正中早接触点与颞下颌关节慢性疼痛的关系

目的:定位颞下颌关节慢性疼痛患者的正中早接触点,评价解除早接触干扰对缓解颞下颌关节疼痛的作用。方法:通过面弓转移,记录正中关系,上颌架,测量13例颞下颌关节慢性疼痛患者正中弧差及疼痛指数的变化,并在颌架的介导下去除正中早接触干扰。结果:正中弧差与疼痛指数完全负相关(P<0.001),调牙合可减少疼痛指数和增大正中弧差(P<0.001)。结论:调牙合是改善颞下颌关节慢性疼痛的一种可行方法。     

Occlusal objectives in orthodontic treatment.

An attempt has been made to present a means for preventing the temporomandibular joint pain-dysfunction syndrome by treating to the terminal hinge position and using postreatment occlusal adjustment procedures. 1. Any postorthodontic patient who is not in centric relation and has occlusal interferences has the potential for temporomandibular joint pain-dysfunction syndrome symptoms to develop in the future. 2. The orthodontist should manipulate the mandible of every patient at each visit, placing the condyle in the terminal hinge position. He should close the mandible until initial tooth contact is reached and diagnose the patient's problems from this position and not from the centric occlusion position. 3. The case should be finished with the teeth in centric relation occlusion. 4. The orthodontist should equilibrate the occlusion of every completed case to eliminate the minute occlusal interferences which are always present. 5. The case treated to centric relation can be equilibrated effectively without mounting on an articulator. 6. If we have the concept of building an occlusion to fit the jaw mechanism, the temporomandibular joint pain-dysfunction syndrome can be virtually eliminated in the postorthodontic patient.     

Occlusion and orthodontics.

The importance of considering the functional aspects as well as the static concepts of an occlusion was demonstrated in the case of an 11-year-old girl with postorthodontic temporomandibular joint muscle pain dysfunction. The following characteristics of an ideal occlusion were discussed as they relate to the entire masticatory system: 1. There should be no slide in centric; that is, there should be a stable jaw relationship when occlusal contact is made in centric relation closure. 2. There should be freedom in centric, that is, freedom for the mandible to move from centric relation to centric occlusion and slightly anterior to centric occlusion without interference. 3. Centric relation should be at the same contact vertical dimension as centric occlusion. 4. There should be no buccolingual thrust or impact to any tooth on closure to contact in centric relation or to centric occlusion. 5. Between centric relation and centric occlusion there should be an unrestricted glide with maintained occlusal contact. 6. Complete freedom for smooth-gliding occlusal contact movements in various excursions from both centric occlusion and centric relation. 7. Occlusal guidance should be on the working or functioning side rather than on the balancing or nonfunctioning side. 8. There should be no soft-tissue impingment from occlusal contacts. In effect, the occlusion should be related to centric relation and centric occlusion prior to, during, and at the completion of active treatment. The final occlusion should provide unhindered closure in centric relation, smooth-sliding lateral and protrusive movements, and an optimal bilateral vertical contact dimension. Orthodontic treatment must include proper occlusal adjustment procedures to obtain the goals of an ideal occlusion in most instances.     

Checking the occlusal relationships of complete dentures via a remount procedure

Correct occlusal relationships are part of the successful prosthetic treatment of edentulous patients. Occlusal checking should be performed via a remount procedure because denture base materials and fabrication procedures cannot provide dimensionally accurate complete dentures. Occlusal errors caused by the adjustment of denture bases to the denture foundation after a certain period of wearing can also be corrected by means of remounting. The following remount procedures for complete dentures are described: fabrication of transfer casts, transfer of a maxillary denture with a facebow, centric relation record, and mounting of dentures with transfer casts in an articulator with a dental stone. Deflective occlusal contacts of denture teeth in centric occlusion can be eliminated by selective grinding and by tooth-guided excursive movements. In complete denture treatment, priority is given to anterior/canine-guided occlusion.     

Posterior bilateral condylar displacement: its diagnosis and treatment.

