Analysis of the morphometric characteristics of the cervical spine and its association with the development of temporomandibular disorders

Analysis of the Effect of Exams on Perceived Stress and Temporomandibular Joint Status in Physiotherapy Students: A Pilot Study

Background and Objectives: Temporomandibular disorders or dysfunction (TMDs) encompass a range of complex conditions that impact the temporomandibular joint (TMJ), chewing muscles, teeth, and/or their supporting tissues. Stress is one of the most associated factors studied as a TMD predictor. The aim is to figure out the influence of stress on TMJ status and salivary cortisol in university students during and before exams. Materials and Methods: The study was non-experimental, employing a longitudinal, analytical, observational cohort design. The study population consisted of students enrolled in the physiotherapy degree program at the Alfonso X El Sabio University (Madrid, Spain). Data were collected during two distinct academic periods: the first period was characterized by low academic stress and no exams, and the second period coincided with the high academic stress of final course exams. The collected results included sociodemographic data, assessment of TMJ status (Fonseca Index), evaluation of muscle evaluation (masseter, upper trapezius, and sternocleidomastoid) using a MOXY Monitor (muscle oxygenation) and Neurotrac® (surface EMG, sEMG), assessment of perceived stress (PSS-14), and measurement of salivary cortisol (enzyme immunoassay with Elisa). The statistical analysis was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. Results: 70 students were analyzed during two different measurement periods. According to the Fonseca Index, initially, 37.14% of the analyzed students showed mild TMDs, 17.14% moderate TMDs, and 45.72% showed no TMDs. In general terms, stress increased with age and is related to female sex, maximum mouth opening decreased with age, oxygen saturation decreased with age and academic stress, and myoglobin concentration was related to age. Furthermore, muscle contraction decreased during higher academic stress and increased with age. For women, age was a risk factor for suffering from TMDs, and stress worsened the transition from having TMDs to having no TMDs in both sexes. Conclusions: Academic stress influences TMJ status and muscle outcomes such as oxygen saturation, myoglobin concentration, and muscle contraction, although more research is needed.

The effect of temporomandibular joint dysfunction on the craniocervical mandibular system: A retrospective study

BACKGROUND

Temporomandibular disorders are the most common condition affecting the orofacial region, resulting in pain and dysfunction.

OBJECTIVE

This study aimed to elucidate the ambiguous association between cervical features and temporomandibular disorders by measuring the rotations between the skull-atlas, atlas-axis and mandible-atlas and examining the relationship between these rotations and temporomandibular disorders.

METHODS

Cone-beam computed tomography (CBCT) images from 176 patients, 97 females and 79 males with an average age of 25.7 years were used in this study. The patients were divided into two groups: those with joint dysfunction (n = 88) and those without (n = 88). The study employed various methods to determine rotations in the skull-atlas, atlas-axis and mandible atlas based on anatomical landmarks and measurements. These methods include the use of specific planes, angles and distances to identify and measure rotation. Data analysis was performed using the TURCOSA statistical software (Turcosa Analytics Ltd Co, Turkey, www.turcosa.com.tr).

RESULTS

The results showed that the degree of rotation between the skull and the atlas was higher in the TMD group than in the control group (p < .001). Similarly, Atlas-axis rotation was significantly higher in the TMD group (p < .001). However, no significant difference was found between mandible atlas rotations in the two groups (p = .546). The study also found a significant difference between the direction of rotation between the atlas and axis and the direction of mandible atlas rotation (p < .001) as well as between skull and atlas rotations and mandible-atlas rotations (p < .001).

CONCLUSION

Overall, the study suggests that there is a relationship between the skeletal structures of the cranio-cervico-mandibular system and TMD. Skull-atlas and atlas-axis rotations may play an important role in the aetiology of TMD in individuals with TMD. Therefore, it is important to evaluate rotations in the skull-atlas-axis region for the treatment of TMD.

An investigation of biomechanics, muscle performance, and disability level of craniocervical region of individuals with temporomandibular disorder

OBJECTIVE

To investigate biomechanics, muscle performance, and disability of the craniocervical region in temporomandibular disorder (TMD) patients and compare them with controls.

METHODS

Craniocervical posture was evaluated using lateral photography and radiography. Range of motion, muscle performance, disability, and TMD severity were assessed using an inclinometer, Functional Strength Testing of Cervical Spine, Neck Disability Index, and Fonseca Anamnestic Index, respectively.

RESULTS

Compared to the control group, the TMD group demonstrated higher cervical flexion angle (p=0.005) and neck disability (p<0.001) as well as lower cervical extension (p=0.040), right cervical rotation (p=0.005), left cervical rotation (p<0.001), and tragus-C7-horizontal (p=0.048) angles, and reduced muscle performances (p≤0.001). Most patients had higher than normal craniocervical angle (p<0.001). Muscle performance in each cervical motion (p<0.005) and disability (p<0.001) were associated with TMD severity in the TMD group.

