The effect of dental occlusal disturbances on the curvature of the vertebral spine in rats

Objective:

To determine whether a unilateral increase or decrease in the bite affects the curvatures of the vertebral spine in rats.

Methods:

25 male Sprague Dawley rats were included. Five animals received no alteration on their bite. Bite was increased on 10 animals and molar teeth were extracted on 10 other animals. Frontal and lateral radiographs were taken on days 0, 7, 14 and 21. Distances from landmarks to a true vertical line were measured on both radiographs.

Results:

Repeated measures analysis showed statistically significant differences between the amount of the curvature at the cervical and thoracic spines on frontal and lateral radiographs over time (P<0·05 and P<0·0001). One-way ANOVA computed significant differences (P<0·05) at D14 at the cervical and thoracic spines on both, increased and decreased vertical dimension.

Conclusion:

Alterations in the dental occlusion affects the normal curvatures of the vertebral spine in rats.     

Low-level laser therapy for management of TMJ osteoarthritis

Aims:

This study investigated the efficacy of low-level laser therapy (LLLT) for the management of temporomandibular joint (TMJ) osteoarthritis.

Methodology:

In a double-blind clinical trial, 20 patients with TMJ osteoarthritis were randomly divided into laser and placebo groups. The patients in the laser group received irradiation from an 810 nm low-level laser (Peak power 80 W, average power 50 mW, 1500 Hz, 1 μs pulse width, 120 seconds, 6 J, 3·4 J/cm² per point), which was applied on four points around the TMJs and on painful muscles three times a week for 4 weeks. In the placebo group, the treatment was the same as that in the laser group, but with laser simulation. The patients were evaluated before laser therapy (T1), after 6 (T2) and 12 (T3) laser applications and 1 month after the last application (T4), and the amount of mouth opening and the pain intensity were recorded.

Results:

No significant differences were found in mouth opening either between the study groups or between the different evaluation times in each group (P>0·05). There was no significant difference in pain symptoms of the masticatory muscles and TMJ between the laser and the placebo groups (P>0·05), but some significant within-group improvements were present for Visual Analogue Scale (VAS) scores of the body of the masseter and TMJ in both groups.

Conclusions:

LLLT using the present laser parameters was no more effective than the placebo treatment for reducing pain and improving mouth opening in patients with TMJ osteoarthritis.     

One-leg standing time with eyes open: comparison between the mouth-opened and mouth-closed conditions

Objective:

Many studies report a significant relationship between the one-leg standing time with the eyes open and the occlusal relationship. To determine the association between proprioception (the periodontal membrane vs muscle spindle) to the one-leg standing time, the authors compared the one-leg standing time with eyes open between mouth-opened and mouth-closed conditions.

Methods:

The study participants were 107 healthy, elderly patients. The authors measured the one-leg standing time with eyes open between mouth-opened and mouth-closed conditions.

Results:

The one-leg standing time was significantly shorter with the mouth opened (21·1±19·1 seconds) than with the mouth closed (25·1±21·4 seconds). Patients whose one-leg standing time was equal or shorter with the mouth opened than with the mouth closed were not different from the other patients with regard to age, handgrip strength, BMI, and the number of remaining teeth.

Discussion:

The vertical mandibular position may affect body balance.     

The effect of reduced disclusion time in the treatment of myofascial pain dysfunction syndrome using immediate complete anterior guidance development protocol monitored by digital analysis of occlusion

Statement of problem:

Chronic myofascial pain dysfunction syndrome (MPDS) has been a nightmare for patients suffering from it, who have been treated with various treatment options with varied outcomes. This population of patients has been neglected, due to nagging revisits to a clinician and decreased percentage of success.

Objective:

T-Scan-based immediate complete anterior guidance development (ICAGD) has been shown by a researcher to reduce the muscle hyperactivity consistent with MPDS. The purpose of this study is to evaluate the effect of reduced disclusion time in lateral excursions in treating the MPDS symptoms.

Materials and methods:

Fifty-one myofascial pain patients with symptoms in the area of the head and neck region were treated with ICAGD. The quantified force and time data from T-Scan records were used to correct the prolonged disclusion time, and the subjects were assessed for the symptom relief. The Wilcoxon Signed Ranks Test was used for statistical analysis (P<0·05 denotes significant changes).

