Hyperdivergent Class Research Articles

Nonsurgical synergistic full-arch vertical intrusion treatment of bimaxillary protruded hyperdivergent skeletal Class II malocclusion using aligners.

A bone-borne full-arch vertical control strategy using miniscrews was deployed with aligners to treat a case of skeletal hyperdivergent Class II malocclusion with bimaxillary protrusion. Miniscrews were inserted in the posterior buccal and palatal regions and the anterior buccal region of the maxilla to distribute vertical intrusive force through the upper arch by anchoring vertical elastics from the miniscrews to the aligners. Synergetic lower anterior intrusion was completed using bilateral posterior miniscrews to counteract the extrusive force generated. Substantial full upper arch and lower anterior vertical intrusion was achieved. In conjunction with en masse anterior-posterior retraction, synergetic posterior and anterior vertical intrusion facilitated counterclockwise rotation of the mandible, creating significant esthetic improvement. Anterior vertical elastics also provided flaring of the anterior teeth, reducing the side effect of lingual tipping from en masse retraction, while successfully controlling overbite and incisor torque during space closure. The bone-borne full-arch vertical intrusion strategy can work well with aligners to address hyperdivergent skeletal Class II malocclusion with bimaxillary protrusion.

Long-term skeletodental changes with early and late treatment using modified C-palatal plates in hyperdivergent Class II adolescents.

To compare skeletodental changes between early and late treatment groups using modified C-palatal plates (MCPP) and long-term retention outcomes in hyperdivergent Class II adolescents. Seventy-one hyperdivergent Class II patients were divided into four groups according to treatment modality and treatment timing: group 1, early treatment with MCPP (n = 16; 9.9 ± 0.9 years); group 2, late treatment with MCPP (n = 19; 12.3 ± 0.8 years); group 3, early treatment with headgear (HG; n = 18; 9.6 ± 0.8 years); and group 4, late treatment with HG (n = 18; 12.1 ± 1.2 years). Lateral cephalograms were taken and skeletal and dental variables were measured. For statistical analysis, paired t-tests, independent t-tests, and multiple regression were performed. The early MCPP group showed a more significant decrease in mandibular plane angle than the late MCPP group did, and vertical control was more efficient in the early group than in the late group. In the MCPP groups, both FMA and SN-GoGn were increased with late treatment but decreased with early treatment, and the difference was statistically significant (P < .01). The early-treatment MCPP group had a significant decrease in SN-GoGn of 0.6° compared with an increase of 1.7° in the early treatment HG group (P < .01). Posttreatment stability of both the early and late MCPP groups was maintained in long-term retention. Early MCPP showed more significant vertical control than late MCPP. However, there was no difference in long-term stability between early and late groups.

Upper airway sagittal dimensions in children with hyper-divergent class II/1 malocclusion

Upper airway sagittal dimensions in children with hyper-divergent class II/1 malocclusion

Outcome differences after orthodontic camouflage treatment in hypo- and hyperdivergent patients – A retrospective cephalometric investigation

ObjectivesTo compare differences in outcome in skeletal and dental parameters in hypo- and hyperdivergent Class II patients after extraction of upper first premolars and comprehensive orthodontic treatment.Materials and methods37 Class-II-patients with dental camouflage treatment were divided into a hypo- (n = 18) or a hyperdivergent (n = 19) group depending on the mandibular plane angle (hypo: < 34° or hyper: ≥ 34°). Lateral cephalograms were available before (T1) and after (T2) treatment and were analyzed with customized measurements. Data from a growth survey served as a control and were used to calculate the actual treatment effect. Data were analyzed by one-sample Student’s t-tests and independent Student’s t-tests. Statistical significance was set at p < 0.05.ResultsThe measurements showed similar changes in both groups. The effects were mainly dentoalveolar. Hypodivergent patients showed an almost equal increase in anterior and posterior facial height, while hyperdivergent patients only showed an increase in anterior facial height.ConclusionsIn hyperdivergent patients, the anterior facial height increases despite camouflage treatment. This indicates a tendency towards bite opening and backward rotation of the mandible. Hypodivergent patients do not experience deepening of the bite.Clinical relevanceIn hyperdivergent patients with upper first premolars extraction the anterior facial height increased differently than in hypodivergent patients. This should be considered if a bite opening is a possible contraindication to treatment.

