Juvenile idiopathic arthritis.

Juvenile Idiopathic Arthritis (JIA) is the most chronic musculoskeletal disease of pediatric population. The chronic course of disease has a great impact on oral health. Temporomandibular joint is involved in JIA causing limited mouth opening with progressive open bite, retrognathia, microgenia and bird like appearance. Joints of upper and lower extremities are also involved. Effect on upper limb function leads to difficulty with fine motor movements required for brushing and flossing. This increases incidence of caries and periodontal disease in children. The cause of JIA is still poorly understood and none of the available drugs for JIA can cure the disease. However, prognosis has improved as a result of progress in disease classification and management. The dental practitioner should be familiar with the symptoms and oral manifestations of JIA to help manage as multidisciplinary management is essential.

Introduction

Juvenile Idiopathic Arthritis (JIA) is the most common chronic rheumatic diseases in the pediatric population. Worldwide prevalence of JIA varies between 16 and 150 per 100,000;[1] frequency of different subtypes vary with location and ethnicity. Prevalence in India is assumed to be around 1.25 per 1000 children.[2]

It is divided into seven categories by International League of Association for Arthritis[3] as Systemic, Oligoarthritis, Polyarthritis (RF positive), Polyarthritis (RF negative), Psoriatic, Enthesitis-related and Idiopathic. Morbidity results in temporomandibular joint damage and craniofacial growth disturbance. All children with JIA require a multi-disciplinary approach along with regular Orthodontic evaluation.

Case Report

A 14-year-old girl reported to Department of Oral Medicine and Radiology for management of multiple carious teeth and temporomandibular joint evaluation.

Patient had a history of abnormal gait. This subsequently led to inability to maintain posture. Patient presented with fixed plantar flexion deformities and limited dorsiflexion of both ankles. Examination of joints revealed no swelling, pain and erythema. Patient had micrognathia and presents with posterior or downwards mandibular rotation, a steep mandibular plane and mandibular retrognathia. Examination of temporomandibular joints revealed limited excursion and protrusion of jaw, with absence of translation of joint and microgenia. This gave patient a ‘Bird face’ appearance. Teeth bearing area of the mandible had undergone minimal growth. Temporomandibular joint involvement resulted in restricted mouth opening thereby impeding plaque removal. Patient had multiple carious teeth and poor periodontal condition. A provisional diagnosis of condylar hypoplasia associated with any syndrome was made and patient was referred for investigations.

Panoramic radiograph illustrated that condylar head is flattened. Ramus appears short along with deepened antegonial notch bilaterally [Figure 1a].

Figure 1

(a) Panoramic image illustrating bilateral condylar resorption and flattening. Attenuated antegonial notching seen bilaterally. (b-c) Trascranial radiographs of right and left temporomandibular region showing elongation of condylar surface. Articulating surface of the temporal component appears to be flattened

Trascranial radiographs of right and left temporomandibular region showed apparent elongation of condylar surface. Articulating surface of the temporal component appears to be flattened [Figure 1b, c].

Radiographs of hands and feet showed severe osteopenia, with fixed flexion deformities at distal phalanges. Radiographs of elbow and hip joint revealed severe osteopenia and joint space appeared to be obliterated [Figure 2a–d].

Figure 2

(a-d) Radiographs of hands and feet showing osteopenia, with fixed flexion deformities at intermediate and distal phalanges. Radiographs of elbow and hip joint revealed joint space appears obliterated. (e) Chest radiograph showing parenchymal abnormality. Spine appeared deviated suggestive of scoliosis

Provisional radiographic diagnosis was juvenile arthritis.

Chest radiograph showed basilar reticulonodular infiltration indicating parenchyma abnormality indicative of Interstitial Lung Disease. Spine appeared deviated suggestive of scoliosis [Figure 2e].

Dexamethasone (DXA) Bone Densitometry Scan which reveals Bone Mass Density (BMD) score is less in comparison to reference data of same age and gender [Figure 3a–c].

