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This article describes the 'adaptable condylectomy' and highlights two innovative treatment protocols for the variety of acquired facial asymmetry and associated malocclusion caused by condylar hyperplasia, as illustrated by the cases of seven patients presenting different manifestations of condylar hyperplasia. Protocol I (three cases) is applied for condylar hyperplasia with a normal occlusion and involves a high condylectomy, with the goal of guiding the mandible back to the original occlusion. Protocol II (four cases) is applied for condylar hyperplasia with diverse acquired malocclusions and involves condylectomy at a level adapted to the malocclusion, allowing the mandible to be guided back to the occlusion that pre-existed the active change caused by the condylar hyperplasia, or to a position as close to the midline as possible. Both protocols are followed by gradual self-correction of the acquired facial asymmetry. These protocols often obviate the need for further surgical intervention and, if further correction is needed, it is much simpler., Competing Interests: Competing interests None., (Copyright © 2023 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

The introduction of temporomandibular joint (TMJ) arthroscopy by Onishi in 1970 (results published in 1975 and 1980) opened a new modality for TMJ treatment. The efficiency of arthroscopic lavage and lysis led in the 1990s to its simplification: TMJ arthrocentesis. Always associated with load control, physiotherapy, and elimination of any occlusal hazards, arthrocentesis, a simple procedure, entails less expensive and more available tools and is performed under local anesthesia. Although lacking direct visual inspection of the joint structures, it has become quite popular. Arthrocentesis is most efficient in localized joint pain and limited joint movements such as closed lock, anchored disc phenomenon, osteoarthritis, and various inflammatory diseases. In clicking joint, the results are somewhat controversial. The efficiency of arthrocentesis elicited many enquiries that led to the study and a better understanding of joint function and dysfunction and the actual role of disc location. The release of closed lock without disc repositioning was quite surprising; it improved our understanding of the pathogenesis of closed lock and led to the discovery of the anchored disc phenomenon. This was followed by the awareness of the joint-lubrication system and, in turn, alternative suggestions for the pathogenesis of TMJ disc displacement with and without reduction, open lock, and osteoarthritis, and ultimately by the development of an effective bio-lubricant. Awareness of the role of joint overloading led to the development of an interocclusal appliance that reduces intraarticular pressure; it has become a "must" support for arthrocentesis and any surgical intervention. In our view, arthrocentesis is the definitive indication of the need for surgical intervention and, therefore, should be the first in the cascade of interventions in TMJ disorders., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: The aim of this case series was to describe a modification of the classic "closed reduction" technique to manage unilateral or anterior open bite owing to a loss in vertical height (LVH) caused by several disorders and pathologies other than displaced condylar fractures., Materials and Methods: The protocol included insertion of an occlusal appliance to increase the height of the premature contact and the width of the open bite, stabilization of the dental arches by rigid arches, and the use, during sleep, of rubber bands in the open bite region to pull the mandible cranially. In addition, when awake, the patient performed physiotherapy exercises to guide the mandible into maximum intercuspation. The increased open bite enhanced the effect of the rubber bands in guiding the mandible into the original habitual occlusion and the rigid arches served to minimize tooth eruption., Results: The present cases showed the favorable outcome of this low-risk treatment in the re-establishment of the original habitual occlusion within 1 to 4 weeks and without reconstruction of the LVH., Conclusion: The efficacy of this complication-free approach to correct occlusion in various conditions of LVH suggests that this protocol should be applied before venturing into surgical intervention., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the long-term outcome of arthrocentesis in patients with symptomatic temporomandibular joint (TMJ) osteoarthritis that was unresponsive to nonsurgical interventions., Materials and Methods: Seventy-nine patients (83 joints) with symptomatic TMJ osteoarthritis that had not responded to nonsurgical interventions and who underwent arthrocentesis were included in this study. Demographic, clinical, and radiologic data, including assessment of pain, dysfunction, improvement, and satisfaction, and maximal mouth opening were analyzed., Results: The analysis included 67 female patients (84.8%) and 12 male patients (15.2%), 13 to 70 years old, who were followed for 56.9 ± 6.7 months. Sixty-four (81%) reacted favorably to arthrocentesis. For these patients, maximal mouth opening increased from 26.3 ± 0.8 to 39.24 ± 0.9 mm (P < .001). Pain and dysfunction scores decreased from 6.92 ± 0.2 to 2.36 ± 0.3 (P < .001) and from 7.37 ± 0.2 to 2.24 ± 0.4 (P < .001), respectively. Overall score for patient satisfaction with arthrocentesis was 8.78 ± 0.3. The procedure had no lasting complications. Remarkably, the severity of preoperative pain, dysfunction, and range of motion and of radiographic changes did not correlate with the outcome of arthrocentesis. The severity of preoperative or postoperative signs and symptoms was not correlated with the severity of radiographic changes., Conclusions: For most patients, arthrocentesis offers long-term favorable outcomes for symptomatic TMJ osteoarthritis that has not responded to nonsurgical treatments and otherwise would have required surgical arthroplasty. Severity of preoperative clinical and computerized tomographic findings is not predictive for the success of arthrocentesis. In addition, the lack of correlation between the clinical and radiologic findings negates the commonly used Wilkes classification, which presumes that the clinical signs and symptoms deteriorate together with radiologic changes., (Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Limited mouth opening is a constant annoyance and can be life-threatening should intubation be needed. The causes are numerous and are categorised as intra-articular or extra-articular, which are often difficult to distinguish. We present what we regard as a new clinical entity - long-standing limited mouth opening of unknown cause - and describe our treatment. Four female patients presented with limited mouth opening and lateral and protrusive movements within normal limits, which were typical of restriction of extra-articular origin. However, the radiological findings were within normal limits, with no visible cause of the restriction. All four were treated by bilateral coronoidectomy that resulted in the immediate return of mouth opening to within normal limits that was preserved over subsequent years. Histopathological examination showed atrophy and degenerative changes in the temporalis band that had been attached to the coronoid, which accounts for the stiffness of the temporalis muscle but does not explain the pathogenesis. In the light of this "diagnostic coronoidectomy" further studies are required to document the underlying pathological changes and to develop more accurate imaging that will enable correct diagnosis in future., (Copyright © 2015. Published by Elsevier Ltd.)