Orthodontic Surgical Approach of Severe Skeletal Hyperdivergent Class II Malocclusion Treated by Le-Fort I Osteotomy, BSSO and Genioplasty

Orthodontic Surgical Approach of Severe Skeletal Hyperdivergent Class II Malocclusion Treated by Le-Fort I Osteotomy, BSSO and Genioplasty

The Evaluation of Maxillary Sinus Dimensions in Different Craniofacial Patterns: A Systematic Review and Meta-Analysis.

This systematic review was intended to evaluate the maxillary sinus dimensions in vertical and sagittal craniofacial patterns and to assess if there was a difference among the craniofacial patterns. A systematic search was performed in seven databases till February 2021. The risk of bias was performed with modified Newcastle Ottawa scale. Meta-analysis was performed using random effects model. Twelve studies were included in the review and 8 in the meta-analysis. Compared to Class I malocclusion, the maxillary sinus area is greater in Class II and lesser in Class III malocclusion. On comparing normo-divergent growth pattern, the maxillary sinus area is lesser in hypo-divergent and greater in hyper-divergent individuals. Most of the studies were graded as satisfactory. The measurements are greater in hyper-divergent Class II malocclusion and in males.

Effects of fixed functional orthodontic treatment in hypodivergent and hyperdivergent class II patients—a retrospective cephalometric investigation

ObjectiveTo compare skeletal and dentoalveolar changes after orthodontic treatment of class II malocclusion in patients with hypodivergent and hyperdivergent growth patterns through cast splint fixed functional appliances (FFA).Materials and methodsN = 42 out of n = 47 patients with mandibular plane angles < 34° or ≥ 34° were divided into a hypodivergent (n = 24) and a hyperdivergent (n = 18) group. All patients received a single-step mandibular advancement protocol through an FFA. Lateral cephalograms were analyzed after initial leveling and alignment (T1) and immediately after FFA removal (T2). The therapeutic effect was calculated through comparison with age-matched controls from a growth survey. Statistical significance was set at p < 0.05.ResultsHypodivergent and hyperdivergent patients showed different treatment outcomes, but significant differences existed only for overbite and interincisal angle. Nearly all measurements suggested similar treatment-related changes for both groups with exception for dentoalveolar parameters.ConclusionTreatment with FFA causes similar skeletal and dentoalveolar effects in hypodivergent and in hyperdivergent patients. The correction of overjet and molar relationship is mainly caused by dentoalveolar changes.Clinical relevanceHyperdivergent patients do not respond unfavorably to FFA treatment compared to hypodivergent patients. Lower incisor protrusion occurs more pronounced in hypodivergent patients. The growth pattern ought to be considered when choosing FFA for class II treatment.

ENHANCING SMILE ESTHETICS IN A PATIENT WITH VERTICAL MAXILLARY EXCESS BY TOTAL MAXILLARY ARCH INTRUSION USING TEMPORARY SKELETAL ANCHORAGE SYSTEM

Smile esthetics is a prime concern in contemporary orthodontic therapy. This case report is about a growing female patient with the inability to close the lips, vertical maxillary excess and hyperdivergent class II skeletal pattern. To enhance skeletal therapy benefits , differential intrusion of segments in the upper arch was required. Bilateral Bollard type miniplates were inserted on the infrazygomatic crest . The technique employed helped this patient avoid orthognathic surgery by allowing a complete upper arch intrusion, treating lip incompetence and causing counterclockwise movement of the mandible.

Treatment outcome of class II malocclusion therapy including extraction of maxillary first molars: a cephalometric comparison between normodivergent and hyperdivergent facial types.

