UNIVERSITÀ DEGLI STUDI DI MILANO
DOTTORATO Di Ricerca In Scienze Odontostomatologiche XXXIII CICLO
Dipartimento Di Scienze Biomediche, Chirurgiche e Odontiatriche
EVALUATION OF ARTHROCENTESIS WITH HYALURONIC ACID INJECTIONS FOR MANAGEMENT OF TEMPOROMANDIBULAR
DISORDERS
Dottoranda: FUNDA GOKER
Matricola: R11884
Tutor: Professor MASSIMO DEL FABBRO
Coordinatore del Dottorato: Professor MASSIMO DEL FABBRO
A.A. 2019/2020
INDEX
1- INTRODUCTION A. ANATOMY
A.1. Temporomandibular Joint A.2. Innervation and Vascularization A.3. Ligaments of the TMJ
B. TEMPOROMANDIBULAR JOINT DISORDERS (TMD) B.1. Classification of Temporomandibular Joint Disorders (TMD) B.2. Etiology and Identification of Temporomandibular Disorders (TMD) B.3. Muscular Etiopathogenesis
C. FUNCTIONAL TMJ DISORDERS
C.1. Derangements Of The Condyle-Disc Complex C.1.1. Disc dislocation (displacement) with reduction C.1.2. Disc dislocation without reduction
C.1.3. Luxation, Subluxation, Hypermobility C.1.4. Compression
C.2. Structural Incompatibility of the Articular Surfaces C.3. Inflammatory Joint Disorders
D. DIAGNOSTIC IMAGING MODALITIES FOR THE ASSESSMENT OF PAIN SYMPTOMS IN TMD
E. TMD THERAPY
F. SURGICAL INTERVENTIONS FOR TMD
G. ARTHROCENTESIS G.1. History and Description G.2.Rationale of Arthrocentesis G.3. Indications for Arthrocentesis
G.4. Contraindications for Arthrocentesis G.5. Postoperative complications
G.6. Irrigating solutions and volume/pressure considerations G.7.Temporomandibular joint arthrocentesis procedure G.8. Post-arthrocentesis injections and considerations
H. Quality of life and the SF-36 Health Survey in patients with TMD 2- MATERIALS AND METHODS
A. Systematic Review
B. Clinical case series protocol 3- RESULTS
4- DISCUSSION 5- CONCLUSION 6- REFERENCES
ABSTRACT
Objectives: Although, arthrocentesis is an accepted safe treatment modality used for the management of TMD patients with pain, the benefit of hyaluronic acid (HA) injections remains uncertain. The aim of this study was to investigate whether intra-articular injections of
hyaluronic acid as an adjunct therapy with arthrocentesis can be more effective than other medications for the improvement of symptoms associated with temporomandibular disorders.
Materials and methods: For this purpose, an electronic search of Medline, Scopus and Cochrane databases was performed up to September 2020. No language, and publication date limitation was set. The following search terms were used: “arthrocentesis”, “hyaluronic acid”,
“intra-articular injections”, “viscosupplementation”, with “temporomandibular disorders”.
Inclusion criteria was prospective or retrospective studies, case reports, and randomized clinical trials that reported the application of HA injections compared to other intra-articular drugs for the treatment of temporomandibular disorders. Exclusion criteria included systemic reviews, animal studies. Additionally, a retrospective clinical study was performed on 12 TMD cases for evaluation of changes before and after arthrocentesis with hyaluronic acid (HA) injections in quality of life (QoL) of these patients.
Results: In the systemic review, the initial screening included 1327 articles. After a more detailed evaluation of the titles, abstracts, and full texts; a total of 29 studies were selected (26 randomized studies, 2 controlled clinical trials, 1 retrospective report). In the clinical study 12 patients were included. According to the results, intra-articular injections of HA and other medications together with arthrocentesis seemed to be beneficial for improvement of functional symptoms of TMD and pain. The case series also supported support the efficacy of HA
injections with a significant improvement of QoL of these patients. However, after the evaluation of the reports in literature, it was impossible to identify an optimum drug or a protocol in
improving the pain and/or functional symptoms of temporomandibular problems due to diversity of treatment modalities and conflicting results.
Conclusion: As a conclusion, there was no consensus in the studies that HA injections showed better results in comparison with other treatment modalities. According to the results of this systematic review and clinical study HA injections with/without arthrocentesis seems to be beneficial in terms of clinical symptoms and QoL of the patients.
Keywords: arthrocentesis, hyaluronic acid, intra-articular injections, temporomandibular disorders, quality of life
1- INTRODUCTION A. ANATOMY
A.1. Anatomy of the TMJ
TMJ, located in the area where the mandible articulates with cranium just anterior to the external auditory meatus, is considered as one of the most complex joints in humans (Okeson, 2008, Shaffer, et al., 2014a). TMJ consists of the “mandibular condyle” of the mandibular bone (Shaffer, et al., 2014a) sitting in the “glenoid fossa” or “mandibular fossa” of the temporalis bone (Figure 1) (Okeson, 2008, Shaffer, et al., 2014a, Gray, et al., 2011).
Upper articular surface consists of temporal bone’s “articular eminence” or “articular tubercule”,
“mandibular fossa” or “glenoid fossa” and posteriorly “tympanic plate”. Immediately anterior to the glenoid fossa is a convex prominence, called the “articular eminence” or “articular tubercule”
of the temporal bone. The degree of the convexity of the articular eminence dictates the pathway of the condyle in anterior positions (Okeson, 2008).
Inferior articular part consists of condylar head of the mandible which is positioned in the mandibular fossa. The mandibular condyle usually manifests variable shapes with the posterior articulating surface greater than anterior surface (Okeson, 2008). The articulating part of the condyle is usually described as convex, angular, rounded, or flat (Alomar, et al., 2007) with an anteroposterior width of 8-10 mm, and a mediolateral length of 18-23 mm (Okeson, 2008).
Articular surfaces are covered with fibrocartilage and the intraarticular disc situated between the condyle and fossa divides the joint cavity into upper and lower parts. TMJ is a synovial joint with condylar variety. TMJ is considered as a ginglymo-arthrodial joint, because it is capable of providing both hinging (as ginglymoid joint) and gliding movements (as arthrodial joint) (Okeson, 2008).
The biconcave intraarticular disk within the joint capsule (Okeson, 2008, Shaffer, et al., 2014-a) is attached to the capsular ligament anterior-posteriorly and medial-laterally). The disc has concave superior surface and convex inferior surface. The disc separates the joint into disco-mandibular lower and disco-temporal upper spaces (Shaffer, et al., 2014-a). The upper compartment permits gliding movements, while the lower compartment permits rotatory as well as gliding movements.
The disc prevents the friction between the articular surfaces. It also acts as a cushion and helps in shock absorption.
The disc of TMJ consists of fibrocartilage (not hyaline cartilage like other synovial joints), devoid of any blood and nerve vessels (Shaffer, et al. -a, 2014, Kuroda, et al., 2009). However, the extreme periphery of the disc is slightly innervated. From anterior view the medial part of the disc is usually thicker than lateral part and in sagittal plane articular disc can be divided into 3 regions. The posterior border of the disc is thicker than anterior border, while the intermediate zone is the thinnest. The articular surface of the mandibular condyle is located on the intermediate zone of the
disc, bordered by the anterior and posterior zones (Okesan, 2008). During articulative movements the shape of the disc is somewhat flexible and can adapt to the functional demands of the articular surfaces (Figure 2) (Okesan, 2008).
