A case of refractory perforation at the floor of the mouth with ectopic bone formation.
Article Type:
Case study
Osteomyelitis (Diagnosis)
Osteomyelitis (Care and treatment)
Osteomyelitis (Research)
X-rays (Usage)
Bones (Growth)
Bones (Research)
Ohba, Seigo
Sekine, Joji
Tobita, Takayoshi
Ikeda, Hideyoshi
Asahina, Izumi
Pub Date:
Name: CRANIO: The Journal of Craniomandibular Practice Publisher: Chroma, Inc. Audience: Academic Format: Magazine/Journal Subject: Science and technology Copyright: COPYRIGHT 2011 Chroma, Inc. ISSN: 0886-9634
Date: July, 2011 Source Volume: 29 Source Issue: 3
Event Code: 310 Science & research
Geographic Scope: Japan Geographic Code: 9JAPA Japan

Accession Number:
Full Text:
ABSTRACT: Although most fistulae are not problematic, (1) surgeons occasionally encounter recurrent and/or refractory fistulae in the field of oral and maxillofacial surgery. In this case report, the authors describe a case in which a patient experienced a recurrent and refractory fistula or perforation at his oral floor through the submandible, with heterotopic bone formation arising on both sides of the mylohyoid line. These heterotopic bones were connected to each other, forming a bone bridge at the center of the oral floor. A fistulectomy and wound closure with a tongue flap was successful. The perforation has not recurred after over four years of follow-up, and the bone bridge is still present.


Fistulae that cause inflammation and infections after surgery are often encountered by surgeons, but their occurrence can usually be controlled by adequate treatment. If incomplete treatment for inflammation is performed, they often recur. Conservative fistula closing strategies include wound drainage and minimal debridement. When fistulae do not close after conservative interventions, debridement and surgical approaches such as a flap closure should be performed. (2) Several techniques that are performed to close oral fistulae, including the use of grafts and flaps, have been reported, and the results are generally good. (3) In particular, tongue flaps have been reported to be very useful for repairing defects because of the volume and excellent blood supply of this tissue. (4)

Infections sometimes induce heterotopic ossifications. Sclerosing osteomyelitis such as Garre disease and diffuse sclerosing osteomyelitis are well known to form new bone due to a periosteal reaction. (5) Here, the authors report a case of refractory perforation with ectopic bone formation, successfully treated with a tongue flap.

Case Report

A 76-year-old male Japanese patient presented with a sensation of swelling and pain in his left mandibular angle. He suffered from hypertension and cataracts, but had no history of allergy and no significant family medical history. He was diagnosed with osteomyelitis of the posterior mandible and was admitted to the hospital for treatment. An incision into the patient's skin to his mandibular bone was made to drain the affected region, and the patient was given antibiotics for osteomyelitis of the left mandible. Following that treatment, the patient's swelling and pain disappeared, and he was discharged from the hospital. The authors followed up with the patient once a month.

