Functional Jaw Movements Research Articles

Evaluation of Patient Comfort and Impact of Different Anesthesia Techniques on the Temporomandibular Joint Arthrocentesis Applications by Comparing Gow-Gates Mandibular Block Anesthesia with Auriculotemporal Nerve Block.

Aim Temporomandibular disorders (TMDs) are clinical situations that are characterized by pain, sound, and irregular movements of the temporomandibular joints. The most common method in the treatment of TMDs is arthrocentesis. This study aims to compare the effect of conventional extraoral auriculotemporal nerve block (ANB) and Gow-Gates (GG) mandibular anesthesia techniques on patient comfort in an arthrocentesis procedure. Materials and Methods We performed this study on 40 patients who underwent TMJ arthrocentesis with ANB (n = 20) or GG (n = 20) mandibular anesthesia techniques at the Marmara University Faculty of Dentistry between 2016 and 2019. The predictor variable was the type of an anesthesia technique, and the outcome variables included were pain, maximum mouth opening (MMO), and protrusive movement (PM). They were compared at the preoperative period and 3rd and 6th month periods. Statistical analysis included means with standard deviations, a one-way ANOVA for continuous data, and the results were evaluated at the significance level of p < 0.05. Results No statistically significant difference was observed between the VAS values, MMO, and PM averages of preoperative, 3rd and 6th months of ANB and GG (p=0.142, p=0.209, and p=0.148). Conclusion Both anesthesia techniques have provided effective results in terms of pain and functional jaw movements in the postoperative period in arthrocentesis treatment.

Evaluation of the efficiency of different treatment modalities in individuals with painful temporomandibular joint disc displacement with reduction: a randomised controlled clinical trial

The aim of the study was to investigate and compare short and long-term effects of occlusal splints (OS), ultrasound (US), and high-intensity laser therapy (HILT) in patients with painful temporomandibular joint (TMJ) disc displacement with reduction (DDWR). This prospective, randomised, single-blinded, controlled clinical study was conducted on patients with DDWR at a university oral and maxillofacial surgery clinic. A total of 140 patients were allocated randomly to four groups (OS, US, HILT, and control), with 35 patients in each. Patients were evaluated for pain, range of motion of the jaw, disability, and quality of life. A total of 132 patients completed the study. In all treatment groups (OS, US, and HILT), a significant improvement was observed in terms of pain, function, disability, and quality of life, at both weeks four and 12 compared with the control group (p < 0.001). Improvements in VAS pain and maximum mouth opening were not significantly different between the treatment groups. However, compared with the OS group, there was a significant improvement in the HILT and US groups in terms of total Oral Health Impact Profile (OHIP-14) and Jaw Functional Limitation Scale-20 (JFLS-20) scores at week four, but no difference between the groups at week 12. The results of this study show that OS, US, and HILT are effective treatments for pain and functional jaw movements in patients with DDWR. HILT, a new method, can be an alternative treatment in cases of TMD.

Full mouth rehabilitation for severely worn dentition using fixed prostheses and tooth-supported partial overdenture: a case report.

Rehabilitation of severely worn dentition represents a significant clinical challenge, especially when the restorative space is not sufficient. Creating restorations that fulfil the aesthetic, occlusal and functional parameters are essential to long-term success. This case report describes a 48-year-old male, who had severely worn dentition, which resulted in collapsed vertical dimension. The initial treatment involved careful planning, stabilization of existing dental diseases and construction of provisional prostheses at increased vertical dimension. Once the compatibility of the new vertical dimension had been confirmed, permanent reconstruction was performed. As with all full mouth prosthetic rehabilitation cases, equal-intensity centric occlusal contacts on all teeth and an anterior guidance in harmony with functional jaw movements were critically taken into account in each treatment phases.

