Orthognathic Surgery in Patients With Congenital Myopathies and Congenital Muscular Dystrophies: Case Series and Review of Literature
CM and CMD are uncommon diseases with similar clinical manifestations. Patients with these conditions often manifest facial weakness and respiratory insufficiency, among other findings. Overlap of clinical features makes no single clinical finding diagnostic of the type of myopathy or dystrophy. Clinical signs usually present in the perinatal period, but can occur later in childhood or even adult life. Respiratory and facial weaknesses in these patients present unique surgical considerations and challenges in peri-operative management and anesthesia administration for orthognathic surgery. Surgical, peri-operative, and anesthetic considerations have previously been reported in only a few case reports.1,2
According to IRB-approved protocol, chart records from Mayo Clinic were reviewed for all orthognathic surgery patients with a clinical, genetic, or muscle biopsy-proven diagnosis of CM or CMD: all cases of CMD were confirmed as myotonic dystrophy. Descriptive data on patient demographics, general anesthesia administration, peri-operative care, and post-surgical follow-up were collected.
7 patients qualified for the study, and they were treated by 4 different surgeons in the Division of Oral and Maxillofacial Surgery at The Mayo Clinic between the years of 1992 and 2007. Patient population included 6 males and 1 female with an average age of 19.9 years at time of orthognathic surgery. 6 patients had Class III skeletal and dental diagnoses, and 1 patient had Class II skeletal and dental presentation. 5 patients had apertognathia with lip incompetence. All 7 patients underwent LeFort level osteotomies: 5 of these 7 also had mandibular setback surgery with or without mandibular inferior border osteotomies, while 1 of these 7 had only mandibular inferior border osteotomy. Average hospital length of stay was 19.14 days [3 – 75]. 5 patients required planned ICU care post-operatively, averaging 18.4 days in ICU [4 – 65]. Post-operative respiratory complications resulting in significant blood oxygen desaturations occurred in 4 patients; 2 of these patients required intubation during emergency code response. Average post-operative follow up interval was 27 weeks [6 – 128]. Nasoendotracheal intubation with a difficulty of 0/3 was performed in all cases. Routine induction and maintenance anesthetics and depolarizing and non-depolarizing muscle relaxants were administered without adverse outcomes. Prolonged post-operative ventilatory support was required in 5 cases.
Although CM and CMD are uncommon, these patients overwhelmingly have features such as Class III skeletal and dental malocclusions, apertognathia, and lip incompetence. These clinical features combined with a tendency for facial muscle weakness often resulted in difficulties with mastication; orthognathic surgery was indicated for functional benefit. LeFort level osteotomies and movements were required in all cases, many of which also required mandibular setback surgery due to the magnitude of the pre-operative discrepancy. Respiratory difficulties comprised the majority of post-operative complications, often requiring the rapid response team or prolonged ventilatory support.
Orthognathic surgery in patients with CM or CMD often requires maxillary surgery and mandibular setback; these procedures can be performed safely but usually require multi-disciplinary pre- and post-operative evaluation and care over lengthy hospital stays with risk of respiratory complications.
1 Kaufman J, Friedman J, Sadowski D, Harris J. Myotonic Dystrophy: Surgical and Anesthetic Considerations during Orthognathic Surgery. J Oral Maxillofac Surg41:667-671, 1983.
2 Hada L, Doron H, Tarazi E, Stheyer A, Casap N. Orthognathic Surgery in Primary Myopathies: Severe Case of Congenital Fiber Type Disproportion With Long-Term Follow-Up and Review of the Literature. J Oral Maxillofac Surg 2012 Jul;70(7):1636-42.