Results:

The changes in disclusion time and intensity of various symptoms were found to be statistically significant (P<0·05) from Day 1 onwards, and patients were relieved of their symptoms after reduction of disclusion time of less than 0·5 seconds.

Conclusion:

The results clearly indicated that ICAGD protocol reduces musculoskeletal-based symptoms of MPDS patients, and this protocol can prove beneficial for the clinical treatment success.     

Clinical predictive factors for temporomandibular disorders following combined orthodontic and orthognathic surgical treatment in patients with Class III malocclusion

Objective: The aim of this study was to identify clinical factors predisposing to the development or worsening of temporomandibular disorders (TMDs) following orthodontic surgical treatment for Class III malocclusion.

Methods: A retrospective cohort study was performed on 88 patients with Class III malocclusion having undergone a combined orthodontic and orthognathic surgical treatment. Temporomandibular joint and masticatory muscle examinations were available prior to treatment and one year post-operatively. Multivariate logistic regression was used to predict the development of post-operative TMDs, and linear regression was used to predict the worsening of TMDs using Helkimo indices.

Results: Patients with Class III malocclusion presenting with pre-treatment anamnestic TMJ clicking (OR = 5.8; p = 0.03) and undergoing bimaxillary osteotomy procedures (OR = 18.6; p = 0.04) were more at risk for the development of TMDs.

Discussion: TMDs must be evaluated, monitored, and managed with caution in patients with Class III malocclusion presenting with pre-treatment joint clicking and who are planned for bimaxillary osteotomies.     

Features of occlusal state in female Japanese patients with migraine: a case-controlled study

Objectives: The prevalence rate of migraines is 8.4%; it is mostly diagnosed in women at 20s to 40s, and is known to cause major physical and mental disruption to daily life. This study was conducted on women aged between their 20s and 40s, in order to investigate the possible differences in the features of the occlusal state between a migraine and a non-migraine (control) group.

Methods: Age-matched female patients with migraine (n = 60) diagnosed by headache specialists and healthy controls (n = 57) were enrolled. Dental casts were used to evaluate some features.

Results: The maxillary and mandibular dentition casts from the migraine group showed significantly characteristic findings in their Angle’s classification, overjet, and deviation in the anterior tooth midline, compared to the control group.

Discussion: The results relating occlusal state to both tension-related headaches and migraines, which have different pathogeneses, suggest the possibility of dental intervention to improve the symptoms of primary headaches.     

Cephalometric risk factors associated with myocardial infarction in patients suffering from obstructive sleep apnea: A pilot case-control study

Introduction: Obstructive sleep apnea (OSA) and its craniofacial anatomic risk factors might play a role in several cardiovascular diseases, including myocardial infarction (MI). However, there are no data about cephalometric findings among OSA patients with MI.

Methods: In this pilot case-control study, about 2000 individuals referred to the sleep center were evaluated according to apnea – hypopnea index (AHI) and other inclusion criteria. Included were 62 OSA male patients (AHI > 10), of whom 6 had an MI history. In both control (n = 56) and MI groups (n = 6), 18 cephalometric parameters were traced. Data were analyzed using independent samples t-test.

Results: Compared with control OSA patients, OSA patients with MI showed a significantly larger tongue length (p = 0.015). The other cephalometric variables were not significantly different between the two groups.

Conclusion: An elongated tongue might be considered a risk factor for MI in OSA patients. The role of other variables remains inconclusive and open to investigation with larger samples (determined based on pilot studies such as this report) collected in longitudinal fashion.     

Lifestyle and oral facial disorders associated with sleep bruxism in children

Objective: The aim of the study was to investigate the routine, sleep history, and orofacial disorders associated with children aged 3–7 years with nocturnal bruxism.

Methods: Children (n = 66) were divided into groups of parent reported nocturnal bruxism (n = 34) and those without the disorder (n = 32). Data about the child’s routine during the day, during sleep and awakening, headache frequency, temporomandibular joint (TMJ), and hearing impairments were obtained through interviews with parents/caregivers. Electromyography examination was used to assess the activity of facial muscles. Multiple logistic regression (MLR), chi-square test, and t-test analyses were performed.