Figure 1: Temporomandibular joint
The periphery of the disc is attached to fibrous joint capsule. This capsule is attached to articular tubercule, circumference of mandibular fossa, squamo-tympanic tissue and the neck of the mandible. The fibrous capsule is loose above the intraarticular disc and tight below the disc. The joint capsule contains synovial fluid, is lined by a synovial membrane, and possesses a lateral ligamentous thickening (temporomandibular ligament) that reinforces the joint (Shaffer, et al., 2014-a). The synovial membrane lines the fibrous capsule and the neck of the mandible. The synovial fluid, which is present in both joint cavities acts as a lubricant during function between articular surfaces. And because the articular surfaces of TMJ joint are free of vascular tissues, it also acts as a medium for providing metabolic requirements. There is a rapid exchange between the synovial fluid, the articular surfaces, and the vessels of the capsule (Okesan, 2008).
Figure 2: Normal closed and open disc location: Diagrammatic representation showing normal condyle disk position with junction of posterior attachment and posterior band of disk aligned approximately at the 12 o’clock position with regard to the condylar surface (Quinn & Granquist, 2015)
The TMJ is tentative to local and extensive degeneration. The degenerative changes can be seen in the upper joint part or in the lower joint part. Although the temporal bone and upper joint space generally undergo less degeneration relative to the mandibular condyle and lower joint space. In cases of local degenerations, the lateral aspect of the articular tubercle of the temporal bone is most likely to be affected and mandibular condyle is not much effected. Extensive changes can culminate in a total loss of articular cartilage. The inferior surface of the disk undergoes degenerative changes more frequently than the superior aspect. The intraarticular disk can displace in the anterior, medial, lateral, or posterior directions (Shaffer, et al., 2014 -a).
A.2. Innervation-vascularization
Motor and sensory innervation of TMJ is by the trigeminal nerve, while branches of the mandibular nerve provide the afferent innervation. Auriculotemporal nerve provides most of the innervation, since it leaves the mandibular nerve behind the joint and ascends superiorly and laterally and wraps posterior part of the joint (Okesan, 2008, Schmidt, et al., 1998). Because of its course, is at greatest risk for irritation or entrapment since the auriculotemporal nerve bundles can become displaced and impinged between the articular fossa and the mandibular condyle (Okesan, 2008, Shmidt, et al., 1998). Other additional nerves, that provide innervation to TMJ, are the deep temporal and masseteric nerves (Okesan, 2008).
Vascularization of the TMJ is mostly by the superficial temporal artery posteriorly and by the middle meningeal artery anteriorly, the internal maxillary artery inferiorly, and additionally by ascending pharyngeal, deep auricular, anterior tympanic arteries (Okesan, 2008).
A.3. Ligaments of the TMJ
The capsular ligament surrounds and encompasses the entire TMJ. Superiorly, the fibers of the capsular ligament are attached to temporal bone along mandibular fossa and extend anteriorly to include the articular eminence. Inferiorly they are attached to the neck of the mandibular condyle.
The function of this ligament is to resist medial, lateral, and inferior forces that tend to dislocate articular surfaces.
Collateral ligaments attach the lateral and medial borders of the articular disc to the lateral and medial poles of the condyle. They are composed of collagenous connective tissue and they divide the joint mediolaterally into superior, and inferior cavities. These ligaments provide the hinging movement of the TMJ. They allow the disc to be rotated on the articular surface of the mandibular condyle as it glides anteriorly and posteriorly. These ligaments do not stretch and a strain on them can be painful.
Temporomandibular ligament (lateral ligament)
Lateral temporomandibular ligament is attached to articular tubercule and posterior lateral aspect of the mandible. It strengthens the lateral part of the capsular ligament. Fibers of it are directed downwards and backwards. Lateral ligament is composed of horizontal and oblique parts. The outer oblique portion influences the normal rotational opening movement of the jaws and limits the extend of mouth opening. When the mouth opens, the teeth are separated approximately 20- 25mm, the outer oblique portion is stretched and tense, the neck of the condyle cannot rotate any further. In case the mouth is to be opened wider, the condyle would need to move forward and downward out of the fossae and across the articular eminence, which shall create a second arc of opening. This can be demonstrated in the clinics by closing the mouth and applying mild posterior force to the chin of the patient. At this point patient will be able to open until the teeth are 20-25 mm apart, and if the jaws are opened wider, a distinct change in opening movement will occur because of the tightening of TM ligament. This serves as to prevent the mandible to impinge on the vital retro- and sub-mandibular structures of the neck.
The inner horizontal portion prevents the posterior movement of the condyle and the disc into the posterior region of the mandibular fossa, thus protects the retrodiscal tissues. It also protects the lateral pterygoid muscle from extension. In cases of extreme trauma to the mandible, the neck of the condyle fractures before retrodiscal tissues are damaged or before the condyle enters the middle cranial fossa.
Stylomandibular ligament
The stylomandibular ligament represents a thickened part of the deep cervical fascia, which separates the parotid and submandibular salivary glands. This ligament limits excessive protrusive movements of the mandible. It extends between the styloid process and below the angle and adjacent part of the posterior border of the ramus mandible. It is most relaxed when the mouth is opened, but it becomes taut, when the mandible is protruded (Okesan, 2008, Alomar, et al., 2007).
Sphenomandibular ligament
Sphenomandibular ligament is an accessory ligament that lies on a deep plane away from the fibrous capsule and it does not present any limiting action on mandibular movements. It is attached superiorly to the spine of the sphenoid and inferiorly to the lingula of the mandibular foramen. Its relations are as follows; i) laterally to lateropterygoid muscle, auriculotemporal nerve and maxillary nerve, ii) medially to chorda tympani, and the wall of the pharynx, iii) near to its end, it is pierced by the mylohyoid nerve and vessels. Sphenomandibular ligament is a remnant of Meckel’s cartilage (Okesan, 2008, Alomar, et al., 2007).
B. TEMPOROMANDIBULAR JOINT DISORDERS (TMD)
B.1. Classification of Temporomandibular Joint Disorders (TMD)
The ultimate goal of a classification is to provide clinically useful schemes for an easier management of patients in the clinical setting. However, despite all efforts by the several international experts and organizations, none of the proposed classifications of OFP (oral facial pain)/TMD is free of any shortcomings (Klasser, et al., 2018, Ohrbach, et al., 2019).
Table 1: The classification of TMD (Schiffman, et al., 2014) TMJ DISORDERS:
1. Joint pain: i-Arthralgia ii-Arthritis 2. Joint disorders.
A-Disc disorders: i- Disc displacement with reduction
ii- Disc displacement with reduction with intermittent locking, iii- Disc displacement without reduction with limited opening iv- Disc displacement without reduction without limited opening B-Hypomobility disorders other than disc disorders: i- Adhesions/adherence ii- Ankylosis a. Fibrous, b. Osseous
C-Hypermobility disorders: Dislocations a. Subluxation b. Luxation 3. Joint diseases
4. Degenerative joint disease: i- Osteoarthrosis, ii- Osteoarthritis 5. Systemic arthritides
6. Condylysis/idiopathic condylar resorption 7. Osteochondritis dissecans
8. Osteonecrosis 9. Neoplasm
10. Synovial chondromatosis
11. Fractures
12. Congenital/developmental disorders: A- Aplasia B- Hypoplasia C-Hyperplasia MASTICATORY MUSCLE DISORDERS:
Muscle pain: A. Spasm, B. Tendonitis, C. Myositis, D. Myalgia:
1. Local myalgia 2. Myofascial pain
3. Myofascial pain with referral: contracture, hypertrophy, neoplasm, masticatory muscle pain attributed to systemic/central pain disorders, fibromyalgia/widespread pain, headache attributed to TMD
Movement disorders: a. Orofacial dyskinesia, b. Oromandibular dystonia
B.2. Etiology and Identification of Temporomandibular Disorders (TMD) 1- Local muscle soreness (Protective co-contraction)
2- Myofascial Pain and trigger points
3- Myospasm (CNS mediated acute muscle disorder) 4- Chronic Centrally mediated myalgia
5- Derangement of the condyle-disc complex a- disc displacement and disc dislocation with reduction, b- disc dislocation without reduction, c- Compression
6- Structural incompatibility a- Deviation in form and adhesions b- subluxation- hypermobility, c- spontaneous dislocation (open lock)
7- Inflammatory disorders of the TMJ a- Capsulitis, b- synovitis, c-retro-discitis, d- traumatic arthritis, e- osteoarthritis, f- infectious arthritis,
8- Ankylosis (Okesan, 2008).
