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Papers by Robert Dmd

Advanced Dental Technologies & Techniques, Jan 12, 2021

Ideal static occlusal relationships do not necessarily result in ideal functional occlusal relati... more Ideal static occlusal relationships do not necessarily result in ideal functional occlusal relationships. Current Orthodontic outcome indexes assess and satisfy aesthetic and morphologic endpoints but do not measure or determine any functional occlusal relationships, or report on the quality of the occlusal contacts that follow tooth movement. The T-Scan 10 Computerized Occlusal Analysis system can measure the occlusal contact distribution, can diagnose both static and dynamic functional occlusal relationships following orthodontic treatment, and can aid in the diagnosis of TMD/ Occluso-muscle disorder patients. Comprehensive evidence supports the use of T-Scan analysis as an outcome measure in conjunction with the well-accepted means of registering occlusion (articulating paper, shimstock, occlusal wax, stone dental casts). This manuscript presents a rationale and a treatment protocol for the use of T-Scan in Orthodontics. It details T-Scan implementation during the initial examination, the active treatment appointments in extraction and non-extraction orthodontic treatment, before debonding the fixed orthodontic appliances, and during the settling and retention stages. TScan occlusal force and timing data sets can guide tooth movement decision making to improve functional occlusal contact interrelationships, optimize the occlusal balance and the functional posterior disclusion, speed up orthodontic treatment, and increase the long-term stability of the orthodontic outcome to prevent relapse.

The Journal of prosthetic dentistry, 2003

The Journal of Prosthetic Dentistry, 2009

Handbook of Research on Computerized Occlusal Analysis Technology Applications in Dental Medicine, 2015

The newly designed T-Scan 8 Computerized Occlusal Analysis system represents the state-of-the-art... more The newly designed T-Scan 8 Computerized Occlusal Analysis system represents the state-of-the-art in occlusal diagnosis. The reliability of the system's high definition recording sensors, the many occlusal analysis timing and force software features, and the modern-day computer hardware electronics that record occlusal function in 0.003 second real-time increments affords a clinician unparalleled occlusal contact timing and force information with which to predictably diagnose and treat many occlusal abnormalities. T-Scan 8 represents the culmination of 30 years of T-Scan technology innovation and development with revised desktop graphics and less toolbar buttons for simpler graphical display designed to shorten the T-Scan learning curve. The chapter also discusses five useful diagnostic occlusal recordings employed when treating commonly observed occlusal problems. Lastly, the chapter outlines the three Learning Levels of T-Scan mastery that must be accomplished for a clinician ...

Handbook of Research on Computerized Occlusal Analysis Technology Applications in Dental Medicine

Since its inception in 1984, Computerized Occlusal Analysis technology has revolutionized both de... more Since its inception in 1984, Computerized Occlusal Analysis technology has revolutionized both dental Occlusal Science and daily clinical practice, by bringing objective precision measurement to the largely subjectively analyzed Dental Medicine discipline of Occlusion. The evolution of this technology has required much iteration over the past 30 years beginning with T-Scan I, then T-Scan II for Windows®, to T-Scan III with Turbo recording, to the present day version known as T-Scan 8. Numerous authors since the mid-1980s have studied the various T-Scan versions, which inspired the manufacturer to improve the hardware and its recording sensors to be more accurate, repeatable, and precise. The software has also evolved such that the present day T-Scan 8 includes many high-tech measurement tools that aid the clinician in diagnosing and treating a wide range of occlusal abnormalities. This chapter's specific aims are to detail the evolution of the differing T-Scan system versions wh...

The Journal of Prosthetic Dentistry, 1976

CRANIO®, 2014

The aim of this study was to determine whether Subjective Interpretation of paper markings is a r... more The aim of this study was to determine whether Subjective Interpretation of paper markings is a reliable method for identifying the relative occlusal force content of tooth contacts. Methodology: 295 clinicians selected the ''Most Forceful'' and ''Least Forceful'' occlusal contacts in six occlusal-view photographs of articulating paper marks that were later compared against computerized occlusal analysis relative occlusal force measurements of the same tooth contacts. Means and standard deviations were calculated by years in clinical practice and by number of occlusion courses taken. A Chisquare analysis was also performed. Results: The mean correct for 295 participant dentists was 1.53 (61.234). There were no significant differences found for years in practice (P.0.16) or number of occlusion courses taken (P.0.75). The Chisquare analysis showed a sensitivity of 12.6%, a specificity of 12.4%, a positive predictive value of 12.58%, and a negative predictive value of 12.42%. Chance was calculated at 12.5% correct. Conclusions: Subjective Interpretation is an ineffective clinical method for determining the relative occlusal force content of tooth contacts. The reported low scores obtained from a large group of participant dentists suggest clinicians are unable to reliably differentiate high and low occlusal force from looking at articulating paper marks. This longstanding method of visually observing articulating paper marks for occlusal contact force content should be replaced with a measurement-based, objective method.

