Computerized occlusal analysis as an alternative occlusal indicator

Background: All disciplines of dentistry require that clinicians assess the articulation of the teeth/prosthesis with respect to simultaneous contacts, bite force and timing.

Aims: This article intends to describe the advantages and limitations of the data acquired when using a computerized occlusal analysis as a dynamic occlusal indicator.

Methodology: A search of the literature was completed (Medline, PubMed) using the keywords occlusion, occlusal registration, computerized occlusal analysis and T-Scan for dental.

Results: According to the evidence available, the computerized occlusal analysis system is the only occlusal indicator that demonstrates the ability to provide quantifiable force and time variance in a real-time window from the initial tooth contact into maximum intercuspation.

Conclusion: The reported advantages to accurately indicate occlusal contacts make the computerized occlusal analysis system a better occlusal indicator when compared with other non-digital convention indicator materials available.     

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 role of occlusal factors on the occurrence of temporomandibular disorders

Aims:

The aim of this study was to investigate the relationship between occlusal factors and temporomandibular disorders (TMD).

Methodology:

One hundred patients were selected among those who sought medical or dental care in public practice in Recife, Brazil. The presence of malocclusions and absence of five or more posterior teeth were evaluated by the clinical exam. TMD diagnosis was given using Research Diagnostic Criteria (RDC/TMD). Statistics were carried out using Fisher and Mann–Whitney methods with 5% significance level, as well as multiple logistic regression analysis.

Results:

The sample was mainly comprised of women (83%), individuals over 30 years old (57%) and singles (53%). The percentage of TMD and malocclusion in total sample was 42% and 50%, respectively, while in TMD subjects, malocclusion was present in 38·1%. There was no association between TMD and the occlusal factors studied.

Conclusion:

It can be concluded that malocclusion and loss of five or more posterior teeth does not contribute to TMD.     

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.     

The efficacy of a specific stabilization splint

Background:

The use of a Tanner type stabilization splint, fabricated on a leaf gauge articulation for the treatment of patients with disc displacement without reduction, is lacking in the literature.

Objectives:

The purpose of the study is to collect non-controlled, therapy-related observations; in other words, to demonstrate the efficacy of this appliance for the treatment of patients with disc displacement without reduction.

Methods:

The study enrolled 55 patients, 5 men, and 50 women, with the clinical diagnosis disc displacement without reduction, 42 with and 13 without limited mouth opening. All patients received a splint in the musculoskeletally stable centric relation (CR) position. Mouth opening, clinical performance, and the timeframe of splint treatment were assessed.

Results:

For 37 patients with a disc displacement without reduction with limited opening, the largest increase in mouth opening (9·5±5·6 mm) occurred in the first week (7·9±2·5 days). No occlusal adjustment of the splint was needed during the treatment sequence. For three patients, treatment took up to 3 months (8·1%), for 13 patients, between 3 and 6 months (35·1%), and for 17 patients, within a year (45·9%), making a total of 89·1% successfully treated patients. Out of 50 patients, 29 had a total resolution of signs and symptoms, whereas 21 patients still suffered from solitary temporomandibular disorder (TMD) signs.

Conclusion:

A Tanner type stabilization splint, fabricated in the musculoskeletally stable CR position, appears to be an effective and efficient means for the treatment of patients with disc displacement without reduction. Its efficacy makes it eligible to be tested in a randomized controlled trial.

Clinical implications:

The efficacy of this specific splint, fabricated in the musculoskeletally stable CR position, makes it a promising tool to treat TMD patients with disc displacement without reduction.     

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.     

Comparison of masticatory muscle myofascial pain in patients with and without a chief complaint of headache

Objectives:

Headaches are a common complaint in temporomandibular disorder (TMD) patients. However, few studies have compared the symptom characteristics between TMD patients with and without a complaint of headache. The aim of this study was to compare subjective symptoms and treatment outcomes between myofascial TMD patients who had a chief complaint of headache and those who did not.

Methods:

One hundred sixty one patients underwent comprehensive examinations and scored their pre- and post-treatment symptoms on a form (4 items assessing pain intensity and 1 assessing sleeping difficulty). On the basis of the primary diagnosis, patients were divided into two groups: myofascial pain with and without a chief complaint of headache (MPH and MP).

Results:

Before treatment, patients in the MPH group scored significantly higher with respect to pain intensity and level of sleeping difficulty than did patients in the MP group (jaw/face pain, P = 0·015; headache, P < 0·001; neck pain, P < 0·001, and difficulty in sleeping, P = 0·005; Mann-Whitney U-test). Patients in the two groups demonstrated similar treatment outcomes, except for neck pain.

