Overjet Reduction Research Articles

A case of maxillary protrusion and excessive overjet treated successfully by implantation of a temporary anchorage device

This case report describes the treatment of a 15-year-old girl showing Angle’s Class II Division 1 malocclusion with maxillary prognathism and marked labial inclination of the maxillary anterior teeth, which was characterized by a large overjet, overjet occlusion, and mild crowding in the lower jaw. Our treatment completed without root resorption as a result of the combined use of a wire mechanism and anchors has rarely been reported before. The left and right maxillary first premolars were extracted, a temporary anchorage device (TAD) was used for space closure, and oral hygiene maintenance guidance was provided. The total treatment time was approximately 2 years and 7 months. Ideal overjet and overbite relationships were established, and the facial profile improved substantially. The 2-year follow-up assessment showed a morphologically and functionally stable result. For patients with marked maxillary prognathism, orthodontic treatment using TADs enables simultaneous and efficient maxillary anterior tooth retraction and reduction of overjet. Moreover, this treatment has the potential to shorten the treatment duration and contribute to the long-term stability of excessive overjet correction.

A Comparative Evaluation of the Dentoskeletal Treatment Effects Using Twin Block Appliance and Myobrace System on Class II Division I Malocclusion.

The study aimed to evaluate the dentoskeletal effects of twin block appliance and myobrace system in treating skeletal Class II Division I malocclusions in growing children taking into account the effects of normal growth in an untreated control group. Twenty subjects with Class II Division I malocclusion considered as study group were allocated randomly to two treatment groups of 10 each, consecutively treated with twin block appliances (mean age 10.850 ± 1.37 years) and myobrace system (mean age 10.40 ± 1.89 years). Ten children (mean age 10.60 ± 1.77 years) with untreated Class II Division I malocclusion were considered as a control group to eliminate possible growth effects. At the start of the treatment and end of the observation period of 18–24 months, lateral cephalograms were taken. All the angular and linear parameters measured were subjected to statistical analysis. Twin block group subjects produced more measurable and statistically significant skeletal and dentoalveolar changes at the end of the observation period, demonstrated by correction of full cuspal Class II molar relationship to Class I molar relationship and yielding mandibular growth in increments greater in magnitude than the myobrace system. Meanwhile, the myobrace system-induced favorable dentoalveolar changes by a significant reduction of overjet. The retrognathic profile, however, improved in both the intervention groups as the upper lip protrusion, mentalis strain, and the lower lip curl were eliminated in striking contrast to the untreated control group. The study demonstrates that with appropriate patient selection both myobrace system and twin block appliances can be used in conjunction with the fixed appliance therapy to achieve more stable Class II corrections.How to cite this article: Johnson JS, Satyaprasad S, Sharath Chandra H, et al. A Comparative Evaluation of the Dentoskeletal Treatment Effects Using Twin Block Appliance and Myobrace System on Class II Division I Malocclusion. Int J Clin Pediatr Dent 2021;14(S-1):S10–S17.

Dentoskeletal effects of Twin Block appliance in patients with Class II malocclusion.

Background and aimClass II malocclusions are most commonly seen in orthodontic practice and in the recent times Twin Block appliance has been the most popular and widely used among removable functional appliances for the correction of Class II malocclusion in growing patients. The aim of this retrospective study was to evaluate the dentoskeletal effects produced by the Twin Block appliance for the correction of Class II division 1 malocclusion with retrognathic mandible.MethodsPre-treatment (T1) and post-treatment (T2) lateral cephalograms of 30 patients treated with Twin Block appliance (mean age = 10.8 ± 1.2 years) for the correction of class II division 1 malocclusion were compared with the 30 untreated class II control patients (mean age 11.2 ± 0.8 years) who did not undergo any treatment during this period. Both the groups were evaluated for the dentoskeletal changes using 24 angular and linear cephalometric measurements. The differences between the pre and post-treatment were calculated using a paired t-test.ResultsThe cephalometric analysis revealed that the Twin Block appliance stimulated mandibular growth and statistically significant differences were found between the two groups. Twin Block patients showed a statistically very high significant (p<0.001) increase in mandibular length (6.02 mm) compared with the control group (0.3 mm). “Headgear effect” on the maxilla, increase in lower anterior facial height, significant reduction of overjet, overbite and Class I molar relationship were achieved in the Twin Block group. However, no significant changes appeared in the control group.ConclusionThe results of the present study conclude that the Twin Block appliance is effective in the treatment of Class II malocclusion and this is due to a combination of skeletal and dentoalveolar changes in both the arches.