One type of condylar displacement (posterior bilateral) was discussed as an etiologic factor in TMJ dysfunction. Joint noise, tenderness on muscle palpation, and acute TMJ pain are all considered signs of TMJ dysfunction. Any joint noise is considered to be an early dysfunctional symptom because of its higher incidence in association with palpable muscle pain or acute TMJ dysfunction. Sometimes the joint noise will immediately precede acute muscle pain and/or fluctuate with the painful symptoms. The treatment of bilateral posterior condyle displacement has been described. The mandibular anterior teeth were shortened and the maxillary posterior occlusion adjusted so that the mandible could be respositioned in an anterior position without increasing the vertical dimension of occlusion. A silver-plated maxillary cast was obtained and mounted on a semiadjustable articulator (Hanau) with a face-bow. The mandibular cast was mounted in the dysfunctional (retruded) centric relation. The articulator was moved into a protrusive position by the amount of anterior correction that is needed to reposition the condyles into the middle of the fossae symmetrically on both sides. The original TMJ radiographs provide the necessary information for this clinical judgment. Acrylic resin was placed in the space created between the condylar sphere and stop on the articulator. An acrylic resin temporary repositioning prosthesis constructed on the metal cast has two functions. It provides a therapeutic trial for the anterior condylar respositioning, and it holds the mandible in the therapeutic position while TMJ radiographs confirm the corrective position of the condyles in the fossae. After a successful 6 to 8 week trial period with remission of symptoms, a gold prosthesis was constructed on the same cast in the same therapeutic position. It remains to be seen whether, after several years, the condylar suspension system changes from a dysfunctional centric relation to a new functional centric relation in which the patient can no longer return to the posterior displaced condylar position in the fossa. Only with painstaking observations, accurate TMJ radiographs, complete documentation, and after-care can a more scientific approach to the diagnosis and treatment of TMJ dysfunctional pain syndrome be achieved.     

Occlusal interferences and temporomandibular dysfunction

Disagreement exists regarding the relationship between occlusal interferences and temporomandibular joint dysfunction (TMD). This study sought to determine how a balanced occlusion, providing uniform contact in centric relation, would affect signs and symptoms of TMD. A randomly chosen group of 60 patients with occlusal interferences and signs and symptoms of TMD used a mandibular orthotic to balance their occlusions at centric relation (CR). When the occlusions of symptomatic patients were balanced in CR, there was a significant reduction or elimination of TMD complaints, suggesting a relationship between balancing occlusion in CR and optimum management of TMD.     

A computer analysis of condylar movement as determined by cuspal guidances

In 1926 Hanau proposed a link between incisal, condylar, and occlusal guidances of the stomatognatic system. This work has been extended by undertaking a computer simulation of the movement of the mandible between centric occlusion and centric relation in an effort to establish a possible mathematical relationship between the variables in Hanau's "Quint." One scheme is proposed by which the geometry of the guidances might be analyzed. The results of the analysis show that there could be a direct link between an altered occlusal guidance and one of the factors involved in the initiation of the temporomandibular joint dysfunction syndrome.     

A Positional Analyzer for Measuring Centric Slide

Centric relation (CR) has been considered mainly as a position posterior to habitual occlusion or maximum intercuspation (MI). Awareness of the tooth contacts relationship in centric relation position of the mandible and diagnosing the case from this position is essential to consistently select treatment plans that will allow to treat to or very near to centric relation occlusion. Centric slide and other occlusal relationships are conceived of as positions, which can be studied in three dimensions. Clinically, the difference between the two occlusal positions namely CR and MI (centric slide) can easily be determined, but for a more precise evaluation of its length and directions, an occlusal analysis on articulator mounted casts is necessary. Study was under taken on the mounted casts of ten subjects on a semi adjustable articulator to which a stylus and recording table was devised and attached for measurement of CR-MI slide in the three planes namely anterior-posterior, medio-lateral and superior-inferior. It was found that there was a displacement from CR to MI (centric slide) in all the three planes and numerically the mean slide was 0.688 ± 0.623, 0.261 ± 0.627 and 0.127 ± 0.541 mm in the antero-posterior, medio- lateral and superior-inferior directions respectively. The stylus and table attachment may be an accurate indirect method to measure positional changes of the condyle in 3D.     

一种牙齿重度磨耗的全牙列固定修复咬合重建方案

目的 介绍一种步骤明确、技术评价指标清晰的咬合重建方法。方法 选择无颞颌关节-咀嚼肌疼痛不适、承受咀嚼压力无痛、重度磨耗的恒牙列病例,在正中关系铰链运动的轨迹上,以满足修复空间需求的最小距离来确定垂直距离,从而构建牙尖交错牙合。以微笑分析原则进行前牙美学设计和“简单治疗牙合“原则设计咬合接触关系。结果 对10例固定修复咬合重建患者观察1～5年,患者对美学、功能恢复满意;咬合稳定无干扰;无关节区、咀嚼肌的疼痛不适,口颌系统健康舒适。结论 本研究提供了一种可以实现颞颌关节-咀嚼肌-咬合关系协调舒适的咬合重建技术体系。     

Centric relation. Its effect on occluso-muscle harmony.