Unlabelled: Osteoarthritis (OA) is a common joint disorder affecting circa 2% of the population., Objectives: It has been suggested that secretion of vascular endothelial growth factor (VEGF) could play a role in the chain of events leading to OA., Methods: In the present study, healthy mice were injected intra-articularly with VEGF., Results: Shortly after the administration of VEGF, synovial hyperplasia, increased calcification of the articular cartilage and bone sclerosis were observed. Consequently, cartilage degradation characteristic of OA was found. These changes were seen to a lesser degree in the opposite knees of VEGF-injected mice and did not occur in the control mice., Conclusions: The findings suggest an active role of VEGF in the pathogenesis of OA and render support to a possible role for subchondral bone sclerosis in the pathogenesis of cartilage degradation., (Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Purpose: Temporomandibular joint (TMJ) ankylosis that occurs after TMJ condylar fracture constitutes a treatment challenge. The purpose of the present study is shed light on an alternative treatment approach for certain such cases where the displaced condylar head or part of it can be detected in computed tomography. The leading principle of this protocol is accurate removal of the ankylotic mass only, leaving the condyle-disc apparatus un-touched., Patients and Methods: The study is based on such cases of post trauma ankylosis where the displace condyle was detected. Thirteen cases are reported (10 unilateral and 3 bilateral) age ranged from 8 to 51 years (mean 20). All patients were treated according to the presented protocol that emphasizes the significance of preserving the condyle-disc apparatus while accurately removing the ankylotic mass. To achieve the required precision, 3-dimensional computed tomography was used. An integral part of the treatment plan is intensive guided physiotherapy, which is intended to re-establish normal joint function, the original occlusion and facial symmetry (in growing individuals)., Results: The patients were followed up for 6 to more than 60 months. After guided physiotherapy, all patients had significant postoperative improvement in maximal mouth opening from a mean of 18.4 mm (range 8 to 28) to a mean of 41.2 mm (range 35 to 50). All patients had returned to their original occlusion. In all the growing patients, a marked improvement in facial symmetry was observed., Conclusions: In post trauma ankylosis the displaced head of the condyle and disc should be searched for using computed tomography. If detected we recommend its preservation while accurately remove only the ankylotic mass. Using this approach, in addition to achieving adequate mandibular motion, good occlusion, and normal facial growth, major surgery, with all its inconveniences and potential complications, is avoided., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

