Cephalometric evaluation of pharyngeal airway and tongue space following treatment with Herbst and AdvanSync appliances : A prospective randomized clinical trial

OBJECTIVES

To evaluate and compare pharyngeal airway and tongue space changes after treatment with fixed functional appliances-Herbst and AdvanSync™ (Ormco, Orange, CA, USA) appliances-in skeletal class II patients in pre- and posttreatment lateral cephalograms.

METHODS

For this randomized, controlled trial, 40 patients (21 male, 19 female) were divided into two groups-a Herbst group (mean age 12.6 ± 0.67 years) and an AdvanSync group (mean age 12.8 ± 0.66 years). Pre- and posttreatment (appliance therapy duration-8 months) lateral cephalograms were traced using a software program to evaluate pharyngeal airway and tongue space changes.

RESULTS

Nasopharyngeal airway, velopharyngeal airway, glossopharyngeal airway, and hypopharyngeal airway increased in the Herbst group by 2.12 mm (p ≤ 0.001), 2.33 mm (p ≤ 0.001), 2.40 mm (p ≤ 0.01), and 1.57 mm (p ≤ 0.05), while in the AdvanSync group the increases were 1.89 mm (p ≤ 0.001), 1.21 mm (p ≤ 0.001), 1.18 mm (p ≤ 0.001), and 1.53 mm (p ≤ 0.001), respectively. In the Herbst group, tongue length and height increases were 2.04 mm (p ≤ 0.01) and 3.74 mm (p ≤ 0.001), while the values in the AdvanSync group were 2.41 mm (p ≤ 0.05) and 2.69 mm (p ≤ 0.001). The change of the tongue tip from the lower occlusal plane was 0.69 mm (p ≤ 0.001) in the Herbst group and 0.77 mm (p ≤ 0.001) in the AdvanSync group. The velopharyngeal airway dimension was correlated positively with that of the retroglossal oropharyngeal airway, which in-turn positively correlated with the laryngopharyngeal airway which correlated well with the distance of the tongue tip from the lower occlusal plane.

CONCLUSIONS

The airway dimensions and tongue parameters increased significantly in both treatment groups in the present study. These changes were higher in the Herbst appliance than in the AdvanSync group, except for the distance of the tongue tip from the lower occlusal plane. A significant difference between the pharyngeal airways was found only for the retropalatal oropharyngeal airway.

Effect of fixed functional appliances on pharyngeal airway dimensions in Skeletal Class II individuals - A scoping review

BACKGROUND

Skeletal Class II malocclusion due to a retrognathic mandible produces a backwardly positioned tongue and soft palate, emanating compromised upper airway dimensions and breathing difficulties.

AIMS

The present review aims to explore and concise the findings of the existing studies assessing the effects of fixed functional appliances on pharyngeal airway dimensions by advancing the mandible.

DESIGN

A literature search was carried out on MEDLINE/PubMed, Cochrane Library, Science direct, Semantic Scholar and Google Scholar databases for studies up to December 2020, resulting in 1037 studies. Specified inclusion/exclusion criteria guided the selection of 18 relevant articles. The sample size, type of the appliance, method of assessment and outcomes of these articles were assessed in detail and tabulated.

RESULTS

Out of 18 studies included, 12 were retrospective longitudinal and the remaining were clinical trials. Majority of the studies (72%) reported a positive influence of the fixed functional appliances on the dimensions of the oropharyngeal and hypopharyngeal airways with minimal effects on nasopharyngeal airway.

CONCLUSION

Thus, it can be concluded that fixed functional appliances have a beneficial effect on the middle and lower pharyngeal airway dimensions by advancing the mandible.

Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances

OBJECTIVES

The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance.

MATERIALS AND METHODS

Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed.

RESULTS

The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05).

CONCLUSION

The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors.

CLINICAL RELEVANCE

Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.

Management of skeletal class II malocclusion using bimaxillary skeletal anchorage supported fixed functional appliances : A novel technique

AIM

To evaluate the treatment effects in growing skeletal class II patients subjected to a novel treatment technique, i.e., bimaxillary miniplates supported fixed functional appliance. The null hypothesis was that there is no statistically significant difference in skeletal changes of patients with class II malocclusion treated with bimaxillary skeletal anchorage supported fixed functional appliance and those who were not provided any intervention.

METHODS

The sample comprised 32 skeletal class II subjects (17 males and 15 females) with a Cervical Vertebrae Maturity Index (CVMI) demonstrating peak of pubertal growth spurt. Sixteen patients (12.37 ±1.09 years of age) were treated with bimaxillary skeletal anchorage supported fixed function appliance, while 16 well-matched subjects (12.06 ± 1.34 years of age) were included as controls. For both groups, cephalograms (T1, T2) were taken with a matched observational interval of about 7.5 months; 17 linear and 10 angular measurements were recorded. The intraclass correlation coefficient (ICC) was used to determine reliability of measurements recorded. Student t test was carried out to determine the changes produced by the treatment relative to control.