Figure 3: Wilkes classification for TMJ internal Derangements (Wilkes, 1989)
B.3. Muscular Etiopathogenesis
Table 2: Etiopathogenesis of Temporomandibular Disorders (Okesan, 2008, Prati, 2017) Muscular disorders
Causes: parafunction, stress, trauma, TMJ pathology
Progressive overload of the muscle and metabolic alteration
Manifestation: rigidity/muscle fatigue, muscular pain, spasm, trigger points, cephalalgy (=headache)
Protective co-contraction
In case of injury or in a threat of injury, normal sequencing of muscle activity seems to be altered so as to protect the threatened part from further injury. Ex: in case of high crown protective co- contraction as a protective mechanism. Limited mouth opening. The patient can achieve full opening when asked to open slowly. The key identifying factor is co-contraction is that it immediately follows an event (Okesan, 2008).
Local muscle soreness (noninflammatory myalgia)
In cases of prolonged muscle tissue contraction, local trauma, excessive use of the muscle. It can be also referred as delayed onset muscle soreness or postexercise muscle soreness. Changes in local environment of muscle tissues are seen such as, bradykinin, histamine (algogenic substances) release. Deep pain is present, which can further produce protective co-contraction as a cycle.
Clinically muscles are tender to palpation. There is muscle weakness and limited mouth opening.
The patient has great difficulty opening any wider.
Central nervous system (CNS) effects on muscle pain
Muscle pain with central origin as a secondary respond to one of these three factors: 1-The presence of ongoing deep pain input, 2- increased level of emotional stress, 3-changes in the descending inhibitory system that lead to a decrease in the ability to counter afferent input (okesan). Treatment: Relaxation, splints/night guards, medication, botox, pain killers, muscle relaxants, release techniques sach as stretch.
C. FUNCTIONAL TMJ DISORDERS
Functional Disorders can be divided as follows:
• Derangements of the condyle-disc complex
• Structural incompatibility of the articular surfaces
• Inflammatory joint disorders (Prati, 2017, Schiffman, et al., 2014).
C.1. Derangements Of The Condyle-Disc Complex C.1.1. Disc dislocation (displacement) with reduction
Figure 4: Disc dislocation (displacement) with reduction
Diagnosis: Disc is located anterior-medial with respect to the condyle. While opening the condyle moves into the posterior border of the disc, which can be accompanied by clicking sound.
Treatment: Treatment modalities include repositioning bite and exercises of remodeling of the disc 10x6 with progressive retrusion
non symptomatic - just click à exercises
Symptomatic- (Pain and block without dislocation of the disc) à if Pain and block is intenseà bite.
if Pain and block is not intense à exercises.
Symptomatic- (Pain and block with dislocation of the disc) à If prognostic grid is unfavorable à exercises
If prognostic grid is favorable àrepositioning bite Table 3: Prognostic Grid (Prati, 2017)
Unfavorable clinical factors Unfavorable instrumental factors Late reduction ++ Partial reduction +++
Advanced therapeutic position +++ Disc deformity ++
Hyperlaxity of the ligaments ++ With construction bite: Partial reduction +++
With construction bite: extremely advanced position of the condyle +++
C.1.2. Disc dislocation without reduction
Disc is dislocated when mouth is closed, while opening the condyle does not move into the disc, but rather it pushes the disc forward.
Diagnosis: 1. Jaw locked so that the mouth would not open all the way; AND 2. Limitation in jaw opening severe enough to limit jaw opening and interfere with ability to eat.
(note: without limited opening- Positive for those in the past)
Figure 5: Disc dislocation without reduction
When this diagnosis needs to be confirmed, TMJ MRI Imaging is the reference standard for this diagnosis.
1. In the maximum intercuspidal position, the posterior band of the disc is located anterior to the 11:30 position and the intermediate zone of the disc is anterior to the condylar head, AND 2. On full opening, the intermediate zone of the disc is located anterior to the condylar head.
Note: Maximum assisted opening of < 40 mm is determined clinically.
Presence of TMJ noise (ex: clicking sound during opening) does not exclude this diagnosis.
Disc displacement without reduction with limited opening: Positive for the following:
1. Maximum assisted opening (passive stretch) movement including vertical incisal overlap < 40 mm.
Disc displacement without reduction without limited opening: Positive for the following:
1. Maximum assisted opening (passive stretch) movement including vertical incisal overlap ≥ 40 mm. (Schiffmann, et al. 2014)
Therapy: “Dislocation of the disc without reduction acute”: repositioning bite and manual therapy. “Dislocation of the disc without reduction chronic”: distraction bite, and if patient does not get better in 40-50 days arthrocentesis (Prati, 2017).
C.1.3. Luxation, Subluxation, Hypermobility
A sudden forward movement of the condyle during the latter phase of mouth opening. Condyle moves beyond the crest of the eminence and appears to jump forward to the wide-open position.
hypermobility disorder involving the disc-condyle complex and the articular eminence: In the open mouth position, the disc-condyle complex is positioned anterior to the articular eminence and is unable to return to a normal closed mouth position without a manipulative maneuver. The duration of dislocation may be momentary or prolonged. When the patient can reduce the dislocation himself/herself, this is referred to as subluxation. When the patient needs the assistance of the clinician to reduce the dislocation and normalize jaw movement, this is referred to as luxation.
This disorder is also referred to as “open lock.” The sensitivity and specificity have been established for only subluxation (Schiffmann, et al. 2014).
Positive for both of the following:
In last 30 days, jaw locking or catching in a wide-open mouth position, even for a moment and inability to close the mouth from a wide-open position without a self-maneuver. When this diagnosis needs to be confirmed, imaging criteria are positive for the condyle positioned beyond the height of the articular eminence with the patient unable to close his/her mouth (Schiffmann, et al. 2014).
Spontaneous Dislocation (open lock): Hyper-extention of the TMJ, resulting in a condition that fixes the joint in an open position and prevents any translation. Normal at resting position, when mouth is open, TMJ can be either posteriorly or anteriorly dislocated, and the patient is unable to close the mouth.
Dislocations of the jaw should not be confused with subluxation. Dislocation is a complete disruption of the joint, while luxation is a partial dislocation followed by a relocation. In luxation, the joint is still partially attached to the bone, and it is the point where the joint begins to dislocate.
In dislocation, the two parts of joint lose contact. Subluxation is loosening without displacement, however in luxation there is partial displacement. In Subluxation, there is a moment of sense of not being able to close the mouth is present, while in luxation there is a block in opening movement. Luxation can be detected radiographically.
Hypermobility of the TMJ posteriorly favors the dislocation of the disc, hypermobility of the TMJ anteriorly favors the “luxation” and mandible and disc can exit the glenoid, generally with a click noise “subluxation” or in some cases, remains luxated and prevents closing of the jaws “open lock”. In pathologies of a block of opening/closing in luxation, the contraction of the reflex muscles plays an important role mainly due to panic affecting the block patient. While in cases of subluxation, the fear of being blocked triggers an autonomically controlled mechanism of opening which results in the disfunction of the muscles (Prati, 2017).
Treatment modality in subluxation is counselling and home exercises, while in luxation manual therapy of reduction is considered appropriate (Prati, 2017).
C.1.4. Compression
Condyle in retro-position with reduction of the anterior space. The disc is dislocated anteriorly when mouth is closed. At maximum opening, there is “end -feel, which can provoke pain.
C.2. Structural incompatibility of the articular surfaces (Degenerative joint disease)
A degenerative disorder involving the joint characterized by deterioration of articular tissue with concomitant osseous changes in the condyle and/or articular eminence. Positive for at least one of the following:
1. In the last 30 days, any TMJ noise(s) present with jaw movement or function; OR 2. Patient report of any noise present during the exam. Positive for the following:1. Crepitus detected with palpation during at least one of the following: opening, closing, right or left lateral, or protrusive movement(s). When this diagnosis needs to be confirmed, then TMJ CT criteria106 are positive for at least one of the following: Subchondral cyst(s), erosion(s), generalized sclerosis, or
osteophyte(s). Note: Flattening and/or cortical sclerosis are considered indeterminant findings for degenerative joint disease (DJD) and may represent normal variation, aging, remodeling, or a precursor to frank DJD (Schiffmann, et al. 2014).
It is important to distinguish acute compression from chronic one. Acute form is the one which is present less than 3-4 months, while chronic compression can be considered in case of duration more than 4 months. Treatment modalities: In “post-traumatic acute compression”- Anti-
inflammatory drugs for a week, and counselling. These patients should be controlled at a follow- up visit after 15 days. In case of no resolution, they should be reevaluated by use of MR. In
“non-traumatic acute compression”- Manual therapy, counselling, and home exercises are indicated. In “chronic compression”- Bite of distraction is indicated (Prati, 2017)
C.3. Inflammatory joint disorders
Inflammation of the various tissues that make up the joint structure (such as, synovitis, capsulitis, retrodiscitis, arthritides) as a result of unusual function, trauma, insult or breakdown. In disc derangement disorders, pain is often momentary and associated with joint movement. In inflammatory joint disorders, pain is constant and dull, which is accentuated by joint movement (Prati, 2017, Okeson, 2008).
Progressive changes in internal derangement: Traditionally, internal derangement of the TMJ is described as a progressive disorder that may be classified into four consecutive clinical stages (Barkin &Weinberg, 2000, Dolwick, et al.,1983). Although, in most of the cases, internal derangement of the disc undergoes a progressive change, it is still not clear whether this
progression happens in all cases. Longitudinal epidemiological studies do not support the idea of progression and clinical evidence does support progressive worsening of the condition in some patients. The probability that TMJ clicking would disappear in a symptomatic individual seems to be equal to the probability of it appearing in an asymptomatic individual (Barkin &Weinberg, 2000).
C. DIAGNOSTIC IMAGING MODALITIES FOR THE ASSESSMENT OF PAIN SYMPTOMS IN TMD
Panoramic radiography= For initial diagnosis and assessment of TMJ alteration. Diagnosis of highly advanced bone alterations in the condyle such as asymmetries, erosions, osteophytes, fractures, changes in size and shape, degenerative and inflammatory processes, growth alterations, maxillary tumors, metastases, ankylosis, and fractures. However, it does not provide functional information. Also useful for detecting odontogenic alterations whose symptoms can overlap with TMD (Ferreira, et al., 2016).
Planigraphy (or panoramic radiography with programs for TMJ)= In addition to the conventional panoramics, this technique can be useful for functional assessment of mouth opening, evaluation of morphological alteration and the joint spaces, analysis of dimension, fractures, and ankylosis.
Transcranial radiography= Anatomical assessment of the condyle, fossa, and articular tubercle.
However, this type of projection is limited by the fact that it produces an image with a large overlap of the skull bones.
Arthrography= A technique to assess the TMJ soft tissues by contrast injection into the superior and/or inferior joint spaces. After the injection, dynamic images were obtained, recording mandibular movements. However, it is not currently recommended as it is an invasive procedure and carries a risk of iatrogenic disc perforation, facial nerve damage, pain and limitation of movement after the injections, infections, allergies to the injected dye, and presence of the risks of radiation to radiosensitive structures such as, crystalline and thyroid.
Medical CT and cone beam CT = Structural assessment of bone components of the TMJ.
Pathological bony changes such as fractures, neoplasms, ankylosis, erosion, osteophyte, deformity, osteochondritis dissecans, hyperplasia of condylar, coronoid, and styloid processes. However, few details are provided on soft tissue and it is not possible to evaluate the joint disc Additionally, levels of radiation and costs are high.
Magnetic resonance (MR)= MRI has been the method of choice to study disease processes involving the TMJ soft tissues. The articular disc, ligaments, retro-disc tissues, intra- capsular synovial content, adjacent masticatory muscles, as well as cortical and medullary integrity of bone components can be examined by MR. It is considered the gold standard for assessing disc position
and is highly sensitive for intraarticular degenerative alterations. The technique allows three- dimensional analysis in the axial, coronal, and sagittal plane. Its disadvantages are related to the high cost and the need for sophisticated facilities. It is contraindicated in claustrophobic patients, those with pacemakers and metallic heart valves, ferromagnetic foreign bodies, and pregnant women. It has some limitations that could influence the final diagnostic outcome, such as the lack of standardization concerning the range of mouth opening, and even the parameters for image acquisition, such as surface coil, time of repetition, field of view, and slice thickness (Pupo, et al 2016).
Static MR imaging= Disk positional abnormalities such as, sideways or anterior disc
displacements with/ without reduction. Bone marrow abnormalities such as osteonecrosis and edema. Joint effusion. Posterior disc attachment evaluation by T2 weight image in cases of higher T2 signal (MR images with the timing of frequency pulse sequences that are capable to highlight excess fat and water). Marked joint effusion. Tumor involvement, inflammatory diseases and autoimmune processes such as rheumatoid arthritis. Proximity between the TMJ disk and the mandibular nerve.
Dynamic MR imaging with contrast material= Contrast enhancement of joint effusion, the posterior disk attachment
Functional MR imaging= The regions and the network of brain activation associated with TMD MR spectroscopy= Ascending of insular glutamine levels
Magnetization transfer contrast imaging= Edematous and ischemic changes in the muscles Ultrasonography= A high-resolution imaging equipment for the assessment of disc position in internal TMJ disorders. Muscular edema by low-level contraction. However, it does not have accuracy for the cortical and articular disc morphological diagnosis. However, it can be a useful option particularly in patients with contraindications to MRI.Moreover, it is less expensive, allows real-time visualization without the use of ionizing radiation, and is quick and comfortable
Nuclear medicine evaluation
Bone scintigraphy= neoplastic activity, metabolic disorders, bone growth, synovitis and osteoarthritis. It has some advantages over radiographies, conventional CT, and MRI because it provides an estimate of metabolic and inflammatory activity. It can facilitate an early diagnosis and is less costly than CT and MRI. However, it does not differentiate among bone scar disorders, infections, osteoarthritic manifestations, or tumors.