Retrospective evaluation of the effect of stabilization splint therapy on functional jaw movements and pain

Retrospective evaluation of the effect of stabilization splint therapy on functional jaw movements and pain

Evaluation of the efficacy of different treatment modalities for painful temporomandibular disorders

The purpose of this study was to clinically evaluate the efficacies of three treatment methods and to compare their outcomes in patients with painful disc displacement. The study group comprised 45 patients with unilateral temporomandibular disorders who fell into Axis I group II (with limited mouth opening) of the Research Diagnostic Criteria for Temporomandibular Disorders. Magnetic resonance imaging was used for definitive diagnosis. The patients were divided randomly into three groups according to the treatment method: splint therapy, splint therapy with ultrasound-guided arthrocentesis, and splint therapy with low-level laser therapy. Patients were followed up after treatment for 6 months. The groups were compared in terms of pain and functional jaw movements (unassisted mouth opening without pain, maximum unassisted mouth opening, and contralateral movements). At the end of treatment, functional jaw movements were significantly increased while pain values were significantly decreased in all groups (P<0.05). Group 2 had a quicker improvement in terms of mouth opening scores at the end of the first month, and unassisted mouth opening without pain was found to be more than 35 millimetres in all groups at the end of 6 months. All treatment modalities showed effective results on pain and functional jaw movements in the treatment of temporomandibular disorders.

Pre-arthroplastic and simultaneous mandibular distraction for correction of facial deformity in temporomandibular joint ankylosis

IntroductionIn cases of temporomandibular joint (TMJ) ankylosis, interposition arthroplasty allows return of functional jaw movements. In order to improve the facial appearance, distraction osteogenesis is the treatment of choice, and may be timed either as a pre-arthroplastic, simultaneous or post-arthroplastic procedure. This study was planned to compare the treatment outcomes of pre-arthroplastic distraction (PAD) and simultaneous arthroplastic distraction (SAD) to establish the better treatment modality in terms of improvement in function and aesthetics. Materials and methodsThis prospective randomized experimental study included 20 children and adolescents suffering from facial deformity due to long standing unilateral TMJ ankylosis. They were randomly allocated to the two surgical groups with ten in each group. ResultBoth groups resulted in good facial symmetry and aesthetics. Initially, during the distraction period, mouth opening of SAD group scored less than that of PAD group but became comparable in 30 days. More pain at the distraction site and over the normal TMJ was observed in PAD group. The excursive movements were almost comparable in both the groups. ConclusionWe conclude that both procedures are effective in correcting the post-ankylotic deformity and improving function. Although PAD has better control over movement of the distracting segment, the contralateral TMJ may experience pain. SAD requires a shorter management period but is associated with a temporary decrease in function. Also, control of distraction may be difficult and chances of reankylosis are always there.

Full Mouth Reconstruction of a Bruxer with Severely Worn Dentition: A Clinical Report.

Tooth wear is attributed to several factors many of which often remain unidentified. Management of tooth wear is challenging in preventive and restorative dentistry. Correct assessment of occlusal vertical dimension, interocclusal rest space, and centric relation records are critical for successful treatment. In order to evaluate different treatment modalities and select the treatment of choice some information can be obtained from study casts and diagnostic wax-up. In order to achieve a predictable and desirable result, a systematic approach may be helpful. This paper describes the full mouth rehabilitation of a 36-year-old bruxer with severely worn dentition and other dental problems such as unfavorable restorations. A diagnostic work-up was performed and provisional restorations were made; then, they were clinically evaluated and adjusted based on the criteria dictating esthetics, phonetics, and vertical dimension. After endodontic therapy, clinical crown lengthening was performed. Two short implants were inserted in the posterior mandible. Custom-cast dowel cores and metal-ceramic restorations were fabricated and a full occlusal splint was used to protect the restorations. We ensured stable contacts on all teeth with equal intensity in centric relation and anterior guidance in accord with functional jaw movements.

Effect of temporomandibular joint sensory receptors on functional jaw movements following intra-articular anesthesia during gum-chewing

Basic patterns of masticatory rhythm are generated by the intrinsic neuronal network, so called masticatory central pattern generator, in the brain stem, and are fine tuned in response to both peripheral feedback and central afferent inputs. It is well known that peripheral receptors responsible for the regulation of masticatory rhythm are distributed in the periodontium, lips, oral mucosa, jaw muscles and temporomandibular joint (TMJ), and that they play an important role in adjusting the movements of the jaw. There are many reports about mechanoreceptors in periodontium, lips, oral mucosa and jaw muscles. However, the effect of mechanoreceptors in the TMJ on functional jaw movements has not been clarified clinically, even though there is abundant neurohistological evidence of TMJ innervation in animals and man. We attempted to establish the effect of TMJ sensory receptors on functional jaw movements in humans.