Objective: Essential Palatal Myoclonus and Perioral Myoclonus (POM) are rare soft palate conditio... more Objective: Essential Palatal Myoclonus and Perioral Myoclonus (POM) are rare soft palate conditions which may present idiopathically or with structural brain epilepsies. Palatal Myoclonus is characterized by uncontrolled, rhythmic, jerky movements of the soft palate, which can be accompanied by other ear, nose, and throat symptoms that appear in the muscles innervated by the brainstem. A particularly annoying symptom is a rhythmic clicking sound in the ear, resultant from theuncontrolled palate movements repeatedly opening and closing the Eustachian tube. Alternatively, Orofacial Buccal Dystonia presents as focal, sustained spasms of the masticatory facial or lingual muscles, and of the nostrils. Both of these related spastic muscle conditions can best be diagnosed with a proper understanding of the functional orofacial neuroanatomy that is responsible for the clinical signs and symptoms. This Clinical Report details a rare case of Palatal Myoclonus with inner ear clicking that was ...

IGI Global eBooks, May 26, 2010

records, and quickly displays for clinical interpretation, tooth contact Time-Sequences while sim... more records, and quickly displays for clinical interpretation, tooth contact Time-Sequences while simultaneously Force-Mapping each tooth contacts' fluctuating relative occlusal force levels which occur during functional jaw movements (known as Occlusal Events) (Maness 1993, Montgomery and Kerstein 2000, Kerstein 2001, Kerstein and Wilkerson 2001). These occlusal event measurements are recorded intraorally, with an ultra-thin, electronically charged, mylar-encased sensor that is connected to a computer via a USB interface. By measuring Relative Force, the T-Scan III system can detect whether an occlusal force on one set of contacting opposing teeth is greater, equal

PubMed, Sep 1, 2010

Muscle hyperactivity is a potential source of symptomatology in patients with temporomandibular d... more Muscle hyperactivity is a potential source of symptomatology in patients with temporomandibular disorders. Various occlusal adjustment procedures have been advocated to reduce hyperactivity. A new, measurement-driven, occlusal adjustment procedure, known as immediate complete anterior guidance development (ICAGD), has been shown through nonsimultaneous electromyography to lessen masticatory muscle hyperactivity effectively by reducing posterior disclusion time to <0.4 sec in all mandibular excursions. This reduction, in turn, lessens the volume of periodontal ligament compressions that create additive and excessive functional muscle contractions via a feedback mechanism involving the trigeminal nerve. This case report describes the treatment of chronic muscular hyperactivity with a computer-guided ICAGD enameloplasty and simultaneously recorded electromyography. Follow-up visits showed that after reduction, the pretreatment levels of excursive muscular hyperactivity were lessened and lasting. This result is caused by the shorten ed posterior disclusio time resulting in an equally reduced time to muscle shutdown.

Cranio-the Journal of Craniomandibular Practice, Apr 1, 2004

Current advances in computer technologies have afforded dentists precision ways to examine occlus... more Current advances in computer technologies have afforded dentists precision ways to examine occlusal contacts and muscle function. Recently, two separate computer technologies have been synchronized together, so that an operator can record their separate diagnostic data simultaneously. The two systems are: the T Scan II Occlusal Analysis System and the Biopak Electromyography Recording System. The simultaneous recording and playback capacity of these two computer systems allows the operator to analyze and correlate specific occlusal moments to specific electromyographic changes that result from these occlusal moments. This synchronization provides unparalleled evidence of the effect occlusal contact arrangement has on muscle function. Therefore, the occlusal condition of an inserted dental prosthesis or the occlusal scheme of the natural teeth (before and after corrective occlusal adjustments) can be readily evaluated, documented, and quantified for both, quality of occlusal parameters and muscle activity and the responses to the quality of the occlusal condition. This article describes their synchronization and illustrates their use in performing precision occlusal adjustment procedures on two patients: one who demonstrates occlusal disharmony while exhibiting the signs and symptoms of chronic myofascial pain dysfunction syndrome, and the other who had extensive restorative work accomplished but exhibits occlusal discomfort post-operatively.

