Does Maxillary Protraction with Alt-RAMEC Protocol Affect Inferior Sclera Exposure? A Controlled 3dMD Study.

OBJECTIVE: The purpose of this controlled retrospective study was to measure and evaluate the inferior sclera exposure changes using 3dMD stereophotogrammetric images in a prepubertal Class III patient sample that underwent maxillary protraction with alternate rapid maxillary expansions and constrictions protocol followed by facemask. METHODS: The study group included 15 prepubertal patients (mean age: 9.85 ± 1.44 years) with Class III malocclusion due to maxillary retrognathism. Nine weeks of alternate rapid maxillary expansions and constrictions protocol was followed prior to 7 months of face mask treatment and 3 months of retention with Bionator. Pretreatment (T0) and post-retention (T1) lateral cephalometric radiographs and 3dMD images were retrieved from clinical archive. The same records were used for a control group of 15 well-matched, untreated patients (mean age: 9.4 ± 0.79 years). The distance between the upper eyelid margin and the lower eyelid margin was recorded as the overall eye height (E), and the distance between inferior limbus and the lower eyelid margin was recorded as inferior sclera exposure (S). The S : E ratio in percentage was calculated. Sella-nasion-A point angle (SNA) was used as the skeletal variable. RESULTS: SNA angle, right S : E, and left S : E changed significantly in both groups at T1-T0. The intergroup comparison was highly significant for SNA angle but was not significant for right and left S : E variables. CONCLUSION: The S : E ratio decreased significantly in both alternate rapid maxillary expansions and constrictions/facemask and the control groups. However, the change in S : E ratio between groups was not significant.

Influence of facial type on attractiveness of vertical canine position from the perspective of orthodontists and laypeople.

OBJECTIVES: To evaluate the attractiveness of changes in vertical position of maxillary canines in frontal smiles of different facial types, and to evaluate the esthetic perceptions of orthodontists and laypeople, and the influence of facial type on these perceptions. MATERIALS AND METHODS: Three adult female volunteers were selected as individuals with normal, vertical, and horizontal growth patterns. Frontal posed smile photographs were digitally altered by adjusting vertical positions of the maxillary canines above, below, or coincident with the incisal line in increments of 0.5 mm within a range of 1 mm of extrusion and intrusion. For assessment, a web-based survey was formed with 18 images (six images for each model). A scale was present underneath each image, graded from 0 to 10 (0: unattractive; 10: the most attractive). Images were rated by 233 participants (105 orthodontists; 128 laypeople). RESULTS: Orthodontists scored 0-mm images significantly as the highest in all groups. Laypeople scored significantly higher for -0.5 mm images regardless of facial type. The lowest scored images were -1 mm (except for horizontal pattern) and +1 mm images. Mean values of scores given by men were higher (P < .05). CONCLUSIONS: Orthodontists favored ideal dental alignment and preferred the incisal edges of central and canine teeth to be at the same level. Laypeople preferred a smoother smile arc than orthodontists and found harmony with the soft tissue more attractive. Facial type affected perceptions of the vertical changes of maxillary canines.

Scleral exposure changes after Le Fort I maxillary advancement with vertical component in individuals with skeletal Class III malocclusion-A stereophotogrammetric image study.

OBJECTIVE: This retrospective study aimed to evaluate inferior scleral exposure changes in Class III patients that underwent orthognathic surgery with Le Fort I osteotomy with and without vertical displacement. MATERIALS AND METHODS: Preoperative and 6 months postoperative cephalograms and stereophotogrammetric images of 45 subjects (mean age: 21.66 ± 2.97 years) who underwent orthognathic surgery for Class III correction were retrieved. Subjects were divided into 3 groups: maxillary advancement-only (AO), maxillary advancement + impaction (AI) and maxillary advancement + downfracture (AD). Exclusion criteria were mandibular-only surgery, occlusal canting, facial asymmetry, orbital surgery and craniofacial syndrome. One investigator measured inferior scleral exposure on both sides using following landmarks: upper eyelid margin (A), inferior limbus (B) and lower eyelid margin (C). Distance between A and C was recorded as overall eye height (E), and distance between B and C was recorded as inferior sclera exposure (S). S:E ratio in percentage was calculated to standardize sclera exposure relative to overall eye height. Wilcoxon signed-rank and Kruskal-Wallis tests were used for statistical analysis (P < .05). RESULTS: Mean value of maxillary movements was as follows: 4.21 ± 1.82 mm advancement in AO, 5.08 ± 2.18 mm advancement and 2.33 ± 0.99 mm impaction in AI, 3.95 ± 1.45 mm advancement and 3.1 ± 0.71 mm downfracture in AD. Change in reduction of scleral exposure was significant in all groups (P < .05). AI group bilaterally and AO group right side had highest differences (-4.96 ± 4.86, -6.09 ± 4.21, -4.99 ± 3.23, respectively). There was no significant difference between groups in S:E ratio changes (P > .05). CONCLUSION: Intergroup comparisons showed no statistically significant difference, revealing similar reduction in all three groups despite the differences in the vertical movement variable.