RESULTS

When compared with the control group, the treatment group demonstrated significant maxillary retrusion. No significant changes were seen in mandibular growth pattern, whereas mandibular length increased significantly more than in the control group (B-VP: 3.05 mm; Co-Gn: 2.65 mm). Treatment mechanics had minimal effects on maxillary dentition. Mandibular incisors proclined by an average of 3.06°. Maxilla-mandibular relation improved significantly (ANB: -4.29°; NA-Pog: -3.76°).

CONCLUSION

The new bimaxillary skeletal anchorage supported fixed functional appliance technique was found to be highly effective in the treatment of class II malocclusion with significant skeletal changes.

Angle class II correction: stepwise mandibular advancement or bite jumping? : A systematic review and meta-analysis of skeletal, dental and condylar effects

INTRODUCTION

There is no consensus regarding which mode of activation or mandibular advancement (stepwise [SW] or maximum bite-jumping [BJ]) of fixed or removable functional appliances (FFA; RFA) for correction of Angle class II malocclusion is advantageous to produce dental, skeletal or condylar effects and has the lowest rate of undesired dental or technical side-effects.

METHODS

A systematic search was conducted up to Oct. 20, 2019 in the MEDLINE, EMBASE, Scopus, Central Cochrane Library, and BBO databases. Included were preadolescent, adolescent, and adult humans with initial (pretreatment) Angle class II malocclusion, without further restriction. The intervention group was composed of subjects treated with FFA or RFA in SW mandibular advancement; the control group received BJ advancement. Search terms included prospective randomized and nonrandomized trials in English, German, Spanish, and Portuguese with the primary outcomes of skeletal and dental class II correction, effects on condylar growth, lower incisor proclination, overjet and overbite reduction. The risk of bias (ROB) was assessed using the Cochrane Collaboration's ROB2 tool. Mean differences were calculated and pooled by a meta-analysis using a random effects model.

RESULTS

Data from five randomized controlled trials (RCT) with 401 participants (mean age 13.84 years; SD 1.53) were included; 331 derived from four studies were included in the meta-analysis. The ROB in the selected articles was high. We detected a slightly increased reduction of the ANB (mean difference [MD] -0.95°, 95% confidence interval [CI] -1.80 to -0.10°; I² = 72%) that may be attributed to a slightly more pronounced increase of the SNB angle in SW-advanced mandibles (MD 0.27°; 95% CI -0.47 to 1.00°; I² = 38%). SW advancement tended to reduce the undesired side effect of lower incisor proclination (MD = -1.59°; 95% CI -3.98 to 0.8°; I² = 0%), indicating more pronounced mandibular incisor changes with bite-jumping advancement.

CONCLUSION

There is weak evidence indicating a slightly increased reduction of the ANB and less lower incisor proclination with SW advancement compared to BJ, but the clinical relevance is debatable due to the small overall magnitude and small number of high-quality papers.

REGISTRATION

Prospero #CRD42017075469 (www.crd.york.ac.uk/prospero).

The Evaluation and Clinical Efficiency of Power Scope: An Original Research

AIMS AND OBJECTIVES

Managing mild-to-moderate Class II malocclusion is one of the common and major challenges to orthodontists. Class II discrepancies with mandibular deficiency during active growth are usually treated using myofunctional appliances. Fixed functional appliances evolved due to the noncompliance with conventional myofunctional appliances. One of the latest Class II correctors is the PowerScope appliance. The purpose of this study was to determine the amount, time, and rate of molar correction and efficacy of PowerScope.

MATERIALS AND METHODS

A total of 10 participants, between 15 and 19 years' age group (mean = 16.8 years; 5 males and 5 females), requiring treatment of Class II malocclusion were considered for this study. All routine records were made. After initial leveling and alignment, lateral cephalogram was taken in standardized natural head position using Planmeca ProMax unit. Later, PowerScope was installed and a patient was monitored every month for further adjustment and reactivation. On achieving Class I molar relation, skeletal, dental, and soft-tissue linear and angular parameters were measured using Dolphin Imaging Software. Amount, rate, and total treatment time for molar correction were measured. Molar correction was calculated by taking S vertical as reference plane. The obtained values were statistically analyzed using paired t-test.

RESULTS

There were statistically significant changes seen in dentoalveolar parameters such as lower incisor proclination, mandibular molar advancement, and reduction in both overjet and overbite. In skeletal parameters, due to the anterior positioning of the mandible, sagittal parameters showed statistically significant changes. In the soft tissue, a significant improvement in facial profile was seen, due to the anterior movement of soft-tissue pogonion.

CONCLUSION

The results of this study have shown that statistically significant differences were found in dentoalveolar, soft-tissue, and skeletal parameters.

Effects of Sabbagh Universal Spring 2 fixed functional appliance on class II/1 patients at their postpubertal-peak growth period compared with the extraction method : A randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the therapeutic effects of the Sabbagh Universal Spring 2 (SUS 2) fixed functional appliance compared to the premolar extraction method in correcting class II/1 malocclusion in patients who had passed their peak of postpubertal growth (stages 4-6 of Cervical Vertebral Maturation Index).