First molar extractions related to molar-incisor hypomineralization (MIH) in a special need patient: case report

Although most orthodontists avoid extractions, treating patients with biprotrusion traditionally involves removing teeth. In the current case report, a 15-year-old deaf patient had a Class II molar and canine relationships, 8 mm overjet and 3mm overbite, 3 mm of a discrepancy between U/L midline, crowding in both arches (3 mm in the upper and 7 mm in the lower). The first right upper molar (16) and the first right and left lower molars (36 and 46) were severely MIH affected. Extraction of the first four molars was proposed, since a large amount of space was required and three of the four molars were very compromised with severe MIH. Tooth 26 was extracted to maintain the symmetry of the arch and because the extraction of a premolar would not allow for alignment associated with class II correction of canines on the left side. During the closure of the extraction spaces, upper and lower third molars eruption was observed, in an appropriate position. Facial analysis shows us the coincidence of the upper midline with the face and good exposure of the incisors in the smile. There was considerable reduction of overjet and dental protrusion, enabling passive lip sealing. A perfect fit of the Class I superior teeth was not obtained since the patient considered that the treatment was already very good and did not want to collaborate with hygiene and the use of orthodontic appliances for more time.

Management of Class II Division 1 Subdivision malocclusion using unilateral bicuspid extractions and fixed functional appliance: A Two Year Follow-Up

Introduction: Management of Class II Subdivision cases pose a clinical dilemma and require a careful diagnosis to ascertain the source of asymmetry. Various treatment modalities involving: different protocols of tooth extractions; molar distalization; fixed functional appliances or orthognathic surgery have been proposed for the same.&#x0D; Objective: This article reports a unique approach for management of a severe skeletal Class II with Angle’s Class II Division 1 subdivision malocclusion using unilateral bicuspid extractions in mandibular and maxillary arches and a fixed functional appliance.&#x0D; Results: A 13 year 1 month old male in CVMI transition stage was successfully treated. Extraction of #44 was done to alleviate crowding in the mandibular anterior region and #15 was extracted to protract #16 to achieve a Class II molar relationship. A pre-functional Class II molar and canine relationship with co-incident midlines was achieved. The functional phase consisted of a fixed functional appliance (Forsus FRD) for mandibular advancement to correct the severe skeletal Class II. Class I molar and canine relationships were achieved with reduction of facial convexity and overjet. Result remained stable 24 months after treatment. The improvement can be quantified by the reduction in scores of orthodontic indices measured pre and post treatment.&#x0D; Conclusions: Management of Class II subdivision malocclusion requires careful planning. This paper presents a unique approach utilizing unilateral extractions and fixed functional appliance to address severe skeletal Class II discrepancy and the subdivision dilemma.

Comparative Evaluation of Esthetic and Structural Aspects in Class II Functional Therapy. A Case-Control Retrospective Study.

Background: To compare the skeletal, dental, and esthetic changes produced by three functional devices, Fränkel-2 appliance (FR-2), Twin Block (TB), and Occlus-o-Guide® (O-o-G®), for the treatment of Class II malocclusion. Methods: Sixty-five patients with Class II Division 1 malocclusion were divided into three groups and were analyzed through cephalometric analysis of skeletal, dental, and esthetic variables before and after treatment. The first group of 23 patients (F: 9; M: 14; mean age: 10.3 ± 1.08 years) was treated with FR-2, the second group of 18 patients (F: 8; M: 10; mean age 10.7 ± 1.05 years) was treated with TB, the third group (F: 11; M: 13; mean age: 9.05 ± 0.39 years) of 24 patients was treated with O-o-G®. The structural effects of the three devices were compared with a control group generated by the growth variations reported in the cephalometric atlas of Bhatia and Leighton. Esthetic analysis was performed comparing the results of the patients treated with a control group of 20 subjects with mandibular retrognathia and Class II Division 1 malocclusion, not subjected to therapy. Results: The three devices resulted in a significant increase in mandibular length, with higher results obtained for FR-2 and TB. A statistically significant increase in the IMPA angle was found for the O-o-G® group, and a notable reduction of both overjet and overbite was detected in all three groups of treated patients. The esthetic evaluation showed overall more significant results in the TB group, especially with regard to the reduction of facial convexity. The retrusion of the upper lip was on average more significant in the O-o-G® group, followed by that in the TB. Conclusions: All three devices have proven to be effective overall in resolving skeletal changes and improving facial esthetics.