Conclusion:

Significant differences in symptom characteristics and outcomes were observed between primarily myofascial TMD patients with and without a chief complaint of headache.     

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.     

Oral appliances for the treatment of obstructive sleep apnea in patients with low C-PAP compliance: a long-term case series

Objectives:

To assess the effectiveness of mandibular advancement devices (MADs) for the treatment of obstructive sleep apnea syndrome (OSAS) over a long-term follow-up in patients non-compliant with continuous positive airway pressure (CPAP) and to identify potential predictive factors of response to MADs.

Methods:

Fifteen OSAS patients were enrolled. Apnea-hypopnea index (AHI) and daytime sleepiness were assessed at baseline and at the end of follow-up. Potential baseline predictors of treatment effectiveness were assessed.

Results:

AHI and Epworth Sleepiness Scale (ESS) scores improved significantly with MADs. Sixty per cent of patients were ‘responders’, of whom 33% were ‘full responders’. Sixty-seven per cent of patients showed total compliance. No correlations between the potential predictors and the response to MAD therapy were found.

Discussion:

Effectiveness of MAD therapy was shown over a long-term follow-up in OSAS patients with low compliance to CPAP. Efforts to identify predictive success factors fell short.     

Conservative reduction by lever action of chronic bilateral mandibular condyle dislocation

Aims:

The treatment of long-standing dislocation of the temporomandibular joint is broadly classified into open reduction and closed reduction. The current study presents a case of long-standing dislocation of the temporomandibular joint treated 3 years after dislocation. In this study, the authors evaluated the long-term outcome of conservative reduction by lever action of chronic bilateral mandibular condyle dislocation.

Methodology:

Manual repositioning of temporomandibular joint dislocation lasting for 3 years in a 31-year-old woman was attempted without success; therefore, conservative reduction by lever action was carried out because the patient declined treatment under general anesthesia.

Results:

The treatment was discontinued after 6 days because of the subluxation of the retaining tooth. The retainer was changed from tooth to screw for intermaxillary fixation, and treatment was reinstituted. Fifteen days later, reduction was achieved and retention was started and continued for 2 months. The outcome was good, with no recurrent dislocation within 24 months of the treatment.

Conclusions:

Conservative reduction by lever action, involving minimally invasive treatment and little dysfunction, should be considered an optional conservative treatment.     

Spindle cell carcinoma arising at the buccal mucosa: a case report and review of the literature

Aims:

Spindle cell carcinoma (SPCC) is a subtype of squamous cell carcinoma, and it mainly occurs in the upper aerodigestive duct. On the other hand, it rarely arises in the head and neck region. The prognosis of this tumor is usually poor because of its highly malignant behavior, such as its high incidence of recurrence or metastasis to cervical lymph nodes. However, the number of accumulated cases is still too low to provide the full details of SPCC.

Methodology:

The case of SPCC was counted by using database, PubMed. The authors also present a case of SPCC arising at the left buccal mucosa in a 72-year-old Japanese female in the current study.

Results:

Only six cases of SPCC arising at the buccal mucosa have been reported previously. The authors’ patient died from a recurrent tumor 15 months after the first operation.

Conclusion:

The authors have added this case to the previous knowledge of SPCC arising at the buccal mucosa, and discuss the clinical behavior of SPCC to help suggest a standard treatment strategy for the disease.     

Status of occlusal contact during sleep bruxism in patients who visited dental clinics – A study using a Bruxchecker®

Objective: Bruxism-induced mechanical load causes various dental problems, and its treatment is challenging. The present study analyzed upper and lower tooth contacts to determine actual occlusal contact during sleep bruxism.

Methods: Tooth contact patterns were analyzed in 49 patients attending dental clinics, using a Bruxchecker®, cephalograms, and condylographs.

Results: Approximately 80% of individuals demonstrated contact from the anterior teeth to the molar region (ICPM); about 96% had mediotrusive grinding and contact. The tooth contact area increased with the flatness of the anterior occlusal plane. The ratio of the contact area of the anterior teeth to the overall tooth contact area increased with overbite. Bilateral ICPM and mediotrusive contact patterns were associated with a high frequency of temporomandibular disorder symptoms, clicking, and/or pain.

Discussion: The tooth contact area, anterior occlusal plane, and overbite are closely related, suggesting that tooth contact with the anterior teeth should be controlled with occlusal therapy.     

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.     

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.     

Oral pre-trigeminal neuralgia pain: clinical differential diagnosis and descriptive study results

Aims:

To better quantify oral pre-trigeminal neuralgia (PTN) symptoms, attempt to identify PTN symptoms that could reliably differentiate between PTN and odontogenic tooth pain, and determine whether an anesthetic test would reliably differentiate these disorders.