Sensors

Objective—To perform a Randomized Controlled Trial (RCT) Disclusion Time Reduction (DTR) study at... more Objective—To perform a Randomized Controlled Trial (RCT) Disclusion Time Reduction (DTR) study at five Dental Colleges, using intraoral sensors and muscular electrodes. Methods and Materials—One hundred students were randomly assigned to a treatment group to receive the ICAGD coronoplasty, or a control group that received tooth polishing. All subjects answered symptom questionnaires: Beck Depression Inventory-II, Functional Restrictions, and Chronic Pain Symptom and Frequency. Subjects self-reported after ICAGD or placebo at 1 week, 1 month, 3 months, and 6 months. The Student’s t-Test analyzed the measured data. The Mann–Whitney U Test analyzed the subjective data (Alpha = 0.05). Results—The Disclusion Times, BDI-II scores, and Symptom Scales were similar between groups prior to treatment (p > 0.05). At 1 week, all three measures reduced in the treatment group, continuing to decline over 6 months (p < 0.05), but not for the controls (p > 0.05). Symptom Frequency, Functiona...

**Objective**: The efficacy of splint therapy remains a controversial topic. Some studies show oc... more **Objective**: The efficacy of splint therapy remains a controversial topic. Some studies show occlusal appliances can reduce TMD symptoms, while other authors report contradictory results. Splints adjusted with conventional occlusal indicators attempt to establish an “ideal” occlusion. This pilot study evaluated whether stabilization splints that were adjusted with articulation paper and operator judgment, were actually balanced when assessed with the T-Scan technology, and to determine if T-Scan data, could further refine the splints into more ideal occlusal force balance. **Material and Method**: Eleven Thai patients (mean age 30 years) being treated with maxillary full arch hard acrylic Stabilization Splints, had their splints conventionally adjusted with articulating paper only, before being measured by the T-Scan. Each splint was then further refined by T-Scan guided adjustments. The mean force imbalance difference between the left and right-side occlusal force distribution from the conventional adjustments and the digital adjustments were subjected to the Wilcoxon Signed Ranks test (p < 0.05). **Results**: The unadjusted splint (Pre group) had a greater mean imbalance difference compared to the no splint (WS group). The paper-only adjustments slightly reduced the splint imbalance from the baseline (Post 1 group), but not significantly. The (Post 2 group) with T-Scan adjusted group had differences that were significantly lower than the three other conditions (p < 0.05). **Conclusion**: Conventionally adjusted Stabilization Splints, using articulation paper and an operator’s judgement, had markedly worse occlusal force imbalances than did the same splints that were adjusted using the T-Scan system. Computer-guided occlusal adjusting created more precise balance, than did unmeasured, articulation paper-based, subjective occlusal adjusting.

Subjective Interpretation of articulating paper markings is still being taught as being safe for ... more Subjective Interpretation of articulating paper markings is still being taught as being safe for patients, despite that studies show dentists choose incorrect forceful and non-forceful contacts when using its principles. The Specific Aims of this study were to replicate or contradict prior Subjective Interpretation study findings, by using T-Scan contact force levels in a single articulating paper-marked quadrant photograph, to see if dentist-participants could visually select the 2 highest force occlusal contacts.

Objective Less than ideal contacts have been reported following aligner therapy, which is believe... more Objective Less than ideal contacts have been reported following aligner therapy, which is believed will resolve with settling, despite settling improving occlusal balance has not been scientifically confirmed. The aim of this study was to compare the outcome quality of occlusal contacts in patients treated with fixed appliances or clear aligners. Methods 39 orthodontic patients (14 treated with aligners; 25 with fixed appliances) were evaluated with a digital occlusal analysis system (T-scan10 ™), assessing Maximum Intercuspation contact simultaneity, symmetry, and relative force distribution. The Occlusion Time, the Right/Left force percentage (%R/L), the Anterior/Posterior contact ratio (RAP), and the anteroposterior Center of Force (COF) locations were recorded at treatment completion, and 3 and 6 months after. Results No significant differences in measured occlusal contact quality parameter were found between groups at treatment completion or follow-up (OT, %R, RAP nor COF posit...

CRANIO®, 2020

Objective: To assess botulinum toxin-A (BTX-A) on mandibular movements and bite force (BF%) in br... more Objective: To assess botulinum toxin-A (BTX-A) on mandibular movements and bite force (BF%) in bruxism. Methods: Ten bruxers were divided into 2 groups based on BF% imbalance (G1: >10%, G2: <10%). BTX-A 140U was total injected into the masseter and temporalis muscles. A T-Scan® recorded BF%, occlusion time (OT), right, left, and protrusive disclusion time (DT) before administering BTX-A, as well as 15, 45, 90, and 120 days after injection. Results: The Friedman and Wilcoxon tests found significant differences in BF% in G1 subjects at 15 days (p = 0.028 s), OT at 90 (p = 0.043 s), and 120 (p = 0.027 s) days, DTR at 90 (p = 0.046 s) and 120 (p = 0.028 s) days, DTL at 15 (p = 0.043 s) and 90 (p = 0.027 s) days, and DTP 45-90 days (p = 0.043 s). Conclusion: BTX-A induced BF% starting at 15 days post-injection and influenced lateralities later.