Results: MLR revealed association of nightmares (p = 0.002; OR = 18.09) and snoring (p = 0.013; OR = 0.14) with bruxism. Variables related to awakening revealed an association with bruxism (p < 0.05). Parents of the main group (children with nocturnal bruxism) reported more complaints of orofacial pain, facial appearance, and headache occurrence (p < 0.05). Auditory and muscle disorders were not significant variables (p > 0.05).

Conclusion: Nightmares and snoring are associated with nocturnal bruxism in children. Bruxism in children elicits consequences such as headache, orofacial pain, and pain related to awakening.     

The craniofacial morphology and maximum bite force in sleep bruxism patients with signs and symptoms of temporomandibular disorders

Objectives:

The purpose of the present study was to compare craniofacial morphology and bite force of bruxist patients with signs and symptoms of temporomandibular disorders.

Method:

Fourteen subjects with sleep bruxism and 14 healthy subjects participated. The signs and symptoms of the temporomandibular disorders were identified according to the Craniomandibular Index (CMI). Maximum bite force was measured using strain-gage transducers. Lateral cephalometric films were taken, and linear and angular measurements were performed.

Results:

Bite force between bruxist and non-bruxist females was not significant, whereas males with bruxism revealed higher bite forces. None of the linear and angular measurements differed significantly between bruxist and non-bruxist males. However, higher mandibular corpus length and anterior cranial base length, and lower gonial angle were observed in bruxist females compared to non-bruxist females. Negative correlation between bite force and CMI values was found in both genders.

Discussion:

Bruxist females had higher CMI values than bruxist males, which could lead to relatively lower bite forces.     

Thirty-year follow-up of a TMD case treated based on the neuromuscular concept

Aim:

Occlusal therapy is employed to alleviate the symptoms of a temporomandibular disorder (TMD) at times. However, the long-term effect of occlusal therapy in the masticatory system is not well understood. This case study aims to present a 30-year follow-up of a TMD case.

Methodology:

The patient developed TMD with intermittent closed lock of the left temporomandibular joint (TMJ). Chief complaints included trismus, pain, and noise of the left TMJ during function. The patient’s occlusal disharmony was assessed with use of electronic instruments and corrected based on the neuromuscular concept. A minimum-invasive and reversible approach using adhesive occlusal restorations was used.

Results:

The jaw movement and masticatory muscle activity assessed at the 7- and 23-year follow-ups revealed that the established occlusion was well adapted, and re-established the patient’s functional occlusion system. The patient has been free from TMD symptoms with the corrected occlusion for 30 years.

Conclusions:

Occlusal reconstruction based on the neuromuscular concept can be stably integrated into the patient’s functional occlusion system.     

Single-needle arthrocentesis (Shepard cannula) vs. double-needle arthrocentesis for treating disc displacement without reduction

Objectives: To compare single- vs. double-needle arthrocentesis with viscosupplementation for treating disc displacement without reduction of the temporomandibular joint.

Methods: Fifty-six patients with a magnetic resonance imaging diagnosis of non-reducing disc displacement were included. Arthrocentesis with viscosupplementation was performed on patients in group I using the Y-shaped needle (Shepard cannula) technique; the standard double-needle technique was performed on patients in group II. Patients were evaluated on postoperative day 1, and 1, 3, and 6 months later, patient- and procedure-related parameters were assessed.

Results: In both groups, significant improvement in the baseline levels was achieved (p < 0.01). Both techniques were equally effective at reducing pain and increasing the maximal mouth opening. The single-needle technique was easier to perform and required a shorter operative time (p < 0.01).

Discussion: Single-needle (Shepard cannula) arthrocentesis can be an alternative to the standard technique; however, it might add to the cost of the procedure.     

