The three-dimensional assessment of dynamic changes of the proximal segments after intraoral vertical ramus osteotomy

Objectives: The aim of this study was to assess the positional changes of the proximal segments after intraoral vertical ramus osteotomy (IVRO).

Method: Fifteen patients underwent IVRO and were followed according to the authors’ unique postoperative management regimen. The analyses of the positions and angles of the proximal segments were performed on frontal and lateral cephalograms, which were taken before surgery (T1) and within 3 days (T2), at 4 weeks (T3), and later than 6 months after surgery (T4). The three-dimensional positions of the condylar heads were also assessed by CT images, which were taken before and 1 year after surgery.

Results: The proximal segments temporarily swung posteriorly and laterally with a center on the condylar head as a fulcrum point at T2 and T3, compared with T1, and they repositioned at T4. The condylar heads moved inferior approximately 2 mm with lateral rotation one year after surgery, as seen in the CT.

Discussion: The condylar heads changed their positions physiologically for newly established jaw movement after IVRO with the authors’ post-operative management regimen because the post-operative skeletal stability and the jaw function were good and stable using this method.     

MRI changes in the temporomandibular joint following mandibular setback surgery using sagittal split ramus osteotomy with rigid fixation

Objectives: This study examined the changes in temporomandibular joint dysfunction (TMD) symptoms and investigated the variations in the disc position, disc and condylar morphology following sagittal split ramus osteotomy (SSRO) with rigid fixation in patients with mandibular prognathism. Furthermore, the authors examined the correlation between mandibular setback and TMD symptoms.

Methods: The study included 24 Japanese patients with jaw deformities who were treated using bilateral SSRO and Le Fort I osteotomy. The clinical and magnetic resonance imaging findings in the temporomandibular joint were evaluated preoperatively and at three and six months postoperatively.

Results: The preoperative TMD symptoms were significantly associated with the prevalence of TMD symptoms at six months postoperatively. Anterior disc displacement improved in four joints with slight displacement and with no morphological change. There were no postoperative changes in condylar morphology. There was no significant correlation between mandibular setback and the postoperative TMD symptoms.

Conclusion: Postoperative TMD symptoms may be influenced mainly by preoperative TMD symptoms rather than mandibular setback using SSRO with rigid fixation. Therefore, patients with TMD symptoms require physical examination and MRI for appropriate diagnosis preoperatively.     

Physiological positioning strategy alters condylar position after mandibular ramus sagittal split osteotomies for mandibular prognathism

Objective: The aim of this study was to elucidate the physiological position of the proximal segment for postoperative jaw movement in patients with mandibular prognathism.

Methods: Twenty-two patients with mandibular prognathism were treated by orthognathic surgery using bilateral mandibular sagittal split ramus osteotomies (SSRO) with a physiological positioning strategy. The skeletal stability was assessed, and the movement of the proximal segment was evaluated by cephalography and computed tomography performed preoperatively, immediately postoperatively, and one year postoperatively.

Results: The patients were divided into two groups: the stable group (SNB relapse <1.5°) and the relapse group (SNB relapse ≥1.5°). In the stable group at one year postoperatively, the average SNB relapse was only 0.29° (7%), the condylar head had moved posteriorly by 0.75 mm, and the proximal segment had rotated counterclockwise by 1.2°.

Conclusion: This new physiological positioning strategy improves the position of the condyle compared with the preoperative position in patients with mandibular prognathism.     

Keratocystic odontogenic tumor arising at the mandibular ramus with an impacted tooth: a case report and mimic lesions

Objectives: To consider the biologic behaviors of keratocystic odontogenic tumors (KCOTs) and

ameloblastomas and dentigerous cysts.

Methods: A 63-year-old Japanese man presented with swelling and discomfort in the left cheek during jaw movement. Examination revealed a multilocular lesion within the mandible extending from the left second premolar to the left mandibular ramus and coronoid process; the lesion contained a deviated impacted tooth. The tumor had expanded beyond the bone and was invading the masseter and medial pterygoid muscles. Marginal mandibulectomy with a free iliac bone graft was performed.

Results: No recurrence was observed during a 7-year follow-up.

