Background: The incidence of TMJ dislocation in Germany is estimated at at least 25/100,000 inhabitants.A correct diagnosis and immediate initiation of adequate therapy are essential to avoid permanent damage to the temporomandibular joint.Method: A systematic literature search was carried out in the databases PubMed, Cochrane, Embase and ZB Med.Results: From 24 650 identified sources, 136 studies were selected after excluding duplicates.Diagnosis of TMJ dislocation is primarily clinical based on a fixed open mandible.In the case of an acute dislocation, manual repositioning is carried out immediately.The most common method is the Hippocratic reduction, in which the practitioner's thumbs are placed laterally next to the row of teeth and the remaining fingers are placed externally on the lower mandible.Pressure is then applied first caudally and then dorsally.A two-stage reduction is carried out.If the dislocation persists for a long time, manual reduction may be unsuccessful, making invasive surgical measures necessary.In the case of a recurring dislocation, a minimally invasive botulinum toxin injection or autologous blood therapy can be carried out.In the absence of improvement, surgical treatment options may be indicated.Conclusion: There are only a few randomized controlled studies, especially for the minimally invasive and open surgical therapy approaches, so that evidence-based statements are only possible to a limited extent.Despite this, internationally widely accepted standards have been established in medical diagnostics and therapy in recent years.The temporomandibular joint dislocation represents 3% of all documented dislocations and is currently estimated to have an incidence of at least 25/100,000 inhabitants in Germany (Mail survey of the DGMKG 2017).This makes it a disease that occurs just as frequently as, for example, giant cell arteritis.It primarily affects young adults, but also older people with a corresponding disposition (1, 2).For patients, the temporomandibular joint dislocation is an extremely unpleasant experience due to the painful restriction of movement, which leads to an impairment of essential needs (speaking, chewing) (1).Since, in addition to neurological and neuromuscular diseases (3), advanced tooth loss with loss of support in the posterior region is also considered a predisposition for mandibular dislocation (4, 5), a future increase in incidence can be assumed in an aging society (6).A considerable number of unreported cases for the patient group mentioned is already assumed today.Due to the often less pronounced symptoms and reduced ability to communicate their symptoms, older, multimorbid people in particular belong to the group of patients with delayed diagnosis of the dislocation, which makes therapy even more difficult (5).Due to the individually low number of cases, non-specialist practitioners face the problem of a lack of routine in diagnostics and therapy.Rapid reduction is essential because reduction becomes more difficult the longer it takes and the risk of recurring dislocations increases (7–9).The latter are associated with significant limitations in the quality of life for the affected patients and lead to consequential damage in the temporomandibular joint in the long term (7).Therapy is often based on traditional surgical experience, which is published at an established but not evidence-based textbook level.Recent publications on the treatment of temporomandibular joint dislocation are predominantly from non-European or Anglo-American-speaking countries and often have a rather low level of evidence (small case series, inhomogeneous endpoints, short follow-up).In terms of optimal patient care, it is therefore the aim of the S3 guideline to present a procedure for temporomandibular joint dislocation that is as standardized and literature-based as possible.Research, selection and grading of scientific evidenceThe literature search was carried out from May 2014 in the databases PubMed, Cochrane, Embase and ZBmed.The initial search for English or German literature from the year 2000 using the search term “temporomandibular joint dislocation” yielded 24,650 sources.In addition, the sources of the processed literature were checked for literature that had not yet been considered for a manual search.Older literature was also taken into account.The sources were updated in August 2015 using the same search strategy to take into account the studies newly published during the preparation of the guidelines.A total of 136 sources were processed based on the selection criteria and summarized in tables (eFigure) .The subsequent grading of the evidence was based on the Oxford criteria (eTable 1) .Recommendations, structured consensus finding, external assessment and approvalThe draft guideline, which was created on the basis of the literature research, was first presented to the members of the guideline group for temporomandibular joint surgery of the German Society for Oral and Maxillofacial Surgery (DGMKG) for a structured consensus finding and was unanimously approved as a template.The external specialist societies listed in eTable 2 participated in the interdisciplinary Delphi process and the adoption of the guideline.On June 30, 2016, the S3 guideline was published online by the AWMF.Since publication of the guideline, 2 new studies on TMJ dislocation have appeared.These support the statements of the previous literature, so that there are currently no changes to the statements made in the guideline.The temporomandibular joint dislocation of the non-fractured mandible usually describes an anterior, bilateral dislocation of the temporomandibular joint heads in front of the articular tubercle without spontaneous reduction (Figure 1) (10).Young adults between the ages of 25 and 45 are particularly affected (2, 11, 12).In most cases, triggers are everyday movements with a wide jaw opening, such as yawning, laughing, or biting (1, 8, 13).Less