Positron-emission tomography (PET)= Positron-emission tomography (PET) is usually indicated for the assessment and staging of metastatic tumors. It is able to provide accurate functional, morphological, and metabolic information.
Single photon emission computed tomography (SPECT/CT) = Currently, single photon emission computed tomography with technetium-99m methylene diphosphate (SPECT/CT with 99m Tc- MDP) is largely employed. The radiotracer 99m Tc is able to reflect the local osteometabolic rate, while the anatomic mapping is obtained by tomographic technique. As in the PET, anatomical and functional data are fused into a single image. Its main advantage is its sensitivity and specificity (Ferreira, et al., 2016, Suenaga, et al., 2016).
E. TMD THERAPY
1- Counselling or Patient Education
Counselling is a central component and indicated in all types of TMD. Each patient should receive individualized education (Prati, 2017, Shaffer, et al. 2014 b). “Counselling” includes: i- communication with the patient about the cause, diagnosis, prognosis, and options of treatment, ii- auto-controlling of the parafunction, iii- home exercises (Prati, 2017).
2- Splinting (Bite)
Splint therapy has very frequently been indicated for treating TMD. The most common conditions are masticatory myalgia, TMJ arthralgia, and TMJ dysfunction (9 Hasegawa). The therapeutic advantage of splint therapy, especially stabilization appliances, lies in producing stability of occlusion and equal distribution of abnormal forces causing overload of the masticatory muscles and the TMJ. There is a high probability that splint therapy would not be successful in patients with abnormalities such as bone marrow abnormalities and biconvex disc configuration of the TMJ (Hasegawa, et al., 2017). Oral splints can be in a variety of different materials and styles. One fabrication method involves obtaining impressions of the upper and lower teeth to make a custom splint. Others do not cover the teeth at all. Generally, splints are worn only while sleeping to protect the teeth, decrease nighttime bruxism, and/or reduce TMD symptoms (Prati, 2017, Shaffer, et al.
2014 b).
a- Neuromuscular bite
Indications: Chronical muscular disorders, protection against bruxism, for correcting physiologic position of the mandible. Contraindications: muscular pathologies with dislocation of the disc with reduction or subluxation.
If occlusion has a predisposing role, the following should be corrected by the bite:
Modification of the mandibular position with correction of pre-contacts. Modification of the vertical occlusal dimension. Modification of the masticatory interferences. Modification of the oral-buccal proprioception (Prati, 2017).
b- Bite for repositioning the mandible
Indications: dislocation of the disc with reduction, acute dislocation of the disc without reduction. Contraindications: All other disorders (Prati, 2017).
c- Bite for distraction
Indications: Chronic compression of the disc, chronic dislocation of the disc without reduction (chronic locking), arthrosis. Contraindications: All other disorders.
It should be discussed with the patient that in case of this treatment modality shall be unsuccessful after 2 months, arthrocentesis and arthroscopy shall be considered (Prati, 2017).
3- Therapeutic Exercise and Manual therapy
Perhaps the most widely known exercise routine for TMD is the Rocabado 6x6 program, which utilizes six exercises six times per day (Table below) (Prati, 2017, Shaffer, et al. 2014 b, Rocabado & Iglarsh 1991).
Table 4: Rocabado’s 6x6 exercise program
Rocabado’s 6x6 exercise program
Rest position of the tongue= The anterior 1/3 of the tongue is placed at the palate with mild pressure, which rests the tongue and jaw musculature and promotes diaphragmatic breathing
Control of TMJ rotation = The jaw is repeatedly opened and closed with the anterior 1/3 of the tongue on the palate, which decreases initiating jaw movements (e.g. protrusive movement in opening, talking, or chewing)
Rhythmic stabilization technique= Gentle isometrics in the resting position are performed for jaw opening, closing, and lateral deviation to promote muscular relaxation via reciprocal inhibition, which promotes an improved resting position of the jaw through proprioceptive input.
Axial extension of the neck= Combined upper cervical flexion with lower cervical extension, allowing reduction of tension in the cervical musculature.
Shoulder posture= Shoulder girdle retraction and depression to facilitate postural corrections.
Stabilized head flexion= Upper cervical spine distraction via chin tuck (without additional cervical flexion), during which it is recommended that the fingers be laced behind the neck to stabilize C2- 7 while the head nods
4- Pharmacological Therapy
Articular pathologies, especially in dislocation of the disc without reduction and arthrosis: Anti- inflammatory and analgesic medications such as, Ibuprofene 40mg, Naproxene 250-500 mg, Ketorolac 15 mg (every 12 h) etc.
Muscular pathologies: Anti-inflammatory drugs have modest effect. Paracetamol (with/ without opoids) and muscle relaxants. Anxiolytics such as diazepam can be also useful (Prati, 2017).
5- Antidepressants:
Bruxism and TMDs are commonly associated with depression. Bruxism results from an imbalance between the direct and indirect pathways of the basal ganglia through the disruption of action potential transmission, which is medi- ated by dopamine. Dopamine agonists are therefore helpful in treating bruxism because they increase dopamine levels and restore the balance between the basal ganglia pathways (Abouelhuda, et al., 2018, Prati, 2017).
6- Orthodontic therapy
To date there has never been a satisfactory evaluation of orthodontics with respect to TMD.
However, it might be useful for the patients with severe malocclusion (Luther, et al., 2010).
7- Low level laser therapy, Ultrasound and electrical stimulation
LLLT can result in muscle relaxation and an increase in blood microcirculation, thereby accelerating the clearance of catabolites from tissues. Masseter and temporal muscles with painful symptoms were reported to be treated with the use of LLLT GA-Al-As (gallium-aluminum- arsenide) diode laser (Abouelhuda, et al., 2018).
Therapeutic ultrasound has an output of 20 to 60 kHz. It produces deep heat at joints and treats joint contracture by increasing the stretch of the extra capsular soft tissue. It also decreases non- acute pain, muscle spasms, and tendonitis, facilitating the stretch of soft tissue by decreasing the viscosity of collagen (Abouelhuda, et al., 2018).
Electrical stimulation devices for the treatment of TMDs have two main purposes: relief of pain and relief of muscle hyperactivity or spasm (Abouelhuda, et al., 2018).
In particular, various types of electrotherapy, such as pulsed radiofrequency energy, TENS, and LLLT, were reported not to show no better results than their respective placebos in the treatment of TMD (Gil-Martínez, et al., 2018)
8- Muscle Injections with Botox
BTX is a strong biological exotoxin produced by Clos- tridium botulinum, a Gram-positive anaerobic bacterium. According to the literature, BTX treatment seems to be useful to treat bruxism, myofascial pain, disorders associated with TMJ disc displacement, and habitual dislocation of the mandible. Treatment with BTX is contraindicated in women during pregnancy and lactation, in patients with known hypersensitivity to any component of the drug (Abouelhuda, et al., 2018).
9- Surgical Therapy
F. Surgical interventions for TMD
MINIMALLY INVASIVE: Arthrocentesis, Arthroscopy (lysis and lavage) (Politi, et al.,2007).
Arthroscopy 1. Disc release 2. Disc repositioning
DISK REPOSITIONING (open): Disk plication (with or without recontouring), Eminoplasty in conjunction with disk repositioning
DISK REMOVAL (open): Discectomy (without replacement), Discectomy (with replacement) dermis, fascia, muscle flap, platelet rich plasma (Quinn & Granquist, 2015).