Discussion: The histopathological diagnosis of the lesion showed it was a KCOT. These tumors usually grow within the bone, causing bone expansion. However, this tumor had expanded beyond the bone and invaded surrounding muscles. Thus, KCOTs can, in rare cases, manifest themselves as described here. Evaluating preoperative images and histopathological findings is important to determine the optimal treatment strategy.     

Reliability of mandibular movement assessments depending on TMD

Objective: This study determines the effect of temporomandibular disorders (TMD) on the reliability of mandibular movement assessments.

Methods: The vertical and horizontal jaw movements, as well as overjet and overbite, were measured twice in 56 consecutively recruited adult subjects with TMD according to the RDC/TMD and 29 controls without TMD diagnosis by experienced dentists utilizing a millimeter ruler. The reliability was determined by intraclass correlation coefficient (ICC).

Results: Neither statistically nor clinically relevant differences in the repeatability between both subgroups could be detected (all p ≥ 0.077). The mouth opening and overjet proved an excellent reliability (ICC 0.85–0.92). Overbite and laterotrusion showed good to excellent reliable results (ICC 0.74–0.82). The second measurement of the vertical jaw movement resulted in systematically higher values (p < 0.003).

Discussion: The assessment of the mandibular movement with a millimeter ruler is a reliable procedure irrespective of TMD. To decrease the variances in the mouth opening measurements, the patient should be asked beforehand to practice this movement.     

The correlation between direction and amount of retrusive movement and condyle position and joint space

Objective: The direction and amount of retrusive movement may be correlated with the amount of joint space and the maximum intercuspal position of the condyle. The aim of this study was to identify any such correlation using an ultrasonic jaw motion analyzer and digital volumetric tomographic (DVT) scans.

Methods: Thirty-five dental students were selected as subjects. DVT scans were obtained using a next-generation i-CAT CBCT unit, and the direction and amount of retrusive movement were measured with a 3-D analyzer.

Results: Spearman Rho correlation tests showed no correlation between the amount of retrusive movement and the condyle position and joint space on either the right or left side.

Discussion: There is sufficient reason to suggest that retrusive movement of the condyle does not occur in isolation but is influenced by glenoid fossa bone morphology.     

Mandibular movement during speech of two related Latin languages

Objectives/hypothesis: This study assessed the kinesiographic recordings of jaw movements during reading a text in Galician and Spanish language.

Study design: Cross-sectional blind study.

Methods: A homogeneous healthy group of 25 normal stomatognathic system and native Galician participants was studied. Frontal and parasagittal plane recordings of the intraborder lateral jaw movements and during reading Galician and Spanish texts were recorded using a calibrated jaw-tracking device, kinesiograph.

Results: Although movements were similar in both languages, a greater retrusion of the jaw in the Spanish language was shown; moreover, a tendency exists for a left-side motion envelope in this right-handedness preference sample.

Conclusions: This study supports the hypothesis that speech is controlled by the central nervous system rather than by peripheral factors and that the hemispheric dominance influences the asymmetry of the speech envelope.     

The impact of a total hip replacement on jaw position,upper body posture and body sway

Objectives:

The purpose of this study was to examine whether, and to what extent, a total hip replacement can influence the position and the movement of the jaw, the upper body posture and body sway.

Methods:

Twenty test subjects (6 females, 14 males) participated in this study pre- and post-total hip replacement, in addition to a healthy control group of 20 subjects (5 females, 15 males). The measurements were conducted by means of an ultrasound system to measure jaw condyle position and movement of the lower jaw, a three-dimensional back scan to analyze upper back posture, and a static and dynamic force plate to measure body sway. For statistical analysis the Wilcoxon-Matched-Pairs-Test or Man–Whitney-U-Test, including a Bonferroni–Holm correction, respectively, was used.

Results:

After surgery, the mean values of the left and right jaw condyles of the test group moved posterior, and the left condyle position was located more caudally. There were no significant differences concerning the jaw position between the two groups. There was little change in upper body posture in both groups. The test group had a more anteriorly inclined thoracic spine and a less pronounced lumbar lordosis. During static body sway measurements, increased fluctuations in the test group after surgery could be seen.

Conclusion:

Differences between both groups in the pre- and post-surgical condition could be detected. These differences were more prominent when the measured body segments were more distally located with respect to the hip region.     

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.     