The dentoalveolar component of a Class II division 1 malocclusion can be orthodontically treated either with extractions or by distalization of the molars. This study aimed to compare skeletal, dentoalveolar and profile changes in normodivergent and hyperdivergent Class II Division I growing patients orthodontically treated with fixed appliances including maxillary first molar extraction. Sixty-four patients treated orthodontically with full fixed appliances including maxillary first molar extractions were retrospectively analyzed. Patients were divided into a normodivergent group (Group N; 30° ≤ SN^GoGn < 36°) consisting of 38 patients (17M, 21F; mean age 13.2 ± 1.3 years) and a hyperdivergent (Group H; SN^GoGn ≥ 36°) including 26 patients (12M, 14F; mean age 13.7 ± 1.1 years). Lateral cephalograms were available before (T0) and after treatment (T1) and cephalometric changes were calculated for 10 linear and 13 angular variables. The Shapiro-Wilk test confirmed a normal distribution of data, hence parametric tests were employed. The Student t-test was used to compare groups at baseline. The paired t-test was used to analyze intragroup changes between timepoints, and the Student t-test for intergroup comparisons. The level of significance was set at 0.05. The Class II division 1 malocclusion was successfully corrected, and the facial profile improved both in normodivergent and hyperdivergent patients. Divergency increased by 0.76 ± 1.99° in Group N (p = 0.02) while it decreased -0.23 ± 2.25° (p = 0.60); These changes were not significant between groups after treatment (p = 0.680). Most dentoskeletal measurements changed significantly within groups but none of them showed statistically significant differences between groups after treatment. Dental and soft tissue changes were in accordance with the biomechanics used for this Class II orthodontic therapy. The effect of orthodontic treatment of Class II division 1 malocclusion including extraction of the maxillary first molars in growing patients can be considered clinically equivalent in normodivergent and hyperdivergent patients. For this reason, this orthodontic treatment can be considered a viable option in the armamentarium of the Class II Division I therapy for both facial types.

Three-dimensional evaluation of soft tissues in hyperdivergent skeletal class II females in Guangdong

ObjectivesTo establish the three-dimensional facial soft tissue morphology of adolescent and adult females in the Guangdong population and to study the morphological characteristics of hyperdivergent skeletal class II females in Guangdong compared with that of normodivergent class I groups.Materials and methodsThe 3dMDface system was used to capture face scans of 160 patients, including 45 normal and 35 hyperdivergent skeletal class II adolescents (aged 11–14 years old) and 45 normal and 35 hyperdivergent skeletal class II adults (aged 18–30 years old). Thirty-two soft tissue landmarks were mapped, and 21 linear, 10 angular and 17 ratio measurements were obtained by 3dMDvultus analysis software. Data were assessed with a t-test of two independent samples between the normal adolescent and adult groups and between the normal and hyperdivergent skeletal class II groups.ResultsThe linear measurements of the Guangdong adult females were larger than those of the adolescents in both Class I and Class II groups. However, the angular and ratio measurements had no significant difference. The vertical linear measurements were higher and the sagittal and transverse linear measurements were smaller in the hyperdivergent class II group (p < 0.05). The soft tissue ANB angle, chin-lip angle, and mandibular angle were significantly larger and the soft tissue facial convexity angle and nasal convexity angle were significantly smaller in the hyperdivergent class II group (p < 0.05). Additionally, there were significant differences in the ratio measurements between the hyperdivergent class II groups and the control groups (p < 0.05).ConclusionsThe three-dimensional facial morphology of Guangdong adolescent and adult females was acquired. The facial soft tissue measurements of the adults were higher in the three dimensions except for the facial convexity and proportional relationships which were similar, suggesting that the growth pattern remained the same. The three-dimensional facial soft tissue features of hyperdivergent skeletal class II were characterized by the terms “long, convex, and narrow”. Three-dimensional facial measurements can reflect intrinsic hard tissue characteristics.

Elastodontic Therapy of Hyperdivergent Class II Patients Using AMCOP® Devices: A Retrospective Study

Background: The management of a hyperdivergent growth pattern is one of the most challenging in orthodontics and different treatments are advocated. The present study analyses the effectiveness of elastodontic therapy with AMCOP® devices in treating children with hyperdivergent class II malocclusion and the effect on the upper airway patency. Methods: The study group included 21 patients (10 males and 11 females, mean age 8.22 ± 1.17 years) with a hyperdivergent growth and a class II malocclusion treated with AMCOP® devices. Cephalometric analysis was performed before treatment (T0) and after treatment (T1). Results: After treatment, the cephalometric analysis revealed a correction of the class II malocclusion and a modification of the growth pattern with a divergence reduction. The improvement of the upper airway space was also observed. Conclusion: The elastodontic therapy effectively corrected hyperdivergent class II malocclusion in growing patients over a short period.