After six months, the patient complained of oral floor submental wound dehiscence and that saliva and food leaked through the perforation to the outside of the oral cavity [Figure I(A)]. Therefore, the perforation was closed and a sequestrectomy performed at the lingual side of the anterior body of the mandible while the patient was under general anesthesia. The surgical approach was via a submandible incision in which the mandible bone was exposed and the mandible's marginal and lingual bones were removed as blocks, along with the granular tissue. Finally, the wound was closed after lengthy irrigation with saline. At this time, heterotopic bone formation was found around both ends of the mylohyoid line, and the bones were connected to each other at the center of the oral floor like a bone bridge, as seen on an occlusal x-ray film [Figure 1 (X-Ps)]. Because the patient's wound dehiscence occurred three weeks after the first operation, the authors tried to close the opened wound in the same region under general anesthesia (during the second operation). Pathology of the excise specimen was osteomyelitis and no bone sequestrum was found. During this time, both intraoral and submental approaches were used. The intraoral wound was tightly closed, and the submental wound remained open. Finally, the submental wound was completely closed at one month after surgery, and the patient was discharged from the hospital. We again followed up with him once a month. After one year, there was no recurrence of the perforation; however, the oral floor-submental wound had reopened. The authors closed the perforation the same way as in the second operation (third operation). Because the wound reopened again so soon after the surgery [Figure 1(B)], a fourth operation was performed, and the perforation was closed using a bone bridge. The tissue around the perforation was fibrous, granulation tissue. Briefly, the bone bridge was cut at the center and both fragments (still connected at the mylohyoid line of the mandible) were pulled forward with wire and ligated to the mental region of the mandible. However, wound dehiscence soon recurred. Using a tongue flap, the authors performed a fifth operation to close the perforation (Figure 2) on the basis of a previous report. (5) Briefly, the anteriorly-based dorsal tongue flap was separated from donor site. The flap was designed on the raw undersurface to fit the defect at the oral floor and sutured with submental skin. Because there was no sign of wound rupture, the flap was cut, and the tongue was released two weeks after the surgery.


There was no evidence of recurrence of the perforation, and this patient still has the bone bridge on his oral floor at his four-year follow-up. The treatment process is shown in Figure 3.



In the present case, the size of the fistula was small after the first fistulectomy. The authors thought the wound would close spontaneously, but perforation recurred. Because remaining infection is the most critical reason for wound dehiscence, (1) insufficient treatment of osteomyelitis is considered to be the most critical cause for a first recurrence of wound dehiscence. However, the authors believe that the repeated wound dehiscence after the second operation was caused by scar contraction and a lack of blood supply. The patient's oral floor had a strong tension, and the skin was very thin, resulting in ischemia. This may have caused the wound to open repeatedly. In addition, continuous leaking of saliva may have prevented the perforation from closing spontaneously. The oral floor consists of thin elastic skin and a bone bridge that may lead to more tension on the skin. Moreover, chronic inflammation results in thinner skin, which may have caused increased tension and ischemia in the patient's oral floor. The authors were finally able to close the perforation using a tongue flap; tissue that is reported to provide enough volume to supply sufficient blood flow. (4)


The authors experienced a rare case in which heterotopic bone had formed on both sides of the mylohyoid line of the mandible, and these bones were connected to each other, creating a bone bridge. The authors believe that myositis ossificans (MO), which is characterized by non-neoplastic bone formation in soft tissue and skeletal muscle and is induced by trauma, burns, or other events, (6) may have triggered formation of the ectopic bone in the current case. Although several MO cases of the masseter and temporalis have been reported, there have been no reports of MO in the sublingual region. Chronic inflammation may be the most important cause of ectopic bone formation in this case, based on a previous report that described the relationship between inflammation and a periosteal reaction. (7) However, according to Seung-Jun, et al., (8) static tension force induces bone absorption and formation, which depends on the force direction. Thus, it is possible that continuous tension led to heterotopic bone formation at the oral floor in this case.


The authors' conclusions in this case are as follows: 1. shortage of the surrounding tissue caused by infection resulted in ischemia and tension of the tissue, leading to repeated perforations; 2. spontaneous stimulation by chronic infection caused ectopic bone formation in the sublingual region; and 3. the tongue is a good donor tissue for use as a flap to close the perforation at the oral floor.


(1.) Demir Z, Velidedeoglu H, Celebioglu S: Repair of pharyngocutaneous fistulas with the submental artery island flap. Plast Reconstr Surg 2005; 115:38-44.

(2.) Papazoglou G, Doundoulakis G, Terzakis G, Dokianakis G: Oharyngocutaneous fistula after total laryngectomy, incidence, case. and treatment. Ann

Otol Rhinol Laryngol 1994: 103:801-805.

(3.) Oswald TM, Stover SA, Gerzenstein J, Lei MP, Zhang F, Muskett A, et al.: Immediate and delayed use of arteriovenous fistulae in microsurgical flap procedures: a clinical series and review of published cases. Ann Plast Surg 2007; 58:6-13.