The most common cause of pain in the region of the temporomandibular joint is occluso-muscle imbalance. This results most often from disharmony between the articulation of the teeth and the centric relation of the condyles. Muscle tenderness of palpation indicates that muscle is involved. An examination must then be done to determine the cause of the muscle tenderness. Before the condyle-occlusion relationship can be evaluated, an accurate centric relation must be determined and verified. The condyles are in centric relation when they are in the most superior position possible in the fossae. From that apex of force position, the condyle can travel neither forward nor backward without moving downward. This position can be located with careful bilateral manipulation and then verified if it can resist firm pressure with no tension or tenderness. Until this correct centric relation is located and verified, it is not possible to properly evaluate the occlusal relationship to the temporomandibular joints. If the occlusion is harmonized to a centric related condyle that can resist firm pressure with pressure with no discomfort, there will be no reason for the muscles to protect either the teeth or the joints. If an occlusion is adjusted to a malrelated condylar position, the occluso-muscle imbalance will be perpetuated and often intensified. Centric relation is the starting point of occlusal contact. Incline interferences in excusive movements must also be eliminated and the occlusion must be harmonized to the envelope of function for each patient. If centric relation is not properly located, occlusal interferences will remain regardless of what procedures are used to record or adjust excursive movements.     

Patient response to variations in denture technique. Part III: Five-year subjective evaluation.

Dentures were constructed for 64 patients by two different techniques. One technique, designated as "complex," involved more complicated procedures such as a true hinge axis location, balanced occlusion, dentures remounted on an articulator after processing with new interocclusal records, and occlusal corrections made on the articulator. The "standard" technique involved an arbitrary mounting of the maxillary cast on the articulator, arranging the occlusion with centric relation coincident with centric occlusion but without a balanced occlusion, and making occlusal corrections in the mouth. Subjective evaluations were made for each of the 64 patients at initial placement of the dentures and for all active patients at five yearly recall visits following placement. The evaluation method was designed to determine clinical differences between the dentures made by the two techniques. At the end of 5 years, the data obtained at five yearly recall visits were subjected to statistical testing. These tests were performed to determine if the technique by which the dentures were made had any effect on the performance of the dentures that could be detected clinically. The results of the test showed that there was no significant difference between dentures made using two denture techniques that could be detected by subjective means.     

Comparison of the replicability of routinely used centric relation registration techniques

PURPOSE: This study was conducted to determine statistically the most repeatable mandibular position of 3 centric relation methods. MATERIALS AND METHODS: Three centric relation recording methods commonly reported in the literature were selected: bimanual mandibular manipulation with a jig, chin point guidance with a jig, and Gothic arch tracing. Fourteen healthy adult volunteers (7 males and 7 females), with an average age of 26.61 +/- 4.20 years and no history of extractions, temporomandibular joint dysfunction, or orthodontic treatment, were selected for the study. Accurate casts were mounted on an articulator (Denar D4A) by means of a facebow and maximum intercuspation silicone registration record. A mechanical 3-dimensional mandibular position indicator was constructed and mounted on the articulator enabling the operator to analyze the mandibular positions in 3 spatial axes (x, anteroposterior; y, superoinferior; z, mediolateral shift). Each centric relation method was recorded four times on each subject (at baseline, 1 hour, 1 day, and 1 week at approximately the same time of day). Records were transferred to the articulator, and data were extracted using a stereomicroscope modified to accept the mandibular position indicator. RESULTS: Variability within subjects ranged from 0.03 mm (left-side z axis for the bimanual method) to 1.6 mm (left-side y axis for the Gothic arch method). To indicate the least variable (most repeatable) method a comparison was made using the F test. The bimanual method was the most consistent, showing between 10.11 (p = 1) and 0.438 (p = 0.005) times less variation than the Gothic arch method (the least consistent). The repeatability of the chin point guidance method was somewhere between the other 2 methods. CONCLUSIONS: The results of this study showed that of the 3 centric relation methods evaluated, the bimanual manipulation method positioned the condyles in the temporomandibular joint with a more consistent repeatability than the other 2 methods, whereas the Gothic arch was the least consistent method.     

