Prevalence, magnitude, and incidence of labial gingival recession with Herbst-multibracket appliance treatment: A retrospective cohort study

Class II subdivision treatment and stability with asymmetric Herbst appliance: A case report

Non-surgical treatment of Class II subdivision may involve complex mechanics or asymmetric tooth extraction in its resolution. This report demonstrates the result and the short-term stability of Class II subdivision treated with asymmetrically installed Herbst appliance followed by conventional fixed orthodontic appliance. The approach allowed the correction of the unilateral Class II molar relationship and increased overjet, as well as the deviation of dental midlines, with improvement in lip posture and facial profile. The results remained stable two years after treatment, confirming the treatment success.

Herbst-multibracket appliance treatment: is there an association between lower incisor position changes and the development of labial gingival recessions?

PURPOSE

To assess a potential association between lower incisor (LI) position changes during Herbst-multibracket appliance (Herbst-MBA) treatment and the development of labial gingival recessions (LGR).

METHODS

All class II patients (Department of Orthodontics, University of Giessen, Giessen, Germany) who had undergone Herbst-MBA treatment until 2015 with study models and lateral cephalograms available from before (T0) and after treatment plus ≥24 months of retention (T3) were included (n = 259). Lateral cephalograms were evaluated regarding LI position changes: iiL/ML (angle between LI long axis and mandibular plane [MP]), ii-MLPg (distance between LI incisal edge and a line perpendicular to MP through pogonion), apex-MLPg (distance between LI apex and a line perpendicular to MP through pogonion), ii-MLii (distance between LI incisal edge and MP on a line perpendicular to MP through incisal edge). Using study models the distance between the cementoenamel junction and the deepest point of the gingival margin was defined as LGR.

RESULTS

The following cephalometric mean changes were recorded (T0-T3): iiL/ML +5.9 ± 5.76° (p = 0.929), ii-MLPg -0.2 ± 0.25 mm (p = 0.430), apex-MLPg +0.1 ± 0.32 mm (p = 0.363), ii-MLii +0.1 ± 0.36 mm (p = 0.206). The mean increase of LGR magnitude measured on the study models was 0.1 ± 0.35 mm. However, no association with the cephalometric LI position changes was found (|R| ≤ 0.2).

CONCLUSION

There is no association between the amount of LI position changes and the development of LGR during Herbst-MBA treatment plus retention. Nevertheless, individual predisposition or excessive treatment changes and extraordinary treatment approaches, respectively, might still lead to development of LGR.

Skeletal and dentoalveolar contributions during Class II correction with Forsus™ FRD appliances : Quantitative evaluation

PURPOSE

Primary objective of the study is to quantify and evaluate the skeletal and dental contributions during sagittal Class II correction with the Forsus™ fatigue resistant device (FRD; 3M Unitek Corp., Monrovia, CA, USA). Secondary objective is to evaluate the overall vertical, soft tissue and chin-throat relation changes with the Forsus™ appliance.

PATIENTS AND METHODS

A retrospective sample of 27 Class II patients treated with the Forsus™ FRD appliance was compared to 20 untreated control subjects who were matched according to age and craniofacial morphology. Pre-Forsus™ (T0) and Post-Forsus™ (T1) cephalograms were subjected to composite cephalometric analysis. Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. The data were analyzed using Student's t‑test and independent t test.

RESULTS

Significant differences were found between the treated and the control group in 16 of 29 measured variables. The overjet and molar relation improved by 4.23 mm and 4.49 mm, respectively. This was mainly achieved by backward movement of maxillary incisors (1.4 mm) and molars (1.22 mm) and forward movement of mandibular incisors (2.26 mm) and molars (2.70 mm). Overbite decreased by 2.24 mm with no changes in mandibular and nasal plane angles.

CONCLUSION

The Forsus™ FRD was effective in correcting Class II malocclusion mainly at the dentoalveolar level. The net skeletal and dentoalveolar contributions towards both overjet and molar correction was 13% and 87%, respectively. The improvement in soft tissue profile and chin-throat configuration was statistically insignificant.

Class II:2 malocclusion-prevalence and progression of labial gingival recessions during Herbst-Multibracket appliance treatment

OBJECTIVES

To determine the prevalence, incidence, and changes in magnitude of labial gingival recessions (LGR) in class II:2 patients during Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention.

SUBJECTS AND METHODS

All class II:2 patients of the Department of Orthodontics, University of Giessen, Germany who completed Herbst-MBA Tx (mean pre-Tx age 15.6 years). The cohort had undergone a Herbst phase (mean 8.1 months) as well as a subsequent MBA phase (mean 14.4 months). Study casts were evaluated from pre-Tx and after Herbst-MBA Tx plus ≥ 24 months of retention.

RESULTS

Ratable pre-Tx and post-retention study casts (total observation period 53.5 ± 10.3 months) were available from 94 out of 173 patients. No significant difference existed regarding pre-Tx LGR data between patients with and without complete records. The prevalence for teeth with LGR ≥ 0.5 mm was 1.4% pre-Tx respectively 6.7% post-retention. The highest values of up to 5.3% (pre-Tx) and 20.2% (post-retention) were determined for the upper first premolars and lower central incisors. Incidence values of 4.7% (all teeth) and up to 14.9% (upper first right premolars) respectively 11.1% (lower central incisors) were calculated (LGR ≥ 0.5 mm). The overall LGR mean magnitudes were 0.01 mm pre-Tx respectively 0.06 mm post-retention.

CONCLUSIONS

For the prevalence of LGR ≥ 0.5 mm an average increase of 5.3% was determined during ≈ 4.5 years of Herbst-MBA Tx plus retention. The highest incidence was seen for lower central incisors and upper right premolars (11.1/14.9%). The overall LGR mean magnitude increased by 0.05 mm.

CLINICAL RELEVANCE

Herbst-MBA Tx is a common approach for class II:2 malocclusions. Very little, however, is known regarding LGR development in respective patients.