frequently, dislocations can also be triggered iatrogenically, for example with anti-dopaminergic medication, intubations, endoscopic examinations, or prolonged dental treatment (e.g. tooth extractions) (1, 8, 14).The cause is then a prolonged and forced opening of the jaw with muscle tension reduced by medication (15).Patients should therefore be asked before any operation with intubation anesthesia about any dislocations that have already occurred and risk factors for a dislocation (recommendation grade [EG] B; evidence level [EL] IV–V +) (14, 16).In addition, functional jaw movement should be checked clinically before and after each intubation to rule out a dislocation (EG B; EL IV–V +) (14, 16).Predisposing risk factors include neurological and neuromuscular diseases (e.g. Parkinson's disease, oromandibular dystonia), advanced tooth loss, and constitutional hyperlaxia (e.g. Marfan syndrome) (1, 3, 5).This results in a second incidence peak in older patients (5, 6).Persistent mandibular dislocation is understood to be the persistent blockage of the condyle by the tuberculum and thus the long-lasting dislocation outside of the acetabulum.This leads to irreversible, intra- and pericapsular pathological changes (16, 17).An accidental (acute, one-off) temporomandibular joint dislocation can develop into a recurrent mandibular dislocation.This describes repeated, possibly fixed dislocations within a short period of time.Once this mechanism has been initiated, habitual dislocations of the affected temporomandibular joint are the result, in which dislocations can already occur within the framework of physiological movements.The main symptoms of TMJ dislocation are an occlusal disorder or an inability to close the jaw and pain (1, 8).Clinically, an empty joint socket and, in the case of a long-standing dislocation, malnutrition can be noticed (8).In patients under sedation, patients after trauma, patients with dementia or persistent dislocation, the symptoms can be weakened so that the dislocation of the temporomandibular joint initially goes unnoticed (1, 8, 14, 16).In the case of a mandibular dislocation occurring for the first time without current trauma to the face, the diagnosis can be made on the basis of the medical history and physical examination, provided the symptoms are sufficiently indicative of a temporomandibular joint dislocation (EL 0; EL IIIa–V +) (8–10, 18).If the symptoms permit other differential diagnoses, to rule out fractures in the facial area and for further therapy planning, imaging studies should be used (panoramic tomography, CT/DVT, MRI) (EG B; EL I–V +) (8, 10, 16, 19 ).In older, multimorbid patients in particular, a dislocation can initially be overlooked because the symptoms are less pronounced in these patients and the ability to communicate is often reduced (5).In the case of any non-traumatic temporomandibular joint dislocation, manual reduction should first be attempted (EG B; EL IIIa) (3).The earlier this is done, the higher the chances of a successful reduction (2, 9).The most common method is the Hippocratic reduction (8, 9, 20) (Figure 1a).Recent studies show the “wrist pivot” method as an alternative reduction technique that can be regarded as at least equivalent to the Hippocratic reduction in terms of success rate, pain during reduction, and duration of reduction (9, 19, 21) (Figure 1b).Due to the potential risk of injury with these intraoral repositioning procedures, repositioning can also be carried out extraorally in the case of a unilateral dislocation (EG 0; EL I) (19) (Figure 1c) .However, this method is somewhat more painful and time-consuming than the intraoral manipulations described (19).In the case of a bilateral dislocation, the success rate of the extraoral method is low (54.5% for bilateral versus 96.7% for unilateral dislocation), so it is only recommended if there is an increased risk of biting or infection (e.g. in patients with dementia, hepatitis C patients). ) (19).Graphic 2 shows a flow chart of the possible procedure for anterior temporomandibular joint dislocation.During the repositioning of the seated patient, the patient's head should be stabilized with a headrest (EG B; EL IV–V +) (21, 22).In the case of intraoral reduction, using a bite block and wearing gloves can help protect against bite injuries and the associated infections (EL B; EL V +to V) (21, 23).According to the recommendation of the group of authors, when using the modified Hippocratic grip, care should be taken not to place the fingers on the occlusal surfaces of the molars of the lower jaw, but rather laterally to them (EL B; EL V; expert consensus).In recent years, a number of studies with new reduction methods have been published, but their informative value is low due to the small number of cases and the lack of control groups (13, 24, 25).In general, the practitioner's experience with the respective technique makes a decisive contribution to the success of the repositioning and that successful mobilization for repositioning can be achieved with different manipulations.Manual repositioning of the acute dislocation can initially be performed without medication (EL 0; EL IIIa–V +) (3, 7, 9, 20, 21).If unsuccessful, further reduction attempts can be made with medication (muscle relaxants and/or analgesics) and, if necessary, analog sedation or anesthesia (EL 0; EL IIIa–V +) (3, 7, 9, 20, 21, 26).Approximately 30% of all temporomandibular joint dislocations presented to a doctor present as a persistent dislocation (1, 3).Due to the low incidence, the therapy recommendations are based on case series and case reports.If the dislocation lasts three to four weeks, manual reduction is usually no longer successful.If this is the case, surgical reduction should be considered (EL B; EL I–V +) (1, 7, 20).Redressive procedures (repositioning by opening the joint capsule) and, if necessary, more invasive measures (eminectomy, condylectomy, special osteotomy