Related Experiment Video
Updated: Apr 10, 2026
A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
Vertical effects of cervical headgear in growing patients with Class II malocclusion: a systematic review and
Umar Hussain1, Ahsan Memood Shah2, Fazli Rabi3
1Department of Orthodontics, Saidu College of Dentistry, Khyber Pakhtunkhwa, Swat, Pakistan.
Background:
Cervical headgear (cHG) has been shown to be effective in Class II correction both with dental and orthopaedic effects but has traditionally been associated with vertical adverse effects in terms of posterior mandibular rotation.
Objective:
To assess the treatment effects of cHG treatment in the vertical dimension.
Search Methods:
Unrestricted literature search of five databases up to May 2023.
Selection Criteria:
Randomized/non-randomized clinical studies comparing cHG to untreated controls, high-pull headgear (hp-HG), cHG adjuncts, or other Class II treatment alternatives (functional appliances or distalisers).
Data Collection And Analysis:
After duplicate study selection, data extraction, and risk-of-bias assessment according to Cochrane, random-effects meta-analyses of mean differences (MD)/standardized mean diffences (SMD) and their 95% confidence intervals (CIs) were performed, followed by meta-regressions, sensitivity analyses, and assessment of certainty on existed evidence.
Results:
Two randomized/16 non-randomized studies (12 retrospective/4 prospective) involving 1094 patients (mean age 10.9 years and 46% male) were included. Compared to natural growth, cHG treatment was not associated on average with increases in mandibular (eight studies; SMD 0.22; 95% CI -0.06, 0.49; P = 0.11) or maxillary plane angle (seven studies; SMD 0.81; 95% CI -0.34, 1.95; P=0.14). Observed changes translate to MDs of 0.48° (95% CI -0.13, 1.07°) and 1.22° (95% CI -0.51, 2.94°) in the SN-ML and SN-NL angles, respectively. No significant differences were seen in y-axis, facial axis angle, or posterior face height (P > 0.05). Similarly, no significant differences were found between cHG treatment and (i) addition of a lower utility arch, (ii) hp-HG treatment, and (iii) removable functional appliance treatment (P > 0.05 for all). Meta-regressions of patient age, sex, or duration and sensitivity analyses showed relative robustness, while our confidence in these estimates was low to very low due to the risk of bias, inconsistency, and imprecision.
Conclusions:
cHG on average is not consistently associated with posterior rotation of the jaws or a consistent increase in vertical facial dimensions among Class II patients.
Registration:
PROSPERO registration (CRD42022374603).
More Related Videos
Related Concept Videos
01:19Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
01:16Eccentric Axial Loading in a Plane of Symmetry
01:12General Case of Eccentric Axial Loading
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical...