Dental occlusion and posture: an overview

Head and Cervical Posture in Sagittal Skeletal Malocclusions: Insights from a Systematic Review

Background: This systematic review aims to evaluate the relationship between craniocervical posture and sagittal skeletal malocclusions, focusing on cervical curvature, head posture, and the influence of skeletal classification on craniofacial development. Methods: A comprehensive electronic search was conducted across PubMed, Scopus, and Web of Science for studies published between January 2015 and January 2025. Studies meeting the PICOS criteria, which assessed craniocervical posture in individuals with skeletal Class I, II, or III malocclusions, were included. A total of 12 studies were reviewed and analyzed for relevant data. Results: Significant correlations were identified between sagittal skeletal malocclusions and craniocervical posture, particularly cervical curvature. Class II malocclusion was associated with increased cervical curvature and forward head posture, whereas Class III malocclusion was linked to straighter cervical columns and a more posterior head position. Variations in cervical vertebral morphology were also observed, especially in relation to head posture and craniofacial structure. However, considerable heterogeneity was noted among studies regarding sample populations, measurement techniques, and classification criteria. Conclusions: This review highlights a strong interrelationship between craniocervical posture and sagittal skeletal classification, with potential clinical implications for orthodontic diagnosis and treatment planning. Further longitudinal studies are needed to establish causal relationships and improve orthodontic management strategies.

Exploring postural dynamics and cervical functions in temporomandibular disorder patients: A comprehensive evaluation

OBJECTIVE

To investigate several postural parameters and upper cervical functions in patients with temporomandibular disorders (TMD).

METHODS

Patients diagnosed with different subtypes of TMD and healthy individuals without complaints of TMD were evaluated for pain, functional limitation, and anxiety by validated instruments. For evaluating upper cervical functions and postural parameters, cervical joint range of motion, cervical performance test, tragus wall distance, hamstring flexibility measurement, and measurement of the sacrum angle were recorded.

RESULTS

Pain and jaw functional limitation scores were statistically higher in all groups with TMD. Patients with internal derangement and myofascial pain were significantly linked to a severe limiting of functions, higher anxiety, and depression scores. Postural parameters and cervical functions were similar between groups.

CONCLUSION

Although postural parameters and cervical functions remained unaffected, parameters such as pain, anxiety, and functional limitation that may affect the quality of life were related to unfavorable values in the TMD groups.

The Association between Body Posture and Malocclusion in Adolescents: A Cross-sectional Study

AIM

The purpose of this study was to determine the association between body posture and dental malocclusion in adolescents.

MATERIALS AND METHODS

This descriptive cross-sectional study evaluated the relationship between malocclusion and body posture in 37 adolescents aged 10-14 who met the selection criteria. A trained and calibrated evaluator assessed malocclusion using Angle's classification and evaluated the severity with the dental esthetic index (DAI). Frontal and lateral body postures were reviewed by a licensed medical technology specialist in physical therapy and rehabilitation using a plumb line, with postures classified as correct or incorrect. Data analysis utilized Chi-square tests and binary logistic regressions (p < 0.05).

RESULTS

No association was found between Angle malocclusion and body posture (p = 0.277). However, an association was identified when considering severity, with incorrect frontal posture observed in 77.8% of adolescents with defined malocclusion and 71.4% in those with severe malocclusion (p = 0.035). When malocclusion was regrouped into 2 categories (normal occlusion and malocclusion), a significant association with frontal posture was found (p = 0.035). Logistic regression showed that individuals with defined malocclusion are 9.09-fold more likely to develop improper frontal posture (p = 0.048). Furthermore, when severity was categorized into 2 groups, individuals with malocclusion were found to have a 7.29-fold higher risk of developing incorrect frontal body posture in the position.

CONCLUSION

The severity of malocclusion is associated with incorrect frontal body posture, with individuals with defined malocclusion being more likely to develop improper frontal posture.

CLINICAL SIGNIFICANCE

Patients with the presence of malocclusion has more risk of developing incorrect frontal body posture. Therefore, orthodontists should consider this relationship when treating their patients. How to cite this article: Morales-Atarama PG, Arriola-Guillén LE. The Association between Body Posture and Malocclusion in Adolescents: A Cross-sectional Study. J Contemp Dent Pract 2025;26(1):48-54.

An observational analysis to evaluate the influence of occlusion on body posture and plantar pressure - An in vivo study

AIM

The aim of this study is to evaluate the influence of occlusion on body posture and plantar arch pressure.

SETTINGS AND DESIGN

An Observational analysis to Analyze the Influence of Occlusion on Plantar Pressure and Body Posture.

MATERIALS AND METHODS

A total of 30 asymptomatic subjects were selected for the study including 18 females and 12 males from age group 22 years to 28 years with a mean age of 24.83 years. Each subject underwent evaluation of occlusion at MIP using a Digital Occlusal analyzer (T-Scan III). At this point, the subjects were made to stand on a mat scan which consisted of a large postural platform sensor and a computer that displayed the plantar pressure data. The computer connected to the T Scan displayed the occlusal pressure analysis. This was followed by an evaluation of body posture using a posture grid where the photographs were taken and an evaluation of the frontal and lateral photos was done using the APECS - posture analysis app.

STATISTICAL ANALYSIS USED

Statistical package for social sciences (SPSS) for windows version 22.0 Released 2013, Armonk, N Y: IBM Corp., was used to perform Statistical Analysis. A chi-square test was applied for qualitative variables to find the association. Paired t-test was applied to compare the changes in the quantitative parameters in eye-open and eye-closed conditions. The level of significance was set at 5%.

RESULTS

As observed from the results, occlusion for 40% of the subjects, where n = 12, was dominant on the right side. Occlusion for 23.3% of subjects, where n = 7, was dominant on the left side. Whereas, for 36.7% of subjects, where n = 11, the pressure distribution was almost equal on both sides. The inclination of body posture for 23.3% of subjects, where n = 7, was towards the right side. The inclination of body posture for 50% of subjects, where n = 11, was towards the left side. And, the inclination of body posture for 26.7% of subjects, where n = 8, was neutral i.e., balanced on the right and left side. Plantar pressure for 6.7% of subjects, where n = 2, was dominant on the right side. Plantar pressure for 36.7% of subjects, where n = 11, was dominant on the left side. Whereas, for 56.7% of subjects, where n = 17, the plantar pressure distribution was almost equal on both sides.

CONCLUSION

On correlating the three parameters, it was found that occlusion for most of the subjects dominated on the right side, while body posture and plantar pressure dominated on the contralateral i.e., left side.

Assessing cervical spine and craniofacial morphology in Class II and Class III malocclusions: A geometric morphometric approach

To compare craniofacial and cervical morphology between skeletal Classes II and III applying Geometric Morphometric Methods (GMM). Twenty-six cervical and craniofacial landmarks of 40 Class II and 39 Class III individuals were digitalized on lateral cephalograms. Procrustes ANOVA, generalized Procrustes, principal component analyses, and thin-plate spline function were applied to assess the pattern of shape variation of craniofacial structure and the cervical spine in relation to skeletal classes. Compared with Class III, Class II individuals presented a maxillary protrusion, mandibular retrusion, shorter mandibular corpus, posterior mandibular ramus rotation, anterior cranial base rotation, and a smaller centroid size. Furthermore, a forward and smaller cervical spine were observed. With GMM, the shape and size differences between skeletal classes can be analyzed visually and numerically.

Assessment of the Relationship between Antero-Posterior Dental Malocclusions, Body Posture Abnormalities and Selected Static Foot Parameters in Adults

Objectives: This study aimed to find if a relationship exists between antero-posterior malocclusions and the level of musculoskeletal disorders in adults, including body posture and static foot analysis. Methods: In all, 420 participants were recruited through convenience sampling (Kraków University students and patients of a local dentist's practice). Following general medical interviews, dental examinations and consideration of inclusion and exclusion criteria, 90 healthy volunteers (ages 19-35) were enrolled and assigned to three groups (n = 30) based on occlusion type (Angle's molar Class I, II or III). The research procedure involved occlusion and temporomandibular disorder assessment conducted by a dental specialist. Comprehensive morphological measurements of body asymmetry were performed using the Videography 2D package and FreeSTEP software, which calculated the parameters determined from anterior, posterior and lateral projection photos. Foot loading distribution was analyzed using the FreeMED baropodometric platform. Results: Significant differences were demonstrated in the positioning of the head, cervical and lumbar spine in the sagittal plane among individuals with the analyzed occlusal classes (p < 0.05). Individuals with Angle's Class II exhibited significantly greater forward head positions and greater depths of cervical and lumbar lordosis compared with individuals with Class III or Class I. Those with overbites had higher forefoot loading. The Class III individuals exhibited greater L-R displacement, indicating a larger angle of displacement of the centers of the right and left feet relative to the lower edge of the measurement platform, suggesting pelvic rotation. Conclusions: An inclination for concurrent occurrences of malocclusions and posture deviations in the sagittal plane was observed. An interdisciplinary approach involving dentistry and physiotherapy specialists which utilizes tools for comprehensive posture assessment is crucial for diagnosing and treating such conditions.

The Correlation between Malocclusion and Body Posture and Cervical Vertebral, Podal System, and Gait Parameters in Children: A Systematic Review

Background: This study investigates the relationship between malocclusion and body posture, head posture, podal system, and gait parameters in children. Methods: A systematic review of observational studies from 2010 to 2023 was conducted and 24 cross-sectional studies involving 6199 participants were identified. These studies were categorized into those dealing with body posture (10 studies, 3601 participants), cervical vertebral column and head posture (6 studies, 644 participants), the podal system (5 studies, 1118 participants), and gait (3 studies, 836 participants). Results: Evidence suggests a significant association between malocclusion and body posture, balance, podal system, and gait parameters. Notably, eight studies found a significant relationship between malocclusion and body posture, while five studies identified this relationship with the cervical vertebral column and head posture, five with the podal system, and three with gait parameters. Conclusions: Overall, the quality of evidence was strong for the association between malocclusion and body posture and the podal system and moderate for head posture and gait parameters. These findings offer insights for therapists to design interventions tailored to children with malocclusion based on considerations of body posture, head posture, podal system, and gait parameters, though further longitudinal cohort studies are needed for better predictive understanding.

Mandible Position and Chewing Preference Side Do Not Alter Plantar Support in Children Aged 4-11 Years

Introduction

Mandible positioning can cause global postural adaptations. Physiotherapists and dentists try to relate the mandible position and chewing side to plantar support; however, this indication is uncertain.

Objectives

To check the existence of a relationship between mandible position, preferred chewing side, age, and plantar support in children.

Materials and methods

This is a cross-sectional study with 93 children, aged between 4 and 11 years. Photogrammetry was used to confirm the mandibular positions (centralized, to the right, and to the left), and baropodometry was used to measure plantar support. The mandibular displacement distance to the right and left was evaluated, and the plantar support in the three mandibular positions was compared as a function of age (4-7 and 8-11 years) and preferred chewing side.

Results

There was greater mandibular displacement in left laterality [13 (9-19) cm] compared to right laterality [7 (3.50-12.00) cm] (p < 0.01). Mandibular position did not alter mean pressure, maximum pressure, or plantar support surface (p > 0.05). With the mandible centralized, higher mean pressure, maximum pressure, and surface area were observed in the left foot (p < 0.01). Older children showed greater mandibular displacement to the left (p < 0.01). No differences were observed for the variables of plantar support as a function of age (p > 0.05) and chewing side (p > 0.05). There was a moderate to strong correlation between age, body mass, height, and plantar surface area (0.63 < r < 0.83; p < 0.05) and between mean and maximum pressures of plantar support (0.58 < r < 0.89; p < 0.05).

Conclusion

Mandibular position, age, and preferred chewing side do not influence plantar support in children.

How to cite this article

Bittar KCB, Zamboti CL, Macedo CSG. Mandible Position and Chewing Preference Side Do Not Alter Plantar Support in Children Aged 4-11 Years. Int J Clin Pediatr Dent 2024;17(6):658-664.

Evaluating the Plantar Pressure Loading and Its Correlation to Craniocervical Posture in Subjects With Skeletal Class II Malocclusion Before and After Surgical Mandibular Advancement

Class II malocclusion is one of the most prevalent types of malocclusions following Class I. The most typical postural features observed in Class II patients are extended craniocervical posture, cervical lordosis, and increased forward loading away from the body's centre of mass for compensating the mandibular deficiency and reduced airway. Its treatment involves orthodontic, functional, and orthognathic surgery. The type of treatment regimen opted for depends upon the age, severity of malocclusion, and need of the patient. Thus, appropriate intervention brings about improvement in dentition along with an overall enhancement of the body posture and plantar loading. These variables undergo a significant change whenever there is a change in the maxillomandibular relationship. The main aim of this paper is to correlate the variation in the craniocervical angulation to the plantar pressure distribution during various phases of orthodontic treatment and bilateral sagittal split osteotomy (BSSO) advancement surgery. The craniocervical angulations were determined from the lateral cephalograms of the patients using cephalometric variables and the plantar pressure was estimated using a digital quanpressurometer device (designed and patented in India by Meenakshi Academy of Higher Education and Research; patent number 390136) at each phase, i.e., during pre-treatment, pre-surgery, post-surgery, post-treatment intervals. The outcome of this study indicated that there was a significant change in the craniocervical angulation and the plantar pressure distribution pattern of the subjects before and after orthognathic surgery and it remained constant for six months after orthognathic surgery. The limitation of the study was the limited sample size. This study reveals that there was an improvement in the craniocervical angulation and plantar pressure distribution during the course of orthodontic decompensation and orthognathic surgical treatment, thus bringing about change in the individual's overall body posture and their plantar loading pattern after orthognathic surgery. Therefore, the change in the stomatognathic system by orthodontic and orthognathic treatment influences the overall muscular and functional balance of an individual thereby improving their attitude and lifestyle.

Association between constitution, axiography, orthodontic cast analysis, and upper body posture in women aged 31 to 40 years

OBJECTIVE

Whether it is primarily the spine that reacts with pain to the negative consequences of everyday stress and possibly the temporomandibular system as a result (ascending chain), or whether incorrect stress in the dental area has an influence on body geometry (descending chain), is still a controversially discussed topic. The aim of this study is to investigate possible relationships between constitutional, axiographic, and dental parameters with upper body posture.

MATERIAL AND METHODS

A total of 106 subjectively healthy women between 31 and 40 years of age voluntarily participated in this study. Data collection was done by filling out a questionnaire with constitutional and anamnestic parameters and by evaluating orthodontic casts, axiographic measurements, and video raster stereographic measurements. These data were analyzed using correlations and group comparisons, with the significance level set at p ≤ 0.05.

RESULTS

Positive correlations were shown between the constitutional factors of body weight and BMI and the lumbar bending angle (p = 0.01), the kyphosis angle (p = 0.001), and lordosis angle (weight p = 0.05; BMI p = 0.03). In the cast analysis, regardless of the direction of the midline shift (left/right/none), a left lateral tilt can be seen which is greatest at 2.12° with a left midline shift. In addition, the elevated pelvic side correlates with the side of the displacement of the jaw, with the stronger manifestation being on the left side. With a vertical anterior bite in the normal range, the kyphosis angle is 48.09°, while with a deep bite, it is 60.92°, and with an open bite, it is 62.47°; thus, the group in the normal range differs significantly (p = 0.01) from the other two. The greater the protrusion, the smaller the sagittal plane angles (kyphosis angle, lumbar bending angle, each p = 0.03), and the more dorsal the posture (p = 0.04). The lordosis angle differs significantly (p = 0.001) between the group of subjects with a protrusion in the normal range (52.34°) and the group with an increased advancement of the mandible (41.79°).

CONCLUSION

There is a correlation between body weight, BMI, midline shift, and protrusion, as well as the vertical anterior step and upper body posture in women between 31 and 40 years of age. Interdisciplinary functional examinations of the temporomandibular musculature, and also sustained orthodontic treatment, can contribute to an improvement in upper body posture.

Dental Malocclusion in Mixed Dentition Children and Its Relation to Podal System and Gait Parameters

BACKGROUND

Dental malocclusion is an increasingly frequent stomatognathic disorder in children and adolescents nowadays. The purpose of this study was to confirm or deny the correlations between body posture and malocclusion.

METHODS

In the study, gait, distribution of foot pressure on the ground, and body balance were examined. The research group consisted of 76 patients aged 12-15 years. The research group was obtained from patients attending periodic dental check-ups at Healthcare Center Your Health EL who agreed to participate in the study. The patients were divided into two groups without malocclusion and with malocclusion, using Angle classification, which enabled determination of the anteroposterior relationship of the first molars. The pedobarographic mat was used to analyze the distribution of foot forces on the ground, the diagnostic system Wiva^® Science was used for gait analysis, and Kineod 3D was used for posture analysis. The Shapiro-Wilk test used for analysis showed inconsistency with normal distribution for all measurement parameters. The Mann-Whitney U test was used for the analysis, and the significance level was set at p ≤ 0.05.

RESULTS

Examination of the relationship between stabilometric and gait parameters showed that the position of the mandible in relation to maxilla has an important effect on gait rhythm, gait cycle duration, and right step duration time. Patients diagnosed with malocclusion showed high-speed walking rhythm in comparison to patients with Angle's class I (p = 0.010). The duration of the whole gait cycle (p = 0.007) and the duration of right step (p = 0.027) were prolonged in students without orthodontic disorders compared to the other.

CONCLUSIONS

The conducted study proved that there is correlation between the presence of a stomatognathic disorder and gait cycle parameters. There is a statistically noticeable correspondence between the position of the mandible in relation to maxilla and walking rhythm, gait cycle duration, and right step duration time. Namely, students who presented malocclusion had a high-speed walking rhythm and decreased duration of the gait cycle and of the right step. On the other hand, students without disorders (Angle's class I) showed low-speed rhythm and increased duration of the gait cycle and of the right step in comparison to Angle's classes II and III.

Is There a Correlation between Dental Occlusion, Postural Stability and Selected Gait Parameters in Adults?

Background: There is still an ongoing debate about the role of the craniomandibular system, including occlusal conditions, on postural stability. This study aims to assess the role of antero-posterior malocclusion on postural control and plantar pressure distribution during standing and walking. Methods: 90 healthy volunteers (aged 19 to 35) were qualified for the study. The subjects were assigned to three groups, depending on the occlusion type. Each group (Angle Class I, II and III) consisted of 30 people. The research procedure included a clinical occlusal assessment performed by a dentist. Postural control measurements were carried out using a force platform by measuring plantar pressure distribution during standing (six trials with and without visual control) and walking test conditions. Results: The tendency to shift the CoP forward is demonstrated by Angle Class II subjects and backwards by Class I and III subjects (p < 0.001). Individuals with a malocclusion demonstrated significantly higher selected stabilographic parameters while standing on both feet (with eyes open and closed) and during the single-leg test with eyes open (p < 0.05). The analysis of the dynamic test results showed no significant correlations between Angle Classes and the selected gait parameters. Conclusions: Analyses conducted among individuals with malocclusions showed the impact of occlusion on static postural stability. In order to diagnose and effectively treat malocclusion, a multidisciplinary approach with the participation of dentists and physiotherapy specialists is necessary, with the use of stabilometric and kinematic posture assessments.

Improvement of cervical spine mobility and stance stability by wearing a custom-made mandibular splint in male recreational athletes

OBJECTIVES

The range of motion (ROM) of the cervical spine and postural stability are important for an economical and motorically adequate adaptation of the body to any situation. Therefore, this study aims to analyze whether these two components of postural and movement control can be influenced by means of a splint in a centric position compared to habitual occlusion.

METHODS

38 recreational male athletes volunteered. Cervical spine ROM was recorded using an ultrasound system and the a pressure measuring plate for postural stability (length of center of pressure (CoP) movement, area of CoP). The two dental occlusion conditions employed were the habitual occlusion and wearing a splint in an idealized, condylar position close to the centric position. Level of significance was set at ρ ≤ 0.05.

RESULTS

The cervical spine mobility increased significantly by wearing the splint regarding rotation to the left (+3.9%) and right (+2.7%) and lateral flexion to the left (+4.4%) and right (+6.7%). Wearing the splint reduced the area of sway deflections by about 31.5% in the bipedal stance and by about 2.4% (left) and 28.2% (right) in the unipedal stance. The CoP trace was reduced in the sagittal plane by approximately 8.2% in the right single-leg stance.

CONCLUSIONS

The major findings seem to demonstrate that wearing a splint that keeps the jaw close to the centric relation may increase the cervical ROM and may improve balance stability in male recreational athletes. Changing the jaw relation in athletes can possibly aid the release of performance potentials by improving coordination skills.

Does head and cervical posture correlate to malocclusion? A systematic review and meta-analysis

BACKGROUND

The association of head and cervical posture with malocclusion has been studied for many years. Despite extensively encouraging researches, no conclusive evidence has been reached for clinical application.

OBJECTIVE

To identify the question "Does head and cervical posture correlate to malocclusion?", a systematic review and meta-analysis based on the available studies were carried out (PROSPERO registration number: CRD42022319742).

METHODS

A search of PubMed, Embase, Cochrane Library, and the grey literature was performed without language restrictions. The study screening, data extraction, risk-of-bias evaluation and methodological quality assessment were performed by two independent investigators. When a disagreement arose, a third author was consulted.

RESULTS

6 original cross-sectional studies involving 505 participants were included, which were of moderate methodological quality. NL/VER in Class Ⅱ group and NL/CVT in Class Ⅲ group showed significant differences compared to Class Ⅰ group, but no significant differences were observed in most of the variables like NSL/VER, OPT/CVT, OPT/HOR, CVT/HOR, NSL/OPT, NSL/CVT, NL/OPT in Class Ⅱ and Ⅲ groups.

CONCLUSIONS

The results suggested that the current research evidence is not sound enough to prove the association of head and cervical posture with sagittal malocclusion. Better controlled design and a larger sample size are required for clarifying this question in future study.

Temporomandibular Joint Disk Displacements in Class II Malocclusion and Cervical Spine Alterations: Systematic Review and Report of a Hypodivergent Case with MRI Bone and Soft Tissue Changes

(1) Background: This study aimed to perform a literature review related to disk displacement (DD) in class II malocclusion or cervical vertebrae position alterations and to report a hypodivergent case with cervical pain and right anterolateral DD with reduction, left anterolateral DD with reduction, and left joint effusion. (2) Methods: A structured electronic search was conducted between March 2022 and April 2022, without time limits, following PRISMA guidelines, in the following databases: PubMed, Scopus, Embase and Cochrane; the terms “disc displacement”, “disk displacement”, “temporomandibular joint”, “class II malocclusion” and “cervical vertebrae” are searched. (3) Results: the following thirteen publications are included in this review: two prospective studies and eleven cross-sectional studies; for evaluating disk position, eight included publications used magnetic resonance imaging (MRI), whilst six studies used lateral cephalogram to determine craniofacial morphology and relationships between the cranial base, vertical skeletal pattern, maxilla and mandible. (4) Conclusions: although the literature still shows contradictory opinions, a relationship between temporomandibular disorders and cervical posture has been shown in the presented case as well as in the literature review.

Effects of 8-week oral splint usage on body flexibility and muscle strength-endurance performance in Pilates practitioners

Purpose

We investigated the acute and chronic effects of oral splint on muscle strength-endurance performance and body flexibility.

Methods

Twelve Pilates practitioners (age 49.5 ± 5.8 years; mass 58.6 ± 6.5 kg) were evaluated with (OS) and without (CTRL) oral splint. Before (PRE) and after (POST) 8 weeks of oral splint usage during Pilates activity, muscle strength-endurance and body flexibility were evaluated through a frontal plank exercise and a Toe-touch test in OS and CTRL. Before each test, the highest electrical activation (EMG) of masseter and temporal muscles during maximal occlusion was determined. During frontal plank, the time-to-exhaustion, the maximum voluntary activation of masticatory muscles and the time of muscles activation have been determined.

Results

No OS vs CTRL and PRE vs POST differences were found in the maximum voluntary activation of temporal and masseter muscles. The time-to-exhaustion in OS was longer than CTRL in both PRE (P = 0.049) and POST sessions (P = 0.043). Time of masticatory muscles activation during plank was moderately greater in OS at PRE (P = 0.020) and POST (P = 0.022), while no difference between PRE and POST emerged in both conditions. Higher muscular activation was found in OS than CTRL at PRE (P = 0.031) and POST (P = 0.031), whereas no difference between PRE and POST appeared. No effect on flexibility emerged neither acutely nor chronically.

Conclusion

Acute and chronic oral splint usage improved strength-endurance performance but not body flexibility. These findings suggest biomechanical and neural mechanisms influencing the muscle length and the concurrent activation potentiation, but not muscle tone and stiffness.

Prosthetic Rehabilitation and Its Effect on Head Posture

Background: Edentulism is a debilitating and irreversible condition. It is often accompanied by compromises in the surrounding joint’s range of motion and changes in the posture of the head. The natural head position is maintained by a balanced tension between cranio-cervical bones, myofacial structures and the dental occlusion. Loss of teeth may cause changes in the head posture that may disturb the patency of the spinal cord and lead to the loss of postural balance. Therefore, this study aimed at evaluating the head posture in the edentulous subjects before and after prosthetic rehabilitation.

Methods: A total of 16 completely edentulous subjects were selected for the study. Removable complete denture prosthesis was fabricated for all the subjects. Lateral photographs were taken at different time intervals i.e., pre-rehabilitation, 30 minutes, 2 days and 30 days post-rehabilitation. The cranio-vertical angle obtained was digitally calculated using Kinovea software and the results obtained were statistically analysed.

Results: The paired-sample t-test and repeated measures analysis of variance showed an increase in the cranio-vertical angulation of edentulous subjects after rehabilitation, indicating a mild extension of the head.

Conclusion: The insertion of prosthesis leads to a mild extension of the head. Hence, rehabilitation with a removable prosthesis has a positive effect on the head posture and could therefore aid in maintaining a stable head posture.

The Case of Insertional Adductor Tendinopathy of an International-Level 3,000-m Steeplechase Runner

Background: Groin pain is a frequent condition among athletes. One of the causes of groin pain is tendinopathy, a frequently diagnosed medical condition, which can also occur in the adductor muscles. Despite the high prevalence of this medical condition among athletes, it is infrequent to observe tendinopathic groin pain in steeplechase runners. The aim of this case study is to describe the case of an international-level 3,000-m steeplechase runner with groin pain, who was subsequently diagnosed with adductor insertional tendinopathy.

Case Presentation: We present the case of an Italian 3,000-m steeplechase and long distance runner, Ala Zoghlami (180 cm, 57 kg), with groin pain, diagnosed as insertional adductor tendinopathy. The runner, after manifesting the painful symptomatology, underwent medical screening (ultrasound and MRI). The radiological investigations highlighted adductor tendinopathy. After refraining from training, the runner underwent medical and physical therapy which, in the first phase, did not improve the painful symptomatology. Further evaluation, after 6 months from the initial training cessation, highlighted a case of malocclusion. Such was treated from a dentistry perspective with the creation of a personalized dental bite.

Results: A multidisciplinary approach which included medical and physical therapy, osteopathy, and dentistry, in adjunct with refraining from training, was able to reduce the symptomatology and allowed a correct return to run (after 9 months from the first painful manifestation) of the steeplechase runner. To date, Ala Zoghlami has fully recovered and was able to win the 3,000-m steeplechase race during the 2021 national Italian competition.

Effect of dental malocclusion on cerebellar neuron activation via the dorsomedial part of the principal sensory trigeminal nucleus

Occlusion has been proposed to play a role for body posture and balance, both of which are mediated mainly by the cerebellum. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) has direct projection to the cerebellum. The experimental unilateral anterior crossbite (UAC) has an impact on the motor nuclei in the brain stem via trigeminal mesencephalic nucleus (Vme). The current aim was to explore whether UAC has an impact on Vpdm‐cerebellum circuit. The inferior alveolar nerve was injected into cholera toxin B subunit (CTb), the cerebellum was injected into fluoro‐gold (FG), and the Vpdm was injected into biotinylated dextran amine (BDA) to identify the activation of Vpdm‐cerebellum circuit by UAC. Data indicated that there were more neuronal nuclei (NeuN)/CTb/FG triple‐labelled neurons and NeuN/CTb/vesicular glutamate transporter 1(VGLUT1) triple‐labelled neurons in the Vpdm, and more NeuN/BDA/ VGLUT1 triple‐labelled neurons in the cerebellum of rats with UAC than in control rats. The VGLUT1 expression in the Vpdm and cerebellum in the UAC group was higher than that in control rats. These findings indicate an excitatory impact of UAC on the Vpdm‐cerebellum pathway and support the role of occlusion for body posture and balance.

The Role of Dental Occlusion and Neuromuscular Behavior in Professional Ballet Dancers' Performance: A Pilot Study

Clinical practice and some scientific evidence seem to suggest that there is some kind of relationship between the components that form the postural chain. For professional dancers, good posture and balance are essential. The aim of the present retrospective study is to evaluate whether gnathological treatment could have an impact on the postural balance and sports performance of professional ballet dancers. Electromyographic (EMG) data and balance tests were recorded before and after six months of treatment with a customized occlusal splint. Twenty athletes were examined during ballet exercises in terms of balance and speed of execution by two experienced clinicians. The results showed statistically significant changes for all EMG tests carried out and the Flamingo Balance Test. It appears that the use of a customized occlusal device improved neuro-muscular coordination and the overall performance of dancers.

Symmetrical dental occlusion blocking - changes of body sway and weight distribution in healthy subjects across 4 age decades

Objectives

Symmetrical dental occlusion blocking is used in dentistry as a quick diagnostic tool to test for potential influences of the craniomandibular system on body sway and weight distribution. This study presents the changes of body sway and pressure distribution in healthy subjects, free of a temporomandibular dysfunction (TMD). Immediate effects between occlusal blocking and rest position on body sway and body weight distribution in general, as well as for both genders and for four age decades will be evaluated.

Materials and methods

725 (396f/329 m) subjects (neither subjective signs of TMD nor acute/chronic complaints in the musculoskeletal system) volunteered (21 to 60 years) while both genders were divided into four age groups according to decades. A pressure measuring platform was used. Body sway and weight distribution were recorded in two dental occlusion conditions (a) in rest position and (b) symmetrical blocking (bicuspid region) by cotton rolls.

Results

Both, the frontal sway and the sagittal sway reduced by 0.67 mm (t(724) = − 3.9 (p <  0.001)) and by 0.33 mm (t(724) = − 3.4 (p <  0.001)). The relative pressure under the left forefoot increased by 0.33% (t(724) = 2.88 (p <  0.001)) and the relative pressure overall under the forefoot increased by 0.67% (t(724) = − 3.4 (p <  0.001)). Gender-specific, age-specific and BMI-specific reactions could not be identified.

Conclusions

Subjects, free of any TMD and with no complaints of the musculoskeletal system, show small changes of the body sway and weight distribution when biting symmetrically on a cotton roll. These changes are independent of age, gender or body mass index (BMI). Due to the relative large sample size, the presented results can also be seen as norm values when body sway is used as an additional assessment of a TMD.

Relationship between back posture and early orthodontic treatment in children

Background

The 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.

Methods

Angle 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.

Results

In 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).

Conclusion

Overjet reduction during early orthodontic treatment may be associated with a detectable effect on pelvic torsion.

Dental Malocclusion and Its Relation to the Podal System

Background and Objective: This study analyzes the possibility that Stomatognathic and Postural systems are related by muscle chains. Malocclusion may influence the posture, contact between the foot and the ground, center of mass, footprint or vice-versa. This study aimed to verify whether there is a relationship between dental occlusion and podal system. Materials and Methods: A cross-cutting, descriptive study was carried out on 409 children (222 boys and 187 girls) between 8 and 14 years old. Dental occlusion was assessed on the sagittal plane (Angle's classification) the contact between the foot and the ground and the center of mass were evaluated using a stabilometric platform. Results: There was a statistically significant relationship between the plantigrade phase, the contact surface area and center of gravity. There was a prevalence of molar and canine Angle's class II malocclusion. In molar class II, an anterior center of gravity was predominant, in class I it was centered and in class III, it was posterior. There was significant correlation between malocclusions and the FPI (foot posture index) of the left foot and the height of the scaphoid in the right foot (P < 0.001). Conclusions: Some authors agree with our results. There is still much uncertainty in terms of showing a relationship between both systems. In addition, there is scarce scientific evidence on the topic. Some kind of relationship between the two systems has been proven. Studies that evaluate a group of subjects in a longitudinal manner are necessary to enable the changes taking place in both systems to be defined.

The correlation between back posture and sagittal jaw position in adult orthodontic patients

Objective

A debate remains in evidence-based medicine about the reciprocal interchange between dental occlusion and body postural therapy. Back posture deformity has been found to be related to trunk asymmetry as one characteristic of scoliosis that is commonly reported in occlusal development issue. This study aims to determine the correlation between back posture and sagittal jaw position in adult orthodontic patients treated at the dental hospital of Universitas Sumatera Utara.

Methods

This observational study was conducted on orthodontic patients who had routine orthodontic control between October 2019 and February 2020. The sagittal jaw relationship on pre-treatment cephalometry lateral-based on Steiner analysis was done with OrthoVision software. The back posture that related to cervical, thoracic, and lumbar measurement was performed using scoliometer plastic economy (Baseline®).

Results

From 128 patients, aged between 18 and 30 years, we found 72 patients with Class I, 41 patients with Class II, and 15 patients with Class III skeletal malocclusion. There were no significant differences of trunk asymmetry based on sagittal jaw relationship (p = 0.651). Additionally, there was no significant correlation between back posture and sagittal jaw position in Class II and Class III patients (r = 0.112, p > 0.05).

Conclusion

In this study, the sagittal jaw relationship had poor correlation to back posture in orthodontic adult patients due to a compensatory mechanism. The presence of temporomandibular dysfunction, sella-nasion-B point, and head posture are specific variables in a particular dento-skeletal type that should be considered in further studies.

Performance, balance and posture variations with Occlusal Splint and Taopatch® devices: a retrospettive cross-over study

BACKGROUND

The aim of the study was to evaluate how muscular performances, balance and posture were influenced applying Occlusal Splints and Taopatch^® 8 (Tao Technologies Srls, Cittadella, Padua, Italy) devices in athletes.

METHODS

Eighteen athletes, 7 females and 11 males, with an average age of 23.8 years, were included. Two devices were used: 1) a customized soft occlusal splint to be applied to the lower ach; 2) nanotechnological devices based on carbon nanotubules and quantum dots (Taopatch^®) positioned on C7 and xiphoid process. Four functional tests were performed: surface electromyography (sEMG), kinesiography, the squat jump and counter movement jump and handgrip test. The tests were performed in the following order: at the baseline (no treatments), and after having applied the bite alone, the occlusal splint and Taopatch^® devices together and the Taopatch^® devices alone.

RESULTS

The sEMG showed an increased maximum clenching voltage in respect of the baseline for all treatments that included the occlusal splint. The kinesiography showed an improvement of the movements of the occlusal muscles. The squat jump increased the height of 10-14 mm, the best results registered with the bite. The handgrip showed an increased strength, that was higher with the bite and the Taopatch^® devices used alone (~5 lbs.).

CONCLUSIONS

The use of an occlusal splint and Taopatch^® devices use alone or in conjunction immediately influenced strength and balance of the occlusal postural muscles.

Relationship between Unilateral Posterior Crossbite and Human Static Body Posture

Background: We compared photogrammetry-assessed body posture between young adults with and without unilateral posterior crossbite (UPCB). Assessments were controlled by vision, mandibular position and sitting/standing position. In addition, we aimed to determine the relationship between UPCB laterality and the direction of body posture using photogrammetry and a static postural platform. Methods: Adults with natural dentition, with and without UPCB, were enrolled. Static body posture was assessed by photogrammetry based on horizontal acromial alignment and horizontal anterior-superior iliac spine (ASIS) alignment. Frontal photographs were taken with participants asked to open or close their eyes and hold their jaws at rest, at an intercuspal position, and at left or right lateral positions. Distribution of foot pressure was recorded using a static postural platform at different visual input and mandibular positions. General linear models with repeated measures were used to assess the effect of the various within- and between-subject factors. Results: In total, 36 adults (left UPCB = 12; Right UPCB = 6; controls = 18) participated. There were significant differences between the control and UPCB groups in horizontal alignment at the acromion (p = 0.035) and ASIS (p = 0.026) levels when controlled by visual input and mandibular position. No significant differences in horizontal alignment or foot pressure distribution were observed by laterality in the UPCB group. Conclusion: The presence of UPCB affects static body posture, but the side of crossbite is not related to the direction of effect on static body posture.

Vibrotactile -Feedback Device for Postural Balance Among Malocclusion Patients

Multiple studies have suggested that some associations exist between occlusal factors and postural alterations. Objectives: This study aimed to evaluate the effectiveness of a vibrotactile posture trainer device, comprised a wearable device containing an accelerometer sensor to measure the angle of the neck flexion (input) and provided real-time vibrotactile biofeedback (output) for postural balance among patients with malocclusion. Methods: Twenty-four subjects were divided in 3 groups based on occlusion and using Angle’s classification. Each group consisted of 8 patients for class I, II and III malocclusion. The Posture Trainer System was used for feedback concerning neck flexion angles when higher than 15 degrees. A 4-week training program to adjust posture balance in 2 axes (flexion-extension, lateral-flexion) was applied in activities for daily living. The assessments in this study were comprised of neck flexion angles from the Posture Trainer System and the center of pressure (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\text{N}\cdot \text{m}$ \end{document}) using a force plate. The effects of a vibrotactile posture trainer (baseline vs. post-training test) were evaluated using the paired t-test and were assumed to be significant at p < 0.05 (two-side). All analyses were conducted using the Statistical Package for Social Sciences, Version 21.0 (SPSS, Chicago, IL, USA). Results: Neck flexion angles and center of pressure significantly decreased post-training by the Posture Trainer System among patients with class II malocclusion. No changes in the above parameters post-training were found in class I and class III. Conclusion: The results demonstrated that patients with class II malocclusion training by the Posture Trainer System lowered neck flexion angles and COP compared with pre-training. Clinical Impact: Feedback by the Posture Trainer System can help improve the postural balance in class II malocclusion.

Do different dental conditions influence the static plantar pressure and stabilometry in young adults?

Background

Posture is influenced by many factors and dental occlusion seems to have its role on postural stabilization. Our rationale to perform the study was to find out if there are differences of static plantar pressure and stabilometric parameters depending on different dental conditions.

Methods

The observational study consisted in plantar pressure assessment and stabilometric analysis of 95 right-handed healthy volunteer subjects (mean age 22.94 ± 2.52 years) by using the PoData system. Each subject followed four measurements with open eyes: mandibular postural position, maximum intercuspation, biting on cotton rolls and maximum mouth opening. Plantar pressure was recorded on 1^st and 5^th metatarsal heads and heel, and was expressed as percentage of weight distribution on each foot. The recorded centre of pressure (CoP) parameters were: CoP path length, 90%confidence ellipse area and maximum CoP speed. Statistical analysis used repeated-measures ANOVA with Bonferroni posthoc analysis and Friedman test.

Results

Loading on the left 5^th metatarsal head was significantly higher in maximum mouth opening condition when compared to maximum intercuspation and to biting on cotton rolls. The left heel loading was significantly lower in the maximum mouth opening in comparison to maximum intercuspation. The CoP path length and maximum CoP speed were significantly higher in maximum mouth opening compared to the other three conditions. Confidence ellipse area had significantly lower values in maximum intercuspation and in the biting on cotton rolls conditions compared to the mandibular postural position, and in maximum intercuspation compared to maximum mouth opening.

Conclusion

In young adults with an optimum functional occlusion the static plantar pressure is influenced by the maximum mouth opening. An improved postural stability was recorded in maximum intercuspation (a condition used during swallowing) in comparison to mandibular postural position (a condition that allows relaxation of the masticatory muscles after functional moments).

The Influence of Dental Occlusion on Dynamic Balance and Muscular Tone

Excellent postural control is essential to improve the physical performance of athletes. Stability of the body during motor tasks depends on different physiological systems. The influence of dental occlusion on body balance has been widely investigated in the past few years. It has been suggested that this relationship is strengthened by disturbing environments for balance control (i.e., unstable platform, fatigue, development tasks.). Moreover, dental occlusion may influence the muscle tone of both masticatory and postural muscles, which are involved in the preservation of balance. Therefore, we attempted to determine whether (i) there are differences in dynamic balance assessed by the modified star excursion balance test between opposed dental occlusion conditions (dental contact: intercuspal position/no dental contact: cotton rolls mandibular position) and (ii) dental occlusion influences the biomechanical and viscoelastic properties of the masticatory and postural muscles assessed with MyotonPRO^®. Thirty physically active subjects were recruited for the study. The main findings were the following: (i) the Star Excursion Balance Test composite score was significantly higher for measurements made in cotton rolls mandibular position (p < 0.001) and also in subjects showing a correct occlusion (p = 0.04), and (ii) the biomechanic and viscolelastic properties of selected muscles showed different trend according to the presence of malocclusal traits. It is concluded that dental occlusion conditioned both dynamic stability and the biomechanic and viscoelastic properties of the analyzed muscles.

A kinematic analysis on the immediate effects of occlusal splints in gait and running body sway patterns

Objective: This study aims to determine whether changes in dental occlusion are correlated to body posture during walking and running.Methods: Fifteen healthy subjects were assessed by a prosthodontist and deemed asymptomatic. Analyses of gait and running were performed in three conditions, in random order: a) occlusal splint; b) placebo splint; and c) no splint. The occlusal splint used in this study positioned the mandible in a stable position. Kinematic data was collected using a 3D motion capture system.Results: Changes in dental occlusion induced by occlusal splints did not influence body sway during gait or running. No significant differences were found between any of the test conditions.Conclusion: Occlusal splints have no effect on body sway during gait or running. High inter-subject variability in kinematic parameters was found, which should be considered in future studies.

Evaluation of a relationship between malocclusion and idiopathic scoliosis in children and adolescents

PURPOSE

Idiopathic scoliosis is a developmental deformation of the vertebral column of an unknown aetiology. Its clinical symptoms and hypothetical causative factors may affect the stomatognathic system. The aim of this study was to analyse the relationships between the prevalence and type of malocclusions, and the presence of idiopathic scoliosis, its location and severity.

METHODS

This was a prospective longitudinal study. The study group consisted of 80 patients with idiopathic scoliosis and the control group of 61 healthy individuals. Standard standing long-cassette radiographs were taken of all of the patients in the idiopathic scoliosis group in order to confirm diagnosis, to determine localization and the Cobb angle of the curve. Both groups underwent standard clinical dental examination.

RESULTS

The most commonly observed types included right main thoracic (R-MT) and thoracolumbar or left lumbar scoliosis (Cobb angle 11° to 125°). In the idiopathic scoliosis group, prevalence of malocclusions was greater than in the control group (95% versus 82%). In the idiopathic scoliosis group more than one type of malocclusion was observed with a higher incidence than that in the control group (63.8% versus 37.7%; p = 0.002). A correlation between the left proximal thoracic (L-PT) curve with anterior partial open bite was demonstrated (p = 0.323), between thoracic dextroscoliosis main thoracic with lateral partial cross bite (p = 0.230) and a correlation between scoliosis severity and malocclusion in the event of L-PT and anterior partial open bite (p = 0.330) and R-MT and scissors bite (p = 0.248).

CONCLUSION

The incidence of malocclusions is greater in children with idiopathic scoliosis than in their healthy peers.

LEVEL OF EVIDENCE

III.

Relationship between craniocervical posture and skeletal class: A statistical multivariate approach for studying Class II and Class III malocclusions

Objective: To investigate the relationships between craniocervical posture and skeletal Class in cephalometric radiographs of adult subjects.Methods: Sixty-five cephalometric radiographs were classified after Delaire, as skeletal Class II and III. The craniocervical posture was evaluated using the variables proposed by Solow (1976) and Rocabado (1983). In order to test the null hypothesis (absence of an association between craniocervical posture and skeletal Class), uni- and multivariate statistical protocols were carried out.Results: Skeletal Class II presented a more posterior rotation of the ramus in relation to the cranium and a more extended head than skeletal Class III. Additionally, significant correlations were observed in Class II individuals between the rotation of mandibular ramus and cervical lordosis, as well as between rotation of mandibular ramus and craniocervical posture.Discussion: The findings of this research may help to understand the contradictory results described in clinical literature about the effect of skeletal class on craniocervical posture.

[Assessment of postural control and balance in persons with temporomandibular disorders: A systematic review]

The stomatognathic system is the anatomo-functional unit of the cranio-cervico-facial region. Some dysfunctions affect its motor control. The aim of this study was to analyse the clinical usefulness of the various scales and instruments used in the assessment of postural control in people with temporomandibular disorders. A systematic review was carried out by 2independent reviewers in the PubMed, Medline, Ebsco, Science Direct and PEDro databases, selecting observational studies published between January 2006 and March 2017. The risk of bias and methodological quality was analysed following Cochrane indications and the Downs and Black quality scale. Ten studies were included, of which 9used computerised platforms, one added photogrammetry and one used electromyography. Seven studies were classified as moderate quality and 3as low quality. Posturography was the most widely used assessment instrument. Methodological differences did not allow determination of their clinical implications or the relationship between balance and the presence of temporomandibular disorders.

Analysis of Dental Malocclusion and Neuromotor Control in Young Healthy Subjects through New Evaluation Tools

The presence of a correlation between stomatognathic and postural systems has been investigated by different authors trying to identify a possible influence of dental occlusion on body posture and balance. The aim of this study was to evaluate the relationship between dental occlusion and neuromuscular control in a healthy young population using modern evaluation tools. 25 subjects (9 males and 16 females, aged 23 to 44) were evaluated for dental occlusion, particularly in relation to overjet and overbite parameters, anterior and posterior crossbite, scissor bite, mandibular crowding, molar and canine class, and deviation of the median dental line. Neuromotor control was assessed using two different types of stabilometric platforms in both monopodalic and bipodalic equilibriums (Prokin-B and MF-Stability, Tecnobody, Italy). All subjects were evaluated with and without cotton rolls positioned between the upper and lower arches at the premolar level in order to temporarily eliminate any pathological contact. In all 25 subjects, no statistically significant differences were revealed between the evaluations performed with and without cotton rolls in all the analyzed conditions (in static, in dynamics, with open and closed eyes). This study did not find a significant correlation between dental occlusion and neuromuscular control in a young and healthy population.

Does occlusal splint affect posture? A randomized controlled trial

OBJECTIVE

The aim of this study was to evaluate the effect of an occlusal splint on body posture of intra-articular temporomandibular joint (TMJ) disorders patients.

METHODS

The study was performed on 45 women affected by TMJ disorders divided into an occlusal splint group and a control group. Rasterstereographic recordings were performed at baseline and after 1, 3, and 6 months, in order to analyze the following postural parameters: trunk inclination, cervical and lumbar arrows, kyphotic and lordotic angles, trunk imbalance, pelvic tilt and torsion.

RESULTS

Regarding the postural parameters in the intragroup analysis, no significant differences were detected. The analysis between the two groups revealed significant differences concerning the cervical arrow, the kyphotic and lordotic angles.

DISCUSSION

Even if some differences were found between the control and the occlusal splint group, the low range of statistical significance made these results not significant from a clinical point of view.

Gait and posture analysis in patients with maxillary transverse discrepancy, before and after RPE

AIM

The purpose of this study was to evaluate the effects of the rapid palatal expansion (RPE) on posture and gait analysis in subjects with maxillary transverse discrepancies.

MATERIAL AND METHODS

Forty-one patients between 6 and 12 years were divided into 3 groups: 10 control subjects (Cs), 16 patients with unilateral posterior crossbite (CbMono), 15 patients with maxillary transverse discrepancy and no crossbite (Nocb). Every subject underwent gait analysis and posturographic examination in order to evaluate the presence of balance alterations before (T0) and after (T4) RPE application. The examinations were performed through a six-cameras stereophotogrammetric system (60-120Hz, BTS S.p.A.) synchronized with two force plates (FP4060, Bertec Corp.). Romberg test was performed on a force plate, and the statokinesiogram and joint kinematics were evaluated. One-way Anova was performed among the variables after evidence of normal distribution (Levene's test for equality of variances) and Kruskal-Wallis test (P<0.05), in order to compare the three groups of subjects. While paired t-test was performed, or Kruskal-Wallis test, instead when comparing pre- and post-RPE application within the same group of subjects (P<0.05). Tamane T2 or Bonferroni correction was applied where needed.

RESULTS

The posturographic analysis reveal significant differences across the 3 population: 95% power frequency in medio-lateral and antero-posterior direction in T0, median frequency in medio-lateral direction in T0, mean power frequency in medio-lateral direction in T0. Significant differences were also registered in the three-dimensional joints kinematics variables, mainly between Cs and Cbmono in T0 and T4 and between Cbmono and Nocb in T4.

CONCLUSIONS

A detectable correlation between dental occlusion and body posture is shown in this study that confirms another benefit of the RPE. This was mainly revealed in the dynamic posture where modifications at the mandibular level affect the whole body.

Physical Activities and Lifestyle Factors Related to Adolescent Idiopathic Scoliosis

BACKGROUND

In addition to genetic factors, environmental and lifestyle factors are thought to play an important role in the onset of adolescent idiopathic scoliosis (AIS). This cross-sectional study was conducted to explore lifestyle factors related to AIS.

METHODS

This study included 2,759 Japanese female junior high school students who planned a secondary screening after an initial moiré topography screening indicated possible scoliosis. The students and their mothers, or guardians, were asked to fill out a questionnaire consisting of 38 questions about demographic factors, lifestyle-related factors, social factors, household environment, participation in sports, health status, and factors related to the mother's pregnancy and delivery. The questionnaire was completed by 2,747 students (a 99.6% response rate). After excluding students with heart disease, neurological disease, or a congenital vertebral anomaly, 2,600 students were eligible for assessment. After undergoing a secondary screening with standing radiographs of the spine, students were assigned to the normal (control) group if radiographs showed a curve of <15° or to the scoliosis group if they had a curve of ≥15°. The odds ratios (ORs) for AIS in relation to the possible risk or preventive factors were estimated by logistic regression analyses.

RESULTS

No lifestyle-related factor was significantly associated with AIS. However, AIS was associated with classical ballet training (OR, 1.38; 95% confidence interval [CI], 1.09 to 1.75); the odds of AIS developing increased as the child's frequency of training, number of years of experience, and duration of training in ballet increased. The OR for AIS was 1.5 times higher for participants whose mothers had scoliosis. AIS was also associated with a low body mass index (BMI). These associations remained even after mutual adjustment was performed.

CONCLUSIONS

No association was found between AIS and lifestyle-related factors. However, classical ballet training, a family history of scoliosis, and low BMI may be associated with AIS.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of Treatment with Twin-Block Appliances on Body Posture in Class II Malocclusion Subjects: A Prospective Clinical Study

Background

There is strong evidence that malocclusion and body posture are interdependent. The relationship between improvement of nasopharyngeal airway, correction of malocclusion by orthodontic treatment or orthognathic surgery, and changes in body posture were evaluated in several studies. The purpose of the present study was to analyze the effect of the orthodontic treatment with Twin-block appliance on body posture.

Material/Methods

The study group consisted of 23 children (mean age 12.45 (1.06) years). They were orthopedically (back shape analysis) and orthodontically (cephalometric radiograph analysis) examined before the treatment with Twin-block appliance and 10–14 months after the beginning of treatment.

Results

Treatment with Twin-block appliance caused mandibular protrusion as SNB increased by 0.91°, distance Ar-B increased by 4.9 mm, ANB decreased by 0.15°; and increase of face height. Oropharynx airway increased by 1.54 mm and deep pharynx airway by 1.08 mm. The decrease in kyphotic, lordotic, craniocervical angles, upper thoracic, pelvic, and trunk inclinations was found to be statistically significant. When comparing orthopedic measurements between study and control groups, no differences were detected. The control group also showed reduction of all measured angles. Although the decrease of kyphotic angle, upper thoracic inclination, trunk inclination, and craniocervical angle were more pronounced in the study group, the differences were not significant.

Conclusions

Based on these results, the body posture changes during treatment with Twin-block appliance were an expression of the physiological growth, not a response to improvement in occlusion.

Effects of Jaw Clenching While Wearing a Customized Bite-Aligning Mouthpiece on Strength in Healthy Young Men

Recent studies have investigated the ergogenic effects of different types of mouthguards. There is evidence of the benefits of clenching customized mouthpieces on force and power development. The phenomenon called concurrent activation potentiation (CAP) promoted in jaw clenching seems to enhance the muscular strength and power in maximal isometric contractions and powerful actions in sport. Moreover, a bite-aligning mouthpiece may promote a more aligned and powerful clench. The objective of the present study was to investigate the effects of jaw clenching while wearing a customized bite-aligning mouthpiece (MP) on jump ability and isometric maximal strength tests in contrast to 2 other conditions: nonjaw clenching (NON-JAW) and jaw clenching without the mouthpiece (JAW). A within-subjects design was used to assess the jump performance and the maximal isometric force in 28 physically active male subjects. Statistical analyses revealed significantly higher performance in JAW and NON-JAW conditions for handgrip force (HG-peakforce) and all variables of the back-row exercise (BRW) and countermovement vertical jump (CMVJ) (p ≤ 0.05). Significant differences between NON-JAW and JAW were found for HG-peakforce (p ≤ 0.05). These findings suggest that it is advisable to use a customized bite-aligning mouthpiece to improve strength and power performance.

Can different occlusal positions instantaneously impact spine and body posture? : A pilot study using rasterstereography for a three-dimensional evaluation

PURPOSE

Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions.

METHODS

Optical body scans were collected for 44 subjects, using the Diers formetric 4D system, for seven different mandible positions. In total, ten spinal and body posture parameters were assessed (trunk inclination, trunk imbalance, pelvic tilt, pelvic torsion, fleche cervicale, fleche lombaire, kyphotic angle, lordotic angle, surface rotation, and lateral deviation) for each mandible position and compared with scans performed with habitual intercuspation (HIC).

RESULTS

Significant body posture deviations were found for the fleche cervicale (position of the mandible: right eccentrically), fleche lombaire (positions of the mandible: physiologic rest position, cotton rolls on both sides, bite elevation 1 mm), and the kyphotic angle (positions of the mandible: cotton rolls on both sides, right eccentrically). No other significant differences were detected.

CONCLUSIONS

Data for the parameters that varied with different dental occlusions generated high standard deviations. Therefore, within the limitations of this pilot study, we could not conclusively associate dental occlusion to an instantaneous impact on the tested parameters. The posture changes that we detected could also have arisen from individual neuromuscular compensation; a possibility that must now be ruled-in, or out, by further research studies with a higher number of subjects.

Effect of Jaw Clenching on Balance Recovery: Dynamic Stability and Lower Extremity Joint Kinematics after Forward Loss of Balance

Postural control is crucial for most tasks of daily living, delineating postural orientation and balance, with its main goal of fall prevention. Nevertheless, falls are common events, and have been associated with deficits in muscle strength and dynamic postural stability. Recent studies reported on improvements in rate of force development and static postural control evoked by jaw clenching activities, potentially induced by facilitation of human motor system excitability. However, there are no studies describing the effects on dynamic stability. The present study, therefore, aimed to investigate the effects of submaximum jaw clenching on recovery behavior from forward loss of balance. Participants were 12 healthy young adults, who were instructed to recover balance from a simulated forward fall by taking a single step while either biting at a submaximum force or keeping the mandible at rest. Bite forces were measured by means of hydrostatic splints, whereas a 3D motion capture system was used to analyze spatiotemporal parameters and joint angles, respectively. Additionally, dynamic stability was quantified by the extrapolated CoM concept, designed to determine postural stability in dynamic situations. Paired t-tests revealed that submaximum biting did not significantly influence recovery behavior with respect to any variable under investigation. Therefore, reductions in postural sway evoked by submaximum biting are obviously not transferable to balance recovery as it was assessed in the present study. It is suggested that these contradictions are the result of different motor demands associated with the abovementioned tasks. Furthermore, floor effects and the sample size might be discussed as potential reasons for the absence of significances. Notwithstanding this, the present study also revealed that bite forces under both conditions significantly increased from subjects’ release to touchdown of the recovery limb. Clenching the jaw, hence, seems to be part of a common physiological repertoire used to improve motor performance.

Influence of the Lower Jaw Position on the Running Pattern

Introduction

The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions.

Methods

Twenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification.

Results

Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition.

Discussion

The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be considered when choosing the optimal splint condition for a specific subject.

Relationships between Malocclusion, Body Posture, and Nasopharyngeal Pathology in Pre-Orthodontic Children

BACKGROUND

Malocclusion, body posture, and breathing pattern may be correlated, but this issue is still controversial. The aim of the study was to examine the relationship between the type of malocclusion, body posture, and nasopharyngeal obstruction in children aged 7-14 years.

MATERIAL AND METHODS

The study group comprised 94 patients aged 7-14 years (mean±SD: 11.9±2.1 years); 44 (46.8%) males and 50 (53.2%) females. All patients passed an examination performed by the same orthodontist (study model and cephalometric radiograph analysis), orthopedic surgeon (body posture examined from the front, side, and back), and otorhinolaryngologist (anterior and posterior rhinoscopy and pharyngoscopy) in a blind manner.

RESULTS

Postural disorders were observed in 72 (76.6%) patients. Hypertrophy of the adenoids was diagnosed in 54 (57.4%) patients, hypertrophy of the tonsils in 85 (90.3%), nasal septum deviation in 51 (54.3%), and allergic rhinitis in 19 (20.2%) patients. There was a statistically significant correlation between presence of kyphotic posture and a reduction in the SNB angle, representing sagittal position of the mandible. Also, there was a statistically significant association between kyphotic posture and nasopharyngeal obstruction (54.1% of patients with nasopharyngeal obstruction were kyphotic, compared with 25% of patients with no nasopharyngeal obstruction; p=0.02). Kyphotic posture and reduced SNB angle were more common among males.

CONCLUSIONS

We concluded that: 1) there was a significant association between the sagittal position of the mandible (SNB angle) and a kyphotic posture; 2) kyphotic posture was significantly more common among patients with nasopharyngeal obstruction.

Effects of experimental insoles on body posture, mandibular kinematics and masticatory muscles activity. A pilot study in healthy volunteers

BACKGROUND

It has been hypothesized that different plantar sensory inputs could influence the whole body posture and dental occlusion but there is a lack of evidence on this possible association.

OBJECTIVES

To investigate the effects of experimental insoles redistributing plantar pressure on body posture, mandibular kinematics and electromyographic (EMG) activity of masticatory muscles on healthy subjects.

METHODS

A pilot study was conducted on 19 healthy volunteers that wore custom-made insoles normalizing the plantar pressure distribution for 2 weeks. Body posture parameters were measured by means of an optoelectronic stereophotogrammetric analysis; mandibular kinematics was analyzed by means of gothic arch tracings; superficial EMG activity of head and neck muscles was performed. Measurements were carried out 10 days before the insertion of the insoles, immediately before the insertion, the day after, 7 and 14 days after, in four different exteroceptive conditions.

RESULTS

The outcomes of the present study show that insoles do not modify significantly over time the parameters of body posture, SEMG activity of head and neck muscles and mandibular kinematics.

CONCLUSIONS

In this pilot study the experimental insoles did not significantly influence the body posture, the mandibular kinematics and the activity of masticatory muscles during a 14-day follow up period.