Does head posture have a significant effect on the hyoid bone position and sternocleidomastoid electromyographic activity in young adults?

Relationship of temporomandibular joint disorders with cervical posture and hyoid bone position

OBJECTIVE

To evaluate craniocervical posture and hyoid bone position in patients with and without temporomandibular joint disorder (TMD).

METHODS

A total of 113 people were included in the study, including 55 TMD patients and 58 healthy controls. Using lateral cephalograms, the craniofacial, craniocervical, and hyoid bone positions of the participants were evaluated in terms of 27 variables.

RESULTS

There was no significant difference in craniocervical angles between participants with or without TMD. While the Hy-B, Hy-NSL, Hy-NL measurements and FMA (°), AFH (mm) measurements of participants with TMD were lower than the control group, the hyoid angle was greater than the control group.

CONCLUSION

These study findings provide evidence that TMD is not related to craniocervical posture but to the position of the hyoid bone and craniofacial morphology.

Evaluation of head and cervical spine posture after functional therapy with Twin‑Block and Bionator appliances: A pilot randomized controlled trial

OBJECTIVE

Evaluation of head and cervical spine posture and estimation of sample size.

METHODS

Thirty eligible participants who required functional therapy were randomly assigned to the Control group (C), Twin Block group (TB), or the Bionator group (B). Randomization was accomplished by means of blocks of fixed size stratified by sex and age, with the allocations concealed in opaque and sealed envelopes.

RESULTS

Significant differences were identified between the pre -and post-functional SNB (p = 0.024) and ANB (p = 0.034) angles in the Twin Block group and SNA (p = 0. 019) and ANB (p = 0. 028) angles in the Bionator group. No statistically significant changes were seen in the head or cervical variables in the three groups.

CONCLUSION

The functional appliance did not cause any statistical change in head posture or cervical spinal column in comparison with the non-treatment group.

Preoperative Localization of the Carotid Bifurcation for Cervical Carotid Exposure Using the Mastoid-Hyoid Line

Background and Importance:

The location of the carotid bifurcation (CB) is highly variable, which makes precise exposure of the cervical carotid artery difficult, especially in transverse incisions. The method for preoperative localization of the CB is not well established. We used the distance from the mastoid-hyoid (M-H) line to the CB, measured preoperatively with computed tomography angiography, to localize the location of the transverse skin incision. We describe and evaluate the accuracy of a method for preoperative localization of the CB for cervical carotid exposure.

Methods:

The researchers retrospectively evaluated 16 patients with aneurysms arising from the internal carotid artery (ICA) who had received cervical carotid exposure using the localization method of incision and were retrospectively evaluated from February 2018 to November 2019. The method of measurement and localization of the skin incision are described, and two illustrative cases are demonstrated.

Results:

Saccular aneurysms of the ophthalmic (C2) segment and communicating (C1) segment of the ICA were found in 8 and 8 patients, respectively. Nine patients had left-sided exposure, and 7 patients had right-sided exposure. The mean distance from the M-H line to the CB was 2.1 cm (range 0.5–3.5 cm). The accuracy of this method was 93.8%. No paralysis of the depressor anguli oris or the depressor labii inferioris was found postoperatively.

Conclusion:

The distance from the M-H line to the CB can be used to estimate transverse skin incisions for cervical carotid exposure.

Hyoid Bone Position and Head Posture in Patients With Richieri-Costa Pereira Syndrome (EIF4A3 Mutations)

Robin sequence with cleft mandible and limb anomalies, known as Richieri-Costa-Pereira syndrome (RCPS), is an autosomal recessive acrofacial dysostosis characterized by mandibular cleft and other craniofacial anomalies and respiratory complications. The aim of this cross-sectional study was to describe the hyoid and head posture of 9 individuals with RCPS using cephalometric measurements and provide a discussion about its implications in obstructive sleep apnea syndrome (OSAS). The study was conducted on lateral cephalograms of patients with RCPS and 9 selected age-matched controls in tertiary cleft center in Brazil. The cephalograms were digitized and analyzed on a software to obtain the vertical and horizontal hyoid position, its relationship with the mandible and the relation of the cranial base and postvertebral line. The t test was used for analysis of means and Levene's test for equality of variances.Cephalometric measurements H-S (vertical distance between hyoid bone and sella) (Supplemental Digital Content, Figure 1, http://links.lww.com/SCS/B247) and H-C4lp (horizontal position of the hyoid in relation to the post-pharyngeal space) showed statistically significant difference compared to controls (P < 0.05). Therefore, the hyoid bone was more inferiorly and posteriorly positioned in the study group compared with the control group. The vertebrae measurements did not present differences compared to controls. The described position of hyoid bone could be involved in the severe OSAS of RCPS patients.

