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Revista Española de Cirugía Oral y Maxilofacial

versão On-line ISSN 2173-9161versão impressa ISSN 1130-0558

Rev Esp Cirug Oral y Maxilofac vol.31 no.4 Madrid Jul./Ago. 2009




What would your diagnosis be?

¿Cuál es su diagnóstico?



Male patient 16 years old, comes to our consult because of a history of pain in both TMJ's over the past year. The pain has increased over the last few months and there are bilateral noises and progressively limited oral opening. The only pre-existing condition of interest is that he had 5 years of orthodontic treatment (from 10-15 years). During the physical exam we measured a Maximum Oral opening of 25mm, 0mm protrusion movement, 6mm right lateral movement and 6mm left lateral movement. The patient experiences pain upon palpation on the right and left TMJ and bilateral noises upon oral opening that is compatible with DDCR. Angle's Class I with good occlusion. The patient reports starting to notice the symptoms after finishing orthodontic treatment. In the ortopantomography both TMJ's appear to be without significant changes. The MRI shows limited movement of opening in both mandible condyles and no signs of inflammation in the soft parts.

According to radiological and clinical discoveries we diagnosed the patient with bilateral close lock of the TMJ. In accordance with his diagnosis we carried out bilateral arthroscopy where no significant discoveries were found. Therefore we carried out a lysis lavage and posterior infiltration with hyaluronic acid. There were no immediate consequences in post op.

One month after surgery the patient has an opening of 26 mm with major pain in both bilateral masseters (Figure 2). Given this progress we request a 3D CT in order to rule out the possibility of an extraarticular cause of the joint block.

Bilateral Hypertrophy of the coronoid process

Hipertrofia bilateral de apófisis coronoides



S. Rosón-Gómez1, M. Muñoz-Guerra2, F.J. Rodríguez-Campo2, M. Mancha de la Plata1, J.L. Gíl-Díez2, F.J. Díaz-González3

1 Médico residente
2 Médico adjunto
3 Jefe de Servicio
Servicio de Cirugía Oral y Maxilofacial. Hospital Universitario La Princesa. Madrid. España





The 3D CT shows elongation of both coronoid processes that are in contact with the zygomatic arch, which is limiting oral opening (Fig.1). Diagnosed as Bilateral Hypertrophy of the coronoids, we use an intraoral method to carry out bilateral coronoidectomy. The opening between operations was 38 mm. (Fig. 4) The histological study confirmed that the bone histology was normal and had minimal fibro cartilage in the malar face (Fig. 3).


Rehabilitation therapy started the week after surgery and continued for 3 months. 6 months later the patient had an oral opening of 42 mm without pain and without any growth coronoid process.



Bilateral hyperplasia of the coronoid process is defined as the abnormal elongation of the coronoid process at the expense of histologically normal bones. The prevalence of this entity is 0.5%. Its normal clinical appearance is painless progressive decrease in oral opening. In our case, the patient's initial symptom logy and the initial radiographic tests leads us towards TMJ dysfunction. Therefore it is important to think of this pathology as a possible cause of the painless progressive decrease in oral opening. Also keeping in mind that at the initial state panoramic radiographs did not give us information, the 3D CT was the essential tool in diagnosis because it allowed us to quantify the longitude of the coronoid process as well as its relationship to bone and or cygomatic arch.1 The etiopathogenic mechanisms of this entity continue to be controversial despite the numerous factors proposed in the literature. Hyperactivity of the temporal muscle has been described by different authors as a relevant etiological factor in its own genesis. Since the continuous action of the muscles creates a change in the local vascular input which favors degenerative changes and apposition of calcium with subsequent local ossification of soft tissues, 2-5) Cp. Isberg et al. showed 8 cases of TMJ dysfunction associated with hyperplasia of the coronoid process, correlating this hyperplasia with the incidence of chronic disc displacement of the ipsilateral TMJ, this disc pathology being the cause. Many authors have also suggested that the shock, genetic alterations or endocrine stimuli may be possible etiological factors.6

In our case, the stimulus of orthodontic treatment contributed to the pathological development of the coronoids, the left side larger than the right side just like in Jacob Syndrome.