Prosthodontic Rehabilitation of the Patient with Severely Worn Dentition: A Case Report

The management of tooth wear has been a subject of increasing interest from both preventive and restorative points of view. This paper describes the full mouth rehabilitation of a 63-year-old bruxer man with a severely worn dentition and other dental problems including unsuitable restorations and several missing teeth. The treatment entailed using cast posts and cores, metal-ceramic restorations, and a removable partial denture. As with the treatment procedure of such cases, equal-intensity centric occlusal contacts on all teeth and an anterior guidance in harmony with functional jaw movements were especially taken into account.

Assessment of Optimal Condylar Position in the Coronal and Axial Planes with Limited Cone-Beam Computed Tomography

No quantitative standards for the optimal position of the mandibular condyle in the glenoid fossa are yet available in the coronal and axial planes. We previously reported measurements of this position in the sagittal plane, using recently developed limited cone-beam computed tomography (LCBCT) capable of imaging the craniofacial structures with high accuracy. In this study, we assessed the optimal condylar position in the coronal and axial planes. The study included 24 joints in 22 asymptomatic patients (10 male, 12 female; age range 12-25 years, mean age 18 years) who had no disc displacement as confirmed by magnetic resonance imaging. Their joints had optimum function with the starting and end points of all functional jaw movements coincident with maximum intercuspation. Joint-space distances between the condyle and glenoid fossa were measured at the medial, central, and lateral positions in the coronal plane, and medial and lateral positions in the axial plane. The mean coronal lateral space (CLS), coronal central space (CCS), and coronal medial space (CMS) were 1.8 ± 0.4 mm, 2.7 ± 0.5 mm, and 2.4 ± 0.5 mm, respectively. The ratio of CLS to CCS to CMS was 1.0 to 1.5 to 1.3. The mean axial medial space (AMS) and axial lateral space (ALS) were 2.1 ± 0.6 mm and 2.3 ± 0.6 mm, respectively. There were no significant sex differences in these measurements. These coronal and axial data, along with previously reported sagittal data, might provide norms for 3D assessment of optimal condylar position with LCBCT.

Assessment of optimal condylar position with limited cone-beam computed tomography

There are no quantitative standards for the optimal position of the mandibular condyle in the glenoid fossa. Recently developed limited cone-beam computed tomography (LCBCT) allows measurement of this position with high accuracy. LCBCT was used to assess 24 joints in 22 symptom-free subjects (10 male, 12 female; mean age, 18 years) who had no disc displacement as verified by magnetic resonance imaging. Their joints had optimum function with the starting and end points of all functional jaw movements coincident with maximum intercuspation. Linear measurements of anterior space (AS), superior space (SS), and posterior space (PS) were made to determine the position of the condyle for each joint. The mean AS, SS, and PS values were 1.3 mm (SD +/- 0.2 mm), 2.5 mm (SD +/- 0.5 mm), and 2.1 mm (SD +/- 0.3 mm), respectively. The ratio of AS to SS to PS was 1.0 to 1.9 to 1.6. No significant sex difference was noted in joint space distances. The results showed less variability of condylar position in the fossa than previously reported in normal subjects. These data from optimal joints might serve as norms for the clinical assessment of condylar position obtained by LCBCT.

Prosthodontic rehabilitation of a bruxer patient with severely worn dentition: a clinical case report.

The management of tooth wear has been a subject of increasing interest from both preventive and restorative points of view. This article describes the full mouth rehabilitation of a 54-year-old bruxer woman with a severely worn dentition and other dental problems including unsuitable restorations and several missing teeth. The treatment entailed using cast posts and cores, metal-ceramic restorations, and a removable partial denture. As with the treatment procedure of such cases, equal-intensity centric occlusal contacts on all teeth and an anterior guidance in harmony with functional jaw movements were especially taken into account.