Rigid internal fixation and the effects on the temporomandibular joint and masticatory system: A prospective study

A prospective study of 22 patients who underwent a bilateral sagittal osteotomy to advance the mandible and subsequent rigid internal fixation, were examined for signs and symptoms of temporomandibular joint (TMJ) pain and masticatory dysfunction. A modified Helkimo index was used to analyze the anamnestic, clinical, and occlusal data. In addition, 12 of the cases chosen at random were mounted on a semiadjustable (SAM2) articulator and analyzed with the mandibular position indicator (MPI) to determine the amount and the direction of condylar displacement postoperatively. Anamnestic dysfunction decreased because of a reported decrease in muscular pain, joint noise, headache frequency, and parafunctional habits postoperatively. Clinical dysfunction remained unchanged, with a decrease in muscular soreness but with an increased incidence of joint clicking of 7%. The increased incidence of temporomandibular joint pain postoperatively was 4%. Increase in clinical dysfunction was most often seen in women and older patients. Occlusal dysfunction decreased, with the majority of interferences remaining after surgery as a result of insufficient lingual crown torque of the maxillary buccal segments. Occlusion is thought to have played only a minor role in temporomandibular joint and masticatory dysfunction. Reduction in range of motion was 10%, indicating the added benefit of early mobilization with rigid internal fixation procedures. The MPI study found the condyles inferiorly or inferoposteriorly displaced less than 1 mm from their preoperative position. These findings suggest that rigid internal fixation had no adverse effects on the temporomandibular and masticatory system. The variable responses and results can be attributed, at least in part, to the heterogenous population of patients studied and the variations in surgical techniques employed.     

A technique for evaluation of centric relation tooth contacts. Part II: Following use of an occlusal splint for treatment of temporomandibular joint dysfunction

The purpose of this study was to determine the effect of TMJ dysfunction on the recording of centric relation. Centric relation was recorded using an anterior occlusal stop and by bimanual manipulation. Changes in occlusal contacts were recorded before and after occlusal splint therapy in six subjects with TMJ dysfunction. The pantographic reproducibility index and clinical signs and symptoms were used to determine the presence or absence of dysfunction. Use of the anterior occlusal stop resulted in a more posterior, superior initial tooth contact position when compared with bimanual manipulation. Occlusal contact positions were less consistent in TMJ dysfunction subjects than in control subjects. Initial occlusal contacts changed toward centric relation as the dysfunction disappeared. Final occlusal contact was found on the side where clinical signs and symptoms occurred. The condyle on the affected side appeared to be repositioned posteriorly and superiorly in most instances. Occlusal splint therapy was more effective when the splint was adjusted weekly. This study indicates the need to eliminate TMJ dysfunction before recording centric relation or adjusting the occlusion. Occlusal interferences found with TMJ dysfunction are not the same as occlusal interferences found when TMJ dysfunction is absent. Abnormal features on pantographic tracings may aid in indicating the presence of occlusal interferences. Occlusal adjustment in the presence of TMJ dysfunction would result in erroneous occlusal reduction.     

An electromyographic and roentgen cephalometric study of occlusal morphofunctional disharmony in children.

In a sample of children with dual bite and symptoms in the masticatory system, the activity of the anterior temporal and masseter muscles was studied electromyographically during clench and light tapping in the posterior occlusal contact position and centric occlusion and in protrusive bite on the incisors. The findings indicated that the optimal muscle function during maximal clench and tapping with displayed in the posterior occlusal contact position, which in the present subjects was situated, on the average, 0.5 to 1 mm. anterior to the centric jaw relation. It should therefore be recommended that, in orthodontic treatment of children with dual bite, the intercuspal position (centric occlusion) should be established in the posterior occlusal relationship. This is in accordance with the opinion of several authors who have emphasized the use of the retruded contact position (the centric jaw relation) as key reference position in orthodontic treatment and occlusal rehabilitation. These authors have further emphasized the importance of stable occlusal contacts in centric relation, centric occlusion, and the various jaw excursions in obtaining and maintaining a harmonious function between the dentition, the temporomandibular joints, and the neuromuscular system.     