Comparison of treatment effects from total arch distalization using modified C-palatal plates versus maxillary premolar extraction in Class II patients with severe overjet.

This study aimed to compare the skeletodental and soft tissue changes with total arch distalization using a modified C-palatal plate (MCPP) and maxillary first premolar extraction treatment in Class II malocclusion patients with severe overjet. The sample consisted of 46 adult patients who had Class II Division 1 malocclusion with severe overjet; 25 of them received non-extraction treatment with MCPPs (age, 22.5±7.2years), and 21 received maxillary first premolar extraction treatment (age 23.4±6.5years). A total of 26 variables were measured on pre- and post-treatment lateral cephalograms. To evaluate the differences between pretreatment and post-treatment in each group, t tests and Wilcoxon rank-sum tests were used. To compare the amount of change between the two groups, MANOVA test was used. The overjet was significantly reduced in the MCPP and extraction groups by 4.8mm and 5.4mm, respectively. However, the two groups had no significant difference in the sagittal, vertical and angular changes of the maxillary incisors. In addition, regarding soft tissue changes, the MCPP and extraction groups showed an increased nasolabial angle of 7.5° and 9.4°, decreased upper lip to the true vertical line of 1.8mm and 2.2mm, respectively (P<.001). There was no significant difference in the skeletal changes between the MCPP and extraction groups, and the reduction in overjet was similar in the groups. These results suggest that MCPP might be a viable treatment option for total arch distalization in Class II malocclusion patients with severe overjet.

Comparisons of costs and treatment effects-an RCT on headgear activator treatment of excessive overjet in the mixed and late mixed dentition.

To compare the costs and treatment effects of headgear activator treatment of Class II malocclusion with excessive overjet between treatments started in the mixed (MD) and late mixed dentition (LMD). Two-arm parallel-group single-centre randomized controlled trial (RCT). A total of 56 children presenting Class II malocclusion with excessive overjet were assessed and invited to an RCT designed as intention-to-treat. The children were randomized, by an independent person not involved in the trial into two groups, treatment with headgear activator in the MD starting at the age of 9 or to treatment with a headgear activator in LMD, starting at the age of 11. The primary outcome measure was to compare the treatment costs between the two groups. Societal costs (the sum of direct and indirect costs) were calculated for successful treatments only and when unsuccessful treatments were included. Secondary outcomes were comparisons of oral health-related quality of life (OHRQoL), dental and skeletal treatment effects, lip closure, and trauma incidence. Data collections were performed before and after treatment, corresponding to a treatment period of 2 years. Blinding was accomplished when assessing outcomes. No group differences in costs were found of successful treatments or when unsuccessful treatments were included. The most pronounced treatment effects in both groups were the reduction of overjet and improved molar relation. Treatment started in MD or in LMD were equal and without significant differences regarding effects on OHRQoL, skeletal effects, lip closure, and incidence of trauma. No harm was observed, but 8 of 30 children (27%) in the MD and 6 of 21 children (29%) in the LMD group showed unsuccessful results. Costs depend on local factors and can thereby not be directly transferred to other settings. It was a single-centre trial and can thus be less generalizable. Regarding costs and treatment effects, there is no difference if headgear activator treatment of excessive overjet starts in the MD or LMD. NCT04508322.