Jaw Pain in an Adolescent Boy

A 14-year-old boy was referred to the Department of Oral Medicine at the Hospital of the University of Pennsylvania in Philadelphia for evaluation and treatment of jaw pain. The patient described intermittent pain localized to the right mandible that had begun two years before, with no antecedent traumatic event. In addition, he described brief, stabbing, electric, shocklike pain that occurred when eating and also spontaneously. On a numerical rating scale of 1 to 10, he rated the pain at 10. He reported that each painful attack lasted 10 seconds and that this occurred several times a day. Between pain attacks, the patient reported mild-to-moderate dull pain localized to the right masseter muscle area. The patient also described having intermittent bilateral asymptomatic temporomandibular joint (TMJ) clicking. Reportedly, his dentist, in an attempt to control what the patient described as “muscle spasms,” had treated the patient with an oral appliance and physical therapy. His dentist had also ordered magnetic resonance imaging (MRI) with and without contrast of the TMJs, which were unremarkable for intracapsular pathology. At the time the clinician (A.P.) evaluated the patient at our clinic, his medical history, review of systems and family, and social and medication histories were unremarkable. He also was undergoing fixed orthodontic treatment without complications. The clinical examination revealed a wellnourished and well-developed adolescent boy without affective distress. The findings of the head and neck examination were unremarkable. Examination of cranial nerves II to XII showed that the patient had diminished sensation (hypoesthesia) to light touch with a cotton swab and to cold, and he could not recognize pinpricks localized to the distribution of the right mandibular division of the trigeminal nerve. Functions connected with the other cranial nerves—visual acuity and fields, equal and reactive pupils, eye movement, masticatory muscle strength, facial expression, elevation and symmetry of the palate and uvula, contraction of sternocleidomastoid and trapezius, and extrusion of the tongue—were grossly intact. The patient’s reactions to palpation of his cervical and masticatory muscles and TMJs were unremarkable except for mild-to-moderate tenderness of the right masseter muscle. The patient could open his mouth to a maximum of 48 millimeters without pain or deviation. His functional jaw movements, including eccentric and protrusive movements with and without resistance, were unremarkable and produced no TMJ sounds. On oral examination, the examiner found enlarged tonsils, but otherwise an absence of intraoral pathology. Maxillary and mandibular dentitions were banded with braces. Palpation of the right mandibular ramus area triggered the patient’s jaw pain (which was localized anatomically to the distribution of the right third division of the trigeminal nerve) that lasted approximately 30 seconds. After the pain, the patient experienced a refractory period during which the examiner’s attempts to trigger subsequent episodes were unsuccessful. After a few minutes, palpation of the right buccal mucosa area once again reproduced the pain attack. A panoramic radiograph showed that the patient had impacted third molars, but the results were otherwise unremarkable.

Deranged jaw-neck motor control in whiplash-associated disorders.

Recent findings of simultaneous and well coordinated head-neck movements during single as well as rhythmic jaw opening-closing tasks has led to the conclusion that 'functional jaw movements' are the result of activation of jaw as well as neck muscles, leading to simultaneous movements in the temporomandibular, atlanto-occipital and cervical spine joints. It can therefore be assumed that disease or injury to any of these joint systems would disturb natural jaw function. To test this hypothesis, amplitudes, temporal coordination, and spatiotemporal consistency of concomitant mandibular and head-neck movements during single maximal jaw opening-closing tasks were analysed in 25 individuals suffering from whiplash-associated disorders (WAD) using optoelectronic movement recording technique. In addition, the relative durations for which the head position was equal to, leading ahead of, or lagging behind the mandibular position during the entire jaw opening-closing cycle were determined. Compared with healthy individuals, the WAD group showed smaller amplitudes, and changed temporal coordination between mandibular and head-neck movements. No divergence from healthy individuals was found for the spatiotemporal consistency or for the analysis during the entire jaw opening-closing cycle. These findings in the WAD group of a 'faulty', but yet consistent, jaw-neck behavior may reflect a basic importance of linked control of the jaw and neck sensory-motor systems. In conclusion, the present results suggest that neck injury is associated with deranged control of mandibular and head-neck movements during jaw opening-closing tasks, and therefore might compromise natural jaw function.