An aneurysmal bone cyst (ABC) in the right mandibular condyle and ramus of a 37-year-old woman was surgically resected and immediately reconstructed with a costochondral graft. She was followed up for 5 years. A review of the 10 cases of condylar-ABC available in the literature revealed mean age of 16.8 (± 7.6) years, with equal distribution between men and women. In all cases symptoms included swelling and asymmetry, while temporomandibular disorder/dysfunction symptoms were reported in 50%. Parasthesia was not reported, except for self-limited postoperative neuropathy. Curettage or resection was employed equally and recurrence rates were 60% after curettage, 20% after resection; which are higher than reported in non-condylar-ABC's. All recurrences occurred within 12 months. Thus close post-operative follow up, for at least 12 months, is warranted., (Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Female rats develop haemolytic anaemia and disseminated thrombosis and infarction in multiple organs, including bone, when exposed to 2-butoxyethanol (BE). There is growing evidence that vascular occlusion of the subchondral bone may play a part in some cases of osteoarthritis. The subchondral bone is the main weight bearer as well as the source of the blood supply to the mandibular articular cartilage. Vascular occlusion is thought to be linked to sclerosis of the subchondral bone associated with disintegration of the articular cartilage. The aim of this study was to find out whether this model of haemolysis and disseminated thrombosis supports the vascular hypothesis of osteoarthritis. Six female rats were given BE orally for 4 consecutive days and the two control rats were given tap water alone. The rats were killed 26 days after the final dose. The mandibular condyles showed histological and radiological features consistent with osteoarthritis in three of the four experimental rats and in neither of the control rats. These results may support the need to explore the vascular mechanism of osteoarthritis further., (Copyright © 2009 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Purpose: Much reported variation and discord exist regarding mandibular condylar hyperplasia (CH). This study evaluated some of the characteristics of this disorder in a series of 61 patients with active CH., Patients and Methods: A total of 61 patients with active temporomandibular CH who had been evaluated in our departments were included. Demographic, clinical, radiologic, and bone scintiscan data were collected and analyzed. Asymmetries were classified as transverse, vertical, or combined., Results: CH was diagnosed during the growth period in 22 patients, and 39 patients were older than 20 years (range, 11 to 80 years). In 66% of the patients, the main complaint was progressive facial asymmetry; and in the remainder, the main complaint was pain, dysfunction, or both. Transverse asymmetry predominated (52%), and vertical or combined asymmetry occurred in 31% and 16% of patients, respectively; asymmetry type was independent of age. The occlusal plane deviated in 48% of the patients. Laterality was significantly gender-biased (females, 72% right; males, 64% left; P = .017). The condylar head shape was normal in 15% of patients, deformed in 27%, and enlarged in 58%; the condylar neck was elongated in 69% and enlarged in 19%. All of these changes were uncorrelated with the type of asymmetry (vertical, transverse, or combined)., Conclusions: CH may occur at any age and is more prevalent in females. Clinicians should be aware that only some patients complain primarily of facial asymmetry, and that symptoms of temporomandibular disease also may be present. Because there is no correlation between the radiologic findings and the clinical evaluation, classification should be simplified and based on clinical manifestation only--in other words, the direction of asymmetry.

TMJ arthrocentesis is a nonarthroscopic lavage performed through two needles that are introduced into the upper compartment of the joint. Complemented by joint unloading and physiotherapy, this procedure often replaces surgical intervention in the TMJ. The procedure is highly efficient for resolving TMJ disorders caused by adhering forces or friction that are eliminated by lavage, such as intermittent clicking, anchored disc phenomenon, and open lock, and releases approximately 70% of the symptomatic TMJ osteoarthritis. The outcomes are sufficiently effective to prevent further surgical intervention. Arthrocentesis is a valuable diagnostic tool and the aspirated fluid can be used efficiently for diagnosis, therapy, and research of TMJ disorders.

Normal temporomandibular joint (TMJ) movements primarily depend on free sliding of the disc down the slope of the eminence. Therefore, understanding the lubrication system and how aberrations in this system contribute to TMJ is important. Its effect on dysfunctions, such as disc displacement, anchored disc phenomenon, open lock, and osteoarthritis, are discussed in this article.

Since normal temporomandibular joint (TMJ) movements depend primarily on the disc freely sliding down the slope of the eminence, understanding how aberrations in the lubrication system contribute to TMJ dysfunction is clearly critically important. It provides a possible explanation for the genesis of disc displacement and helps make us familiar with the clinical appearance and ways of treating limited mouth opening caused by the anchored disc phenomenon (ADP) versus disc displacement without reduction, TMJ open lock versus dislocation and osteoarthritis. This understanding clarifies the efficiency of procedures such as joint hydraulic pump, arthrocentesis and arthroscopic lavage and lysis particularly in ADP, open lock and osteoarthritis., (Copyright 2003 S. Karger AG, Basel)

Ankylosis of the temporomandibular joint (TMJ) can be a result of trauma, degenerative changes and infection or of a space-occupying lesion and, when occurring during early childhood, can result in severe functional disability and facial distortion. Septic arthritis of the TMJ is extremely rare in young infants. We report two children with TMJ ankylosis that is believed to have been a consequence of undiagnosed septic arthritis of the TMJ in the neonatal period.

Purpose: In this study, we examined the hypothesis that uncontrolled oxidative stress causes collapse of the lubrication system, which is considered a major initiator of temporomandibular joint (TMJ) dysfunction. The oxidative stress was evaluated by measuring the overall antioxidant capacity of the low-molecular-weight antioxidants in the TMJ, using cyclic voltammetry (CV), in synovial fluid from normal and anchored disc phenomenon (ADP) TMJs., Materials and Methods: Synovial fluids samples were taken from 13 normally functioning and 33 ADP TMJs. The samples were frozen initially on collection and analyzed in CV to measure their overall reducing power., Results: CV measurements of the fluids collected from 90% of the healthy joints showed an anodic waves at peak potential [Ep(a)1/2] of 290 +/- 30 mV. Of the samples 56% showed another wave at 650 +/- 100 mV. These waves were generally absent in the fluid collected from ADP TMJs, but 2 new waves at 465 +/- 90 mV and greater than 750 mV were detected in 68% and 87% of the patients, respectively., Conclusions: The results show more anodic waves, most of which of higher potentials (greater than 750 mV) in ADP TMJs, indicating that the capacity to cope with oxidative stress is lower in these joints. It is not clear whether this is due to absence of low-molecular-weight antioxidants or their consumption by uncontrolled production of reactive oxygen species, which might be the initial step in the collapse of the lubrication system., (Copyright 2002 American Association of Oral and Maxillofacial Surgeons)

