Management of severe sleep apnea secondary to juvenile arthritis with temporomandibular joint replacement and mandibular advancement.

Variations affecting the growth centers can severely affect the normal formation and subsequent function of vital musculoskeletal structures. We report a case of bilateral condylar atrophy with a history of juvenile arthritis (JA) resulting in progressive obstructive sleep apnea (OSA) in adulthood. In addition to this, the case report emphasizes the role of temporomandibular joint replacement and advancement of the mandible to correct progressive OSA secondary to idiopathic JA. Computed tomography revealed micrognathia, condylar hypoplasia, and decreased pharyngeal airway space. The resultant increase in the retrolingual-pharyngeal airway space following the surgery, helped to completely resolve the presenting symptoms. It is hoped that the described technique could be used in similar cases with a predictable outcome.

Juvenile arthritis (JA) with sleep apnea in the adult group is a rarely reported phenomenon. Obstructive sleep apnea syndrome (OSAS) is a sleep disorder characterized by abnormal pauses in breathing (apnea) or instances of abnormally low breathing (hypopnea) during sleep, resulting in excessive daytime somnolence and lethargy on a short term basis.[1] On a long term, OSAS is associated with diabetes mellitus, hypertension, coronary artery disease, and cerebrovascular accidents.[2] The severity of sleep apnea is assessed using clinical questionnaires (e.g. Epworth sleepiness scale), radiographic analysis (e.g. Cephalogram) and polysomnography.[3] In this modern era, there are several methods employed for treating obstructive sleep apnea (OSA). The cause of sleep apnea determines the treatment method. OSAS can occur as a consequence of mandibular deformity and temporomandibular joint (TMJ) destruction occurring in JA.[4] JA is an autoimmune disease which is not fully understood till date. Rheumatoid factor is usually negative in this condition and this leads to the appellation “idiopathic JA”. The notable clinical feature is persistent swelling of the affected joints, which commonly include the knee, ankle, wrist and small joints of the hands and feet. Swellings may be difficult to detect clinically, especially for joints such as those of the spine, sacroiliac joints, shoulder, hip, and jaw, where imaging techniques such as bone scan, ultrasound, and magnetic resonance imaging are very useful.[5] Our case report emphasizes one of such rare findings where bilateral condylar agenesis in a patient with JA resulted in progressive OSA in adulthood.

Case Report

A 29-year-old male reported to the Department of Dental Surgery, CMCH, Vellore, Tamil Nadu, India, with an inability to sleep for the since the past 1-year with a reduced mouth opening from childhood. He also complained about his bird-like facial appearance. A detailed history revealed that he was diagnosed with JA and was managed with methotrexate for a year, before 5 years. He had also been diagnosed with severe sleep apnea syndrome and had an Epworth sleepiness scale of 24/24. On examination, he was found to have a retrognathic mandible, proclined anteriors, decreased chin-neck angle (Andy Gump deformity), hypotonic/hypoplastic lower facial musculature, increased overjet and overbite, deranged occlusion with retruded chin, and a mouth opening of 16 mm [Figures 1 and 2]. Polysomnography was done to assess the degree of sleep apnea and a bone isotope scan was needed to evaluate residual TMJ arthritis. A computed tomography (CT) scan showed the extent of mandibular deformity which was resulting in the mechanical obstruction to breathing [Figure 3]. Bone isotope scan revealed the absence of arthritis in the TMJ and the rest of the skeleton, based on tracer uptake.

Figure 1

Preoperative view of straight and lateral profile

Figure 2

Preoperative mouth opening

Figure 3

Preoperative sagittal view of computed tomography scan

A three-dimensional CT revealed the absence of both the condyles. Condylar atrophy secondary to JA had resulted in a decrease in the mandibular ramal height as well as the length of the body [Figure 4]. On the basis of the presentation, a dual stage surgery was planned wherein a pair of titanium condylar analogues would be used to replace the missing condyles followed by a mandibular advancement at a later period. The Stage I (Condylar analogue) surgery was expected to improve the mouth opening as well as provide a posterior stop to the ramus (proximal segment) while advancing the distal segment of the mandible anteriorly in the second stage. Before surgical intervention, appropriate clearance was obtained from rheumatology, pulmonary medicine, and preanesthetic clinic.

Figure 4

Preoperative three-dimensional view of right and left ramus of the mandible

Treatment Phase 1

A pair of titanium condylar analogue was used to reconstruct bilateral TMJ [Figure 5]. Following the surgery, the mouth opening improved from 16 mm to 35 mm. Postoperatively, a splint was fabricated to guide the mandible into the established occlusion. The patient reported a better sleep rhythm and had a fairly uninterrupted sleep. This was corroborated by his parents who observed improvement in his sleep pattern. After 4 weeks, Epworth sleepiness scale showed marginal improvement from 24/24 to 16/24, but was not satisfactory as the polysomnography revealed an apnea-hypopnea index (AHI) of 47.8/h, with a desaturation index (DSI) of 50.7/h indicating persistence of severe sleep apnea status.