METHODS

In all, 40 class II/1 patients were randomized to receive SUS 2 application (7 males, 13 females, age 15.75 ± 1.02 years) or maxillary premolar extraction (8 males, 12 females, age 15.40 ± 0.99 years). Pre- and posttreatment digital cephalographs were traced at least twice. A paired t test was used to compare the pre- and posttreatment measurements. Treatment changes were compared using an independent samples t test (P ≤ 0.05).

RESULTS

The extent of change was significant in the following variables: ANB, nasolabial angle, Mand1-ML, 1L-NB, anterior and posterior facial heights, N-A-Pog, 1U-NF, 6L-MP, Ar-Go, OP-HP, A-B, A-Sn, B-Sm, APDI, NAPog, AB-NPog, POr-DOP, SN-OcP, POr-OcP, Wits, 1 l-APog, 1LMeLm, S-Go:N-Me, N-ANS-Pog, Ap1LAp1u-DOP, ANS-Cond, Pog-Cond, SS-Ls, A-N-Pog, Pog-Pog', MeGoOcP, 1L-Npog, Go-Me, Go-Me:N-S, S-Me, Ls-(Sn-Pog'), Stms-Stmi, N'-Gn', N'NsPog', 6u-PTV, 1u-NA, FMIA, and IMPA.

CONCLUSIONS

SUS 2 corrected class II/1 malocclusion of patients in the postpubertal growth period by inhibiting the maxilla's forward growth, advancing the mandible, decreasing the nasolabial and interincisal angles, proclining the incisors, increasing the facial height, and clockwise rotation of the occlusal plane. Extraction reduced the interincisal angle and protruded the lower incisors. However, it did not change the soft tissue thickness and did not cause a clockwise rotation in the occlusal plane.

Effects of miniplate anchored and conventional Forsus Fatigue Resistant Devices in the treatment of Class II malocclusion

OBJECTIVE

To compare the skeletal, dentoalveolar, and soft tissue effects of the miniplate anchored Forsus Fatigue Resistant Device (FRD) and the conventional Forsus FRD in the treatment of Class II malocclusion.

MATERIALS AND METHODS

The study was carried out with 30 patients (10 girls, 20 boys). In the MA-Forsus group, 15 patients (2 girls, 13 boys) were treated with a miniplate anchored Forsus FRD for 9.40 ± 2.25 months. In the C-Forsus group, 15 patients (8 girls, 7 boys) were treated with a conventional Forsus FRD for 9.46 ± 0.81 months. A total of 16 measurements were calculated and statistically analyzed to find intragroup and intergroup differences.

RESULTS

Statistically significant differences were found between the groups in IMPA, SN/Occ, SN/GoGn, overjet, overbite, and Li-S measurements (P < .05). In the C-Forsus group, a substantial amount of lower incisor protrusion was observed, whereas retrusion was found in the MA-Forsus group (P < .001). The mandible rotated backward in the MA-Forsus group, whereas it remained unchanged in the C-Forsus group (P < .05). Reductions in overjet (P < .001) and overbite were greater in the C-Forsus group (P < .05).

CONCLUSION

Stimulation of mandibular growth and inhibition of maxillary growth were achieved in both treatment groups. In the C-Forsus group, a substantial amount of lower incisor protrusion was observed, whereas retrusion of lower incisors was found in the MA-Forsus group. The MA-Forsus group was found to be more advantageous as it had no dentoalveolar side effects on mandibular dentition.

Treatment and posttreatment effects induced by the Forsus appliance: A controlled clinical study

OBJECTIVE

To evaluate treatment and posttreatment dentoskeletal effects induced by the Forsus device (FRD) in growing patients with Class II malocclusion in a retrospective controlled clinical study.

MATERIALS AND METHODS

Thirty-six Class II patients (mean [SD] age 12.3 [1.2] years) were treated consecutively with the FRD protocol and compared with a sample of 20 subjects with untreated Class II malocclusion (mean [SD] age 12.2 [0.9] years). Lateral cephalograms were taken at the beginning of treatment, at the end of comprehensive treatment (after 2.3 ± 0.4 years), and at a postretention period (after 2.3 ± 1.1 years from the end of comprehensive treatment). Statistical comparisons were carried out with the unpaired t-test and Benjamini-Hochberg correction (P < .05).

RESULTS

After comprehensive treatment, the FRD sample showed a significant restriction of the sagittal maxillary growth together with a significant correction in overjet, overbite, and molar relationship. During the overall observation interval, the FRD group exhibited no significant sagittal or vertical skeletal changes, while significant improvements were recorded in overjet (-3.8 mm), overbite (-1.5 mm), and molar relationship (+3.7 mm).

CONCLUSION

The FRD protocol was effective in correcting Class II malocclusion mainly at the dentoalveolar level when evaluated 2 years after the end of comprehensive treatment.