Relationship between age, BMI, head posture and superficial neck muscle stiffness and elasticity in adult women

This study determined relationships between age, BMI and cranio-vertebral angle (CVA) (independent variables) and stiffness and elasticity of sternocleidomasteoid [SCM] and upper trapezius [UT] (dependent variables) muscles in sitting posture in 95 women across adult life. Moreover, a stepwise regression was performed to determine to what extent the dependent variables are explained by age, BMI and CVA. Age was moderately correlated with BMI (r = 0.41), and both age and BMI were moderately negatively correlated with CVA (r = −0.54 and −0.55, respectively). High (r = 0.73) and moderate (r = 0.53) linear relationships were present between age and logarithmic decrement (inversely related to elasticity) and stiffness of SCM muscle, respectively. Low (r = 0.36) and moderate (r = 0.47) relationships were present between age and logarithmic decrement and stiffness of UT muscle, respectively. Age accounted for 53% variance in elasticity and 28.5% variance in stiffness of SCM, and for 13% variance in elasticity and 22% variance in stiffness of UT muscle. Introduction of BMI but not CVA to the model explained the variance of these parameters by additional 0–8%. Among the studied factors age is the major correlate of stiffness and elasticity of neck muscles across the adult life.

Influence of Forward Head Posture on Myotonometric Measurements of Superficial Neck Muscle Tone, Elasticity, and Stiffness in Asymptomatic Individuals With Sedentary Jobs

OBJECTIVE

The objective of the study was to assess the influence of forward head posture on the mechanical parameters and pressure pain threshold of superficial neck muscles in clinically nonsymptomatic individuals with sedentary jobs.

METHODS

Twenty-five office workers with forward head posture and 25 office workers with normal head posture were matched for sex, age, body mass index, and the nature and duration of their work and were compared at a single point. The study participants were divided into study groups on the basis of photometric craniovertebral angle measurements. The upper trapezius, sternocleidomastoid, and splenius capitis mechanical properties were assessed in the sitting position. Primary outcome measures were muscle stiffness (N/m), muscle tone (Hz), and muscle elasticity. The secondary variable was perceived pain threshold.

RESULTS

No significant differences between the groups were found for biomechanical properties and perceived pain threshold in the studied muscles.

CONCLUSION

Forward head posture has no impact on muscle stiffness, tone, and elasticity, nor does it increase the pressure sensitivity of superficial neck muscles in healthy, mildly symptomatic office workers. It is most likely that not incorrect posture of the cervical spine, but probably other factors combined with forward head posture, like comorbid acute and chronic cervical pain and musculoskeletal disorders or prolonged sitting, contribute to changes in active myofascial tone and tensegrity as well as increased pressure sensitivity of neck muscles.

A Device Improves Signs and Symptoms of TMD

Background

Temporomandibular joint dysfunction (TMD) therapy remains an open challenge for modern dentistry. Herein, we propose a new neuromuscular lingual device able to reduce signs and symptoms of TMD in female patients with chronic orofacial pain.

Methods

50 females with myofascial TMD according to RDC/TMD were randomly assigned to study (n = 25) and control groups (n = 25). At T0, both groups received sEMG/KNG and pain evaluation by the VAS scale. The study group received the ELIBA device (lingual elevator by Balercia) constructed under ULF-TENS (ultra-low-frequency transcoutaneous electrical nervous stimulation). Subjects were instructed to use ELIBA at least for 16 h/day. After 6 months (T1), both groups underwent to sEMG/KNG and VAS revaluation.

Results

T1 study group compared to controls showed a significant reduction in total (p < 0.0001) and mean (p < 0.0001) sEMG values, as well as a significant increase in both maximum vertical mouth opening (p=0.003) and maximum velocity in mouth opening (p=0.003) and closing (p < 0.0001). Interestingly, a significant reduction in pain measured by VAS (p < 0.0001) was reported.

Conclusions

After 6 months, the ELIBA device is able to significantly reduce TMD-associated myogenous pain and to promote the enhancement of sEMG/KNG values.

Practical Implications

ELIBA can be considered as a new device, potentially useful for head-neck pain relief in patients suffering from chronic TMD. In addition, its use promotes a muscles relaxation inducing freeway space increase. This characteristic makes it particularly useful for rehabilitation of patients with not enough space for construction of conventional orthotics or neuromuscular bites.

Ultrasonographic evaluation of geniohyoid muscle and hyoid bone during swallowing in young adults

OBJECTIVES/HYPOTHESIS

The geniohyoid muscle plays an important role in hyoid bone movement. Adequate hyoid bone movement during swallowing is important for effective bolus flow and pharyngeal clearing. The aim of this study was to estimate the relationship between the geniohyoid muscle size and function and hyoid bone movement during swallowing in healthy young adults, as measured via ultrasound, in different body positions.

STUDY DESIGN

Cross-sectional study.

METHODS

Forty young (20-40 years old) adults (20 male and 20 female) participated. The cross-sectional area of the geniohyoid muscle at rest (seated position), the geniohyoid muscle contraction velocity, and the hyoid bone displacement during swallowing 10 mL of mineral water were measured by ultrasound in seated, supine, and right lateral decubitus positions.