Patterns of cervical and masticatory impairment in subgroups of people with temporomandibular disorders–an explorative approach based on factor analysis

Objectives: To identify clinical patterns of impairment affecting the cervical spine and masticatory systems in different subcategories of temporomandibular disorder (TMD) by an explorative data-driven approach.

Methods: For this observational study, 144 subjects were subdivided according to Research Diagnostic Criteria for TMDs into: Healthy controls, temporomandibular joint (TMJ) signs without symptoms, TMJ affected, temporomandibular muscles affected, or TMJ and muscles affected. Factor analysis and linear regression were applied to cervical spine and masticatory data to identify and characterize clinical patterns in subgroups.

Results: Factor analysis identified five clinical dimensions, which explained 59% of all variance: Mechanosensitivity, cervical movement, cervical and masticatory dysfunction, jaw movement, and upper cervical movement. Regression analysis identified different clinical dimensions in each TMD subgroup.

Conclusion: Distinct clinical patterns of cervical spine and masticatory function were found among subgroups of TMD, which has clinical implications for therapeutic management.     

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.     

Diagnosis of retrodiscal tissue in painful temporomandibular joint (TMJ) by fluid-attenuated inversion recovery (FLAIR) signal intensity

The purpose of the present study is to analyze the fluid-attenuated inversion recovery (FLAIR) signal intensity of the retrodiscal tissue in a painful temporomandibular joint (TMJ), and to develop a diagnostic system based on FLAIR data.

Methodology:The study was based on 33 joints of 17 patients referred for MR imaging of the TMJ. Regions of interest were placed over retrodiscal tissue and gray matter (GM) on FLAIR images. Using signal intensities of GM as reference points, signal intensity ratios (SIR) of retrodiscal tissue were calculated. SIRs in painful TMJ were compared with those in painless TMJ. Wilcoxon’s Rank Sum Test was used to analyze the difference in SIRs between the painful and painless groups (P<0·05).

Results:The SIRs of retrodiscal tissue were significantly higher in painful joints than in painless joints.

Conclusion:FLAIR sequences provide a high signal in patients having painful TMJ, and it suggests that retrodiscal tissue in painful TMJ contains elements such as protein.     

Treatment of frictional dental hypersensitivity (FDH) with computer-guided occlusal adjustments

Objective: To verify the efficacy of treating dentin/dental hypersensitivity (DH) to Cold Ice Water Swish testing before and after subjects undergo the Immediate Complete Anterior Guidance Development (ICAGD) computer-guided occlusal adjustment.

Methods: One hundred chronically dysfunctional patients with known cold sensitivity swished ice water intraorally to elicit a DH response scored on a Visual Analog Scale (VAS). The subjects then underwent the ICAGD coronoplasty, which was followed by a second ice water swish scored with a second VAS. The pre to post ICAGD Disclusion Time values and VAS scores were statistically evaluated by the Wilcoxon Signed Rank for Paired Difference test. The subjects were divided into subgroups with DH sensitivities <4 and ≥4, and analyzed. Limitations were as follows: abfractions were not quantified, dysfunctional symptom resolution was not determined, each subject was their own control, one clinician administered all ice water tests, and protrusive excursions were not included.

Results: Disclusion Time reductions from ICAGD were significant (2.11–0.55 s. p = 0.0000). The DH score changes showed highly significant decreases from pre to post ICAGD (p < 0.0001).

Conclusions: A partial etiology for cold tooth sensitivity exists, resultant from prolonged occlusal surface excursive movement frictional contacts. This cold sensitivity can be lessened with measured, computer-guided occlusal adjustments.     

The prevalence of OSA in snorers presenting with various chief complaints: a pilot study

Aims:

The incidence of obstructive sleep apnea (OSA) in snoring patients is reported in the literature to range from 20% to 70%. The aim of this study was to obtain exact data on the percent of snorers who have OSA, and to classify them as having normal, mild, moderate, or severe sleep apnea.

Methodology:

There were 273 patients who came into the senior author’s office with sleep disorder breathing problems. They suffered with various sleep problems. All 273 patients also had a snoring problem. None of the 273 patients had ever had a sleep test, or polysomnograph (PSG).

