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Bilateral Coronoid Process Hyperplasia With Pseudocartilaginous Joint Formation: Jacob Disease
J Oral Maxillofac Surg 71:316-321, 2013
Bilateral Coronoid Process Hyperplasia With Pseudocartilaginous Joint Formation: Jacob Disease James G. Choi, BSc,* Sang Yoon Kim, DMD, MD,† Antonio R. Perez-Atayde, MD,‡ and Bonnie L. Padwa, DMD, MD§ The first description of coronoid process enlargement was by Langenbeck1 in 1853, but the French anatomist Jacob2 is credited with documenting the first report of an osteochondroma of the coronoid process forming a pseudojoint between the coronoid process and the zygomatic arch in 1899. Since then, there have been 50 reported cases, but only 39 had histologic evidence of a pseudojoint.3 There is a predilection toward male patients (63%) and involvement of the left coronoid process. The mean age at diagnosis is 30 years, with a range of 5 to 73 years.3 The most common clinical feature in this condition is a significant reduction in maximal incisal opening. Treatment requires resection of the coronoid process, and recurrence is rare.4,5 We report 2 cases of bilateral coronoid process hyperplasia consistent with Jacob disease with pseudocartilaginous joint formation between the coronoid process and zygoma. One patient had recurrent coronoid processes hyperplasia with lim-
itation of opening 3 years after bilateral coronoidectomies.
Case 1 A healthy 13-year-old boy presented with a 9-month history of progressive reduction in incisal opening. He had no history of pain or trauma to the temporomandibular joints (TMJs). On physical examination, there was no evidence of facial asymmetry. The patient’s maximum incisal opening was 15 mm without a click, a pop, pain, or deviation. His excursive movements were 10 mm to the left, 9 mm to the right, and 7 mm protrusive. A computed tomography (CT) scan showed the right and left coronoid processes extending above the zygomatic arch to the level of the mid orbit (Fig 1). A magnetic resonance imaging (MRI) scan confirmed normal disc position and no intra-articular pathology. Bilateral coronoidectomies were performed (Fig 2) through an intraoral approach, and at the end of the procedure, the patient’s incisal opening was 45 mm. At the latest visit, 4 months postoperatively, his maximal incisal opening was 40 mm with 8-mm excursive movements. Histopathologically, the surface of the coronoid process showed new (woven) bone formation and a fibrocartilaginous cap (Fig 3).
Case 2 *Dental Student, University of Pennsylvania School of Dental Medicine, Philadelphia, PA. †Chief Resident, Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Massachusetts General Hospital, Boston, MA. ‡Associate Professor of Pathology, Harvard Medical School, Children’s Hospital Boston, Boston, MA. §Associate Professor, Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Boston, MA, and Chief, Section of Oral and Maxillofacial Surgery, Children’s Hospital Boston, Boston, MA. Address correspondence and reprint requests to Dr Padwa: Department of Plastic and Oral Surgery, Children’s Hospital Boston, 300 Longwood Ave, Boston, MA 02115; e-mail: bonnie.padwa@ childrens.harvard.edu
A healthy 13-year-old boy presented with a 6-month history of progressive limitation in jaw opening. He denied having pain, a click, a pop, bruxism, or trauma to the TMJ. On physical examination, the patient had no facial asymmetry, his maximal incisal opening was 20 mm, and he had lateral excursive movements within the normal range at 10 mm. A panoramic radiograph showed the coronoid processes extending well above the zygomatic arch to the mid portion of the lateral orbit bilaterally (Fig 4). On a CT scan (Fig 5), there was no evidence of bony or fibrous ankylosis of the TMJ, and the MRI scan showed no intra-articular pathology, with normal disc morphology and position. The patient had bilateral coronoidectomies through an intraoral approach (Fig 6). The interincisal distance measured at the end of the procedure was 50 mm. Histopathologic examination showed peripheral new (woven) bone formation over pre-existing lamellar bone and a fibrocartilaginous cap mimicking an osteochondroma of the coronoid process (Fig 7). Six months after the operation, the patient’s maximal incisal opening was 45 mm with 10-mm excursive movements. Three years postoperatively, at the age of 16 years, the patient returned complaining of recurrent limitation of
© 2013 American Association of Oral and Maxillofacial Surgeons
0278-2391/13/7102-0$36.00/0 http://dx.doi.org/10.1016/j.joms.2012.05.029
316
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FIGURE 1. A, B, Axial CT images showing pseudoarticulation between the coronoid process and zygomatic arches bilaterally in case 1. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
opening, and his maximal incisal opening measured 15 mm. A panoramic radiograph showed that the coronoid processes were elongated and above the zygomatic arch. Bilateral coronoidectomies were repeated through an in-
traoral approach, and the patient’s incisal opening was 45 mm at the end of the operation. One year later, his maximal incisal opening was 42 mm with 8-mm excursive movements.