Efficacy of elastodontic devices in overjet and overbite reduction assessed by computer-aid evaluation

BackgroundThis study aimed to verify the efficacy of two elastodontic devices in overjet (OJ) and overbite (OB) reduction during treatment with the Equilibrator Series II (Eptamed) and Occlus-o-Guide (Sweden & Martina) devices.MethodSixty patients aged 7–15 years were enrolled in the study, and were divided into test and control groups. The test group included 30 patients (14 males, 16 females; mean age, 10.66 ± 2.12 years) treated with the EQ (Equilibrator) Series II. The control group included 30 patients (15 males, 15 females; mean age, 10.76 ± 2.52 years) treated with the Occlus-o-Guide. The two groups exhibited the same orthodontic features. The orthodontic criteria were: skeletal and dental class II malocclusion (divisions 1 and 2); and the presence of OJ and OB. Evaluation of OJ and OB was performed at two timepoints: T0 (before starting therapy) and T1 (after 1 year).ResultsAt T0, OJ and OB were similar for the two groups; however, at T1, both OJ and OB were significantly lower with the Eptamed device compared to the Occlus-o-Guide device (p = 0.0019).ConclusionsElastodontic devices improve orthodontic outcomes by aiding orthodontic patient management, diagnosis, and treatment planning, reducing the risk relapse acting on the whole organism and the rehabilitation of the tongue.

Treatment effects of "PowerScope" fixed functional appliance - a clinical study.

To study the skeletal, dental effects and evaluate the soft tissue changes with PowerScope-fixed functional appliance in class II malocclusion. This clinical study was carried out where a total of 10 growing (CVMS 3 and 4) Class II Division 1 malocclusion patients, indicated for treatment with fixed functional appliance were allocated based on specific inclusion criteria. PowerScope (American Orthodontics) was used as the fixed functional appliance. Skeletal, dental and soft tissue effects of the appliance with various angular and linear parameters on a digital lateral cephalogram were evaluated for all 10 participants. Records were collected before the insertion of PowerScope appliance (T0) and after 5 months, during the appliance removal (T1). All participants were treated with 0.018"×0.025" MBT (3M Unitek) prescription. Statistical analysis was performed using a paired t-test to compare individual mean changes for each treatment category. Statistically significant changes were seen in skeletal parameters such as forward positioning of the mandible with an increase in SNB angle and N perpendicular-Pogonion distance, the class II jaw base relationship improved with reduction in ANB angle and Wits appraisal. Significant changes were observed in dental parameters such as forward positioning of mandibular incisors, maxillary molar distalization and intrusion with reduction in overbite and overjet respectively. In the soft tissue, a significant improvement in facial profile was seen due to an increase in labiomental angle. The results of this study have shown that statistically significant changes in skeletal, dental and soft tissue parameters.

Three-dimensional cone-beam computed tomography comparison of shorty and standard Class II Carriere Motion appliance.

To compare treatment effects of the standard and shorty Class II Carriere Motion appliances (CMAs) on adolescent patients. Fifty adolescents with Class II malocclusion formed group 1, who were treated with shorty CMA (n = 25, 12.66 ± 1.05 years), and age- and sex-matched group 2, who were treated with standard CMA (n = 25, 12.73 ± 1.07 years). Treatment effects were analyzed by tracing with Invivo software to compare pretreatment (T1) cone-beam computed tomography (CBCT) images with post-CMA (T2) CBCT images. A total of 23 measurements were compared within and between groups. In groups 1 and 2, maxillary first molars showed significant distal movement from T1 to T2 (1.83 ± 2.11 mm and 2.14 ± 1.34 mm, respectively), with distal tipping and rotation in group 1 (6.52° ± 3.99° and 3.15° ± 7.52°, respectively) but only distal tipping (7.03° ± 3.45°) in group 2. Similarly, in both groups, the maxillary first premolars experienced significant distal movement with distal tipping but no significant rotation. In group 1, maxillary canines did not undergo significant distal movement. In both groups 1 and 2, mandibular first molars experienced significant mesial movement (1.85 ± 1.88 mm and 2.44 ± 2.02 mm, respectively). Group 1 showed statistically significantly less reduction in overjet and less canine distal movement with less distal tipping than group 2 (α < .05). The shorty CMA achieved Class II correction similarly to the standard CMA, with less change in overjet and distal tipping movement of the maxillary canines.