Disturbed jaw behavior in whiplash-associated disorders during rhythmic jaw movements.

As shown previously, "functional jaw movements" are the result of coordinated activation of jaw as well as neck muscles, leading to simultaneous movements in the temporomandibular, atlanto-occipital, and cervical spine joints. In this study, the effect of neck trauma on natural jaw function was evaluated in 12 individuals suffering from whiplash-associated disorders (WAD). Spatiotemporal characteristics of mandibular and concomitant head movements were evaluated for three different modes of rhythmic jaw activities: self-paced continuous maximal jaw-opening/-closing movements, paced continuous maximal jaw-opening/-closing movements at 50 cycles/minute, and unilateral chewing. Compared with healthy subjects, the WAD group showed smaller magnitude and altered coordination pattern (a change in temporal relations) of mandibular and head movements. In conclusion, these results show that neck trauma can derange integrated jaw and neck behavior, and underline the functional coupling between the jaw and head-neck motor systems.

Modelling the masticatory biomechanics of a pig.

The relationships between muscle tensions, jaw motions, bite and joint forces, and craniofacial morphology are not fully understood. Three-dimensional (3-D) computer models are able to combine anatomical and functional data to examine these complex relationships. In this paper we describe the construction of a 3-D dynamic model using the anatomical (skeletal and muscle form) and the functional (muscle activation patterns) features of an individual pig. It is hypothesized that the model would produce functional jaw movements similar to those recordable in vivo. Anatomical data were obtained by CT scanning (skeletal elements) and MR imaging (muscles). Functional data (muscle activities) of the same animal were obtained during chewing by bipolar intramuscular electrodes in six masticatory muscles and combined with previously published EMG data. The model was driven by the functional data to predict the jaw motions and forces within the masticatory system. The study showed that it is feasible to reconstruct the complex 3-D gross anatomy of an individual's masticatory system in vivo. Anatomical data derived from the 3-D reconstructions were in agreement with published standards. The model produced jaw motions, alternating in chewing side, typical for the pig. The amplitude of the jaw excursions and the timing of the different phases within the chewing cycle were also in agreement with previously published data. Condylar motions and forces were within expected ranges. The study indicates that key parameters of the pig's chewing cycle can be simulated by combining general biomechanical principles, individual-specific data and a dynamic modelling approach frequently used in mechanical engineering.

Temporal coordination between mandibular and head–neck movements during jaw opening–closing tasks in man

Previous finding of concomitant mandibular and head movements during jaw function suggest a functional relation between the human jaw and neck regions. This study examined the temporal coordination between mandibular and head–neck movements during maximal jaw opening–closing tasks, at fast and slow speed. Twenty-four healthy individuals, median age 25 years, participated in the study. They were seated with firm back support but without head–neck support. Mandibular and head movements were simultaneously monitored by a wireless optoelectronic system for three-dimensional movement recording. The timing of head movement in relation to mandibular movement was estimated at defined time-points (start, peak, end and maximum velocity of movement), and during the entire course of the jaw-opening and jaw-closing phases. The results showed that the head in general started to move simultaneously with or before the mandible, reached the peak position simultaneously with, before or after the mandible, and reached the end position after the mandible. A higher degree of temporal coordination was found for fast speed at the start and the peak positions. The head most often attained maximum velocity after the mandible, and mostly lagged behind the mandible during the entire jaw-opening and -closing phases. These findings support the notion of a functional linkage between the human temporomandibular and craniocervical regions. They suggest that “functional jaw movements” comprise concomitant mandibular and head–neck movements which involve the temporomandibular, the atlanto–occipital and the cervical spine joints, and are caused by jointly activated jaw and neck muscles. It is proposed that these jaw and neck muscle actions, particularly at fast speed, are elicited and synchronized by preprogrammed neural command(s) common to both the jaw and the neck motor systems. From the present results and previous observations of concurrent jaw and head movement during fetal yawning, we suggest that these motor programmes are innate.

Co-ordinated mandibular and head-neck movements during rhythmic jaw activities in man.