All 273 required a PSG for evaluation of their sleep problem. They were referred to a certified sleep lab local to them. When the results of the PSG came back, the authors were able to classify them as having normal, mild, moderate, or severe sleep apnea.

Results:

The results of the 273 PSGs showed the following: 12 patients (4%) had PSGs of apnoea–hypopnoea index (AHI)<5 (normal), 57 patients (21%) had PSGs with AHIs 5–<15 (mild), 79 patients (29%) had PSGs with AHIs 15–<30 (moderate), 119 patients (44%) had PSGs 30 or >30 (severe), and 6 patients (2%) had PSGs >100 (severe).

Conclusions:

Based on this study, of 273 patients who snored, the incidence of OSA is high. Ninety-six percent of the patients suffered with mild to severe sleep apnea. This malady, which can be very serious and degenerating, could be much more prevalent than previously believed. Additional research is needed to verify these figures.     

Disc displacement without reduction: a retrospective study of a clinical diagnostic sign

Objective: The purpose of this retrospective study is to evaluate a clinical diagnostic sign for disc displacement without reduction (DDWR), the absence of additional condylar translation during opening compared with protrusion.

Method: Thirty-eight electronic axiographic and magnetic resonance imaging (MRI) examinations of the TMJ were analyzed in order to compare the opening/protrusion ratio of condylar translation between non-painful DDWR and non-DDWR.

Result: According to the Mann-Whitney U test, the opening/protrusion ratio in non-painful DDWR differs significantly from non-DDWR (p < 0.0001).

Discussion: Among non-painful DDWR, there is no additional condylar translation during opening in comparison with protrusion, and this is probably also the case for DDWR without limited opening, which is a subtype that has not been validated by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Comparative condylar palpation can analyze this sign, and therefore, further comparative investigations between MRI and clinical examination are needed to validate the corresponding clinical test.     

Orthognathic treatment of dentofacial disharmonies: its impact on temporomandibular disorders,quality of life,and psychosocial wellness

Aim: The objective of this literature review was to assess the effect of orthognathic surgical treatment on temporomandibular disorders (TMD), quality of life (QoL), and psychosocial wellness.

Methods: Journal articles and systematic reviews published in English between 1982 and 2015 were searched using PubMed, MEDLINE, and Cochrane database using the search terms “orthognathic,” “temporomandibular disorders,” “quality of life,” and “psychosocial.” The articles were then reviewed and discussed.

Results: Both objective and subjective parameters play a role in orthognathic treatment outcome satisfaction and QoL. Psychological factors and TMD exerted a stronger influence on patients’ QoL more than objective treatment outcome measures.

Conclusion: A paradigm shift in clinical mindset from solely objective measures to a more holistic, patient-centric approach of addressing patients’ expectations and improving QoL is warranted when treating patients with dentofacial disharmonies.     

The application of the Index of Orthognathic Functional Treatment Need (IOFTN): service evaluation and impact

Objectives: (1) To undertake a service evaluation of the Index of Orthognathic Functional Treatment Need (IOFTN). (2) To determine its suitability to replace the Index of Orthodontic Treatment Need (IOTN) in the assessment of patients with dentofacial deformity.

Design: Laboratory- and questionnaire-based study.

Setting: UK hospital-based orthodontic department.

Methods: Cohen’s Kappa was used to assess inter- and intra-operator reliability for the IOTN and the IOFTN against 30 orthognathic patients’ models scored to a ‘gold standard’. Questionnaires gathered feedback on ease of use of the IOFTN. Change in treatment need status for a further 60 orthognathic patients was estimated utilising the IOTN, the IOFTN and a modified IOTN (mIOTN).

Results: Inter-operator agreement with the ‘gold standard’ for the IOTN and the IOFTN ranged from 0.64-0.90 and 0.61-0.91, respectively. Intra-operator agreement for the IOTN and the IOFTN ranged from 0.46-1.00 to 0.59-0.95, respectively. Mean feedback score was 9.08 out of a maximum score of 10. Overall, 88.9% of patients scored grades 4 or 5 on the IOFTN (IOTN = 87.8%; mIOTN = 77.8%).

Conclusions: The IOFTN is simple and reliable to use. It is an appropriate aid in the prioritisation of surgical patients. Further recommendations are given.     

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.     

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.