Influence of incisor position control on the mandibular response in growing patients with skeletal Class II malocclusion

This study aimed to test whether control in maxillary and mandibular incisor position, during treatment with an acrylic splint Herbst appliance, could influence the mandibular response in growing patients with skeletal Class II malocclusion. The lateral cephalograms of 61 patients (mean age, 12.3years; standard deviation, 1.6) with skeletal and dental Class II malocclusion were retrospectively analyzed both at baseline and after Herbst appliance removal, using a modified Pancherz cephalomeric analysis. Forty-five patients had received miniscrew in the mandibular arch to control mandibular incisor anchorage. In 21 patients, the maxillary incisors had been proclinated before starting the treatment for deepbite and maxillary incisor lingual inclination. All the patients were categorized a posteriori into 2 homogeneous groups, according to dental overjet reduction: 30 patients with dental overjet reduction (DR) and 31 patients without dental overjet reduction (NDR). Both groups presented a significant skeletal correction. However, the change was significantly greater in the NDR group than in the DR group (P<0.01). The mandibular bone base reached a median value of 4.0mm (interquartile range, 2.5) in the NDR group vs 1.1mm (interquartile range, 2.8) in the DR group (P<0.001). The 2 groups were also significantly different in terms of the positional change of maxillary incisor, which was proclinated in group NDR and lingualized in group DR (P<0.001). The results showed that dental control of overjet was beneficial to improve the effectiveness of Herbst treatment in increasing mandibular length in growing patients with skeletal Class II malocclusion.

Relationship between back posture and early orthodontic treatment in children

BackgroundThe purpose of this study was to analyze the relationship between body posture and sagittal dental overjet in children before and after early orthodontic treatment with removable functional orthodontic appliances.MethodsAngle Class II patients (mean age 8.2 ± 1.2 years; 29 males and 25 females) with a distinctly enlarged overjet (> 9 mm) were retrospectively examined regarding body posture parameters before and after early orthodontic treatment. In addition, changes in overjet were investigated with the aid of plaster models. Forms of transverse dysgnathism (crossbite, lateral malocclusions) and open bite cases were excluded. Body posture parameters kyphosis, lordosis, surface rotation, pelvic tilt, pelvic torsion and trunk imbalance were analyzed by means of rasterstereographical photogrammetry to determine, if the orthodontic overjet correction is associated with specific changes in posture patterns.ResultsIn nearly all patients an overjet correction and an improvement regarding all body posture and back parameters could be noted after early orthodontic treatment. Overjet reduction (− 3.9 mm ± 2.1 mm) and pelvic torsion (− 1.28° ± 0,44°) were significantly (p < 0.05) and moderately correlated (R = 0.338) with no significant associations found for the other posture and back parameters (p > 0.05).ConclusionOverjet reduction during early orthodontic treatment may be associated with a detectable effect on pelvic torsion.

The stability of Class II correction with functional appliance therapy and orthodontic camouflage: A retrospective cohort study

The aim of this study was to compare the stability of overjet reduction in adolescents treated with either orthodontic camouflage involving extraction of premolar units or functional appliance therapy. A retrospective cohort study was undertaken with data collected at pre-treatment (T0), debond (T1) and 12 months post-treatment (T2). The primary outcome measure was stability of overjet reduction, and secondary outcome measures included Angle's molar relationship, and Little's Irregularity Index score. Forty-two Class II participants, 18 treated with a functional appliance and 24 with camouflage, were included with a mean pre-treatment age of 13.07 years (SD 1.72), with 23 (55%) being female. Mean overjet reduction during treatment in the functional appliance group was 6.99mm with relapse of just 0.62mm present at 12 months post-treatment. In the orthodontic camouflage group, there was a mean overjet reduction of 3.54mm with relapse of 0.27mm at 12 months post-treatment. Linear regression analysis confirmed no statistical difference (P=0.501) in overjet relapse between both treatment groups at 12 months post-treatment, adjusting for overjet at baseline. A further regression analysis revealed no significant association between overjet relapse and pre-treatment skeletal discrepancy, labial segment crowding, retention regime or compliance with the retention protocol. Both functional appliance and orthodontic camouflage therapies appear to have good antero-posterior occlusal stability, with minor degrees of overjet relapse occurring over a 12-month follow-up period. There was no significant difference between the treatments in relation to overjet relapse, buccal segment interdigitation or anterior irregularity.