Purpose: In the temporomandibular joint (TMJ) "open-lock" condition the condyle is entrapped in front of the lagging disc and cannot slide back under the fossa. The aim of this retrospective study was to describe the signs and symptoms and imaging of TMJ "open lock" versus condylar dislocation and clarify its pathogenesis. The study stresses the efficacy of arthrocentesis in restoring the functional capacity of the joint, while obviating the need for surgical intervention., Patients and Methods: The study included 5 patients (3 females and 2 males; ages ranging from 11 to 26 years) presenting 6 open-lock joints that did not respond to conservative treatment. The TMJs postarthrocentesis status in 5 joints (follow-up period, 6 to 32 months) was determined by patient self-assessment and clinical examination., Results: Five TMJs had recurrent open lock and were treated by arthrocentesis. They reacted favorably to the treatment and the open-lock events were eliminated. The first case was apparently misdiagnosed as condylar dislocation, and unnecessary surgical intervention was performed., Conclusions: Arthrocentesis is a safe and rapid procedure that prevents recurrence of open-lock conditions. This disorder should be distinguished from recurrent condylar dislocation, which requires surgical intervention., (Copyright 2002 American Association of Oral and Maxillofacial Surgeons)

The commonly held cause for using the closed lock technique is the prevention of disc sliding by using the non-reducible disc. The purpose of this study was to re-evaluate the pathogenesis of sudden and persistent severely limited mouth opening associated with a total lack of disc sliding in view of the fact that it is promptly released by lavage of the upper compartment of the temporomandibular joint (TMJ). The proposed pathogenesis is based upon earlier clinical and laboratory findings of the first author coupled with pertinent information culled from the literature. It is suggested that sliding of the disc in the TMJ is enabled due to the presence of phospholipids protected by hyaluronic acid (HA) that constitute an efficient lubrication system. Joint overloading may be associated with uncontrolled production of reactive oxygen species (ROS) that causes degradation of the HA, followed by the exposure of the phospholipids to lysis by phospholipase A2 (PLA2). The denuded, smooth and elastic articular surfaces that possess high surface energy become strongly adherent when placed in direct physical contact with each other. The presence of an extremely thin film of fluid (sub-boundary lubrication) between the mating surfaces may cause even higher adhesion. These adhesive forces are probably responsible for the flexible disc anchorage to the fossa and/or eminence. They also explain the immediate release of the disc and rehabilitation of its sliding following arthrocentesis. Since it is uncommon for two opposing surfaces to be stripped bare and to become adherent, the likelihood of anchored disc phenomenon (ADP) occurring and recurring is very low.

Purpose: The goal of this article is to investigate the surface-active phospholipids located on the articular surfaces and in the temporomandibular joint (TMJ) synovial fluid (SF) by means of electron microscopy and biochemical analysis., Materials and Methods: Synovial fluids and articular cartilage samples taken from 6 normally functioning TMJs were studied. The osmiophilic lining of human TMJ articular surfaces has been studied by using special nondestructive fixation procedures. To study the SF, negative staining technique has been used. In addition, thin-layer chromatography has been used to identify the phospholipids extracted from synovial fluid of human TMJs., Results: In the SF, granular bodies were identified with diameter of between 170 and 280 nm. Their diameter decreased dramatically when exposed to phospholipase-A(2). The amorphous and highly osmophilic material on the articular surface include membrane-bound vesicles (270 nm in diameter) with lamellated pattern surrounding the amorphous-dense core. Biochemical extraction revealed phosphatidylcholine as the major component of the polar lipids., Conclusions: This preliminary study presents findings that suggest that phospholipids present in the TMJ may provide an efficient boundary lubrication that enables the disc to slide down the slope of the eminence on joint function., (Copyright 2001 American Association of Oral and Maxillofacial Surgeons)

