Treatment change comparisons between skeletal Class I and II white adolescents with 3 different vertical divergencies-Part 2: Holdaway difference.

INTRODUCTION: The Holdaway difference represents the relationship of the NB line to the mandibular incisor (NB-L1) and the bony pogonion (NB-Pog). This study aimed to evaluate treatment changes of NB-L1, NB-Pog, and the Holdaway difference in patients with skeletal Class I and II relationships with 3 different skeletal divergencies. METHODS: This retrospective study was the second part of treatment outcome assessments of 135 white adolescent patients (females, n = 69; males, n = 66; mean age, 12.8 ± 1.4 years pretreatment and 15.0 ± 1.4 years posttreatment). The NB-L1, NB-Pog, and Holdaway differences (NB-L1 - NB-Pog) were measured. The mixed-model analysis of variance was used to assess within- and between-subject effects responding to horizontal and vertical skeletal discrepancies. RESULTS: For the group with favorable profile changes, the means of the Holdaway difference were maintained in the hypodivergent and normodivergent subgroups and reduced in the hyperdivergent subgroups for patients with skeletal Class I and II relationships. The means of NB-L1 and Holdaway difference were significantly larger in the skeletal Class II group and became greater as skeletal vertical divergencies increased. The NB-Pog means were significantly different only between the hypodivergent and hyperdivergent subgroups. CONCLUSIONS: Based on the findings of this study, the Holdaway difference should be adjusted to individualize the incisor positions, considering not only the anteroposterior but also the vertical skeletal relationships of the patients.

Three-dimensional quantification of mandibular asymmetries in Caucasian adult patients with different sagittal and vertical skeletal patterns. A cone beam study using 3D segmentation and mirroring procedures.

INTRODUCTION: An accurate identification of mandibular asymmetries is required by modern orthodontics and orthognathic surgery to improve diagnosis and treatment planning of such deformities. Although craniofacial deformities are very frequent pathologies, some types of asymmetries can be very difficult to assess without the proper diagnostic tools. The purpose of this study was to implement the usage of three-dimensional (3D) segmentation procedures to identify asymmetries at the mandibular level in adult patients with different vertical and sagittal patterns where the asymmetries could go unnoticed at the observational level. METHODS: The study sample comprised 60 adult patients (33 women and 27 men, aged between 18 and 60 years). Subjects were divided into 3 sagittal and vertical skeletal groups. CBCT images were segmented, mirrored and voxel-based registered with reference landmarks using ITK-SNAP® and 3DSlicer® software's. 3D surface models were constructed to evaluate the degree of asymmetry at different anatomical levels. RESULTS: There was a degree of asymmetry, with the left hemimandible tending to contain the right one (0.123 ± 0.270 mm (CI95% 0.036-0.222; p < 0.001). Although the subjects under study did not present significant differences between mandibular asymmetries and their sagittal or vertical skeletal pattern (p = 0.809 and p = 0.453, respectively), a statistically significant difference has been found depending on the anatomical region (p < 0.001; CI95%=1.020-1.021), being higher in the condyle, followed by the ramus and the corpus. CONCLUSIONS: Although mandibular asymmetries cannot be correlated with vertical and sagittal skeletal patterns in symmetric patients, knowledge about 3D segmentation procedures and color maps can provide valuable information to identify mandibular asymmetries.

World Federation of Orthodontists guidelines for postgraduate orthodontic education.

Advanced dental education programs in orthodontics and dentofacial orthopedics require an extensive and comprehensive evidence-based experience, which must be representative of the current didactic and technical advancements. Over the past 25 years, the World Federation of Orthodontists (WFO) has placed emphasis in the support for the recognized orthodontic specialty training programs in every region of the world. In its early years, the WFO developed general principles for specialty education that culminated in the first comprehensive curriculum recommendations, i.e., the WFO Guidelines for Postgraduate Orthodontic Education, which was published in February 2009. In view of the significant changes in the specialty of orthodontics, the WFO has revised and updated its previous document to reflect the expanded scope and demands of current orthodontic education and practice. The members of the task force participated in a thorough revision of the guidelines and created a new document that takes into consideration the didactic, clinical, and the appropriate physical facilities to provide clinical care, study, and research areas. Although it is recognized that there will be variations in teaching and faculty assets, as well as facilities, access to materials, and equipment, the aim of the WFO Educational Guidelines is to provide the minimum program requirements necessary to provide orthodontic specialty residents the educational experience that prepares them to deliver the best level of orthodontic treatment for their patients. It is recommended that these guidelines be used universally by orthodontic specialty program educators and related educational, scientific, and administrative institutions to evaluate and compare their curriculum to a world standard.