Surgical interventions for Class Wilkes III–V:
JOINT REPLACEMENT (Autogenous: Costochondral, Fibula, Sternoclavicular or Alloplastic:
stock or custom)
JOINT REGENERATION (Distraction osteogenesis)
ARTHROPLASTY (Conservative removal of osteophytes and fibrosis: Inter-positional: • Fat • Temporalis fascia • Temporary silicone)
Surgical options for Ankylosis:
Fibrous (false): Arthroplasty with meniscal salvage, Arthroplasty with meniscectomy
Bony (true): Arthroplasty + 1. Inter-positional graft (fascia, fat, dermis) 2. Temporalis muscle flap.
Gap arthroplasty (2.5–3.0 cm minimal osteotomy) + 1. Autogenous graft, 2. Alloplastic prosthesis (stock or custom)
Surgical options for condylar fractures:
Closed reduction: (1. Intracapsular, 2. Minimal displacement, 3. “Greenstick” in children)
Open reduction: (1. Marked displacement of condyle out of glenoid fossa, 2. Bilateral condylar fractures with apertognathia, 3. Displaced condylar fractures with concomitant midface fractures, 4. Continued pain, malocclusion, or obstructed opening following closed reduction (10-14 days), 5- Medical conditions precluding intermaxillary fixation)
Surgical options for septic arthritis: Joint aspiration, Arthrocentesis, Arthroscopy, Incision and drainage
Surgical options for TMJ hypermobility:
Arthroplasty: Anatomic obstruction removal (Eminoplasty), Restrictive technique (Eminence Lengthening:1. Inter-positional bone graft 2. Autogenous “cap” implant 3. Eminence“down fracture” (Le Clerc).
Arthroscopic procedures: “Scarring procedures”, eminoplasty, lateral pterygoid myotomy.
Muscle procedures: (Lateral pterygoid myotomy, Botox).
Indications for surgery
Ankylosis of TMJ (e.g., fibrous or osseous joint fusion) (Dolwick & Dimitroulis, 1994)
• Neoplasia (e.g., osteochondroma of the condyle)
• Dislocation of TMJ either recurrent or chronic
• Developmental disorders affecting the TMJ
• Relative indications
• Internal derangement of TMJ
• Osteoarthrosis
• Trauma to the TMJ (Soni, 2019).
Indications for surgical (operative) arthroscopy
• Conditions that represent a disability for the patient which are refractory to medical treatment and require internal structural modifications. Any additional myofascial pain symptoms should be under successful management.
• Patient with a significant pain or dysfunction, producing a disability and poor quality of life.
• Failure of appropriate non-surgical treatment over a reasonable length of time.
• TMJ is the origin of the pain or dysfunction.
• Possible therapeutic benefit in arthroscopic surgery as a diagnostic modality prior to open joint surgery.
• subclassifications of TMJ arthropathy
(1) hypomobility secondary to anteriorly displaced discs with or without reduction (adhesions), (2) hypermobility, (3) degenerative joint disease (osteoarthritis) and (4) synovitis (Bouloux, et al. 2017, De Rui, et al., 2019).
G. ARTHROCENTESIS G.1. History and Description
The root word for arthrocentesis, comes from ancient Greek as “arthron” (joint) + “kentesis”
(puncture). Arthrocentesis is commonly defined as a simple, minimally invasive form of surgical therapy, a “lavage of the TMJ without viewing the joint space” using sterile needles and sterile irrigants. The aims are the washing out inflammatory mediators to reduce the pain and or to increase the mandibular mobility by removing disrupting intra-articular adhesions between the surface of the disc and the joint fossa by means of hydraulic pressure of the lavage solution from irrigation of the upper chamber of the TMJ (Soni, 2019, Tvrdy, et al., 2015).
Arterocentesis dates back to 1552, as it was first mentioned in a translation of an Aztec manual of herbal medicine “Libellus de medicinalibus Indorum herbis”, known as the Codexus Badianus, for the Spanish king Charles V. In 1592, in the second edition of “Tractado breve de medicina in Mexico”, a detailed description of indications, technique and therapeutic benefit of knee arthrocentesis was described by Fray Augustin Farfan (Tvrdy, et al., 2015, Aceves‐Avila, et al., 2003). Arthrocentesis of the temporomandibular joint was first described by D. W. Nitzan in 1991 as the simplest form of surgical therapy. (Nitzan, et al., 1991).
G.2.Rationale of Arthrocentesis
Arthrocentesis is generally suggested in TMD patients with pain that fail to respond to conventional conservative therapies (Diraçoğlu, et al. 2009, Barkin et al., 2000). Whether inflammatory or not, TMDs are usually associated with structural changes in the joint tissues, such as cartilage degradation and subchondral bone alterations due to the changes in the articular loading (Soni, 2019). In inflammatory TMDs, various mediators of inflammation, particularly cytokines, might be responsible for rearrangement of the extracellular matrix in joint tissues, altering normal cell reactions and allowing enzymatic degradation of the matrix. Collagenases and matrix metalloproteinases (MMPs), zinc-containing proteins with enzymatic activity, likely play roles in this process. Macromolecular degradation of the matrix determines physical and biological deterioration of the tissues and promotes the disease, because the degradation fragments, proteoglycans, and collagen released into the synovial fluid generate inflammatory pain, with further release of MMPs. (De Riu, et al. 2013). In addition to this, the current clinical evidence
also suggested that the TMJ pain or dysfunction may be attributed to alterations in joint pressure (negative intra-articular pressure) and biochemical constituents of the synovial fluid (failure of lubrication) which may lead to clicking and derangement of the TMJ (Nishimura, et al., 2004, Dolwick 1995, Alpaslan, et al. 2000). Arthrocentesis reduces the pain by allowing the elimination of inflammatory cells from the joint space and increases the mandibular mobility by removing intra-articular adhesions, eliminating the negative pressure within the joint, thus recovering disc and fossa space which reduces the mechanical obstruction caused by anterior disc displacement (Nishimura, et al., 2004, Nitzan, et al., 1991, Dimitroulis, et al., 1995, Kaneyama, et al., 2004, Moses, et al., 1989, Sembronio, et al., 2008).
G.3. Indications for Arthrocentesis
o Patients with internal TMDs not responding to conservative clinical treatment o Anterior disc dislocation with or without reduction
o Hemarthrosis due to recent trauma
o First line procedure for the treatment of acute and chronic closed lock of the TMJ in internal derangement.
o Disc adhesions, either next to the fossa and/or the upper aspect of the articular tubercle, with mouth opening restrictions
o Synovitis/capsulitis not responding to nonsurgical treatment o as palliation treatment for degenerative osteoarthritis
o patients with painful mouth opening and/or closing with joint noises (Soni, 2019). G.4. Contraindications for Arthrocentesis
• An inflammatory abscess or cellulitis at the site of the needle insertion
• Bacteremia
• ankylosis
• Adjacent osteomyelitis
• Coagulopathy
• Malignant tumor (Soni, 2019).
G.5. Postoperative complications
• Injury to the nerves (Fifth nerve deficit, Injury to the facial nerve
• Otic injury
Edema due to leakage of the lavage fluid (Ringer's solution) into the extra-articular space
• Needle breakage within the joint
• Acute joint inflammation
• Allergic reaction to the anesthetics or drugs that are administered
• Intracranial perforation
• Local jaw trauma as a function of the number of repeated punctures
• Violent vertigo, without hearing disorders
• Preauricular hematoma
• Extradural hematoma
• Injury to the superficial temporal artery resulting in aneurysm
• Development of arteriovenous fistula
• Bleeding into the joint.
One of the most frequent complications is the otic injury, which mainly occurs due to close anatomical proximity of TMJ to the middle ear cavity and the cartilaginous wall of the ear canal.