CONCLUSION

Biomechanics, muscle performance, and disability of craniocervical region were altered in the TMD group.

Temporomandibular disorder prevalence and its association with oral parafunctions, neck pain, and neck function in healthcare students: A cross-sectional study

OBJECTIVE

To determine the temporomandibular disorder (TMD) prevalence in female students and to assess its association with oral parafunctions, neck pain, and function.

METHODS

One hundred forty-four participants were included. The severity of TMD was assessed with Fonseca's Anamnestic Index (FAI). The oral parafunctions were self-reported with the Oral Behaviors Checklist (OBC). Neck pain and neck function were recorded with the Core Outcome Measure Index (COMI). The Spearman correlation analysis was used for statistical analysis.

RESULTS

Seventy participants (48.6%) had mild TMD. All participants had a positive OBC score, which indicated an oral parafunction. A moderate correlation between TMD and oral parafunctions (p < 0.001) was detected.

DISCUSSION

TMD is common in female healthcare students, and its presence is associated with oral parafunctions, neck pain, and function. It is recommended to evaluate oral health habits and neck pain and function in females with TMD.

Strength of scapular elevation in women with TMD and asymptomatic women

Temporomandibular disorder (TMD) is recognized for its high prevalence, presenting characteristic signs and symptoms. Cervical spine pain is present in 70% of diagnosed TMD cases. Aim: To verify if women with TMD present changes in isometric muscle strength in the scapula elevation. Methods: This is an observational, cross-sectional study. Thirty-five women, aged 22.89±2.04 years, were divided into the TMD group (TMDG), diagnosed with TMD according to the DC/TMD, and control group (CG), with asymptomatic individuals. The volunteers accessed a online link by the smartphone in order to answer questions on personal data, the Fonseca Anamnestic Index (FAI), Neck Disability Index (NDI), and Masticatory preference. In all participants, evaluation of the force of the scapula elevation muscles was performed, using a load cell model MM-100 (Kratos® SP, Brazil). Data were analyzed descriptively using the maximum, mean, and standard deviation and a two-way ANCOVA test was applied for all variables. A significance level of 5% was considered. Results: There were no statistically significant differences between the TMDG and CG for the maximal and mean muscle strength of scapular elevation. There were statistically significant differences in FAI (p <0.001*) between the CG and the TMDG. Conclusion: Based on the results, it was not possible to confirm the hypothesis that women diagnosed with TMD present lower isometric strength during scapular elevation (right/left).  

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 Occlusal Splints on Spinal Posture in Patients with Temporomandibular Disorders: A Systematic Review

There is still a gap in the scientific knowledge on the linkage between craniofacial structure and spinal postural control in temporomandibular disorder (TMD) patients. This systematic review aimed to assess the role of occlusal splints on spinal posture of TMD patients. PubMed, Web of Science, and Scopus were systematically searched from inception until 5 January 2022 to identify observational studies with a longitudinal study design presenting: patients with diagnosis of TMD according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD); occlusal splint therapy as intervention; postural assessment as outcome. Out of 133 records identified, 104 were suitable for data screening, and only 7 articles were included satisfying the eligibility criteria. We found that occlusal splints might have a positive effect on posture in TMD patients, albeit there is little evidence of appropriate investigation for postural assessment. This systematic review suggested that the occlusal splint might be considered a non-invasive therapeutic approach for patients with TMD. However, the low number of studies with high-quality methodology in these patients showed an urgent need for further research using combined force platform stabilometry and kinematic evaluation of the spine to investigate the impact of occlusal splints on posture.

Orthodontic Treatment and Craniocervical Posture in Patients with Temporomandibular Disorders: An Observational Study

Orthodontic treatment acts through the application of forces and/or by stimulating and redirecting the functional forces within the craniofacial complex. Considering the interrelationship between craniomandibular and craniocervical systems, this intervention may alter craniocervical posture. Thus, our aim is to (a) compare craniocervical posture, hyoid bone position, and craniofacial morphology before, after, and also in the contention phase at least one year after the orthodontic treatment, in patients with temporomandibular disorders and (b) to verify whether the presence of condylar displacement, the skeletal class, or the facial biotype interferes with the abovementioned outcomes. To do so an observational, analytical, longitudinal, and retrospective design study was carried out. A non-probabilistic convenience sampling method was applied. The sample consisted of clinical records of patients diagnosed with temporomandibular disorders in order to compare pre-orthodontic treatment with post-orthodontic treatment (n = 42) and contention phase data (n = 26). A cephalometric analysis of several variables was performed. The p-value was set as 0.05. When the pre- and post-orthodontic treatment data were analyzed, there were statistically significant changes in variables concerning craniocervical posture (CV angle, C0-C1, and AA-PNS) and also concerning hyoid bone position (C3-Rgn). When pre- and post-orthodontic treatment and contention phase data were analyzed the variables concerning craniocervical posture (C0-C1, CVT/Ver, NSL/OPT, NSL/CVT, NSL/Ver; OPT/CVT, OPT/Ver) and facial biotype had statistically significant changes. This allowed us to conclude that in the sample studied, there were significant differences regarding hyoid bone position (pre- versus post-orthodontic treatment) and craniocervical posture (pre- versus post-orthodontic versus contention), with the craniocervical posture being prone to return to basal values. The presence of condylar displacement was found to significantly increase the H-H1 distance in the three moments of evaluation. Facial biotype was found to significantly increase the NSL/Ver angle on hypodivergent compared to hyperdivergent in the contention phase.