Does Alt-RAMEC protocol and facemask treatment affect dentoalveolar structures?

OBJECTIVES: To evaluate dentoalveolar changes immediately after the alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol and facemask (FM) treatment using cone-beam computed tomography images. MATERIALS AND METHODS: Cone-beam computed tomography images of 20 patients (mean age = 9.64 ± 1.3 years) who received the Alt-RAMEC protocol before FM treatment were retrieved in this retrospective study. Dental and alveolar inclinations, buccal and palatal alveolar bone thickness, and buccal and palatal alveolar bone height changes were measured before treatment (T0), after the Alt-RAMEC protocol (T1), and after FM treatment (T2). Measurements for right and left molars were performed separately. The Shapiro-Wilks test was used to assess the conformity of the parameters to the normal distribution. The paired t-test and repeated measures analysis of variance were used for normally distributed data. The Wilcoxon signed-rank test and Friedman test were used for non-normally distributed data. The Bonferroni correction was used to reduce the chances of obtaining false-positive results. Statistical significance was set at P < .05. RESULTS: Buccal alveolar bone thickness and alveolar bone inclinations decreased significantly from T1 to T0 and showed no significant change from T2 to T1. The total reduction T2-T0 was statistically significant. The change in palatal alveolar bone thickness was not significant T1-T0 but increased significantly for T2-T1 and T2-T0. Buccal alveolar bone height, palatal alveolar bone height, and molar inclinations increased significantly T1-T0, but there was no significant change T2-T1. The total reduction at T2-T0 was statistically significant. CONCLUSIONS: The results of this study revealed that the effects of the Alt-RAMEC protocol on dentoalveolar tissues were similar to the changes reported in the literature after rapid palatal expansion.

Evaluation of the Relationship Between Midpalatal Suture Maturation Indicators as Predictors for Surgically-Assisted and Conventional Rapid Maxillary Expansion.

ABSTRACT: Rapid maxillary expansion (RME) is an effective orthopedic procedure to correct maxillary transversal deficiency in young patients. In cases of sutural closure, surgically assisted RME is used to reduce the resistance to sutural disjunction. Foundation of a diagnostic relationship between maturation indices and the expected skeletal response to expansion can enable clinicians to identify the need for surgically assisted RME prospectively. The primary aim of this study was to assess the correlation between the amount of achieved skeletal expansion with midpalatal suture density on computed tomography images, and the secondary aim was to assess the correlation between the amount of achieved skeletal expansion with the recently suggested midpalatal suture maturation indicators: cervical vertebral maturation (CVS), midpalatal suture maturation stage (MPSM) and midpalatal suture density ratio. Forty Digital Imaging and Communications in Medicine data from the archived computed tomography scans of 20 patients (mean age: 15.55 years) before RME (T1) and after 3-month retention period (T2) were analyzed. The tested maturity indicators did not show statistically significant correlation between the skeletal effect proportions. However, clinically and radiologically effective RME was seen in MPSMs A, B, and C and also cervical vertebra stages CVS5 and CVS6. More research is needed to determine a diagnostic predictor for the skeletal effects of maxillary expansion treatment modalities.

Treatment outcome and long-term stability of class II correction with forsus fatigue resistant device in non-growing patients.