Figure 5

Postoperative lateral cephalometric view of Stage 1 surgery

Treatment Phase 2

In this phase, the body of the mandible was advanced by 10 mm. The body osteotomy was performed anterior to the mental foramen and fixed using titanium reconstruction plate with inter-positioning iliac graft bilaterally [Figure 6]. Postoperatively the patient was very comfortable with his sleep pattern and very much satisfied with his facial appearance because he was no longer a “chinless wonder” [Figure 7].

Figure 6

Postoperative lateral cephalometric view of Stage 2 surgery

Figure 7

Postoperative view of Straight and lateral profile

The postoperative Cephalogram confirmed the skeletal changes which were evident clinically. There was also an increase in the retrolingual-pharyngeal space (between the back of the tongue and posterior pharyngeal wall) from 2.7 mm to 10.2 mm, which is an index of the level of respiratory obstruction. Orthopantomogram showed intact plates and screws and condyles in position [Figure 8]. Epworth sleepiness scale had declined to normal limits and was 2/24. A polysomnography revealed marked improvement with an AHI of 7/h and DSI of 6/h, indicating only mild OSAS. A prosthodontic rehabilitation was done after 6 weeks. He had no complaints of sleep disturbance henceforth.

Figure 8

Postoperative orthopantomographic view

Discussion

Obstructive sleep apnea is a growing public health concern because it can cause hypertension, cardiac arrhythmias, stroke, and in rare circumstances, sudden death if untreated. Although nasal continuous positive airway pressure therapy is considered the first-line treatment of OSA, surgery has been shown to be a valid option for patients who are intolerant to positive pressure therapy.[6] Several surgical approaches have been recommended for the treatment of OSA.[7] Orthognathic surgery for repositioning the mandible and the genial tubercles for forward positioning of genioglossus has been recommended as a successful method of increasing the post glottic space and reducing the respiratory obstruction during sleep.[8] Other nonsurgical methods have included weight loss and mandibular repositioning devices.[9]

The use of orthognathic surgery to treat OSAS began toward the end of the 1970s when mandibular surgery was reported to have reversed the symptoms of sleep apnea.[10] Advancement of the mandible and maxilla increase the available tongue space and have a positive influence on the pharyngeal airway.[11] Kawamato seems to have pioneered the maxillomandibular advancement technique for treating OSAS.[12] Maxillomandibular advancement decreases the collapsibility of the velopharyngeal and suprahyoid musculature and improves lateral pharyngeal wall collapse, all of which have been shown to be significant components contributing to the upper airway obstruction in OSA.[13] The outcome of maxillomandibular advancement has been extensively reported, with success rates of 57% to 100%.[13]

The cephalometric radiograph, although rarely used by other specialties, is very valuable because it demonstrates both bony and soft tissue abnormalities related to the soft palate, pharyngeal airway, and maxillomandibular complex. If the radiographic and clinical examinations of the soft tissues of the pharynx reveal a narrow airway in conjunction with retrognathia of the maxilla and mandible, the patient should be considered a candidate for MMA surgery. Because an underlying skeletal abnormality is sometimes hard to detect clinically, it is reasonable for an oral and maxillofacial surgeon to assess these patients. The surgeon's goal is to optimize the advancement of the deficient structures while maintaining a normal facial balance for each patient. It is, therefore, beneficial to use a cephalometric analysis, which will clearly demonstrate all the maxillofacial abnormalities and provide a visual treatment objective.[11] Cephalometric analysis provides a reliable method of evaluating the changes in the tongue base before and after surgery. It is estimated that for each millimeter of maxillary and mandibular bone advancement there was a 0.76 mm increase in the retropalatal region and a 1.2 mm increase in the pharynx in the retrolingual region, respectively.[14] Bilateral TM joint reconstruction has been recommended for the replacement of the joint for the restoration of function and also for elongation of the shortened mandible in joint destructive diseases like Juvenile rheumatoid arthritis. The use of custom made two part total joint reconstruction of the cranial articular surface as well as the condylar head has been advocated.[15]

In this case, condylar analogue prosthesis was fixed to the residual stump of the vertical mandibular ramus. Consequently, the length of the vertical ramus could be increased by 6 mm, which could be maintained by a splint and intermaxillary traction. The mandible with the new condyles was made to function after a period of 1-month of traction. The patient was able to open his mouth more than before and the full range of mandibular movements was possible, proving that the condylar prostheses were functioning well.

Further increase in length of the mandible could be achieved (10 mm) through the second procedure for a single stage mandibular advancement with bone grafting and rigid plating. The forward repositioning of the chin enabled the posterior pharyngeal space to be enlarged in the anteroposterior direction by 7.5 mm, as measured cephalometrically. This resulted not only in a cosmetically pleasing facial appearance but a significant relief from the OSA. Review of the patient over a period of 10 months has shown that the mandibular advancement procedure had a stable outcome. Through the management of the described case it's our observation that OSA secondary to JA could be effectively managed with condylar replacement and mandibular advancement to produce a predictable outcome. However, early identification, diagnosis, and treatment planning could alleviate the agony manifested by these conditions.

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Conflicts of interest

There are no conflicts of interest.