A Comparative Study of Arch Width, Overjet and Overbite between Bilateral Congenital Missing Lateral Incisor and Normal Class I Occlusion

Permanent lateral incisors have been considered as major missing teeth in the mouth. The main aim ofthe present study is to conduct a comparative study of maxillary and mandibular arch widths, overjet andoverbite for a sample with missing lateral incisors and normal class I occlusion.The sample of the study comprises sixty pairs of study models of both genders, which were separated intotwo groups. The first group consisted of thirty casts of bilateral congenital missing lateral incisors, while thesecond group consisted of thirty casts of the class I occlusion. The intercanine width, interpremolar width,intermolar width, overjet and overbite were measured for the sixty samples.The results of this study demonstrate a significant reduction in maxillary and mandibular arch widthin bilateral missing lateral Incisors as compared with normal class I group. The results also revealed asignificant reduction in overjet and overbite in bilateral missing lateral incisors as compared with normalclass I group. A significant difference was also reported between the two groups based on gender differencein the maxillary arch width. Conversely, non-significant difference was found in the mandibular arch width.The present study also shows non-significant difference based on gender difference in overjet and overbitein the two groups.

Early headgear activator treatment of Class II malocclusion with excessive overjet: a randomized controlled trial.

To compare early headgear activator treatment of Class II malocclusion with excessive overjet with untreated control subjects in terms of the primary outcomes overjet and overbite as well as the effect regarding oral-health-related quality of life (OHRQoL), lip closure, incidence of trauma, and skeletal changes. Two-arm parallel group single-centre randomized controlled trial. A total of 60 children (mean age 9.5 years) presenting a Class II malocclusion with excessive overjet were recruited. The trial was designed as intention-to-treat and the participants randomized by an independent person not involved in the trial to either early treatment with headgear activator or to an untreated control group (UG). Dental and skeletal variables as well as registrations of OHRQoL, lip closure, and incidence of trauma were recorded. For the treatment group, data were registered at baseline before treatment and when treatment was finished, corresponding to approximately 2 years. For the UG, registrations were made at baseline and at 11 years of age. Observers were blinded to treatment allocation when assessing outcomes. Early treatment with headgear activator significantly decreased overjet and improved molar relationship when compared with untreated controls. The effects were primarily due to dentoalveolar changes. Early treatment had no evident effect regarding OHRQoL, lip closure, or incidence of trauma. Lack of cooperation resulted in unsuccessful treatments for 27% of the patients. The trial was a single-centre trial and can thus be less generalizable. The main treatment effect of early headgear activator treatment of Class II malocclusion with excessive overjet is reduction of overjet. NCT04508322.

Class II malocclusion correction with Invisalign: Is it possible?

This research aimed to determine whether Class II malocclusion can be treated with clear aligners after completing treatment with the initial set of aligners. A sample of 80 adult patients were divided into Group 1 with Class I molar malocclusions (n=40 [11 men and 29 women]; 38.70±15.90years) and Group 2 with Class II molar malocclusions (n=40 [11 men and 29 women]; 35.25±15.21years). All patientshad finished treatment with the initial set of Invisalign aligners (Align Technology, Santa Jose, Calif) without known centric occlusion-centric relation discrepancies, issues of compliance, or overcorrection. The 7 measurements using the American Board of Orthodontics (ABO) Model Grading System and millimetric measurements for anteroposterior (AP) and vertical dimensions were assessed and compared between the 2 groups at pretreatment, posttreatment ClinCheck (Align Technology) prediction, and posttreatment. No improvements were observed in the APcorrection. The amount of AP correction in patients with Class II malocclusion was 6.8% of the predicted amount. The amount of overbite correction achieved was 28.8% and 38.9% of the predicted amounts in patients with Class I and Class II malocclusion, respectively. Significant improvements in alignment and interproximal contact scores were observed, with only slight improvements in total ABO scores. An increase in mean occlusal contacts score was observed after treatment. No patient with Class II malocclusions would meet the ABO standards after Invisalign treatment. The Invisalign system successfully achieves certain tooth movements but fails to achieve other movements predictably. No significant Class II correction or overjet reduction was observed with elastics for an average of 7-month duration in the adult population. Additional refinements may be necessary to address problems created during treatment, as evidenced by a posterior open bite incidence.