Orthodontic board certifications: Global perspectives, challenges, and evolving trends.

The Society of Orthodontic Specialty Certifying Boards aims to encourage the formation of new certifying orthodontic boards worldwide and stimulate existing orthodontic certifying boards to review and revise their certification process. The main goal of Society of Orthodontic Specialty Certifying Boards is to motivate more orthodontists to become board certified by demonstrating their skills through time to protect the public and the specialty from unqualified practitioners. This article identifies the existing barriers in board certification and suggests a scenario-based clinical examination.

American Board of Orthodontics: Progress of the scenario-based clinical examination.

In 2017, the directors of the American Board of Orthodontics (ABO) decided to move forward with a new clinical examination format-a scenario-based examination. The first examination of this type was administered in February 2019, and 2 more exams have been given since then. Each examination consisted of at least 6 scenarios with 4-7 questions for each scenario. Questions came from 4 domains or categories-data gathering and diagnosis, treatment objectives and planning, treatment implementation and management, and critical analysis and outcomes assessment. As of today, 49% of members of the American Association of Orthodontists are ABO certified. For more information about the scenario-based examination and ABO certification or certification renewal processes, go to AmericanBoardOrtho.com.

American Board of Orthodontics: Update on the new scenario-based clinical examination.

The American Board of Orthodontics has updated its clinical examination process to remove barriers to the case-based examination, strengthen the specialty, and further distinguish board-certified orthodontists from other dental practitioners providing orthodontic care. The ABO adopted a scenario-based clinical examination and discontinued case requirements. The first new exam was administered in February 2019. It consisted of 6 scenarios with 4-7 questions for each scenario. The scenarios represent a variety of problems and patients, and the questions relate to data gathering and diagnosis, treatment objectives and planning, treatment implementation and management, and critical analysis and outcomes assessment. Feedback from the February 2019 exam was positive, and 4 more have been scheduled. For more information about the ABO certification process, go to AmericanBoardOrtho.com.

American Board of Orthodontics: Time for change.

The American Board of Orthodontics (ABO) works to certify orthodontists in a fair, reliable, and valid manner. The process must examine an orthodontist's knowledge, abilities, and critical thinking skills to ensure that each certified orthodontist has the expertise to provide the highest level of patient care. Many medical specialty boards and 4 American Dental Association specialty boards use scenario-based testing for board certification. Changing to a scenario-based clinical examination will allow the ABO to test more orthodontists. The new process will not result in an easier examination; standards will not be lowered. It will offer an improved testing method that will be fair, valid, and reliable for the specialty of orthodontics while increasing accessibility and complementing residency curricula. The ABO's written examination will remain as it is.

Comparison of early treatment outcomes rendered in three different types of malocclusions.

OBJECTIVE: To evaluate the outcome of early treatment in Class I, II, and III malocclusions based on the reduction of weighted Peer Assessment Rating (PAR) scores. MATERIALS AND METHODS: Two hundred thirty subjects (female = 105; male = 125) selected from 400 cases were divided into three groups based on their malocclusions (Class I, II, and III). The PAR index was evaluated prior to early treatment (T0), at the end of phase I (T1), and after completion of phase II therapy (T2). The reliability of overall PAR scores was assessed by Bland-Altman plot and intraclass correlation coefficient. The starting age, total weighted PAR scores and their changes after phase I and II treatments, treatment time, and the percentage of correction in the three different malocclusions were assessed by repeated-measures analysis of variance with post hoc analysis. The level of significance was set at P < .05. RESULTS: More than 30% reduction of the weighted PAR scores and less than 10 points of the remaining weighted PAR scores were observed in all malocclusion groups at T1. The Class III group had the highest percentage of correction during phase I treatment. CONCLUSIONS: Early treatment effectively reduced the complexity of Class I, II, and III malocclusions and accounted for 57%, 64%, and 76% of the total correction, respectively, after phase I treatment, as indicated by an overall reduction in weighted PAR scores. The Class III group responded most favorably to early treatment followed by the Class II group.