OBJECTIVES: Forsus™ Fatigue Resistant Device (FRD) is one of the commonly used semirigid fixed functional devices. Purpose of the present study was to investigate effects and long-term stability of Class II correction following use of Forsus FRD in a retrospective clinical study. SETTING AND SAMPLE POPULATION: Records of 20 patients (mean age 18.3 ± 2.5 years) with Class II malocclusion, who had undergone fixed functional treatment protocol with Forsus FRD, were collected from our clinical archive. MATERIALS AND METHODS: Lateral cephalometric radiographs at pre-treatment (T0), end of comprehensive treatment (T1) and post-retention period (T2, mean duration: 19 ± 3 months) were analysed and superimposed to assess skeletal and dental changes on the long-term. Repeated measurement one way ANOVA was used for the study of the significant differences among the mean values of cephalometric parameters at T0, T1, and T2. To analyse the nature of the bilateral significant differences between two different time points, Bonferroni test was used. RESULTS: Sagittal and vertical skeletal changes at T0-T1 were statistically insignificant while all dentoalveolar parameters exhibited highly significant changes. At T1-T2, all skeletal and dentoalveolar parameters were stable except the slight relapse in overjet (0.3 ± 0.5 mm; P < .05). At T0-T2 interval, no significant skeletal changes were recorded while the dentoalveolar changes remained significantly improved. CONCLUSION: Correction of Class II malocclusion achieved with Forsus FRD was dentoalveolar and treatment effects were stable in the 19 ± 3 months follow-up period.

Evaluation of Hyoid Position and Retroglossal Airway After Mandibular Alveolar Archwise Distraction Osteogenesis.

The interaction between form and function in the craniofacial region is a well-accepted fact in orthodontics. The aim of the present study is to objectively evaluate if mandibular sagittal symphyseal distraction causes an increase in the retroglossal airway size and hyoid position in a retrospective clinical study. The pretreatment (T0) and 3 months post-distraction (T1) cone-beam computed tomography images of 12 patients (mean age 17.1 years) were retrieved. The retroglossal airway volume and hyoid-mandibular plane distance, hyoid-C3 distance, sella-nasion-B point angle angle, lower incisor to mandibular plane, and Mandibular plane angles were measured using 3D medical imaging software. The average amount of distraction at the superior border of the bony transport segment was 6.2 mm and 4.4 mm at the inferior border. The changes in retroglossal airway volume (2943.2 mm), incisor to mandibular plane (6.5°), and mandibular plane (2.1°) were significant. The changes in hyoid-mandibular plane distance and hyoid-C3 distances were not significant. However, a downward repositioning in Hyoid position was observed along with the mandibular clockwise rotation. This study showed that symphyseal dentoalveolar distraction osteogenesis, as a complementary to orthodontic therapy, can affect the form and size of the pharynx. Therefore, the airway size should be one of the diagnostic and decisive factors for an ideal treatment planning.

In-vitro evaluation of the effects of insertion and sterilization procedures on the mechanical and surface characteristics of mini screws.

PURPOSE: The aim of the present study was to investigate the effects of insertion and sterilization on primary stability and to examine the mechanical and surface characteristics of mini screws. MATERIALS AND METHODS: 140 miniscrews (70 Dual-Top; 70 Ortho-Easy) were divided into 3 groups. Group 1: control group, 10 miniscrews of each brand, evaluated without any primary procedure. Group 2: 30 miniscrews of each brand, each inserted into the sawbone once, then sterilized and tested. Group 3: 30 miniscrews of each brand, each inserted into the sawbone twice, sterilized after each insertion and then tested. The miniscrews were evaluated for changes in primary stability, mechanical and surface characteristics with scanning electron microscopy (SEM) analysis, torsion tests, maximum insertion-removal torques and vertical-horizontal pull out strength tests. RESULTS: The maximum insertion torque values of the unused miniscrews (Group 1) were found to be significantly higher than those of the reused (Groups 2, 3) mini screws (p<0.05). Removal torque, vertical-horizontal pull-out strength and torsional strength value changes were found to be statistically insignificant. In SEM analysis, wear and atrophy were seen on the threads of used miniscrews especially in the apical region and the oxide layer was seen to have disappeared from some regions of the coated miniscrews. CONCLUSION: Although wear and atrophy were detected in SEM analysis of used miniscrews, the overall primary stability and fracture torque resistance tests did not show any significant changes after the first and second insertion and sterilization procedures.

Is Counterclockwise Rotation With Double Jaw Orthognathic Surgery Stable in the Long-Term in Hyperdivergent Class III Patients?