These include perforation of the external auditory canal, the occurrence of blood clots in the external auditory canal, perforation of the tympanic membrane, partial hearing loss, a feeling of fullness of the ear, and vertigo. These can be accompanied by preauricular edema, redness, pain, and restricted mouth opening (Soni, 2019, McCain, et al., 1992, Tsuyama, et al., 2000, González- García, et al., 2006, Tozoglu, et al., 2011, Grossmann, 2012, Vaira, et al., 2017 & 2018).
Intracranial perforation following the procedure is one of the most serious potential complication.
The surgeon must be very careful during the needle introduction and must correct the pressure on the needle during its insertion to avoid intracranial perforation (Tozoglu, et al., 2011). The frequency range of arthrocentesis postoperative complications mentioned in the literature is between 2% and 10% (Tvrdy, et al., 2015). However, they are usually transient in nature [ Vaira 2018]. Most of the complications due to repeated attempt in introducing a needle into the joint space after an unsuccessful primary needle insertion and incorrect pressure on the needle during its insertion. The single-needle approach might be suitable in such cases (Rahal et al., 2009, Talaat et al., 2016).
G.6. Irrigating solutions and volume/pressure considerations
Ringer's lactate or physiological saline are the mostly used irrigating solutions for injecting into the superior joint space for arthrocentesis. The fibrous tissue of the articular disc has a better tolerance for Ringer's solution than for an isotonic saline solution (Shinjo, et al., 2002). Since Ringer's lactate in comparison to other irrigants is close to Human serum, it is considered to be better tolerated by the tissues (Soni, 2019, Shinjo, et al., 2002). The volume of solution used for
TMJ arthrocentesis mentioned in various published studies varied widely and ranged from 50 to 500 mL (Soni, 2019).
The injection of fluid under pressure was reported as a useful way of dealing with the adhesions that are considered to be the main cause of anchorage of the disc to the fossa or eminence or both resulting in reduced translation of condyle, and their release may allow an immediate improvement in mouth opening (Dolwick, 2007, Yura et al. 2003) Yura et al. reported that low-pressure arthrocentesis (6.7 kPa) was unsuccessful in patients with severe adhesions whereas arthrocentesis under sufficient pressure (40 kPa) released them. High-pressure irrigation, was reported with the ability to wash away inflammatory mediators, providing immediate pain relief. Guarda-Nardini et al. (Guarda-Nardini et al. 2012) in their study suggested that in case of adhesions or little adhesiveness, it might be recommended to obstruct one of the needles, to increase the pressure on syringe plunger while the patient performs opening and laterality movements. However, it should be kept in mind that the pressure applied on the syringe during the procedure should be under control to avoid any complication (Soni, 2019).
G.7.Temporomandibular joint arthrocentesis procedure
First described technique of TMJ arthrocentesis was made by Murakami et al. in 1987 (Murakami, et al., 1987). This technique included pumping irrigation and hydraulic pressure to the upper joint cavity followed by manipulation of the jaw.
Various techniques for arthrocentesis were proposed in literature (Tvrdy, et al., 2015). However, before performing any of those, there are some common considerations that are listed below: The field of surgery, including preauricular region and ear, should be cleaned and draped by the use of povidone iodine. External auditory canal should be protected from accumulation of blood and fluid using a cotton pledget. The auriculotemporal nerve block is given, and the areas of joint penetration should be infiltrated (Grossmann 2012). Arthrocentesis can be performed under local or general anesthesia, or intravenous conscious sedation, depending on the patient and surgeon preference (Monje-Gil, et al., 2012).
The two-needle technique
The classical technique of arthrocentesis with insertion of two needles into the upper joint compartment, permitting more effective lavage of the joint was first described by Nitzan et al. in 1991 (Nitzan, et al., 1991). The landmarks for the insertion of needles are marked on the skin according to the method suggested by McCain et al. (McCain, et al., 1991 & 1996) for arthroscopy (posterolateral approach to the upper joint space). This technique uses two needles, one for injecting and the other for aspirating the solution (Tozoglu, et al, 2011).
A line is drawn on the skin joining the medial portion of the tragus of the ear to the outer canthus of the ipsilateral eye, at this point “the Holmlund–Hellsing line (canthotragal line)” is taken as indicator (Guarda-Nardini, et al. 2008). Two points are marked on this line, one at a distance of 10 mm from the tragus and 2 mm inferior to canthotragal line, which corresponds to the posterior extent of the glenoid fossa. The second at 20 mm anterior to tragus and 10 mm inferior to canthotragal line, which corresponds to the height of articular eminence (Neeli, et al., 2010, Guarda-Nardini, et al. 2012, Reddy, et al. 2013).
First needle insertion: The patient is asked to open the mouth and deviate it to the opposite side for distracting the condyle from the glenoid fossa, in order to increase the joint space. Nagori et al suggested that a custom-made mouth prop as an effective tool to hold the mandible in eccentric position during arthrocentesis (Nagori, et al., 2017). The first needle is inserted into the superior joint space in the most posterior point directing upward, forward, and inward to a depth of about 20–25 mm, after the tip of the needle has come into contact with the posterior wall of the articular eminence, with the patient's mouth open (Tvrdy, et al., 2015). At this point, the surgeon must be cautious not to insert the needle more than 25 mm depth into the joint space (Nitzan, et al., 2006).
The glenoid fossa is thin, between 0.5–1.5 mm. and the dura and temporal lobe are located beneath the glenoid fossa. It is possible that during the procedure, this structure can get perforated, and joints can be eroded by degenerative arthritis or previous infections (McCain 1996). Irrigating solution of approximately 5 mL of fluid “Hartmann” or “Ringer's lactate” solution or physiological saline is administered through the first needle with the aim of distending the superior joint space (Grossmann, et al., 2012). This is followed by administration of irrigating solution (Hartmann solution = Ringer's lactate solution or physiological saline) through the first needle with the aim of distending the superior joint space (Grossmann, et al., 2012). This compartment will take up to 5 mL of fluid (Guarda-Nardini, et al., 2008).
Second needle insertion: The second needle is introduced in front of the first needle at the marked point, allowing the visualization of the solution and orienting the flow of the joint lavage solution (Grossmann 2012). Some modifications were proposed by researchers, such as, Laskin (Laskin, 1998) proposed insertion in the posterior recess of the upper joint compartment by placing it 3–4 mm anterior to the first one. Alkan and Etöz (Alkan & Etöz, 2010) proposed second needle was adjusted parallel and almost 3 mm posterior to the first until bony contact was made 7 mm anterior from the middle of the tragus and 2 mm inferior along the canthotragal line. They assumed that when the second needle is inserted posterior to the first one in the wider part of the upper joint compartment, the outflow of the solution from the joint cavity is easier to achieve.
The positioning of two needles within the joint cavity may cause some discomfort to patients, especially at the first lavage. It was reported that the patient's perception of tolerability increases with time with the sequential arthrocentesis interventions. The catabolites are removed and adhesions are broken down at the first injections, which can be the possible explanation that makes
the insertion of the needles easier and consequently, the quality of the posttreatment course can be improved (Soni, 2019).
The single-needle technique (SPA)
The single-needle approach for the lavage of TMJ is based on the rationale that pumping saline injection into the superior joint compartment with the patient in an open mouth position provides enough pressure to release joint adherences and to allow fluid outflow when the patient closes his/her mouth (Guarda-Nardini, et al., 2012). The injection-ejection process must be performed for up to 10 repetitions for a total amount of about 40 ml. The single-needle technique indicated in the case of hypomobile joints with strong adherences or joints with degenerative changes that make the insertion of the second needle difficult (Guarda-Nardini, et al., 2008). The single-needle technique provides the underpressure fluid injection to expand the joint cavity (Guarda-Nardini, et al., 2008) and to break joint adherences that are responsible for the reduced translatory movement of the condyle (Nitzan & Etsion 2002, Guarda Nardini, et al., 2012, Soni, 2019).