Recent observations in man of concomitant mandibular and head movements during single maximal jaw-opening/-closing tasks suggest a close functional relationship between the mandibular and the head-neck motor systems. This study was aimed at further testing of the hypothesis of a functional integration between the human jaw and neck regions. Spatiotemporal characteristics of mandibular and associated head movements were evaluated for 3 different modes of rhythmic jaw activities: self-paced continuous maximal jaw-opening/-closing movements, paced continuous maximal jaw-opening/-closing movements at 50 cycles/minute, and unilateral chewing. Mandibular and head-neck movements were simultaneously recorded in 12 healthy young adults, by means of a wireless opto-electronic system for 3-D movement recordings, with retro-reflective markers attached to the lower (mandible) and upper (head) incisors. The results showed that rhythmic mandibular movements were paralleled by head movements. An initial change in head position (head extension) was seen at the start of the first jaw-movement cycle, and this adjusted head position was retained during the following cycles. In addition to this prevailing head extension, the maximal jaw-opening/-closing cycles were paralleled by head extension-flexion movements, and in general the start of these head movements preceded the start of the mandibular movements. The results support the idea of a functional relationship between the temporomandibular and the cranio-cervical neuromuscular systems. We therefore suggest a new concept for human jaw function, in which "functional jaw movements" are the result of activation of jaw as well as neck muscles, leading to simultaneous movements in the temporomandibular, atlanto-occipital, and cervical spine joints.

A two-year kinesiographic study of mandibular movement patterns in denture wearers

Changes in functional jaw movements during a 2-year period of denture wear were investigated. The sample consisted of 27 partially edentulous subjects who were provided with an immediate complete maxillary denture and a removable partial mandibular denture. Recordings of habitual chewing of apple and empty open-close cycles were made with a mandibular kinesiograph. At the pretreatment stage, when the patients occluded on a residual anterior dentition, irregular patterns of movement were observed. After placement of the dentures, which restored posterior occlusion, the chewing and open-close patterns showed marked improvement and were characterized by significant mean decreases in sagittal and transversal range of movement. Relining of the maxillary dentures further stabilized the functional patterns. During the second year, significant reductions in vertical range of movement and lateral chewing excursions were observed, and were probably related to impaired retention of the complete upper denture.

Predatory Behavior and Competition Among Laboratory-Housed Largemouth and Smallmouth Bass

moides) and smallmouth (M. dolomieui) bass were studied in order to document behav.. ioral patterns associated with locating, capturing and ingesting prey, and to evaluate differential responses to a regime of forced competition for limited food. The analyses focused on the behavioral differences associated with (a) different prey species; (b) prey size, and (c) microhabitat. Cinematography aided in the identification of species-specific searching and prey-pursuit behavioral patterns. Both species were able to capture prey using different combinations and sequences of basic functional jaw and head movements. Differences in the relative lengths of jaw bones were not reflected in a difference in the total range of prey sizes consumed by adults of the two species, but rather appeared to affect the efficiency by which various feeding modes were performed (e.g., biting, engulfing and suction). Under the competitive feeding regime, largemouth bass captured significantly higher proportions of large prey and fewer small prey than smallmouth bass in the mixed-species subadult groups. Adult basses exhibited no significant difference in the frequencies of prey captures on the basis of prey size, but did capture prey at significantly different rates from four microhabit/lts in the mixed-species group compared to the conspecific groups. Adult basses of the two species also exhibited significant differences between groups (mixed vs. single species) in the relative proportions of feeding modes used in capturing prey. For each species, there was a significant relationship between the proportions of the feeding modes used and the microhabitats where prey were seized. The microhabitat niche overlap value was 0 = 0.91 for the single species adult groups and 0 =.77 for the mixed-species adult group. Subadult basses did not separate spatially, but rather exhibited lower niche overlap for the prey size dimension in the mixed-species groups (0 =.74), compared to the single species groups (0 = .95). No significant pattern of differential prey captures between bass species was observed on the basis of the five prey species offered. The relationships between morphology, environment foraging efficiency, and behavioral variability are discussed with reference to their potential roles in natural settings.