Two surgical techniques are described for the treatment of this entity: the intraoral route and the extra oral route. Intraoral coronoidectomy is the technique preferred by many authors, despite the limited oral opening that patients frequently experience.7,8 This intraoral approach eliminates the possibility of unaesthetic external scars and minimizes the risk of facial nerve injury.9 Ostrofsky and Lownie use the sub mandible approach to carry out coronoidectomy in a case of zygomatic coronoid anchylosis. It offers a good surgical area even though there is a marginal risk of injuring the nerve, which is why its use has been criticized.10 The extra oral coronal type technique provides excellent visuals of the coronoid process and has an acceptable scar below the implant hairline. Its use is recommended when the coronoid process is too long to be performed below the cygomatic arch using an intraoral route, when there is bilateral affectation or when there is concomitant affectation of the TMJ that requires surgical treatment during the same operational. We propose an intraoral approach when the size of the coronoid process allows it. We also propose the use of arthroscopic techniques if there is associated TMJ dysfunction.

The prognostic depends on initial opening and post rehab therapy. Therefore it is important to start rehab therapy with precaution with the purpose of decreasing postsurgical fibrosis, and the realignment of the clot and hematoma of said area.6)

In conclusion, hypertrophy of the coronoid process is an uncommon entity but we should be suspicious of it in cases when TMJ dysfunction does not respond to arthroscopic treatment. In young patients with painless progressively limited oral opening where arthroscopy doesn't show pathological improvements, we should consider this entity as a possible cause of close lock.



Silvia Rosón Gómez
Servicio de Cirugía Oral y Maxilofacial.
Hospital Universitario de la Princesa
C/ Diego de León, 62
28006 Madrid. España




1. Takahashi A, Hao-Zong W, Murakami S, Kondoh H, Fujishita M, Fuchihata H. Diagnosis of coronoid process hyperplasia by threedimensional computed tomographic imaging. Dentomaxillofac Radiol 1993;22:149-54.        [ Links ]

2. Roychoudbury A, Gupta YK, Parkash H, Karak AK. Jacob disease: report of a case and review of the literature. J Oral Maxillofac Surg 2002;60:699-703.        [ Links ]

3. Hernandez-Alfaro F, Escuder O, Marco V. Joint formation between an osteochondroma of the coronoid process and the zygomatic arch (Jacob disease): report of case and review of literature. J Oral Maxillofac Surg 200;58:227-32.        [ Links ]

4. Isberg A, Isacsson G, Nah KS. Mandibular coronoid process locking: a prospective study of frequence and association with internal derangement of the temporomandibular joint. Oral Surg Oral Med Oral Pathol 1987;63:275-9.        [ Links ]

5. Kai S, Hijiya T, Yamane K, Higuchi Y. Open-mouth locking caused by unilateral elongated coronoid process: report of case. J Oral Maxillofac Surg 1997;55:1305-8.        [ Links ]

6. McLoughlin PM, Hopper C, Bowley NB. Hyperplasia of the mandibular coronoid process: an analysis of 31 cases and review of the literature. J Oral Maxillofac Surg 1995;53:250-5.        [ Links ]

7. Emekli U, Aslan A, Onel D, Çizmeci O, Demiryont M. Osteochondroma of the coronoid process (Jacob´s disease). J Oral Maxillofac Surg 2002;60:1354-6.        [ Links ]

8. Gerbino G, Bianchi SD, Bernardi M, Berrone S. Hyperplasia of the man dibular coronoid process: long-term follow-up after coronoidectomy. J Craniomaxillofac Surg 1997;25:169-73.        [ Links ]

9. Ostrofsky MK, Lownie JF. Zygomatico-coronoid ankylosis. J Oral Surg 1977;35:752-4.        [ Links ]

10. Hayter JP, Robertson JM. Surgical access to bilateral coronoid hyperplasia using the bicoronal flap. Br J Oral Surg 1989;27:487-93.        [ Links ]

11. Capote A, Rodríguez FJ, Blasco A, Muñoz MF. Jacob's disease associated with temporomandibular joint dysfunction: a case report. Med Oral Patol Oral Cir Bucal. 2005;10:210-4.        [ Links ]

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