Upper cervical spine abnormalities as a radiographic index in the diagnosis and treatment of temporomandibular disorders

OBJECTIVE

The aim of this study was to investigate the clinical characteristics and treatment outcomes of patients with temporomandibular disorders (TMD) according to the presence of upper cervical spine abnormalities and craniofacial morphology.

STUDY DESIGN

Clinical examinations were conducted on 43 patients with TMD. Upper cervical spine characteristics (fusion, posterior arch deficiency [PAD], and craniofacial morphology) reflecting head-and-neck posture were evaluated on lateral cephalograms. Condylar bone changes in the temporomandibular joint were evaluated by using cone beam computed tomography. Clinical characteristics and treatment outcomes after 1 year of conservative therapy were statistically analyzed between groups, according to the presence of upper cervical spine abnormalities.

RESULTS

Pain on neck muscle palpation was more frequent in patients with cervical fusion (P = .019) and with either fusion or PAD (P = .004) before treatment. Patients with PAD had smaller comfortable mouth opening ranges compared with those without the deficiency (P = .044) before treatment and smaller comfortable (P = .020) and maximum (P = .021) mouth opening ranges after treatment. Patients with PAD also had mouth opening limitation (P = .028) and pain on masticatory muscle palpation (P = .014) more frequently after treatment compared with patients without the deficiency.

CONCLUSIONS

Associations exist between upper cervical spine characteristics and treatment outcomes in patients with TMD, suggesting such parameters as a possible radiographic index in TMD diagnosis and treatment.

The inconclusiveness of research on functional pathologies of the temporomandibular system and body posture: Paths followed, paths ahead: A critical review

Objective: Literature on the functional pathologies of the temporomandibular system (FPTS) in its relationships with body posture is plagued with inconclusiveness. Despite being sometimes altogether disregarded, the issue is most relevant, due to its clinical implications. This paper aims for a deeper understanding of the origins of the inconclusiveness of research on such relationships by means of a critical analysis of the scientific literature on the subject, in order that clinicians may better treat patients with FPTS.Methods: Analysis of over 100 studies, published from 1918 through March 2018 in the PubMed database, using descriptors temporomandibular joint disorders and posture.Results: The analysis of the paths followed by researchers allowed for pinning down several methodological issues that may have led to the prevailing ambiguity on the matter.Conclusion: This review then proposes certain standardization of procedures in future studies, to be conducted by a proposed consortium of researchers.

Spinal deformity and malocclusion association is not supported by high-quality studies: results from a systematic review of the literature

BACKGROUND

Several reports in the literature have suggested a causative association between oral occlusion and spinal deformity such as scoliosis and Scheuermann's disease or kyphosis. Based on these findings, a growing number of adolescents with spinal deformity receive orthodontic treatment, supposing a beneficial effect on the spine.

OBJECTIVE

The aim of this study was to verify the association between spinal deformity and malocclusion in the orthopedic population and potential effect of orthodontic treatment on the spinal deformity.

METHOD

The databases: MEDLINE, CINAHL, EMBASE, Cochrane Register, OTseeker and ScienceDirect were searched up to August 2017 for studies reporting on associations between spinal and occlusal conditions. Case series, cohort, case-control studies and randomized clinical trials were considered for analysis. Two reviewers independently selected studies, conducted quality assessment and extracted results. Methodological quality was assessed using MINORS score.

RESULTS

Nine publications reporting on 1424 patients were included. Studies were two case series, five case-control studies, one cohort study and one randomized clinical trial. The methodological quality was poor in 8/9 studies.

CONCLUSION

Evidence from three low-quality studies suggests an increased prevalence of occlusal dysfunction in patients with known spinal deformity, but the conclusions have a high risk of bias. No evidence of beneficial effects of orthodontic treatment on spinal deformity was found. These slides can be retrieved under Electronic Supplementary Material.