Morphometry of the cranial base and the cranial–cervical–mandibular system in young patients with type II,division 1 malocclusion,using tomographic cone beam

Aims:

Traditionally, diagnosis and treatment planning of structural and three-dimensional anomalies have been performed using two-dimensional X-rays. Cone beam computed tomography (CBCT), the technology utilized in this study, allows creation of specialized images from the craniofacial region that provide more precise and reliable results. The growth of the cranial base, position and size of the cervical system, and the hyoid bone has an influence upon the morphogenesis and the growth of the maxillofacial complex. The data obtained through this current study offer a better understanding of the origin and manifestation of malocclusions, and will, therefore, offer a better therapeutic approach. The objective of the current study is to describe the measurements of the cranial base and the cranial–cervical–mandibular system in young patients with type II, division 1 malocclusion, using CBCT.

Methodology:

Twenty-four CBCT images were obtained for young patients with type II, division 1 malocclusion. The i-CAT Vision (Imaging Sciences International, Hatfield, PA, USA) was used to view the images. Linear and angular measurements were obtained in the mid-sagittal plane. Univariate and bivariate analyses, as well as a multivariate analysis of principal components, were conducted.

Results:

The only metric with a statistically significant difference regarding gender was S–N major in the male participants. The metrics SNA–SNB and SNPg are positively related and inversely proportional to the angles BA–S–N and PO–P McGregor. The inclination of the upper incisor showed an inverse relationship with the angles SNA–SNB and SNpg. The craniovertebral angle was diminished in the entire sample, and the variable that vertically relates the hyoid was independent of the other variables.

Conclusions:

After evaluating 24 images of young patients with type II, division 1 malocclusion using helical spiral CBCT, it was concluded that relationships exist between the cranial base structures, the structures that determine the sagittal position of the maxilla, mandible and chin, and the cervical vertebrae complex and hyoid bone.     

Interrelations between orthostatic postural deviations and subjects’ age,sex, malocclusion,and specific signs and symptoms of functional pathologies of the temporomandibular system: a preliminary correlation and regression study

Aims:

Studies on the relationships between postural deviations and the temporomandibular system (TS) functional health are controversial and inconclusive. This study stems from the hypothesis that such inconclusiveness is due to authors considering functional pathologies of the TS (FPTS) as a whole, without taking into account subjects’ specific FPTS signs and symptoms.

Methodology:

Based on the author and collaborators’ previous studies, the present study analyzed data on body posture from a sample of 50 subjects with (30) and without (20) FPTS. Correlation analyses were applied, taking as independent variables age, sex, Helkimo anamnestic, occlusal, and dysfunction indices, as well as FPTS specific signs and symptoms. Postural assessments of the head, cervical spine, shoulders, lumbar spine, and hips were the dependent variables. Linear regression equations were built that proved to partially predict the presence and magnitude of body posture deviations by drawing on subjects’ characteristics and specific FPTS symptoms.

Results:

Determination coefficients for these equations ranged from 0·082 to 0·199 in the univariate, and from 0·121 to 0·502 in the multivariate regression analyses.

Conclusions:

Results show that factors intrinsic to the subjects or the TS may potentially interfere in results of studies that analyze relationships between FPTS and body posture. Furthermore, a trend to specificity was found, e.g. the degree of cervical lordosis was found to correlate to age and FPTS degree of severity, suggesting that some TS pathological features, or malocclusion, age or sex, may be more strongly correlated than others with specific posture patterns.     

Thinking of a maladaptive occlusion as an orthopedic cumulative trauma disorder

Aim:

The authors review the possible connection between a dental malocclusion and a temporal mandibular disorder (TMD).

Methodology:

The authors have reflected on several patient case histories to remind us that there may be instances when a simple case of dental malocclusion could be blamed for instigating the signs and symptoms of TMD. The common denominator for this discussion is the situation of joint pain, dysfunction and/or myalgia. Patient-reported signs and symptoms, along with treatment results and progress notes were evaluated.

Results:

The onset of TMD signs could be traced to an altered dental occlusion, which, upon maximum closure drives the mandible in a posterior direction, forcing the condylar head to now impinge upon retrodiscal tissue and the resultant muscle reflex protective response. Correction for the dentally induced malocclusion obviated the symptoms of TMD with patient-reported improved health.

Conclusions:

When a patient presents with signs consistent with those of a TMD, the clinician should include a review of recently placed dental restorations or occlusal equilibration to assess the patient’s adaptive occlusion. Overlooking this quick evaluation on the exam checklist may lead to the clinician missing a simple treatment modality to address a TMD.     