RESULTS

The size of the geniohyoid muscle correlated with body height. Males had larger geniohyoid cross-sectional area than females and greater maximal and anterior hyoid displacement during swallowing than females, and maximal and anterior hyoid bone displacement during swallowing correlated with the size of geniohyoid muscle only when the body was in the supine position; these two movements were positively correlated to each other.

CONCLUSIONS

Genders vary in hyoid bone movement during swallowing, and the correlation between geniohyoid muscle size and hyoid bone displacement varies among different body positions during swallowing. This investigation also illuminates the use of ultrasound in providing quantitative measures of geniohyoid muscle and hyoid bone displacement during swallowing.

LEVEL OF EVIDENCE

2c.

Influence of the chin-down and chin-tuck maneuver on the swallowing kinematics of healthy adults

The purpose of the study was to investigate the influence of the chin-tuck maneuver on the movements of swallowing-related structures in healthy subjects and formulate standard instructions for the maneuver. A total of 40 healthy volunteers (20 men and 20 women) swallowed 10 mL of diluted barium solution in a “normal and comfortable” position (NEUT), a comfortable chin-down position (DOWN), and a strict chin-tuck position (TUCK). Resting state anatomy and kinematic changes were analyzed and compared between postures. Although angles of anterior cervical flexion were comparable between DOWN (46.65 ± 9.69 degrees) and TUCK (43.27 ± 12.20), the chin-to-spine distance was significantly shorter in TUCK than in other positions. Only TUCK showed a significantly shorter anteroposterior diameter of the laryngeal inlet (TUCK vs. NEUT, 14.0 ± 4.3 vs. 16.3 ± 5.0 mm) and the oropharynx (18.8 ± 3.1 vs. 20.5 ± 2.8 mm) at rest. The maximal horizontal displacement of the hyoid bone was significantly less in TUCK (9.6 ± 3.0 mm) than in NEUT (12.6 ± 2.6 mm; p < 0.01) or DOWN (12.1 ± 3.0 mm; p < 0.01). TUCK facilitated movement of the epiglottic base upward (TUCK vs. NEUT, 15.8 ± 4.7 vs. 13.3 ± 4.5 mm; p < 0.01). In contrast, DOWN increased the horizontal excursion of the epiglottic base and reduced movement of the vocal cords. These results quantitatively elucidated the biomechanical influences of the chin-tuck maneuver including reduced horizontal movement of the hyoid bone, facilitation of vertical movement of the epiglottic base, and narrowing of the airway entrance. Comparing DOWN and TUCK, only TUCK induced significant changes in the airway entrance, hyoid movement, and epiglottic base retraction.

Cephalometric investigation of first cervical vertebrae morphology and hyoid position in young adults with different sagittal skeletal patterns

The aim of this retrospective study was to examine hyoid bone position and C1 (atlas) morphology in males and females and analyze these parameters with respect to different sagittal skeletal patterns via cephalometry, with the goal of identifying cephalometric norms. Lateral cephalometric radiographs from 120 individuals (average age: 21.1 ± 2.9 years) were classified according to their ANB angle (Class I, II, or III) and used to assess 14 parameters. Class I and II patients showed significant differences in Hy-NSL, Hy-PD, Hy-CVT, Lum, and a-p measurements. These parameters were consistently larger in males than in females. Intergroup comparisons among males showed significant differences in the SNA, ANB, Hy-CVT, X, and Z measurements. The hyoid was positioned more inferiorly and anteriorly and was more prominent in males than in females in all groups. Among participants exhibiting a Class I skeletal pattern, C1 was also larger in the anterior-posterior direction in males than in females. In the sagittal plane, the hyoid was positioned similarly in males with either Class I or III skeletal patterns but was positioned posteriorly in males with a Class II skeletal pattern. In addition, the vertical position of C1 varied with sagittal skeletal pattern in males.

Sagittal plane kinematics of the adult hyoid bone

The hyoid bone is a unique bone in the skeleton not articulated to any other bone. The hyoid muscles, which attach to the hyoid bone, may play a role in neck mechanics, but analysis of their function requires quantifying hyoid bone mechanics. The goal of this study was to obtain the detailed kinematics of the hyoid bone over a large range of flexion-extension motion using radiographs at 5 postures. The position of the hyoid bone in the sagittal plane was characterized with respect to head, jaw, and vertebral movements. Sex differences in hyoid kinematics were also investigated. We hypothesized that (1) the position of the hyoid bone in the sagittal plane is linearly correlated with motion of the head, jaw, and vertebrae, and (2) the hyoid position, size, and kinematics are sex-specific. We found that the hyoid bone X, Y, and angular position generally had strong linear correlations with the positions of the head, jaw, and the cervical vertebrae C1-C4. Hyoid X and angular position was also correlated to C5. Sex differences were found in some regressions of the hyoid bone with respect to C1-C5. The angular and linear measurements of the hyoid bone showed sex differences in absolute values, which were not evident after normalization by posture or neck size. Incorporating these results to neck models would enable accurate modeling of the hyoid muscles. This may have implications for analyzing the mechanics of the cervical spine, including loads on neck structures and implants.