Common errors observed at the American Board of Orthodontics clinical examination.

The American Board of Orthodontics has developed tools to help examinees select patients to be used for the Board examination. The Case Management Form can be used to evaluate aspects of a patient's treatment that cannot be measured by other tools. The Case Management Form is a structured treatment-neutral assessment of orthodontic objectives and outcomes associated with a patient's treatment. Despite the availability of this form, examiners continue to see problems, including lack of attention to finishing details, inappropriate treatment objectives, excessive proclination of mandibular incisors due to treatment mechanics, excessive expansion of mandibular intercanine width, closing skeletal open bite with extrusion of anterior teeth leading to excessive gingival display, and failure to recognize the importance of controlling the eruption or extrusion of molars during treatment. In addition, some examinees exhibit a lack of understanding of proper cephalometric tracing and superimposition techniques, which lead to improper interpretation of cephalometric data and treatment outcomes.

CBCT assessment of alveolar buccal bone level after RME.

OBJECTIVE: To evaluate the maxillary alveolar buccal bone levels after expansion with banded and bonded expanders, using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The population sample consisted of 22 patients who required expansion during their comprehensive treatment; 10 patients (five males and five females) with a mean age of 13.5 years (CVMS 3) had bonded hygienic expanders, and 12 (six males and six females) with a mean age of 12.6 years (CVMS 3) had banded hyrax expanders. CBCT was taken both before (T1) and 6 months after last activation (T2). Measurements were made for buccal bone thickness (BT), buccal marginal bone level (MBL), and bone thickness level (BTL) at the right first molar (M(Rt)), left first molar (M(Lft)), right first premolar (PM(Rt)), and left first premolar (PM(Lft)). A mixed-design analysis of variance assessed differences between and within the groups. Post hoc t-tests were completed on significant analysis of variance results to determine where differences occurred. RESULTS: Analysis of variance revealed no significant differences between or within the two groups. BT significantly decreased horizontally following rapid maxillary expansion. The amount of bone lost was -0.59 mm M(Rt), -0.72 mm PM(Rt), -0.50 mm M(Lft), and -0.57 mm PM(Lft) (P < .003). CONCLUSIONS: There was no significant difference between or within the two groups. Buccal bone loss in the vertical dimension (MBL) only showed significance in the banded group for M(Rt) (0.63 mm) and PM(LFt) (0.37 mm) as evidenced by the paired t-test (P < .05).

Treatment effects of the mandibular anterior repositioning appliance in patients with Class II skeletal malocclusions.

OBJECTIVE: To examine the changes produced by the mandibular anterior repositioning appliance (MARA) appliance and compare the treatment effects to an untreated Class II control group. MATERIALS AND METHODS: Thirty consecutively treated patients were matched with an untreated control group. Lateral cephalograms were taken at T1, 5 months pre-MARA (CVMS 2.7); T2, immediately after MARA removal and prior to placement of full fixed edgewise appliances (CVMS 4.2); and T3, at least 2 years after MARA removal and completion of edgewise treatment (CVMS 5.4). The mean age of the MARA patients was 11.9 years for boys and 10.8 years for girls. Repeated-measures analysis of variance (ANOVA) was used to assess if the samples were morphologically comparable at the outset and to test if there were significant differences between the groups for the various increments of change. Given a significant ANOVA, the source of the difference was explored via Tukey-Kramer tests. RESULTS: Restriction of maxillary growth and no significant mandibular growth were observed with the MARA appliance. The Class II correction was obtained mainly by slight maxillary molar distalization and intrusion, in addition to mesial migration of the lower molars and flaring of the lower incisors. No vertical effect was observed with this appliance. CONCLUSION: The MARA appliance was effective in the treatment of Class II malocclusions. Restriction of maxillary growth and dentoalveolar changes in the maxillary and mandibular arches were responsible for the correction of the Class II malocclusion. Significant mandibular growth did not contribute to this correction.

Cone beam computed tomography evaluation of changes in the naso-maxillary complex associated with two types of maxillary expanders.

OBJECTIVE: To test the hypothesis that there were no differences in the skeletal and dental effects of banded vs bonded expanders when evaluated using cone beam computed tomography (CBCT). MATERIALS AND METHODS: The experimental sample consisted of 23 patients: 13 (seven male, six female; mean age  =  12.6 ±1.8 years) and 10 (five male, five female; mean age  =  13.5 ± 2.1 years) treated with banded and bonded maxillary expanders, respectively. CBCT images were taken at T1 (pretreatment) and T2 (immediately after expansion) to evaluate the changes in the naso-maxillary complex. Relationships between and within groups were assessed using analysis of variance. If the results were significant, post hoc t-tests were used to determine where the significant differences occurred. RESULTS: Regardless of the appliance, the maxilla was expanded equally at the level of the canines and first and second premolars. At the level of the first molars, more dental tipping and alveolar bending were evident in the banded expander group. Both appliances equally increased the skeletal and soft tissue dimensions of the nasal cavity and maxillary sinus volume. The posterior airway volume did not significantly change with either method of expansion. CONCLUSIONS: The hypothesis was rejected. Both appliances expanded the maxilla similarly. However, in the banded group, more dental tipping and alveolar bending occurred at the level of the first molars. Maxillary expansion affected the palatal suture and demonstrated anterior and posterior skeletal widening of the nasal cavity, with corresponding soft tissue changes and increased airway volume.

Dentoskeletal effects of functional appliances vs bimaxillary surgery in hyperdivergent Class II patients.

OBJECTIVE: To compare treatment outcomes of growing and nongrowing Class II patients characterized by mandibular retrusion and increased vertical dimension. MATERIALS AND METHODS: Seventeen patients (mean age 9 years 5 months) were treated with a Bionator fabricated with posterior bite block and high-pull headgear, while 15 patients (mean age 23 years 6 months) received Le Fort I osteotomy for maxillary impaction and mandibular advancement. These groups were compared with 17 nontreated control subjects from the Bolton and Michigan growth studies. Lateral cephalograms taken for the functional group at T1 (initial records), T2 (completion of functional appliance treatment), and T3 (completion of comprehensive treatment) were compared with radiographs taken at T1 (initial records), T2 (immediate post surgery), and T3 (1 year post surgery) for the surgical patients. A null hypothesis of no difference in treatment outcomes between the functional and surgical groups was proposed. A mixed-design analysis of variance was used to compare changes within and between groups. Significance was set at P ≤ .002. RESULTS: In the functional appliance group, the mandible showed a more favorable growth direction and rotation. Both groups had stable results over time and finished treatment with similar cephalometric measurements. CONCLUSION: Both the functional appliances and orthognathic surgery resulted in similar dentoskeletal treatment changes. The control groups did not self correct either in the anteroposterior or vertical dimensions.

Long-term dentoskeletal changes with the Bionator, Herbst, Twin Block, and MARA functional appliances.

OBJECTIVE: To determine if the long-term dentoskeletal changes in patients treated with tooth-borne functional appliances were comparable to each other and to matched controls. MATERIALS AND METHODS: The experimental sample consisted of 80 consecutively treated patients who were equally divided into Bionator, Herbst, Twin Block, and mandibular anterior repositioning appliance (MARA) groups. The control group comprised 21 children with untreated skeletal Class II malocclusions. Lateral cephalograms were taken for the treated group at T1 (initial records), T2 (completion of functional therapy), and T3 (completion of fixed appliance therapy). A repeated measure analysis of variance (ANOVA) was used to assess the differences between and within groups. If ANOVA results were significant, Tukey-Kramer tests were used to determine where the significant differences occurred. RESULTS: (1) Temporary restriction of maxillary growth was found in the MARA group (T2-T1). (2) SNB increased more with the Twin Block and Herbst groups when compared with the Bionator and MARA groups. (3) The occlusal plane significantly changed in the Herbst and Twin Block groups. (4) The Twin Block group expressed better control of the vertical dimension. (5) The overbite, overjet, and Wits appraisal decreased significantly with all of the appliances. (6) The Twin Block group had significant flaring of the lower incisors at the end of treatment. (7) Over the long-term, there were no significant soft tissue changes among treated and untreated subjects. CONCLUSIONS: No significant dentoskeletal differences were observed long-term, among the various treatment groups and matched controls.