The comparison between the lower airway space, mandibular body, mandibular ramus, chin thickness and chin throat length in vertical and horizontal growers among skeletal class I and skeletal class II patterns – Retrospective cephalometric study

The vertical and horizontal growth influences the height of mandibular ramus and length of the mandibular body. The soft tissue chin thickness, the lower airway space and the chin throat length can vary in different growth patterns and different skeletal patterns. Lateral cephalograms of non-growing patients seeking orthodontic treatment (n=120) were included in the study. The samples were divided into two subgroups based on skeletal pattern (Cl I &amp; Cl II) according to ANB angle and Wit’s appraisal. Further sub divided into four groups based on cephalometric mandibular plane inclination to anterior cranial base (SN-GoGn) and Frankfort’s mandibular plane (FMA) angle in hypodivergent and hyperdivergent patterns. The parameters lower airway space, mandibular body, mandibular ramus, chin thickness and chin throat length were measured. Results showed maximum lower airway space, mandibular body, mandibular ramus, chin thickness, and chin throat length in the hypodivergent skeletal Class I group. The minimum lower airway space, mandibular body, mandibular ramus, chin thickness, and chin throat length observed in the hyperdivergent skeletal Class II group. The inter-group comparison of all samples indicates that there was a statistically significant difference between various groups and the measures of the hypodivergent samples are more than the hyperdivergent samples irrespective of the skeletal pattern. The study concludes that the lower airway, mandibular ramus, mandibular body, soft tissue chin thickness, chin throat length was less in hyperdivergent skeletal Class I and skeletal Class II samples than the skeletal Class I and skeletal Class II hypodivergent.

Biomechanical effects of Teuscher activator in hyperdivergent Class II malocclusion treatment: A finite element analysis

BackgroundIn orthodontic treatment, the combination of an activator with a headgear is commonly used in treatment of the hyperdivergent Class II malocclusion. However, the distribution of stresses transmitted to the maxilla by these appliances has been little studied. This study aimed to compare the biomechanical effects of stresses transmitted to the maxilla and teeth by a Teuscher activator (TA) for different lines of action of extraoral force, using finite element analysis. Material and MethodsA tridimensional finite element model of the maxilla and teeth was created based on the true geometry of a human skull. The (TA) and the face bow were designed in 3D computer-aided design and fixed in the maxilla model. To study the effects of mechanical stress transmitted to the maxilla in the treatment of hyperdivergent Class II malocclusion with (TA) combined with extraoral forces, five different finite element models were used, considering the centers of resistance of the maxilla and dentition. ResultsThe results showed that stresses increased progressively when the force line of action moved in posteroanterior direction. Von Mises equivalent stress was lower in Model 1 (0°) than in Model 5 (60°). In Models 1 (0°) and 2 (15°), molars suffered greater distal displacement and incisors showed extrusion. In Model 3 (30°), the force line of action promoted a distal displacement of molars and incisors. In Models 4 (45°) and 5 (60°), the whole maxillary anterior sector showed counterclockwise displacement. ConclusionsDifferent force lines of action influence the intensity and distribution of orthodontic and orthopedic forces in the maxilla. The extraoral force’s line of action used in Model 3 (30°) is the most compatible with the objectives of the hyperdivergent Class II malocclusion treatment in growing patients. Key words:Class II, Headgear, Early treatment, FEA.

Dental and skeletal effects after total arch distalization using modified C-palatal plate on hypo- and hyperdivergent Class II malocclusions in adolescents.

To compare the dental and skeletal treatment effects after total arch distalization using modified C-palatal plates (MCPPs) on adolescent patients with hypo- and hyperdivergent Class II malocclusion. The study group included 40 patients with Class II malocclusion (18 boys and 22 girls, mean age = 12.2 ± 1.4 years) treated with MCPPs. Fixed orthodontic treatment started with the distalizing process in both groups. Participants were divided into hypo- or hyperdivergent groups based on their pretreatment Frankfort mandibular plane angle (FMA) ≤22° or ≥28°, respectively. Pre- and posttreatment lateral cephalograms were digitized, and 23 variables were measured and compared for both groups using paired and independent t-tests. The hyper- and hypodivergent groups showed 2.7 mm and 4.3 mm of first molar crown distalizing movement, respectively (P < .001). The hypodivergent group had a slight 2.2° crown distal tipping of first molars compared with 0.3° in the hyperdivergent group. After distalization, the FMA increased 3.1° and 0.3°, in the hypodivergent and hyperdivergent groups, respectively (P < .001). SNA decreased in the hypodivergent group, while other skeletal variables presented no statistically significant differences in the changes between the groups. The hypodivergent group showed more distal and tipping movement of the maxillary first molar and increased FMA than the hyperdivergent group. Therefore, clinicians must consider vertical facial types when distalizing molars using MCPPs in Class II nonextraction treatment.

