic and surgical details of patients who received orthognathic-orthodontic treatment at Christchurch Hospital, New Zealand, and to assess treatment using the Severity and Outcome Index (SOI). Methods: An observational and retrospective study was conducted of patients who received surgical orthodontic treatment between 2005 and 2012 at Christchurch Hospital. Pre- and post-treatment lateral cephalometric radiographs of 93 patients were evaluated. Seven cephalometric parameters were assessed using the Severity and Outcome Index. A severity score ranged from 0 for the most severe to 7 for the least severe, while the outcome score ranged from 0 for the worst to 7 for the best outcome. Results: Class II patients had a severity score of 3.4 and the best outcome score of 6.2. Class III patients had a severity score of 3.3 and an outcome score of 6.1. Patients with an anterior open bite (AOB) had the worst severity score of 3.0, and the worst outcome score of 5.9. The overall treatment outcome scores for all groups were statistically significantly greater than the severity scores, which increased from 3.4 to 6.1 (p &lt; 0.05). Conclusions: Favourable outcomes were achieved for a group of patients with a high need for treatment. Christchurch Hospital appeared to be treating cases of increased severity and gained better treatment outcomes when compared with a United Kingdom (UK) national audit.

Changes in the location of the human mandibular foramen as a function of growth and vertical facial type

Objective. A previous cross-sectional investigation showed that the mandibular foramen location depends on the age and the vertical facial pattern of growing individuals. The aim of the present longitudinal study was to explain how these factors influence the distance between the foramen and the occlusal plane. It is known that a certain distance is necessary for a successful inferior alveolar nerve block in clinical dentistry. Materials and methods. This distance, as well as another four cephalometric variables, were measured on both pre-treatment and 10-year post-treatment lateral cephalometric radiographs collected from 50 patients who underwent orthodontic treatment. The changes between these two sets of measurements were also calculated. Results. A multiple regression analysis was performed using the pre-treatment age, the pre-treatment inter-maxillary angle, the rotation of the occlusal plane and the change in mandibular ramus height as independent variables and the change of foramen-occlusal plane distance as a dependent variable. The independent variables under investigation were found to account for more than half of the variability of the foramen-occlusal plane distance (r = 0.732; p < 0.001). Conclusion. In very young individuals the mandibular foramen is located approximately at the level of the occlusal plane. With age it moves upwards relative to the occlusal plane and more so for those individuals with a low anterior facial height (short-face vertical facial type). These observations are, at least, partially explained by the differential growth of the various elements of the maxillo-mandibular complex and the change of the inclination of the occlusal plane.

Cephalometric evaluation of soft tissue changes after extraction of upper first premolars in class ΙΙ div 1 patients.

Introduction: Tooth extraction to provide sufficient space, or camouflage of underlying skeletal problems is quite common in orthodontics. The present study evaluated soft tissue changes after upper first premolars extraction in class ΙΙ div 1 patients. Material and Methods: 20 cases (15 females, 5 males), with a mean age of 17.8±2.9 years with class ΙΙ div1 malocclusion and normal vertical height, who needed upper first premolars extraction were selected. Pre- and post-treatment lateral cephalometric radiographs were digitized. Image analysis was conducted by View Box 3.1.1 software. Paired t-test was used for comparison of pre- and post-treatment results. Results: The relationship of upper and lower lip to E-line and B-line had significant reduction. Dental variables of U1-NA(mm), U1-NA(°), overjet and overbite showed statistically significant reduction. Interincisal angle had significant increase. There were no significant difference in lower incisor variables and skeletal variables like SN-GoGn and FMA. Conclusions: Extraction of upper first premolars in patients with class ΙΙ div 1 malocclusion resulted in normal position of lips as presented by Holdaway, Legan and Ricketts which play a role in aesthetic profile. However, the amount of lip retraction was different from patient to patient. Key words:Soft tissue, fixed orthodontic treatment, class ΙΙ div 1, upper first premolar extraction.