The effect of extraction of lower primary canines on the morphology of dental arch: A systematic review and meta-analysis.

The beneficial effect of the extraction of primary canines in the resolution of incisor irregularity and its side effects are controversial. To systematically review the effects of the extraction of primary canines in incisor irregularity and dental arch morphology. Controlled non-randomized (non-RCT) and randomized clinical trials (RCT) evaluating children treated with extraction of primary canines compared with those without intervention. A total of 984 articles were found, of which two RCTs and one non-RCT met the inclusion criteria. Both had a low RoB. A high level of evidence was observed through GRADE. A meta-analysis showed the extraction of primary canines produced a significant decrease in incisor irregularity (95% CI: -3.56, -2.09mm). This decrease, however, was associated with a reduction of arch length (95% CI: -1.58, -0.94mm), intermolar width (95% CI: -0.61, -0.22mm), and overjet (95% CI: -075, -018). A mild overbite increase was found (95% CI: 0.10, 0.76mm). A high level of evidence showed that the extraction of primary canines improved incisor irregularity in the mixed dentition. Side effects included reduced arch length and intermolar width. A slight reduction in overjet and a mild increase in overbite were also observed. When they are not part of the treatment goal, these occlusal changes can be prevented by installing a lingual arch.

A prospective clinical trial of the effects produced by the extrusion arch in the treatment of anterior open bite

AimTo evaluate the maxillary dentition effects of the extrusion arch for anterior open bite (AOB) correction in mixed dentition patients.Materials and methodsFourteen subjects with an initial mean age of 9.17 ± 1.03 years presenting with dentoalveolar AOB (mean − 1.28 ± 1.46 mm) and normal facial pattern (FMA = 25.76°) were treated with an extrusion arch. The mean treatment period was 7.79 ± 2.58 months. Lateral cephalograms and dental models were taken before (T0) and after the correction of AOB (T1). Data were analyzed using paired t test to evaluate differences between T0 and T1. For all tests, a significance level of P < .05 was used.ResultsAll patients achieved positive overbite at T1, with a mean increase of 3.07 mm. The maxillary incisors extruded 1.94 mm. Retroclination of the maxillary incisors (− 6.15°) and an increase in the interincisal angle (5.57°) were observed. There was a significant decrease in the distance between the incisal edge of the maxillary incisors and the molars (− 2.21 mm). There was significant mesial tipping of the maxillary molar (− 11.49°). Significant reductions of overjet (− 1.65 mm), arch perimeter (− 3.02 mm), and arch length (− 2.23 mm) were noted. The transverse maxillary intermolar distance did not change significantly.ConclusionsThe use of a maxillary extrusion arch was effective in the treatment of AOB. Overbite increased due to incisor extrusion, as well as retroinclination and overjet reduction. However, side effects, such as mesial molar tipping and decreases in arch perimeter and length might occur.

Bone Changes in the Condylar Process of the Mandible in Computed Tomography Images and Cephalogram in a Female Patient during a Growth Spurt Treated with a Removable Functional Appliance.

Introduction Functional treatment is the type of treatment preferred in young patients with lateral bite because it leads to simultaneous improvement of occlusion and facial profile. Objective The aim of this study is to assess bone changes within the condylar process of the mandible and to associate them with the changes observed in the analysis of lateral cephalograms and in the patient's occlusion. Materials and Methods Cone beam tomography of the temporomandibular joint, lateral radiogram of the skull, was performed at the beginning of treatment and after one year of therapy. Changes in cephalometric radiograms were evaluated by analyzing them and shown by making superimposition and staining layers. For the purpose of assessing bone changes within the condylar process, digital 3D solids of these processes were generated using data from computed tomography. Results Correction towards Angle's dental class I, overjet reduction from 8 mm to 3 mm, and improvement of the patient's profile were obtained. A rotation of the occlusal plane and improvement in an ANB by 1° and in the WITS measurement by 2.7 mm were observed. A growth of the condylar processes “backwards” and “upwards” was also observed, as well as a change of their shape and volume. Conclusions The obtained results suggest that the patient's significant improvement in occlusal conditions is due to posterior growth stimulation of the condylar processes of the mandible. The results confirm the validity of using this treatment technique in the case of growing children with complete posterior occlusion.