Figure 3

(a-c) Dexamethasone Bone Densitometry Scan shows Bone Mass Density is less

Rheumatoid Factor (RF) was positive. Anti-Nuclear Antibody test was positive with titer of 1:320. ESR at this time was 12.3 mm at end/hour.

A final diagnosis of polyarticular JIA was made and classified as polyarticular RA positive according to International League of Associations for Rheumatology classification based on inclusion criteria of onset at late childhood or adolescence; more than five joints were involved and serological tests showing IgM as RF-positive.

Patient was treated in pediatric ward with Tab Naproxen 250 mg, Tab Shelcal, Tab Osteoplus 35 mg. Patient is at present scheduled for Methotrexate 10 mL/m2 weekly. An early treatment with a functional splint appliance, a distraction splint, with the purpose of increasing function of the joint and ensuring continuous growth of the mandible should ideally be suggested, but due to low bone mass density, as well as considering the age of the patient any pre-surgical orthodontics and orthognathic surgery was to be considered only after completion of growth spurt.

Discussion

Systemic effect of chronic disease also has a great impact on oral health. Juvenile idiopathic arthritis (JIA), a broad term that describes a clinically heterogeneous group of arthritides of unknown cause. The age at onset of JIA is under 16 years of age. Females are much more frequently affected with almost all types of JIA than males.[4] The term JIA has replaced previous terms such as juvenile chronic arthritis or juvenile rheumatoid arthritis. Temporomandibular arthritis in children with chronic arthritis was first reported by Still in initial case series in 18975.[5] Temporomandibular joint involvement in JIA ranges from 17 to 87%.[6] Manifestations include limited mouth opening with progressive open bite, retrognathia, microgenia and bird-like appearance. This worst form of expression of JIA is seen in the present case.

Effect on upper limb function leads to difficulty with fine motor movements required for brushing and flossing. Mean DMFT (decayed, filled, missing teeth) index scores in patients with JIA was almost twice that of normal population.[7] As seen in presented case, patient has multiple carious teeth and significant dental morbidity.

Reported prevalence of radiographic changes in temporomandibular joint varies between 17% and 63%;[8] about 45%[9] cases can be diagnosed from changes in panoramic radiograph. Radiographic changes manifest in children with severe refractory disease or those who received rheumatology care late in course of disease. Anti-Nuclear Antibody positive, early onset of disease, presence of polyarticular involvement are risk factors for temporomandibular joint arthritis.

As seen in case of 14-year-old, who failed to receive early intervention presented with radiographic features including shortening of mandibular body and ramus, flattening of condyle and increased antegonial notching. Lateral Cephalogram can also be representative showing anterior open bite and lip incompetence. Temporomandibular joint involvement may be subclinical, identified with Ultrasound and Magnetic Resonance Imaging (MRI).

Commonly used drugs for treatment are NSAIDs like Ibuprofen, Naproxen, Paracetamol and Disease modifying Anti Rheumatic Drugs (DMARDs) like Methotrexate, Sulphasalazine, Cyclosporine to control pain, stiffness, swelling, minimize functional disability and prevent joint damage. Etanercept is effective for patients who have polyarticular disease and resistant or intolerant to Methotrexate. Another cause of dental morbidity leading to dental caries and periodontal disease is prolonged administration of drugs. In order to increase the palatability and acceptability by young children these drugs are administered in elixir forms which are sugar based. Cyclosporine can often result in gingival hyperplasia.

The present case has interstitial lung disease, neck and cervical spine instability and osteoporosis. It becomes essential to assess workup prior administrating sedation and general anesthesia for orthognathic surgeries and minor surgical procedures. Jaw surgery is not advocated until systemic aspects have been fully controlled. There is high potential for skeletal relapse.

Conclusion

It is important to identify children who are at risk and propose interventional strategies that are effective. The purpose of presenting this case is to alarm dental personnel about significant dental morbidity, which is preventable on timely intrusion. Close supervision is required to guard against dental caries. They frequently require orthodontic intervention and selected cases eventually benefit from orthognathic surgery.