Purpose: The purpose of this retrospective study was to determine the efficacy of arthrocentesis in restoring the functional capacity of osteoarthritic temporomandibular joints (TMJ)., Patients and Methods: This study involved 36 patients (29 females, 7 males; age range, 16 to 54 years, mean, 37.36 +/- 14.60 years) presenting with 38 dysfunctional joints that had not responded to conservative treatment. The postarthrocentesis status (follow-up period 6 to 62 months, mean 20.7 +/- 20.5 months) of the TMJs was determined by patient self-evaluation using visual analog scales and clinical examination., Results: Of the 38 TMJs treated with arthrocentesis, 26 joints reacted favorably to the treatment; pain and dysfunction scores were reduced from 9.86 +/- 0.73 to 3.39 +/- 0.76 and from 11.34 +/- 0.66 to 3.4 +/- 0.69, respectively (P <.001). Self-assessed general improvement/deterioration was +4.90 +/- 2.10 (on a scale of -7 to +7). Maximal mouth opening increased from 24.40 +/- 2.70 mm to 43.20 +/- 3.10 mm (P <.001). Lateral and protrusive jaw movements also increased in magnitude. In 14 patients in whom no improvement was noted, arthrocentesis acted as a diagnostic tool before surgical treatment., Conclusions: Arthrocentesis is a safe and rapid procedure that in many instances results in the osteoarthritic TMJs returning to a healthy functional state. Failure of arthrocentesis suggests that the painful limitation is most probably caused by changes such as fibrous adhesions or osteophytes that require surgical intervention for their removal., (Copyright 2001 American Association of Oral and Maxillofacial Surgeons)

Background: This in vitro study aimed to elucidate the extent and kind of involvement of hyaluronic acid (HA) in the currently accepted view of synovial joint lubrication, in which surface-active phospholipids (SAPL) constitute the main boundary lubricant. The integrity of SAPL is apparently threatened by the lysing activity of phospholipase A(2) (PLA(2))., Methods: The effects of increasing concentrations of HA degraded by free radicals and non-degraded HA on the lysing activity of PLA(2) were examined in vitro. Liposomes (lipid model membrane) containing phosphatidylcholine (PC) were used as the substrate, on the assumption that they are appropriate representatives of SAPL., Results: HA adhered to the phospholipid membrane (liposomes), inhibiting their lysis by PLA(2). However, in its degraded form, HA not only failed to inhibit PLA(2)-lysing activity, but accelerated it., Conclusions: It is reasonable to assume that HA plays an important indirect role in the steady state of the boundary lubrication process of joints by protecting SAPL from being lysed by PLA(2). However, as excessive loading generates free radicals within the joint (among other effects), the HA that is degraded in this way is incapable of protecting SAPL from lysis by PLA(2). When the rate of degradation exceeds that of synthesis, there will be insufficient replacement of HA and/or SAPL, resulting in denudation of the articular surfaces. These are then exposed to increasing friction, and hence increased danger of degenerative joint changes.

Purpose: This article re-evaluates the chain of events leading to temporomandibular joint (TMJ) disc displacement. The joint lubrication system and the process of its breakdown are clarified and an attempt is made to evaluate the possible effect of increased friction between the disc and fossa on the anterior displacement of the disc., Materials and Methods: The study is based on the author's accumulated clinical data and results obtained from laboratory investigations regarding TMJ lubrication and its possible breakdown, coupled with pertinent information culled from the literature., Results: Translation of the disc in the TMJ is enabled due to the presence of phospholipids and hyaluronic acid, which constitute an efficient lubrication system. This system may break down in the presence of uncontrolled free radicals. In the absence of lubricants, the articular surfaces are smooth, elastic in texture, and possess strong surface energy. Such opposing planes, especially in the presence of a thin fluid film (sub-boundary lubrication) tend to generate high friction while the disc is sliding against the fossa. Such friction is probably the prime mover in loosening the disc attachments to the condyle, with subsequent disc displacement., Conclusions: Increased friction of the contiguous parts may well be a major causative factor in displacement of the articular disc. This should be taken into account in considering the appropriate treatment approach. It also raises some doubts regarding the validity of using repositioning techniques.

Purpose: This article proposes a hypothesis regarding the value of saving the fractured condyle and disc in their displaced position in ankylosis type III for optimal temporomandibular joint (TMJ) function and growth, and describes four cases treated in this manner., Patients and Methods: Four patients (three females and one male, 9 to 48 years old) with TMJ ankylosis type III of 3 to 8 years' duration, a maximal mouth opening of 15 to 19 mm, and severely limited lateral and protrusive movements were treated. The ankylosed sites were resected, leaving the displaced condyle and disc in their medial position., Results: Fifteen to 60 months after surgery, the patients had a maximal mouth opening of 44 to 50 mm, as well as better contralateral and protrusive movements. In addition, two young patients (9 and 11 years old) showed an improved facial symmetry., Conclusions: Treatment of patients with type III TMJ ankylosis should involve retention rather than removal of the displaced condyle and disc. The condyle and disc are left untouched in their precarious medial position so as to provide normal function and growth.