Dental and skeletal effects after total arch distalization using modified C-palatal plate on hypo- and hyperdivergent Class II malocclusions in adolescents.

To compare the dental and skeletal treatment effects after total arch distalization using modified C-palatal plates (MCPPs) on adolescent patients with hypo- and hyperdivergent Class II malocclusion. The study group included 40 patients with Class II malocclusion (18 boys and 22 girls, mean age = 12.2 ± 1.4 years) treated with MCPPs. Fixed orthodontic treatment started with the distalizing process in both groups. Participants were divided into hypo- or hyperdivergent groups based on their pretreatment Frankfort mandibular plane angle (FMA) ≤22° or ≥28°, respectively. Pre- and posttreatment lateral cephalograms were digitized, and 23 variables were measured and compared for both groups using paired and independent t-tests. The hyper- and hypodivergent groups showed 2.7 mm and 4.3 mm of first molar crown distalizing movement, respectively (P < .001). The hypodivergent group had a slight 2.2° crown distal tipping of first molars compared with 0.3° in the hyperdivergent group. After distalization, the FMA increased 3.1° and 0.3°, in the hypodivergent and hyperdivergent groups, respectively (P < .001). SNA decreased in the hypodivergent group, while other skeletal variables presented no statistically significant differences in the changes between the groups. The hypodivergent group showed more distal and tipping movement of the maxillary first molar and increased FMA than the hyperdivergent group. Therefore, clinicians must consider vertical facial types when distalizing molars using MCPPs in Class II nonextraction treatment.

Respiratory and sleep characteristics based on frequency distribution of craniofacial skeletal patterns in Korean adult patients with obstructive sleep apnea.

ObjectiveTo investigate the frequency distribution of various craniofacial skeletal patterns in a large Korean adult obstructive sleep apnea (OSA) population, and to find a relationship between craniofacial risks and respiratory and sleep characteristics.MethodsA total of 1226 OSA patients (mean age of 44.9±13.3 years) were included in this retrospective cross-sectional study. All subjects were evaluated for gender and age using fourteen polysomnographic, five cephalometric, two comorbid variables, and three self-reported indexes. Frequency analysis was used to screen the distribution of main skeletal patterns and subtypes. Intergroup comparisons were performed using independent t-test, chi-square test or analysis of variance. Univariable regression analysis was done to find a relationship between skeletal risks and OSA characteristics.ResultsThe frequency distribution of skeletal patterns was as follows: sagittally 57.2%, 32.3%, and 10.5% of Class II, Class I, and Cass III; vertically 54.0%, 26.7%, and 19.3% of hyperdivergent, normodivergent, and hypodivergent type, respectively. Polysomnographic, symptomatic, and comorbid variables showed no differences among patients with different skeletal patterns. Conversely, skeletal variables showed no differences according to OSA severity. The prevalence of highly risky skeletal pattern of hyperdivergent Class II was more likely to be females (OR 4.52, P < .01) and less obese (OR 3.21, P < .01), irrelevant to OSA and sleep characteristics.ConclusionCharacteristic frequency distributions of skeletal patterns and subtypes were observed in adult OSA patients however, no statistical association was found between the skeletal patterns and OSA characteristics due to the large interindividual variation.

