A Metabolic Stress Fracture of the Mandibular Condylar Head

C l i n M e d International Library Citation: Kalamchi S, Clifton TC (2015) A Metabolic Stress Fracture of the Mandibular Condylar Head. Trauma Cases Rev 1:002 Received: February 26, 2015: Accepted: April 30, 2015: Published: May 02, 2015 Copyright: © 2015 Kalamchi S. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Kalamchi and Clifton. Trauma Cases Rev 2015, 1:1 ISSN: 2469-5777


Introduction
Stress fractures of the human skeleton are categorized by (1) over-use injuries and (2) insufficiency fractures.Over-use fractures result from non-physiologic or repetitive forces on normal, healthy bone, and primarily effect the tibia, tarsals, and metatarsals [1].Insufficiency fractures are caused by physiologic forces on weakened bone such as in metabolic bone disease [2].They are most commonly reported in the pelvic girdle, proximal femur, and vertebral bodies of the lumbar spine [3].One group of patients at risk for insufficiency fractures are those taking anti-epileptic drugs (AED) since AED are known to induce metabolic bone disease by interfering with both vitamin D and parathyroid hormone metabolism reducing bone mineral density (BMD) [4][5][6].
The oral and maxillofacial surgery literature documents stress fractures at donor sites such as iliac crest and long bones following bone graft harvesting [7].However, the literature on metabolic bone disease in the maxillofacial region is mostly limited to radiography techniques used to identify osteoporosis [8].There are few reports of insufficiency fractures in the oral and maxillofacial literature.We found one case where reflex myocontraction of the temporalis muscles caused bilateral coronoid process fracture.Underlying metabolic bone disease in this case was not clear [9].We did not find any published reports of AED use underlying a maxillofacial fracture.

Abstract
Fractures of the mandibular condyle and neck are very common with well recognized anatomical features.This patient sustained an anatomically unusual right condylar head fracture with subluxation secondary to ictal myocontraction where there was no fall or facial trauma during or after the seizure.Investigation suggested an underlying disturbance in bone metabolism.We found one case report of mandibular stress fracture as a result of reflexive myo contraction of the temporalis and lateral pterygoid muscles in the literature.We conclude stress fractures resultant from ictal myo contractions are exceptionally rare without a covert disturbance in bone density.This report also applies to the recognition and treatment of patients at risk for bone fractures due to seizures: such as patients with osteomalacia, osteoporosis, chronic alcoholics, and elderly stroke victims.
The present case report is of an anatomically unusual insufficiency fracture of the right condylar head secondary to ictal myocontraction with evidence of underlying metabolic bone disease induced by an AED.

Case Report
A 64-year-old man presented to the emergency room with his wife complaining of pain in his jaw and difficulty closing his mouth following a seizure.The patient reported they were discussing dinner options when he suddenly yelled, contorted his face, and became noticeably tense for approximately 30 seconds.No tonic clonic activity was observed.His wife confirmed that he did not fall during or after the seizure, and he had no evidence of external trauma (Figure 1).
Prior to the seizure the patient had no signs or symptoms of abnormal jaw function or pain.Following the seizure the patient was unable to close his mouth, and reported to the hospital for evaluation.He reported never having had a previous seizure or facial trauma.The patient's medical history includes gastroesophageal reflux disease, hypertension, and cerebrovascular accident (CVA) five-anda-half months prior to hospital admission.At the time of the CVA the patient experienced a right frontal cerebral hemorrhage resulting in weakness and loss of coordination that resolved during two months of physical therapy.He began taking levetiracetam (Keppra ® ), which was discontinued along with the physical therapy and is possibly another potential etiological contributor to the seizure.Levetiracetam is also implicated in the patient's reduced BMD [4][5][6].
The patient's social history includes drinking at least 3-4 Vodka and tonics per day.Three days prior to the seizure episode the patient had discontinued drinking alcohol, which may also be a contributing factor in the seizure's etiology [10].
A C.T. scan revealed left condylar head subluxation and right condylar head fracture with medial displacement.The margins of the fracture were fresh according to the radiologist's report, which excludes the possibility of a pre-existing fracture (Figure 2a,2b).
The subluxated left condyle was reduced a day later under general anesthesia after the correction of a low serum potassium.The malocclusion was treated with upper and lower arch bars in maxilla mandibular fixation.Intermaxillary training elastics were used two-weeks postoperatively to stabilize the jaw until full mandibular function was achieved without pain (Figure 3).
He was diagnosed with Vitamin D deficiency and osteopenia with borderline osteoporosis.A metabolic bone disease pharmaceutical regimen was started by his physician.

Summary and Conclusion
Most seizure-related facial fractures are sustained when the face of the seizing patient strikes a hard surface during the uncontrolled and spastic myocontractions characteristic of ictal events.Such mandibular fractures secondary to seizures are well recognized [13,14].
We believe this is the first documented case in the literature of ictal myocontraction-induced fracture of the condylar head secondary to metabolic bone disease.Like most uncommon lesions it may be anatomically unrecognized and clinically under investigated.This report is also significant in the light of the patient's history of daily alcohol consumption, which is associated with reduced bone mineralization [15].
The role of levetiracetam in lowering bone mineral density, BMD, by increasing bone turnover with a net increase in bone resorption over bone formations although was taken for around five months cannot be underestimate metabolic effect on bone [16].

Figure 1 :
Figure 1: The patient reported to the hospital unable to close his jaw.He had no signs of facial trauma following his seizure.

Figure 3 :
Figure 3: The patient returned to normal function following treatment with full range of motion and interincisal opening of 42 m.mand normal occlusal alignment.