Case presentation
An 8-year-9-month-old male patient of normal intelligence with SJS was referred to the Department of Orthodontics, Faculty of Dentistry, Mahidol University, Thailand. He is the only child of a healthy nonconsanguineous Thai couple. His birthweight was 3.070 kg with unremarkable prenatal history. Generalized muscle stiffness and abnormal gait have been observed since his first year. The diagnosis based on SJS’s cardinal signs, was made at 3 years of age. His medical history includes hypothyroidism, repeated hospitalization due to severe allergy and respiratory distress, and severe OSA. He regularly receives carbamazepine to relieve his muscle contraction, and levothyroxine for hypothyroidism. Parents noticed occasional snoring at 6 months old and became worsened with increasing age. Other nocturnal symptoms included enuresis, choking, and gasping for air. Daytime symptoms include frequent morning drowsiness and headache, nausea, hypersomnolence, as well as poor concentration. He was referred to a sleep physician for a diagnostic polysomnography at the age of seven. The diagnosis for severe OSA was confirmed with an apnea-hypopnea index of 29 events/hour. The continuous positive airway pressure (CPAP) was prescribed instead of adenotonsillectomy to avoid a potential risk of malignant hyperthermia during a general anesthesia.
On physical examination, the patient had a proportionate short stature with his weight in the tenth percentile. He presented with multiple skeletal deformities, and generalized muscle stiffness. Extra-oral examination revealed a distinctive mask-like facie, blepharophimosis, low-set ears, microstomia and pursed lip, limited mouth opening (25 mm), asymmetrical oval facial form, convex facial profile and bimaxillary retrognathia (Fig. 1). On oral examination, the patient was in mixed dentition with very severe dental crowding especially in the upper arch. The amount of dental crowding was measured at 12 and 6 mm for the upper and lower arch respectively. There was untreated active caries noted. The maxillary arch was severely constricted with a very high-vaulted palate. The upper intermolar width was significantly reduced with a measurement of 36 mm. Bilateral posterior crossbite was observed (Fig. 1). Dental development was within normal range. Permanent mandibular lateral incisors were clinically missing. Enlarged palatine tonsils were present in the retropharyngeal area. Radiographic examination confirmed congenital hypodontia of the lower laterals and supernumerary mandibular teeth at the premolar region bilaterally (Fig. 2). Cephalometric analysis demonstrated that the patient had Type I skeleton relationship with retrognathic maxilla and mandible. The mandible rotated posteriorly while the maxilla exhibited counter-clockwise rotation. This creates a hyperdivergent pattern of the jaw bones. Both upper and lower incisors are retroclined and retruded. Soft tissue measurements showed the upper and lower lip were in a retrusive position following the underlying skeletons. The detailed cephalometric characteristics of the patient is presented in Table 1.