Effects of fixed functional therapy on tongue and hyoid positions and posterior airway

To evaluate how therapy with a fixed functional appliance affects airway dimensions, dentoalveolar changes, and tongue and hyoid positions. A retrospective study was carried out on 46 pre- and posttreatment lateral cephalometric radiographs of 23 post-peak Class II patients (12 girls, 11 boys) treated with a Forsus Fatigue Resistant Device (FRD) appliance. The radiographies were taken at the start and at the end of Forsus FRD appliance therapy when a Class I or overcorrected Class I canine and molar relationship was achieved. The process took an average of 5 months 13 days ± 1 month 4 days. Skeletal and dental parameters were measured using Dolphin software, and the sagittal airway area was measured by AutoCAD software. Analyses of the pre- and posttreatment means revealed that there was no statistically significant skeletal correction of the sagittal malocclusion; increase of lower incisor inclination, decrease of upper incisor inclination, decrease of interincisal angle, and rotation of occlusal plane all contributed to the reduction of overjet. The tongue area and intermaxillary space area increased in response to these dentoalveolar changes; however, there was no statistically significant change in the hyoid position or the oropharyngeal area between the two time points. The dentoalveolar changes produced by Forsus FRD appliance did not cause any significant posterior airway changes in young adult patients.

Midpalatal miniscrews and high-pull headgear for anteroposterior and vertical anchorage control: Cephalometric comparisons of treatment changes

Our aim was to evaluate which anchorage system is better suited for both anteroposterior and vertical anchorage control of maxillary posterior teeth. Fifty-one subjects requiring maximum anchorage were divided into 2 groups according to maxillary posterior anchorage reinforcement: high-pull headgear, conventional transpalatal arch, and interarch elastics (n= 28); or modified transpalatal arch supported by 2 midpalatal miniscrews (n= 23). Bilateral maxillary first premolars were extracted in all patients. Pretreatment and posttreatment lateral cephalometric radiographs were superimposed to compare skeletal and dental changes between the groups. (1) The miniscrew group had less mesial movement of the maxillary first molars (0.85 vs 3.63 mm) and greater maxillary incisor retraction (6.87 vs 4.50 mm) than did the headgear group with the same treatment duration. (2) The maxillary molars were significantly intruded in the miniscrew group (1.30 mm), whereas they were extruded in the headgear group (0.71 mm). In the miniscrew group, intrusion of the maxillary molars resulted in a statistically significant decrease in the mandibular plane angle (0.80°). Patients using high-pull headgear showed no significant decrease in these measurements. In both the anteroposterior and vertical directions, a modified transpalatal arch supported by 2 midpalatal miniscrews provided more stable anchorage.

Comparison of esthetic outcome after extraction or non-extraction orthodontic treatment in class II division 1 malocclusion patients

Introduction:The extraction of premolars as a practical form of orthodontic therapy has been accepted for many years, but there remains a controversy regarding the effect of premolar extraction to improve esthetics as well as dentoskeletal relationship. The esthetic impact of the soft-tissue profile might play a major role in deciding on premolar extraction or non-extraction treatment, particularly in borderline patients. This cephalometric study was undertaken to compare the post-treatment soft-tissue profiles of successfully managed Class II, Division 1 malocclusions treated with either all first premolar extractions or treatment with a non-extraction therapy.Materials and Methods:The sample consisted of 100 post-pubertal female patients of Class II Division I malocclusion. Group 1, treated with four first premolar extractions, consisted of 50 female patients with a mean age of 14 years 1 month. Group 2, treated without extractions, consisted of 50 patients with a mean age of 13 years 5 months. Pre-treatment and post-treatment lateral cephalometric radiographs were evaluated. The pre-treatment to post-treatment stage comparison and the intergroup comparison of the treatment changes were conducted between extraction and non-extraction groups of Class II malocclusion samples with t-tests.Results:The soft-tissue facial profiles of the extraction and non-extraction samples were the same following active treatment except for a more retruded lower lip and a more pronounced lower labial sulcus in those patients subjected to extraction.Conclusions:The extraction or non-extraction decision, if based on sound diagnostic criteria, seems to have no systematic detrimental effects on the facial profile.