procedures, endoprosthesis) are available for this (1, 7, 20).The incidence of the development of recurrences after the first event is given as 22% in the literature (3).Minimally invasive procedures (botulinum toxin injection, autohemotherapy, proliferation therapy) for the treatment of recurrent temporomandibular joint dislocations are particularly suitable for patients with reduced compliance or an increased risk of surgery (12).In the long term, the results are often unsatisfactory and invasive surgical therapy becomes necessary (8, 27–29).Studies on therapy with botulinum toxin include case series with up to 21 patients.In the available studies, single or multiple injections of botulinum toxin into the M. pterygoidus lat. stop dislocations for at least 5 months (12, 30, 31).So far, the use of botulinum toxin in recurrent temporomandibular dislocation has been an off-label use.Therefore, the manufacturer's warnings on the use and area of ​​indication of botulinum toxin should be observed (EG A; EK V; consensus of experts).However, according to the authors of the guideline, the use of botulinum toxin in the treatment of recurrent dislocations should be included in the indication area (RG A; EK V; expert consensus).Studies on therapy with autologous blood include case series with up to 30 patients.The injection of autologous blood in or around the temporomandibular joint should lead to reduced mobility of the joint head in the long term and thus prevent renewed dislocations.Post-injection events were followed in several case studies using MRI.Although a postulated fibrosis cannot be proven and should also be assessed critically in the event of an excessive reaction, mobility in the jaw joint seems to be restricted in the medium term, so that renewed dislocations are reduced in frequency or do not occur at all.However, the exact pathohistological mechanism remains unclear.If you summarize the larger studies of the last few years, around 80% of the patients will be symptom-free for the next 12 months.Complications in the sense of worsening of the symptoms are not reported (28, 32, 33).Similar considerations as for the therapy with autologous blood are made for the proliferation therapy, also called sclerosing therapy.There is currently a case series with 30 patients in which 91% show no redislocations after up to 3 injections for 6 months (18).In patients with recurrent dislocations, open surgery may be indicated if there is no improvement after conservative and/or minimally invasive procedures (EL 0; EL IIIa–IV +) (28, 32).The most common treatment methods are eminectomy, locking or rein plastic surgery and operations on the capsule and ligament apparatus.With regard to the various, sometimes competing surgical procedures, the eminectomy procedures are currently the best documented and most promising (2, 27, 29).If the dislocation persists, the patient should be immobilized after reduction to limit maximum mouth opening over a longer period of time (one to four weeks) to prevent renewed dislocation (EL B; EL IV–V) (7, 34).Immobilization can be done with a bandage, head-chin cap, or elastic intermaxillary fixation (IMF) (1, 7).After each surgical treatment, the patient should eat soft food for a few days and avoid wide jaw openings (EG B; EL IIb–V +) (6, 9, 18, 35–37).Furthermore, immobilizing measures can be used, especially after autohemotherapy and after operations on the capsule and ligament apparatus (RG 0; EL Ib–V) (28, 29, 33, 36, 37–40).The immobilization serves to limit the maximum jaw opening, rigid fixation is not recommended.In the case of consequential damage such as occlusion disorders (for example, an anterior open bite due to persistent dislocations that are refractory to therapy), an individualized approach using the spectrum of functional joint surgery as well as reconstructive and dysgnathic surgical procedures may be necessary (EL 0; EL IIIa–V) (3, 5, 20).Due to the epidemiologically poor data situation on various therapeutic approaches due to the low number of cases and inhomogeneous study designs with sometimes very short follow-up, evidence-based recommendations of a higher degree are still not possible and there will be no results analyzes of a higher degree of evidence (randomized controlled studies, meta-analyses) in the foreseeable future ) be available (8, 27).Nevertheless, some measures have been able to establish themselves as internationally widely accepted standards in recent years thanks to a good success rate.The treatment of temporomandibular joint dislocation should begin as early as possible, since in this way degenerative changes or their progression as a result of recurring dislocations or increasing frequency of dislocations can be limited and conservative/minimally invasive therapy methods have better chances of success (EG B; EL IIIa-V +) (1, 2, 7, 9).Which therapy has the best prospects of success depends on many factors (pathogenesis, age of the patient, secondary diagnoses, compliance, goal, care structures and others).Therefore, the best therapeutic method for each individual case should be determined individually on the basis of a thorough medical history and examination (EL B; EL IIIa–IIIb − (20, 35).PD Ahlers received authorship fees on this topic from dentaConcept Verlag.The other authors declare no conflict of interest.Manuscript dates submitted: September 6, 2017, revised version accepted: November 13, 2017Address for the authors Prof. Dr.medicaldent.drmedicalAndreas Neff Clinic and Polyclinic for Oral and Maxillofacial Surgery UKGM GmbH University Hospital Marburg Baldinger Straße, 35043 Marburg neffa@med.uni-marburg.deHow to cite Prechel U, Ottl P, Ahlers MO, Neff A: Clinical practice guideline: The treatment of temporomandibular joint dislocation—a systematic review.Dtsch Ärzteebl Int 2018;115:59-64.DOI: 10.3238/arztebl.2018.0059►The German version of this article is available online: 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