Impaired salivary function with resultant severe dryness of the mouth, or xerostomia, may occur in association with a variety of systemic disorders or therapies. No adequate treatment exists for this debilitating condition, which impedes normal oral function, in particular alimentation and phonation. This study explores the feasibility of salivary gland autotransplantation, using a canine model. A salivary gland with its duct and surrounding blood vessels still attached was excised and reimplanted in the dog's thigh by anastomosing the graft's blood vessels to the femoral artery and vein. The duct was sutured to an artificial orifice cut in the thigh's skin, from which the saliva was collected. Salivary secretion was induced by a single intravenous bolus of pilocarpine (5 mg). Preoperative (normal) salivation was measured by collecting saliva from the gland in situ. Periodic functional studies showed normal saliva production during the first month after grafting, after which the salivary flow was reduced by 35% over the next 2 months. This reduction was interpreted as a sign of disuse atrophy resulting from the lack of autonomic innervation. To overcome this impediment, oral pilocarpine (5 mg/day) was administered to the recipient dog, after which normal levels of saliva were excreted through the graft during the 3-month follow-up period. The quality of the graft saliva was assessed by its protein and electrolyte levels, which showed close to normal values.

This article establishes a rationale for a particular type of sudden and severely restricted mouth opening caused by anchoring of the disc to the fossa termed anchored disc phenomenon, describes the possible pathogenesis of this disorder, and recommends appropriate treatment. The clinical characteristics supporting the proposed pathogenesis, and treatment of the disorder are based on data published in the literature and clinical experience with the diagnosis and treatment of this disorder.

Purpose: This study analyzed the long-term effect of arthrocentesis for severe closed lock of the temporomandibular joint (TMJ) and reevaluated the pathogenesis of this condition based on the data obtained., Patients and Methods: Thirty-nine patients (40 joints) who had experienced sudden-onset, persistent limited mouth opening were the subjects of this study. After unsuccessful noninvasive treatment, arthrocentesis of the upper compartment of the affected TMJ was performed using saline. The follow-up, which consisted of patient self-assessment and clinical examination, ranged from 6 to 37 months (mean, 16.6 +/- 12.0 months). Visual analog scales were used for preoperative and postoperative self-evaluation of pain and dysfunction on forced mouth opening and for assessment of overall change in these parameters postarthrocentesis. Maximal mouth opening (MMO), contralateral movement (CLM) and protrusive movement of the jaw, and presence of joint noises were noted preoperatively and at clinical follow-up examinations., Results: At 6 to 37 months postarthrocentesis, MMO and CLM had increased significantly (from a mean of 23.10 +/- 5.15 mm to 44.25 +/- 4.96 mm, and from a mean of 4.81 +/- 2.36 mm to 8.20 +/- 1.90 mm, respectively; P < .001). Functional improvement was associated with a significant reduction in pain and dysfunction levels (from a mean of 9.24 +/- 2.90 to 1.45 +/- 1.74, and from a mean of 9.26 +/- 2.82 to 2.68 +/- 2.80, respectively, on a scale of 0 to 15; P < .001). The overall improvement, as expressed in pain and dysfunction levels, was about 95%, with no recurrence of severe closed lock., Conclusions: Arthrocentesis for sudden-onset closed lock provided sustained normal joint function and marked pain relief. Because the available literature shows that arthrocentesis changes neither disc position nor disc shape, it places in doubt the concept of a displaced and deformed disc limiting joint function. Rather, the efficacy of lavage in resolving closed lock suggests that the condition is the result of sudden adherence of the normally shaped disc to the fossa, rendering it incapable of sliding. The characteristic features of sudden-onset, limited mouth opening warrants classification of this disorder as an independent entity within the realm of TMJ disturbances.

Phospholipase A2 (PLA2) and H2O2, secreted from activated inflammatory cells, play a central role in the tissue damage occurring in inflammatory processes. However, while exogenous PLA2 alone does not cause cell lysis, it readily does so when acting with H2O2. We have found that H2O2 degrades cell surface proteoglycans, thus rendering the membrane PL accessible to hydrolysis by exogenous PLA2. This novel mechanism introduces a role for cell surface proteoglycans in protection of cells from damage by pro-inflammatory agents, and may assign a central role for the combined action of H2O2 and PLA2 in inflammatory and bacteriocidal processes.

Intraarticular pressure (IAP) was measured at the posterior slope of the eminence in the upper compartment of the temporomandibular joint (TMJ) of 35 individuals (28 females and 7 males) under local anesthesia. Pressure measurements were obtained with the jaw in rest position, during maximal mouth opening (MMO), and while clenching. During MMO, IAP decreased to levels ranging between -130 and -5 mm Hg (mean, -53.82 +/- 34.40 mm Hg), whereas during clenching the pressure was always positive (range, +8 to +200 mm Hg; mean, 63.90 +/- 52.25 mm Hg). The significance of the fluctuating pressures with respect to the joint's maintenance and performance, as well as the potentially harmful effect of the positive pressure, especially when it is high and prolonged, are discussed. Females generated significantly higher pressures than males (73.70 +/- 61.06 mm Hg vs 31.42 +/- 11.47 mm Hg, P = .017). This gender difference regarding IAP may help elucidate the enigma of the considerably higher proportion of women with TMJ problems. In 22 of the patients IAP also was measured while clenching on a specifically constructed interocclusal appliance (IOA), which uniformly elevated the occlusal plane so as to reduce the force directed toward the TMJ. During clenching without the IOA, pressures ranged from 20 to 200 mm Hg (mean, 68.8 +/- 49.1), decreasing by 81.2% to IAP levels ranging from 0 to 40 mm Hg (mean, 7.9 +/- 10.9; P < .001) with the appliance in place. The use of an IOA as a palliative treatment for symptomatic TMJs is discussed.