(4.) Agrawal K, Panda KN: Management of a detached tongue flap. Plast Reconstr Surg 2007; 120:151-156.

(5.) Francisco JD, Alicia D, Francisco JA, Alamillos MD, Luis N. Jacino Florencio M: Tongue flaps for reconstruction of the oral cavity. Head Neck 1994; 16:550-554.

(6.) McCarthy EF, Sundaram M: Heterotopic ossification: a review. Skeletal Radiol 2005; 34: 609-619.

(7.) Ida M, Tetsumura A, Kurabayashi T, Sasaki T: Periosteal new bone formation in the jaws. A computed tomographic study. Dentomaxillofac Radiol 1997; 26: 169-176.

(8.) Ku SJ, Chang YI, Chae CH, Kim SG, Park YW, Jung YK, Choi JY: Static tensional forces increase osteogenic gene expression in three-dimensional periodontal ligament cell culture. BMB Rep 2009; 42(7): 427-432.

Seigo Ohba, D.D.S., Ph.D.; Joji Sekine, D.D.S., Ph.D.; Takayoshi Tobita, D.D.S., Ph.D.; Hideyoshi Ikeda, D.D.S.; Izumi Asahina, D.D.S., Ph.D.

Manuscript received June 10, 2010; revised manuscript received December 16, 2010; accepted December 17, 2010

Address for correspondence:

Dr. Seigo Ohba

1-7-1 Sakamoto

Nagasaki City

Nagasaki 852-8588




Dr. Seigo Ohba is a lecturer at the Department of Regenerative Oral Surgery at Nagasaki University Graduate School of Medical Sciences, Japan. He received his D.D.S. degree at Nagasaki University in 1999 and his Ph.D. degree from the same university in 2003. During 20072009, he studied the relationship between chondrocyte and leptin at fire Department of Rheumatology, Internal Medicine, University of Michigan, Ann Arbor as a visiting researcher.

Dr. Joji Sekine is a professor at the Department of Oral and Maxillofacial Surgery, Shimane University Faculty of Medicine, Japan. He received a D.D.S. degree at Fukuoka Dental College in 1989 and his Ph.D. degree from Nagasaki University in 1996. He worked for the Department of Oral and Maxillofacial Surgery, Nagasaki University during 1989-2006, and also worked in the Department of Oral & Maxillofacial Surgery, Umea University as a visiting professor during 2006-2007.

Dr. Takayoshi Tobita is a lecturer in the Department of Dentistry and Oral Surgery at the University of Fukui Hospital in Japan since April, 2010. He received his D.D.S. degree at Nagasaki University School of Dentistry in 1997 and his Ph.D. degree at the same university in 2001. He worked as an assistant professor in the Division of Regenerative Oral Surgery at the Nagasaki University Graduate School of Biomedical Sciences from 2001 to 2010. During 2002-2004, he worked for the Department of Oral and Maxillofacial Surgery at the University of Michigan as the visiting researcher.

Dr. Hideyoshi Ikeda is a guest researcher at the Department of Regenerative Oral Surgery at Nagasaki University Graduate School of Biomedical Sciences, Japan. In 2006, he received his D.D.S. degree at Nagasaki University, and his Ph.D. degree from the same university in 2011.

Dr. Izumi Asahina is a chairman at the Department of Regenerative Oral Surgery at Nagasaki University Graduate School of Medical Sciences, and a Vice President of Nagasaki University Hospital, Japan. He received his D.D.S. degree at Tokyo Medical and Dental University in 1983 and his Ph.D. degree from the same university in 1987. During 1991-1993, he studied bone cell biology at Harvard University and Children's Hospital, Boston, and engaged in clinical research for bone regeneration at the Institute of Medical Sciences, University of Tokyo, as an associate professor from 2004 to 2006.
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