CBCT Evaluation of Condylar Changes in Class II Hyperdivergent Adult Patients Following Posterior Maxillary Intrusion Using Miniscrews/Miniplates—A Prospective Study

Aim &amp; Objectives: To evaluate using CBCT, the condylar changes taking place in retrognathic, hyperdivergent Class II adult patients following maxillary intrusion using miniscrew assembly. Materials and methods: In this prospective study design, 20 class II div I high angle cases in the age group of 20-25 years with Class II molar and canine relationship; Overjet &gt; 5mm; ANB angle &gt; 4°; FMA angle &gt;25°; SNGoGn &gt; 35°; Jaraback ratio&lt; 60° and Lower Gonial angle&gt;75° were taken. Each patient had a miniscrew assembly in the maxilla through which intrusive force was applied to the maxilla. Two additional miniscrews were placed between the first mandibular molars and second premolars to prevent extrusion of lower molars. CBCT images were taken at the beginning of the treatment (T1) and at the end of 6-9 months of molar intrusion (T2). Statistical analysis was carried out using student T- test. Results: Prior to treatment, the patients showed significant mandibular retrusion associated with increased maxillary posterior heights. Following maxillary intrusion with miniscrew assembly, CBCT evaluation revealed that the distance from the centre of condyle to the posterior border of the external auditory meatus was 19.2±1.67 mm on right side and 18.1±1.54mm on left side in T1 which increased to 19.6±1.45mm on right side and 18.5±1.36mm on left side in T2. The average forward displacement of condyle was .5mm which was statistically significant. The distance from the centre of condyle to superior border of external acoustic meatus was 3.1±1.7 mm on right side and 3.5 ±1.8 mm on left side in T 1 which increased to 3.8±1.9 mm on right side and 4.1 ±1.3mm on left side in T 2. The average downward displacement was .7mm which was statistically significant. Conclusion: Significant Maxillary intrusion can be achieved using miniscrews/ miniplate in adult hyperdivergent skeletal class II patients.

Simplified upper molar intrusion with modified interim Goshgarian-type palatal archSimplified upper molar intrusion with modified interim Goshgarian-type palatal arch

Surgical-orthodontic management of hyper divergent skeletal Class III malocclusions is often confronted with clinical challenges. Overeruption of the maxillary second molars during longer presurgical orthodontic decompensation phase usually results in occlusal interferences which hinder the setting of desired postsurgical occlusion in preparation for model surgery. Here, a simple, yet effective interim modification of conventional Goshgarian-type transpalatal arch is proposed which can be effectively used to intrude over erupted molars during orthodontic treatment.

Changes of Occlusal Plane in Growing Patients With Increased Vertical Dimension During Class II Correction by Using Cervical Headgear.

This retrospective research aimed to highlight the changes of occlusal plane in Class II hyperdivergent subjects that received cervical headgear treatment and compared them to untreated controls in order to evaluate the occlusal changes that might be connected to a potential mandibular rotation.The sample of this investigation was represented by 20 hyperdivergent Class II subjects (10 males, 10 females; mean age 8.54) corrected by using cervical headgear (treated group) and 21 Class II patients (11 males, 10 females; mean age 8.41) hyperdivergent who had no therapy (control group). Lateral head films were studied for all the patients before treatment (T1) and after therapy (T2) for both groups; cephalometric analysis was used in order to seek the modifications between time points and between groups.Means and standard deviation have been computed for both groups. In order to confront the modification between the time points within the same group the Wilcoxon test was applied. The Mann-Whitney U test was applied to confront the dissimilarities between groups at T2.As a result of the Class II correction by using the cervical headgear treatment the occlusal plane was lowered and flattened compared to T1 and to the control group; the upper molars showed extrusion to the palatal plane, there was a significant forward rotation of mandible and the vertical dimension was not significantly modified. Downward and backward displacement of the upper jaw occurred.

Paediatric Orthodontics. Part 4: SEC III protocol in Class III malocclusion.

SEC III protocol: Early treatment of dentoskeletal Class III malocclusions. The early treatment of dentoskeletal Class III malocclusion is one of the more challenging situations for orthodontists, mainly for the uncertainty of stable long-term results due to the interaction of both environmental and genetic aetiological factors. Several interceptive protocols have been proposed during the past decades. The SEC III protocol includes two occlusal acrylic Splints combined with Class III elastics and chin cup. The protocol was proposed to facilitate Class III dentoskeletal correction by eliminating the intercuspation and the tongue thrust with clockwise mandibular rotation and minimal dentoalveolar compensation. The main difference with all the other appliances is the vertical control, which is crucial in difficult cases such as hyperdivergent Class III malocclusions.