The mandible coronoid process is another site subject to various pathoses that may result in limited jaw movement. Six different pathoses that prevented the free rotation of the coronoid are presented. Differential diagnosis and treatment approach are emphasized.

A condition of sudden, severe, and persistent limited mouth opening, which readily responds to arthrocentesis, is postulated to be the effect of a vacuum between disc and fossa in the upper compartment of the temporomandibular joint. In 16 patients with this condition, the negative intra-articular pressure was found to be significantly lower (mean, -82.6 +/- 25.4 mm Hg) than in the control group (mean, -7.7 +/- 2.5 mm Hg) (P less than .0001). It is suggested that the process underlying the vacuum effect starts with persistent pressure (eg, clenching) resulting in the viscoelastic disc being pressed flat against the fossa. Immediately on cessation of the pressure, the disc resumes its natural biconcave shape, but its rims remain fastened to the fossa. The consequent increased negative pressure in the closed space created firmly anchors the disc to the fossa and any attempt to elicit condyle and disc sliding will only stretch the joint capsule and cause pain. This, in turn, will reflexly prevent the pterygoid muscle from exerting sufficient force to pull the disc and thus release the vacuum. This chain of events may account for the severe and persistent limitation in jaw movement and for the easy reversal of the condition by simple nonsurgical treatment.

Five new patients and six previously described patients with severe limitation in maximum mouth opening following transtemporal neurosurgical procedures are described. Six patients underwent an operation for epidural hematoma and three for skull-base meningloma; two were treated with a pterional craniotomy for an aneurysm. Limited maximum mouth opening in these circumstances is caused by temporal muscle scarring and shortening. Aggressive physiotherapy is potentially beneficial if started early. If, however, diagnosis is delayed, the efficacy of physiotherapy declines, and surgical treatments such as temporal muscle detachment and coronoidectomy are fully indicated. The differential diagnosis, prevention, and treatment of limited maximum mouth opening following neurosurgical procedures are discussed.

Seventeen patients complaining of suddenly occurring, severe, and persistent limited mouth opening were treated by irrigation of the upper compartment of the affected temporomandibular joint with lactated Ringer's solution. This simple treatment was found to be highly effective in reestablishing normal opening and relieving pain for a follow-up period of 4 to 14 months.

Clinical and surgical data on 194 operated joints (135 patients) were used to substantiate a new concept challenging the presumed natural history of temporomandibular internal derangement (ID). A number of findings were incompatible with the traditional depiction of a progressive process based on gradual changes in disc position and shape. These findings were a lack or correlation between increasing age and the stages of the process; the percentage of patients in the third stage (closed lock) with limited opening (less than 25 mm) too severe to be caused solely by a nonreducible, displaced disc; the unexpectedly high incidence (greater than 50%) of normally shaped discs in the third stage of the process. A specific condition of severe and stubborn limited maximal mouth opening caused by total cessation of gliding, liable to occur at any age and unrelated to disc shape or position, which responds successfully to simple treatment by lavage and lysis, pressured injection, or arthrocentesis, was discerned. Lack of gliding was attributed to adherence of the disc to the fossa by a reversible effect such as a vacuum and/or decreased volume of synovial fluid of high viscosity. This condition was deemed worthy of an independent identity, dissociated from disc displacement, as a causative factor in the second and third stages of ID, and particularly as an aid to accurate diagnosis and treatment.

In this study, the clinical and arthrographic findings from 43 internally deranged temporomandibular joints (TMJs) were compared with the intra-surgical observations. In 40 of 43 joints, arthrography did not provide any additional information useful for diagnosis or treatment. In six joints, the problem was misdiagnosed. Only in three joints did arthrography demonstrate the existence of perforation in the posterior attachment that had not been suspected during the clinical examination. Because of the doubtful importance of arthrographic information for the decision-making process, it is suggested that the method be applied only in cases in which clinical examination and plain radiographs have failed to uncover the signs and symptoms indicative of a TMJ disorder.

Synovial chondromatosis of the temporomandibular joint was diagnosed and location of dens particles was assessed by means of computed tomography. Based upon the data collected, the joint was operated conservatively and most of the calcifications were removed leaving the patient symptom free. The importance of an accurate preoperative diagnosis of synovial chondromatosis by use of CT scan is stressed in view of numerous unnecessary condylectomies and parotidectomies reported in the literature.