The Journal of Indian Prosthodontic Society, 2016

Disclusion time reduction (DTR) is an objective treatment protocol using T-Scan III (digital anal... more Disclusion time reduction (DTR) is an objective treatment protocol using T-Scan III (digital analysis of occlusion) and electromyography for treating occlusally activated orofacial pains. Chronic occluso-muscle disorder is a myogenous subset of temporomandibular disorder symptoms. These muscular symptoms are induced within hyperactive masticatory muscles due to prolonged disclusion time, occlusal interferences, and occlusal surface friction that occur during mandibular excursive movements. This case report describes a patient treated by DTR therapy, whereby measured pretreatment prolonged disclusion time was reduced to short disclusion time using the immediate complete anterior guidance development enameloplasty, guided by T-Scan occlusal contact time and force analysis synchronized with electromyographic recordings of four masticatory muscles.

CRANIO®, 2012

The purpose of this study was to determine if a statistically significant reduction in muscle act... more The purpose of this study was to determine if a statistically significant reduction in muscle activity (p<0.05) occurs when prolonged disclusion time (>0.4 sec/excursion) is shortened to <0.4 sec/excursion with the Immediate Complete Anterior Guidance Development (ICAGD) enameloplasty. Forty-five symptomatic, fully informed subjects (29 female, 16 male) had their right and left disclusion times recorded with T-Scan 111 , while simultaneously, the bilateral masseter and anterior temporalis muscle activity was recorded electromyographically with BioEMG III (n=180 muscles). This recording was done twice, once pretreatment and again posttreatment (same day) after undergoing the ICAGD enameloplasty on the same day without changing electrodes. The Student's paired t-test was utilized to detect any significant change in the muscle activity levels between the pre-and posttreatment lateral excursive muscle contractions. Highly significant reductions were found in all four muscles' activities after shortening the pretreatment prolonged disclusion time to less than 0.4 seconds (p<0.0014); after Bonferroni correction (p<0.006). When properly performed, such that the posttreatment disclusion time is <0.4 sec/excursion, the ICAGD enameloplasty predictably reduces excursive muscle activity levels in the bilateral anterior temporalis and masseter muscles. Excursive muscle hyperactivity can be a source of lactic acid accumulation, muscular ischemia, and chronic myalgic temporomandibular joint dysfunction (TMD) symptoms. The ICAGD enameloplasty significantly reduces excursive muscle contractions after completion of the first ICAGD treatment session.

CRANIO®, 2016

Balanced occlusal force distribution is a critical factor for restorative, prosthetic or orthodon... more Balanced occlusal force distribution is a critical factor for restorative, prosthetic or orthodontic treatment. It has been postulated that orthodontic treatment may lead to occlusal discrepancies in the arch due to changing the occlusal relationships. This study was conducted to compare the occlusal force parameters between natural dentition patients and a post-orthodontic treatment group. Fifty Thai subjects were divided into non-orthodontic and post-orthodontic groups comprised of 25 subjects each (mean age 24.8 years). The T-Scan® III computerized occlusal analysis system was used to record a multi-bite closure for each subject. The initial occlusal contact location, the bilateral percentage force distribution, the percentage force in the anterior and posterior quadrants, and the individual tooth force percentages were calculated for both groups. The Student&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s Paired t-Test compared the in-group differences, while a one-way ANOVA analyzed the differences between the two groups. The initial tooth contacts in both groups were found on the second molars and central incisors. Maximum force was most frequently observed on the left second molar tooth (15.9% non-orthodontic; 25.4% post-orthodontic). The bilateral right-to-left side force distribution (51.36% right-48.96% left) was not statistically different for all subjects, nor was it statistically different between the non-orthodontic (48.67% right-51.36% left) and the post-orthodontic groups (48.96% right-51.05% left). Statistically significant differences were found between the quadrants in both the groups (22.46% anterior-77.57% posterior in non-orthodontic subjects; 10.58% anterior-89.42% posterior in post-orthodontic subjects) (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). A significant occlusal force discrepancy was found in the post-orthodontic subjects, with higher force percentages observed posteriorly and much less percentage force anteriorly, when compared to the natural dentition subjects. T-Scan® III digital occlusal analysis may be recommended for orthodontic case finishing, to make visible to the Clinician the severity of the orthodontically created occlusal force imbalance, such that it can be minimized during orthodontic case finishing.

Concepts, Methodologies, Tools and Applications

Time-Sequencing and Force-Mapping with Integrated Electromyography to Measure Occlusal Parameters... more Time-Sequencing and Force-Mapping with Integrated Electromyography to Measure Occlusal Parameters (9781609605612): Robert B. Kerstein: Book Chapters.