This case report describes a 25-year-old female patient presenting to the Department of Orthodontics at the Centre of Dentistry, Oral and Maxillofacial Surgery at the University Hospital Tuebingen due to acute pain in the right TMJ and mouth opening disorders in 2019. There were no general diseases or allergies in her medical history. The patient stated that she did not consume alcohol or nicotine; she was taking contraceptives. Over a period of 5 years the patient’s distal bite was treated with removable and fixed orthodontic appliances. The initial examination showed fixed retainers in both the upper and lower jaws (Fig. 1a + b). Despite orthodontic treatment, there was still a slight asymmetric distal occlusion on both sides (Fig. 1c + d). This was slightly more pronounced on the left due to slight mandibular tilt to the left (Fig. 1e). The mouth opening disorder severely restricted the patient in her everyday life. Previously, craniomandibular dysfunction was assumed due to multiple grinding facets on the teeth and bruxism. Therefore, a bruxism splint was already worn at night.
Figure 2 showing a panoramic radiograph of the patient showing symmetric but flattened condyles with a slightly widened TMJ gap on both sides.
Three months later, the patient reported that she woke up with severe pain in her right TMJ after sleeping and was not able to close her mouth. When repositioning the lower jaw by herself a very loud cracking sound at the right TMJ occured. After that, she had a mouth opening disorder and constant pain. The patient gave this constant pain a score of 7 on the verbal numeric rating scale (VNRS) (0–10). She was prescribed muscle relaxant therapy with Methocarbamol twice a day. Although the pharmaceutical treatment with Methocarbanol resulted in some slight pain relief, it also had some general medical side effects such as circulatory weakness and dizziness. The patient was also referred to the Department of Orthodontics. Due to severe pain a functional analysis of the TMJ was not possible. The mouth opening was limited to 20 mm active and 30 mm passive causing extreme pain. Thus, a muscle spasm was suspected. A dental splint combined with intensive physiotherapy and mouth-opening exercises continued to be recommended as therapy. Mouth-opening exercises and physiotherapy led to a clear deterioration of the condition.
Three months after the first symptoms, the patient showed an acute deterioration of her health status. The main symptom was ever-increasing pain in the right TMJ, which worsened throughout the day. She rated the pain 8 on the VNRS. She also showed an increasing active mouth opening restriction to 20 mm and a habitual deviation of the lower jaw to the left (Fig. 3).
The functional and occlusal analysis of the stomatognathic system showed strong dorsal load vectors of the TMJ on the right side. The ventral and caudal traction of the joint was consistently associated with severe pain on the right. Lateral movements of the lower jaw were restricted and painful. Protrusion movement was not possible. There was neither crepitus nor cracking of either TMJ. The patient had a persistent pain-relieving abduction and outward rotation of the left lower mandible (Bonnet position) (Fig. 3b). The suspected diagnosis at this time was a total ventral deviation of the discus on the right side without reduction and with active mouth opening that was painfully blocked. There was a static contact of the first premolars with the second molars on both sides. The dynamic occlusion had canine guidance on the right side and guidance over the first premolar on the left. The bite position showed an Angle Class II left 3/4 premolar width (PW) right and ¼ PW left with an overjet of 4 mm and an overbite of 2 mm. Further radiological diagnosis was performed using a MRI scan (Fig. 4–6).
The radiology findings showed a discrete erosion of the right mandibular condyle and a bone marrow oedema of the right mandible with increased contrast uptake as well as minor joint effusion in the right temporomandibular joint. Furthermore, an anterior dislocation of the right articular disc with suspicion of a tear in the ligament with closed and open mouth was identified. In the dynamic sequences, there was slightly restricted translational forward movement with mouth opening on the right side. The position of the left TMJ with open and closed mouth was unremarkable. Thus, the findings of the MRT confirmed osteoarthritic changes of the mandibular condyle and joint effusion on the right side corresponding with constant pain. The treatment goals were to prevent the progression of structural damage to the right temporomandibular joint, to improve the mouth opening and to reduce the lateral deviation. Therefore, the patient was prescribed NSAID (Ibuprofen 400 mg) 3x/d to reduce the pain, a bite splint in the lower jaw for 24 hours per day, soft diet and regular adjustment of the splint approximately every 2 weeks.
Despite these therapies the patient complained of increasing pain in the right TMJ and a worsening of her general condition. The patient would then stop the splint therapy at her own discretion. She was also referred to the Department of Oral and Maxillofacial Surgery of the University Hospital Tübingen. The pharmaceutical treatment with NSAID 3x/d was changed to Diclofenac 50 mg 2x/day. The new medication did not achieve pain relief and, unfortunately, the patient suffered an allergic reaction to Diclofenac and resulting in an exanthema, swelling of the oral mucosa and nausea.
For further diagnostic investigation, a cone beam computed tomography (CBCT) was performed and showed bone erosion of the right condyle of the TMJ. The image revealed an arthropathic condylar destruction on the right seen as a pointed structure; the cortex is only partly visible. The left mandibular condyle did not show pathologic findings.
Based on the radiological findings a mandibulo-maxillary fixation (MMF) with elastic loops was applied to stabilize the occlusion. The patient was instructed to follow a liquid diet and intensive physiotherapy was prescribed. However, her condition failed to improve. The MMF was then removed and the jaws were fixed using wire ligatures. This fixation and immobilization of the mandible led to a remarkable improvement for the first time in the period of treatment. For further clinical diagnostics the patient was referred to the Department of Rheumatology of the University Hospital Tuebingen. The rheumatoid serology did not yield any findings indicating a rheumatological disorder. The laboratory examination showed a slightly increased CRP-value of 0.60 mg/L The HLA-B27 examination was negative. The patient's serologic analysis showed a low estrogen level and thus, the contraceptives were discontinued. Further therapy was discussed by an interdisciplinary board (Rheumatology, CMF-Surgeons and Orthodontics) that proceeded to recommend lavage or cortisone injection into the affected TMJ. A cortisone injection in the right TMJ was performed shortly after the interdisciplinary discussion (Fig. 10). After cortisone injection, the patient showed a significant improvement generally and the active mouth opening increased to up to 23 mm. However, pain at maximal mouth opening was still felt in the right TMJ.
Management recommendations continued to include a soft diet in order to relieve the TMJ, no forced mouth opening exercises, physiotherapy and an attempt without MMF. Three months later, a blood test revealed a positive incidental serology finding for Bb IgG and IgM antibodies. Based on the serological finding, the diagnosis of Lyme arthritis affecting the right TMJ was confirmed. Cephalosporins (Cefuroxime 1,5 g 3x/d) i.v. for at least 3 weeks was the immediate treatment of choice. Interestingly, the patient could not recall any tick bite. After one week of antibiotic therapy, the patient stated a clear improvement of her condition. A further functional examination of the temporomandibular joints after antibiotic therapy revealed a not reproducible, persistent cracking sound on the right side during active mouth opening.
A CBCT scan obtained three months after the antibiotic therapy confirmed a pronounced improvement of the situation (Fig. 11). The image of the right temporomandibular joint showed an almost continuous cortex with only a few residual lesions. Thus, the condyle had significantly improved compared to the previous CBCT scan seven months earlier. The functional and occlusal analysis showed that the lateral restraint no longer existed. However, the static contact and the dynamic occlusion on both sides was unchanged compared to the situation seven months ago. Furthermore, the bite position displayed an Angle Class II left 1/4 PW right and ¾ PW left with an overjet of 4 mm and an overbite of 2 mm. The patient still reported a cracking sound during mouth opening on the right side only but this was not reproducible during the clinical examination.