安氏Ⅰ类和Ⅱ类1分类错患者下颌位置的研究

目的：研究错He患者下颌处于正中关系位（centric relation,CR)和最大牙尖交错位（maximum intercuspation,MI)时髁突位置与咬合关系的变化。方法：使用PanadentHe架系统和髁突位置测量仪,检查50名错He患者（安氏Ⅰ类、Ⅱ^1类各25人）的下颌位置和咬合情况。结果：几乎所有的患者均存在CR－MI髁突位置差异,在矢状方向上多为向上移位,65％的受检者CR初始接触位于单侧最后磨砑,当下颌从CR位移至MI位时,咬合变化主要表现为磨牙关系近中化、切牙覆He加深覆盖变浅。安氏Ⅰ类与Ⅱ^1类错He之间,上述改变的差异无显著性。结论：正畸治疗前必须了解患者下颌处于正中关系时的咬合情况,发现He与下颌位置之间的不协调。     

A mathematical method for calculating the compensating anterior stop pin setting of a semiadjustable arcon articulator

The geometry of a semiadjustable arcon articulator and development of mathematical formulae to calculate the setting of the anterior stop pin that compensates for the thickness of the interocclusal centric relation record are discussed. Measurements of the facebow mounted maxillary cast and interocclusal centric relation record are used in these formulae. Testing on 30 diagnostic mountings indicated that the formulae can reliably predict the amount of anterior stop pin opening necessary to allow near parallelism of the maxillary and mandibular bows of the articulator when the interocclusal centric relation record is removed and the mounted casts are brought into occlusion. The vertical component of dental malocclusion is identified as a source of variability in the setting of the anterior stop pin and therefore in the geometry of the articulator; it is defined as a need for further study.     

A comparison of the signs of temporomandibular joint dysfunction and occlusal discrepancies in a symptom-free population of men and women

To date, there has been no conclusive explanation for the predominance of female patients with temporomandibular joint (TMJ) dysfunction. The purpose of this study was to survey a normal population without symptoms for the presence of certain putative signs of TMJ dysfunction in association with certain signs of occlusal discrepancy and to determine the presence of any gender variation. The subjects (217 men and 217 women) were examined for the presence of three putative signs of TMJ dysfunction: limited mandibular opening (under 37 mm), deviation on opening, and joint sounds. The subjects were also examined for the presence of four signs of occlusal discrepancy: an anterior slide from centric relation (CR) to centric occlusion (CO), lateral slide from CR to CO, nonworking occlusal contacts, and working disclusive contacts distal to the canines. CR is the mandibular position at which the condyles are in their most superior position on the posterior aspect of the articular tubercles. CO is the mandibular position at which the mandibular and maxillary teeth are in maximum intercuspation. There were no significant differences in the prevalence of the putative signs of TMJ dysfunction and occlusal discrepancy between men and women. It was concluded that factors other than the presence of these signs of TMJ dysfunction and occlusal discrepancy are responsible for the high predominance of female patients with TMJ dysfunction.     

Anatomic and clinical evaluation of the relationship between the temporomandibular joint and occlusion.

An anatomic and clinical investigation of condylar remodeling; the position of the condyle in centric occlusion; and the relationships of these two factors to each other and to the features of the dentition are reported. Two groups of 100 adult crania were examined. The first group had complete or partially edentulous arches. In the second group, the dentition was complete and there were various degrees of abrasion. In addition, clinical and tomographic data were obtained from 70 patients with temporomandibular joint pain-dysfunction syndrome. Occlusion was also studied by intraoral registration of the gothic arch and by mounting the casts on an articulator in 40 patients. Comparison of the data made it clear that occlusal conditions determine the course of condylar remodeling and lead to marked changes in shape of the joints. Occlusal disorders are also responsible for condylar displacement (noted in 51.4 per cent of patients), which, in turn, may be the cause of typical reshaping of the joint. These findings cast doubt on the proposition that the gnathologic determinants (particularly centric relation) are never changed in the course of time.     

Statistical analysis of an urban population of 236 patients with head and neck pain. Part III. Treatment modalities.

Data collected from standardized temporomandibular joint examination forms and treatment records of patients diagnosed as having Myofascial Pain Dysfunction Syndrome and treated using occlusal adjustment as the primary mode have been presented. A higher success rate was found in those patients: (1) with a chief complaint of pain confined to the area of one or both temporomandibular joints only, (2) whose answer to location of pain on initial examination was identified as confined solely to the region of one or both temporomandibular joints, (3) with muscle tenderness to palpation to one or both lateral pterygoid muscles with no other muscle involvement, (4) recorded as having a centric discrepancy in the absence of a balancing side prematurity, and (5) in the 31 to 40-year-old age group.