Primary extranodal lymphoma of the salivary gland is an extremely rare disease. In this report we describe twelve cases of primary lymphoma of the parotid gland seen at a single centre, and review the relevant literature. The 12 cases were treated in different departments and did not receive a uniform therapeutic approach. All three patients with Hodgkin's disease are still alive and two are in complete remission after initial radiotherapy. One of these cases developed stage 4 disease and had to receive combination chemotherapy subsequently. Of the 9 non-Hodgkin's lymphoma (NHL) patients, four had low grade NHL and 5 intermediate or high grade NHL. Of these, 2 died with disseminated disease. However, 6 are still alive and well from 1 to 5 years after therapy. These cases were treated with surgery alone, radiotherapy alone or combination chemotherapy with an anthracycline-bearing regimen. Consequently, we are unable to draw any conclusions relating the success of therapy in these cases, nor can we suggest therapeutic guidelines on the basis of this study alone. The treatment of parotid lymphoma is discussed briefly in the light of the available literature. In most cases, symptoms related to an enlarging mass in the parotid region, were evident. In the light of the above data, we suggest that, despite its rarity, lymphoma of the salivary gland should always be considered in the differential diagnosis of a parotid mass. No correlation between lymphoma and Sjogren's syndrome was noted in the present study.

Condylectomy accompanied by either simultaneous or postponed surgical correction of facial asymmetry is the treatment of choice in cases of condylar hyperplasia in its active stage. However, spontaneous remodeling processes in facial structures following the elimination of an actively growing hyperplastic condyle may bring about improvement in symmetry without further surgical intervention. Two cases are presented.

Arthroscopic surgery was applied to correct various disorders of the temporomandibular joint (TMJ). Lysis and lavage of the upper TMJ compartment proved of value in patients with anterior disc displacement without reduction ("closed lock"), because it increased the range of mouth motion and alleviated pain in the TMJ. Because this beneficial arthroscopic intervention did not encompass repositioning the disc, its surgical relocation when attempting to overcome dysfunction and pain in the TMJ is questioned.

A 75-year-old woman presented with a painless swelling in the right mandibular retromolar area and numbness of the left lower lip. Radiographic examination of the mandible demonstrated an osteolytic lesion of the ascending ramus. Biopsy revealed adenocarcinoma of obscure origin. Staining of the specimen with a monoclonal antibody specific to colon carcinoma revealed its origin. On subsequent examinations, a primary tumor in the rectosigmoid region with extensive lung, liver and skeletal metastases were diagnosed. This unusual case of colonorectal carcinoma, presenting as a metastatic lesion of the mandible, was readily diagnosed by a novel immunohistochemical technique that utilizes highly specific monoclonal antibodies.

A case of oncogenous osteomalacia due to a fibrosarcoma of the maxilla is reported, with a 19 year course before treatment. Metabolic studies of calcium and phosphorus were performed 3 and 19 years after the first symptomology. There was a negative balance for both phosphorus and calcium with low serum levels of 1,25-dihydroxyvitamin D which were corrected by resection of the tumor. Portions of the tumor were cultured and the supernatant did not affect phosphorus transport by a proximal tubule kidney cell line. Other portions were injected into athymic nude mice where they resulted in hypophosphatemia and phosphaturia, thus confirming the endocrine nature of the oncogenous osteomalacia factor.

2 patients afflicted with beta-thalassemia major presented with pain and swelling of the parotid salivary gland. In 1 patient, the symptoms were of long standing and particularly severe, with diminished and highly viscous salivation. In the other patient, the parotid glands had only recently become painful, while salivary output and quality remained normal. The parotid anatomy in both patients, as demonstrated by sialography, and the clearance of opaque material were normal. Tc99 scintigraphy revealed reduced uptake and rapid clearance of the isotope from the parotid serous glands into the oral cavity, in contrast to the increased uptake by the sublingual mucous glands. Iron deposits were demonstrated in the parotid secretory serous cells. It is postulated that the impaired function of the parotid is linked to iron deposits in the serous cells of this gland, as a sequella of beta-thalassemia.

Pericoronitis is an infectious disease of the operculum overlying an erupting or semi-impacted tooth. It manifests itself mainly in late adolescence and young adulthood and nearly always occurs around the lower third molar. The distinctive location, age, clinical picture, and link with predisposing factors warranted a reappraisal of pericoronitis and its etiology. Spirochetes and fusobacteria proved prevalent at all stages of the disease. The presence of these microbacteria may provide a clue as to the late appearance, particular location, and singular clinical picture of pericoronitis. The fact that spirochetes and fusobacteria are also found in acute necrotizing ulcerative gingivitis, and have been associated with alveolar osteitis, indicates a possible relationship between these disorders and pericoronitis.