Long-term stability of Class III treatment: rapid palatal expansion and protraction facemask vs LeFort I maxillary advancement osteotomy.

INTRODUCTION: The aim of this retrospective cephalometric study was 3-fold: (1) to compare the effects and long-term stability of protraction facemask treatment with untreated Class III controls, (2) to compare the long-term stability of early protraction facemask treatment with later surgical maxillary advancement with LeFort I osteotomy, and (3) to determine whether early intervention with protraction facemask is an effective treatment modality or whether surgical treatment after cessation of growth should be advocated. MATERIALS: The sample consisted of 34 consecutively treated white patients with Class III malocclusions characterized by maxillary deficiency. The protraction sample consisted of 17 children (8 boys, 9 girls). The surgical sample consisted of 17 adults (10 men, 7 women). The protraction group was also compared with a control group of white subjects with untreated Class III malocclusions. Lateral cephalograms were taken at T1 (initial records), T2 (end of functional appliance treatment or 2 weeks postsurgery), and T3 (7 years 6 months postprotraction or 1 year 5 months postsurgery). Means and standard deviations were calculated for descriptive cephalometric measurements. ANOVA was used to assess the differences between and within the protraction and surgery groups at T1, T2, and T3. The Tukey studentized range test was performed to determine the source of the difference. In addition, paired t tests were used to compare the differences between the protraction group and the matched controls as well as between the surgery group and the matched controls. RESULTS: In the protraction group, there was continued favorable growth of the maxilla, even after the removal of the protraction facemask. From T2 to T3, the maxilla continued to move anteriorly in the protraction patients more so than in the control groups, which had decreases in the intermaxillary measurements (ANB angle and Wits appraisal) over time. The surgical group remained stable from T2 to T3 in all measurements studied. CONCLUSIONS: The most striking findings of this study were the general similarity between the protraction and the surgical groups at T3 and the overall stability of both treatment modalities over time.

Long-term comparison of treatment outcome and stability of Class II patients treated with functional appliances versus bilateral sagittal split ramus osteotomy.

PURPOSE: The objective of this study was to compare the treatment outcomes and stability of patients with Class II malocclusion treated with either functional appliances or surgical mandibular advancement. MATERIAL: The early-treatment group consisted of 30 patients (15 girls, 15 boys), with a mean age of 10 years 4 months (range, 7 years 5 months to 12 years 5 months), who received either Fränkel II (15 patients) or Herbst appliances (15 patients). The surgical group consisted of 30 patients (23 female, 7 male), with a mean age of 27 years 2 months (range, 13 years 0 months to 53 years 10 months). They were treated with bilateral sagittal split ramus osteotomies with rigid fixation. Lateral cephalograms were taken for the early-treatment group at T1 (initial records), T2 (completion of functional appliance treatment), and Tf (completion of comprehensive treatment). In the surgical group, lateral cephalograms were taken at T1 (initial records), T2 (presurgery), T3 (postsurgery), and Tf (completion of comprehensive treatment). The average times from the completion of functional appliance treatment or surgery to the final cephalograms were 35.8 months and 34.9 months, respectively. A mixed-design analysis of variance was used to compare changes within and between groups. RESULTS: In the functional appliance group, the mandible continued to grow in a favorable direction even after discontinuation of the functional appliance. Both groups had stable results over time. Both groups finished treatment with the same cephalometric measurements. Significant skeletal and soft tissue changes were noted in the treatment groups due to either functional or surgical advancement of the mandible. More vertical relapse was noted in the surgical group than in the functional group. CONCLUSIONS: This study suggests that early correction of Class II dentoskeletal malocclusions with functional appliances yields favorable results without the possible deleterious effects of surgery.