The effect of a mandibular advancement appliance on cervical lordosis in patients with TMD and cervical pain

Aims:

A preliminary study to compare cervical lordosis by means of cervical cephalometric analysis, before and after six months of continuous mandibular advancement appliance (MAA) use, and to show how physical therapy posture re-education would improve the cervical lordosis angle.

Methodology:

Twenty-two female patients with temporomandibular disorders (TMD) and cervical pain with lordosis <20° were included. Patients had to have a muscle pain history for at least six months, and with an intensity ≥6, measured by means of a visual analog scale (a horizontal 0–10 numeric rating scale with 0 labeled as ‘no pain’ and 10 as ‘worst imaginable pain’). Patients had to present the angle formed by the posterior tangents to C2 and C7 of equal or less than 20°. Cephalometric and clinical diagnostics were performed initially (baseline) and at the end of the study period (six months). During the third month with MAA treatment, a physical therapist evaluated the postural deficit and performed a program of postural re-education. Angular and linear dimension data presented a normal distribution (P>0·05; Shapiro Wilk Test), so the paired comparison of the cephalometric measurements was made by t-test for dependent samples.

Results:

Angle 1 (OPT/7CVT); angle 3 (CVT/EVT) and angle 4 (2CL/7CL) showed a significant increase in the cervical lordosis. Angle 2 (MGP/OP), angle 5 (HOR/CVT) and the distances C0–C2 and Pt–VER, presented no significant changes.

Conclusions:

The increase in cervical lordosis implies that six months of continuous MAA use, together with a program of postural re-education, promotes the homeostasis of the craniocervical system.     

WHO-5 well-being index as screening instrument for psychological comorbidity in patients with temporomandibular disorder

Objectives: The aim of the study was to compare the WHO-Five Well-Being Index (WHO-5) with the Oral Health Impact Profile-49 (OHIP-49) questionnaire as screening tools to detect psychological comorbidity in TMDs.

Methods: A TMD group (92 patients, 42.8 ± 17.1 yrs) and a control group (90 patients of the Department of Prosthetic Dentistry, 38.9 ± 10.1 yrs) completed the WHO-5 and the OHIP-49 questionnaire.

Results: The patients with TMD reported significantly greater OHIP-49 sum scores than controls (47.5 ± 34.7 vs. 7.7 ± 12.1; p < 0.001). The mean raw score of the WHO-5 was significantly less, with 45.6 ± 20.6 points for patients with TMD than the 73.2 ± 15.6 points found for controls (p < 0.001). The OHIP sum score and the WHO-5 raw score were significantly associated (r = 0.705, p < 0.001). Both instruments exhibited excellent internal consistency (Cronbach’s α = 0.967 and 0.883, respectively).

Conclusions: WHO-5 proved to be an effective and economic screening instrument to detect psychological comorbidity in TMDs. Implementing WHO-5 in standard care could contribute to more individualized interdisciplinary psychotherapy and/or functional therapy.     

Frequency of temporomandibular arthralgia among myofascial pain patients with pain on palpation of ipsilateral masseter

Aims:

The masseter muscle is a common source of referred pain to the temporomandibular joint (TMJ), with a possibility of false positive diagnoses for arthralgia when diagnosed by research diagnostic criteria for temporomandibular disorders (RDC/TMD) clinical examination. The current study investigated the distribution of arthralgia diagnoses among individuals with myofascial pain, with or without pain on masseter palpation.

Methodology:

The study was conducted with 255 outpatients. Clinical data and questionnaires were directly entered into software that deploys algorithms based on the diagnostic criteria of the RDC/TMD, and automatically classifies and stores the diagnosis of each patient evaluated. An association between diagnostic subgroups was verified by calculating the odds ratio (OR), and the statistical significance was tested using the Chi-square test.

Results:

A higher frequency of concordance (about three times greater) between myofascial pain and arthralgia occurred when there was pain on palpation in the region of the ipsilateral masseter muscle, and the association was statistically significant.

Conclusions:

The results of this study revealed a threefold increase in the risk for the presence of temporomandibular arthralgia in cases of myofascial pain combined with pain on palpation in the region of the ipsilateral masseter muscle.