Advantages of this technique can be listed as follows: i) It is a simple, easier, and less invasive technique, ii) the positioning of a second needle could interfere with the stability of the first one, so the single-needle technique provides more reliable and stable access to the joint cavity, iii) postoperative pain and discomfort to the patient is less, iv) lesser amount of local anesthetic is needed, which may further reduce the risks of postoperative facial nerve paresthesia, v) an anteriorly positioned second needle may cause trauma to the facial nerve, that lies anteriorly and medially to the glenoid fossa, which is the site where the second needle is usually inserted; single needle approach reduces the chances of such injuries, vi) total time for the procedure is reduced, vii) the risk of hyaluronic acid flowing out through the second point of injection is absent, which might allow full retention of the injected hyaluronic acid within the joint compartment (Guarda- Nardini, , et al., 2008).
Limitations can be listed as follows: i) the total circulating volume of the irrigating solution is lower, so it is hardly able to eliminate algogenic substances present in the synovial fluid of the upper TMJ compartment, responsible for pain and bone and fibrocartilaginous changes, ii) only a part will return through the needle, regardless of patients closing their mouth. Part of the fluid may leak from the upper compartment toward the face, producing local edema which may generate intra- and post- operative pain (Guarda-Nardini, et al., 2008).
The efficacy of the double- and single- needle arthrocentesis techniques were compared in several studies reported that the single-needle technique may be a good alternative with the advantages of easier application in cases where it is not possible to perform the double-needle technique (Soni, 2019, Sindel et al., 2017). Şentürk et al. found that arthrocentesis of the TMJ was successful with both techniques (Şentürk et al, 2016).
Double needles in a single cannula
Double needles in a single cannula with two adjacent irrigation and aspiration tubes that allow sufficient irrigation and lavage of the joint with the same device under the desired pressure was tested by Alkan and Bas (Alkan & Bas, 2007) and was reported as a safe procedure. However, the major limitation of this technique is when there are major degenerative changes with decreased joint space and presence of osteophytes; it can be more difficult to enter this instrument into the joint space.
Shepard's single cannula
A similar device was proposed by Rehman and Hall (Rehman & Hall 2009) “Shepard cannula”
that holds two needles together. However, the device is relatively thick, and has the potential to damage the nerve. By repetitive use the tip of the needles become blunt and increase the risk of infection.
Arthrocentesis technique with automatic irrigation under high pressure
Alkan and Kilic (Alkan & Kilic 2009) described a modification of the two needle technique, in which an irrigation pump from a surgical and dental implant motor was connected to the second needle, and automatic irrigation was performed to irrigate the upper joint space in 2 min with saline solution of 300 ml under high pressure. However, there are some possible complications may develop in the surrounding tissues as a result of the high pressure, in cases when the irrigation pump is connected to the first needle without manual confirmation with the second needle. In addition, if the outlet needle suddenly blocks during the procedure, the irrigation must be stopped immediately(Soni, 2019).
Concentric needles unit
Öreroğlu et al.( Öreroğlu et al., 2011) use a concentric-needle cannula system, i.e., using 2 different gauge needles placed in a concentric manner for SPA in TMJ and reported it to be the least traumatic and perhaps the most feasible and cost-effective method for TMJ lavage.
G.8. Post-arthrocentesis injections and considerations
After arthrocentesis lavage, steroids or sodium hyaluronate injection might be administered into the joint space to alleviate intracapsular inflammation (Ohnishi, 1990). The anti-inflammatory effects of intra-articular corticosteroids might be useful for decreasing pain, swelling, and dysfunction in patients with inflammatory and noninflammatory joint diseases (Wenneberg, et al., 1991). Methylprednisolone and triamcinolone (40 mg/1 ml) preparations are the most commonly used corticosteroids which have long-acting period (Laskin, et al. 2006).
Hyaluronic acid (HA) is a natural glycosaminoglycan produced by synovial cells that is naturally present in the synovial fluid (Nitzan, 2001a). HA is considered an essential component of synovial fluid, participating in joint lubrication, and the degradation of HA is usually observed in cases of TMJ degeneration (Nitzan, 2001a-2001b). HA is a viscous, high- molecular-weight material, which plays a substantial role in joint lubrication and cartilage protection in TMJ internal derangements (Alpaslan & Alpaslan, 2001). HA lowers levels of inflammatory mediators, thus helping to relieve joint pain (Tuncel, 2012). Researchers have advocated the use HA injection with or without arthrocentesis and reported pain relief and great improvement in subjective symptoms and jaw function (Korkmaz, et al., 2016). Intra-articular HA injections into the TMJ have been used for the treatment of TMJ-OA and internal derangement for many years, showing positive results regarding mouth opening and a decrease in pain intensity (Escoda-Francoli, et al., 2010, Gencer, et al., 2014, Korkmaz, et al., 2016). Repeated intra-articular HA injections are commonly used to treat orthopedic disease, a procedure called viscosupplementation, which is believed to supplement the viscosity of the synovial fluid, thereby lubricating and cushioning the joint (Basterzi, et al., 2009, Wen, 2000). Despite the extensive literature on the subject, the exact mechanism of action of HA remains unclear, although it is thought that the positive effects are the result of the increase in viscosity of the synovial fluid, restoration of nutrition, and reduction of inflammatory mediators (Manfredini, et al., 2010, Escoda-Francoli, et al., 2010).
PRP is obtained through the withdrawal of patient’s blood and centrifugation to acquire a high concentration of platelets, which in some cases can exceed 2,000,000/ml (Eppley et al., 2004, Bousnaki, et al., 2018). PRP concentrate has shown great potential as a therapeutic modality due to the abundance of growth factors that it contains (Marx, 2004, Bousnaki, et al., 2018). Despite the fact that the exact mechanism of action of PRP remains unknown, it has become popular in sports medicine and orthopaedics, and has emerged as a prom- ising treatment for degenerative cartilage defects and osteoarthritis (Kon et al., 2010, Bousnaki, et al., 2018). This is mainly attribut- ed to its anti-inflammatory and analgesic properties, as well as the positive out- comes obtained in clinical studies when it has been administered intra-articularly into joints with a cartilage pathology, such as knee osteoarthritis (Fortier, et al., 2011, Vaquerizo et al., 2013). Furthermore, PRP is easily obtained and prepared, and is asso- ciated with few postoperative complica- tions (Zhu et al., 2013). Recently, PRP injections have been ap- plied intra-articularly into the TMJ in patients with TMJ osteoarthritis and disc displacement. Despite the extensive literature on the application of PRP in other joints, especially the knee, its application as a treatment in the TMJ is relatively new (Bousnaki, et al., 2018).
Tenoxicam is a thienothrazine NSAID derivative of the oxicam group which displays good efficacy and tolerability in therapy for rheumatic disorders (Kirchheimer, et al., 1982). It is soluble in water and is suitable for intra- articular injections. The results of previous studies indicate that tenoxicam injected intra-articularly can provide beneficial effects without side effects of local intolerance even in knees with osteoarthritis (Papathanassiou, 1994; Cook, et al., 1997). It was stated that intra- articular application of tenoxicam provides superior post- operative analgesia and reduces