PURPOSE: To evaluate the long-term postsurgical stability of counterclockwise rotation of the occlusal plane (OP) in double-jaw orthognathic surgery in patients with hyperdivergent Class III malocclusion. MATERIALS AND METHODS: This retrospective cohort study evaluated the postsurgical stability of orthognathic surgery in patients with skeletal Class III malocclusion and counterclockwise rotation of the maxillomandibular complex with an OP change of at least -2°. Patients were evaluated with lateral cephalometric analysis before surgery, immediately after surgery, and at longest follow-up. The primary predictor variable was the change in angle of the OP and the Frankfort horizontal (FH) after surgery. The primary outcome variable was stability of the OP at longest follow-up. Other study variables were age, gender, and the following cephalometric measurements: mandibular plane angle; gonial angle; angle formed by the sella, nasion, and B point; maxillary height; angle of the palatal plane to the line connecting the sella and nasion; and distances of the posterior nasal spine and A point to the FH and of the A point to the vertical line passing from the nasion. The Mann-Whitney U test was used to compare stability between groups because the variables were not normally distributed. Bonferroni correction was used to evaluate P values. The χ2 test and Fisher exact test, where appropriate, were used to compare the proportions of groups. A P value less than .05 was accepted as statistically significant. RESULTS: The sample was composed of 15 adult patients (mean age at surgery, 23.5 yr; 40% men). The median duration of follow-up was 48 months (interquartile range, 36 to 60 months). The groups had similar demographic properties and similar surgical changes. Ten patients showed very stable results with an OP-FH change no greater than 1°. Four patients showed unstable results with an OP-FH change of 2.25 ± 0.5° during the follow-up period. The change in the mandibular plane angle was notable between patients with stability and those with instability, which was the variable most affected by relapse of the OP. CONCLUSION: This study found long-term postsurgical skeletal stability of counterclockwise rotation of the OP during double-jaw orthognathic surgery in patients with high angle Class III malocclusion after a median follow-up of 48 months.

Direct usage of miniscrew anchorage to intrude overerupted maxillary posterior teeth before prosthodontic preparation: a case report.

Overeruption of maxillary molars due loss of opposing teeth creates occlusal and functional interferences. Before reconstruction can be initiated, intrusion of overerupted molars becomes essential. This report illustrates treatment of overerupted maxillary premolar and molar via direct use of miniscrew anchorage. A 24-year old female had lost first and second left mandibular molars due to pulpal necrotizing agents, resulting with a large alveolar bone defect and overerupted maxillary premolar and molar. She had a history of unsuccessful alveolar distraction of mandibular left premolars to increase the alveolar bone height prior to implant placement. Patient was satisfied with her smile and refused comprehensive orthodontic treatment. Maxillary premolar and molar were intruded segmentally for 4mm in 8 months, using a combination of a mini-implant and partialfixed edgewise appliances. Biological responses of teeth and surrounding bony structures to intrusion appeared normal and acceptable in radiographic and clinical examination.

Hounsfield Units: a new indicator showing maxillary resistance in rapid maxillary expansion cases?

OBJECTIVE: To determine if density measurements of several maxillary regions in Hounsfield Units (HU) and outcomes of rapid maxillary expansion (RME) are correlated. Is correlation powerful enough to give us direct information about maxillary resistance to RME? MATERIALS AND METHODS: Twenty-two computed tomographic (CT) scans (14 years) are used in this archive study. Two CT records were collected, one before RME (T1) and one after 3 months of retention period (T2). Maxillary measurements were made using dental and skeletal landmarks in first molar and first premolar slides to measure the effects of RME. Density of midpalatal suture (MPSD) and segments of maxillary bone is measured in HU at T1. Correlation analysis was conducted between density measurements and maxillary variables. Regression analysis was then performed for variables that showed positive correlation. RESULTS: There was no correlation between density and skeletal measurements. Intermolar angle (ImA) in molar slice showed statistically significant correlation with density measurements. The ImA variable showed the highest correlation with MPSD in frontal section (r  =  0.669, P < .01). CONCLUSIONS: There is correlation of 32.1-43.3% between density measurements and ImA increase. Our density measurements explain a certain percentage of ImA increase, but density is not the only and definitive indicator of changes after RME.