Methodology:

This was accomplished through a survey of symptom recall for 49 trigeminal neuralgia patients who had PTN tooth and/or gum pain.

Results:

The variability of oral PTN symptoms, factors that worsened or improved them, and how dental anesthesia affected them, explain the reason for variations found in the literature. A throbbing pain quality is not in the literature, but present for 63% of respondents.

Conclusions:

No specific PTN symptom would reliably differentiate PTN from odontogenic tooth pain. The results also suggest that an anesthetic test would not be totally reliable for differentiating these disorders. A protocol is provided that should help practitioners identify the tooth pain source when there is no dental pathology.     

Features and management of intracranial mandibular condyle dislocation after trauma

Background:

Dislocation of the mandibular condyle into the middle cranial fossa is rare in clinics. It often occurs when the mouth is open wide during the injury. It causes restriction of mandibular motion, lower facial asymmetry, pain in the temporomandibular joint (TMJ), etc.

Objective:

To introduce the features of intracranial mandibular condyle dislocation and discuss the management to this kind of trauma.

Major findings:

In this paper, the authors present two cases, describing the diagnosis, surgical management, and 1-year follow-up evaluation. The results of the authors' treatment to intracranial mandibular condyle dislocation were satisfactory and stable, and no surgical complications were detected.

Conculsion:

Advanced imaging studies are mandatory for exact diagnosis and successful treatment of intracranial mandibular condyle dislocation, and individualized management is recommended.     

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.     

Phantom bite: a case report and literature review

Objective:

Phantom bite is a rare and challenging condition that dentists may encounter in their daily clinical practice. Patients with phantom bite typically present with many failed repeated occlusal treatments, such as full-mouth prosthetic reconstructions and orthodontic treatments, to overcome their distressing symptoms.

Method and result:

A 55-year-old female with no history of medical problems presented with bite discomfort. She complained of discomfort from a “bite” and pressure-like feeling in her right upper three maxillary posterior teeth. Examination revealed no temporomandibular disorder (TMD) abnormalities. A thorough evaluation of her oral structures revealed no dental, periodontal, or mucosal pathologies.

Conclusion:

Owing to the great potential of conditions for financial loss and litigation problems, dentists, particularly those who perform bite-changing procedures, should be aware of this condition. This case is presented to highlight many of the clinical characteristics of phantom bite.     

Effect of upper costal and costo-diaphragmatic breathing types on electromyographic activity of respiratory muscles

Aim:

To compare electromyographic (EMG) activity in young–adult subjects with different breathing types.

Methodology:

This study included 50 healthy male subjects with complete natural dentition, and no history of orofacial pain or craniomandibular-cervical-spinal disorders. Subjects were classified into two groups: upper costal breathing type, and costo-diaphragmatic breathing. Bipolar surface electrodes were located on sternocleidomastoid, diaphragm, external intercostal, and latissimus dorsi muscles. Electromyographic activity was recorded during the following tasks: (1) normal quiet breathing; (2) speaking the word ‘Mississippi’; (3) swallowing saliva; and (4) forced deep breathing.

Results:

Sternocleidomastoid and latissimus dorsi EMG activity was not significantly different between breathing types, whereas diaphragm and external intercostal EMG activity was significantly higher in the upper costal than costo-diaphragmatic breathing type in all tasks (P<0·05; Wilcoxon signed rank-sum test).

Conclusion:

Diaphragm and external intercostal EMG activity suggests that there could be differences in motor unit recruitment strategies depending on the breathing type.     

Clinical protocol for occlusal adjustment: Rationale and application

Background: Occlusal adjustment can optimize the result of orthodontics, orthognathic surgery, and comprehensive restoration, and resolve adverse forces to the dentition that affect the entire masticatory system. Mounted diagnostic casts and computerized occlusal analysis offer complementary advantages for evaluating occlusal problems. Predictable occlusal adjustment is facilitated by precise, measured documentation of occlusal force by computerized occlusal analysis.

Clinical presentation: A conservative, structural correction of a pronounced, chronic occlusal problem by additive and subtractive occlusal adjustment was performed after a previous failed occlusal adjustment. The patient’s chief concerns were significant anterior teeth fremitus in maximum intercuspation and “pain in the teeth and a poor bite” after 30+ adjustments over 2.5 years.

Clinical Relevance: Confirmation of specific criteria for a therapeutic occlusion resolved the anterior teeth fremitus and uneven bite. Traumatic occlusal contact on posterior teeth may elicit protective mandibular repositioning affecting anterior teeth relationships and should be considered during comprehensive diagnosis.