FIGURE 2. Panoramic radiograph 2 weeks after bilateral coronoidectomies in case 1. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
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BILATERAL CORONOID PROCESS HYPERPLASIA
FIGURE 3. A, B, Osteochondroma-like overgrowth of the coronoid process with reactive (woven) bone at the base and a well-developed cartilaginous cap (asterisks) in case 1. Under polarized light (B), the absence of lamella in the reactive bone is noticeable. C, D, Images at higher magnification without (C) and with (D) polarized lenses. Reactive bone is shown between the arrowheads. Figures are of H&E (hematoxylin and eosin) stained sections. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
FIGURE 4. Panoramic radiograph showing coronoid hyperplasia in case 2. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
CHOI ET AL
319
Discussion Patients with Jacob disease usually have a painless progressive reduction in mouth opening. The etiology of limitation in oral opening can be from extra- or intra-articular pathology. Extra-articular causes of limited opening are myofascial pain disorder and coronoid hyperplasia. Intra-articular reasons include internal derangement, intra-articular pathology (tumor, etc.), and TMJ ankylosis. One of the hallmarks of an extra-articular etiology is normal excursive movements. The absence of pain helps differentiate between myofascial pain and FIGURE 6. View of medial aspect of right and left mandibular coronoid processes in case 2. Both are curved laterally at the superior portion that articulated with the zygoma. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
FIGURE 5. Axial (A) and lateral (B) 3D CT scans show the close proximity between the coronoid process and zygoma and extension of the coronoid process above the zygomatic arch in case 2. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
coronoid hyperplasia. Patients who have limitation of opening from an intra-articular source often have limitation in excursive movements as well as incisal opening. In addition to the history and physical examination, radiographic imaging can also help the clinician in making the diagnosis. A screening panoramic radiograph shows enlargement of the coronoid processes, and an MRI scan will rule out internal derangement and joint pathology. A CT scan confirms that there is no TMJ ankylosis and will clearly show the coronoid enlargement, as well as the temporal fossa, and the articulating relationship between the coronoid process and zygoma. The majority of surgeons favor an intraoral approach (49%) for coronoidectomy, although many surgeons prefer an extraoral approach (40%) and some use a combined intraoral and extraoral approach (11%).3 The intraoral approach offers direct access without the risk of facial nerve injury or scars on the face,6,7 but herniation of the buccal fat pad into the surgical site can be annoying when the dissection is carried too far superiorly and medially.8 If the exostosis is bulbous and large, an extraoral approach may be necessary.9 Peacock et al10 recently reported a study of ancient Egyptian intraoral osteotomies of the facial skeleton that involved removal of a portion of the zygoma and zygomatic process to provide excellent access to the infratemporal fossa for coronoidectomy. Sreeramaneni et al3 documented the ages of the patients with Jacob disease reported in the literature. Further analysis of these data shows that the majority of patients were diagnosed before the age of 20 years (35%), followed by 20 to 30 year olds (25%), and 30 to 40 year olds (18%). Both of our
320
BILATERAL CORONOID PROCESS HYPERPLASIA
FIGURE 7. A, B, Osteochondroma-like overgrowth of the coronoid process with reactive (woven) bone at the base and a well-developed cartilaginous cap (asterisks) in case 2. In this case the base of reactive bone and the cartilaginous cap are thinner than in case 1. Areas of pre-existing lamellar (remodeled) bone under polarized lenses (B) are indicated by arrows. C, D, Same features without (C) and with (D) polarized light, at higher magnification. The arrowheads indicate new bone (woven) formation, and the arrows show pre-existing lamellar bone. Figures are of H&E (hematoxylin and eosin) stained sections. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
patients were boys in whom limitation of opening developed at the age of 13 years. They both reported a large skeletal growth spurt that began approximately 6 months before the onset of symptoms. One of our patients had recurrence at age 16 years requiring another operation to remove the enlarged coronoid processes. In the other patient, it has only been 6 months since the operation was performed, and to date, he has no limitation of opening. Thota et al5 reported a 15-year-old patient who had regrowth of the coronoid process above the zygomatic arch 14 months after coronoidectomies. At the time of the report, the patient had no significant limitation in incisal opening. The age of onset for our patients and those of Thota et al is early in the pubertal growth spurt, and perhaps this is responsible for the recurrence.
The pathogenesis of Jacob disease is not known, but several theories have been proposed to explain the pseudojoint formation. Roychoudhury et al11 hypothesized that as the coronoid process enlarges, it compresses against the zygoma, and with function, the zygoma resorbs and remodels, forming a pseudojoint. Akan and Mehreliyeva12 have suggested that there is direct contact between the hyperplastic coronoid process and the posterior wall of the maxilla and/or zygomatic arch that occurs either by the coronoid process impinging on a concavity formed on the zygomatic arch6 or by a concavity on the coronoid process that is caused by new bone formation on the medial surface of the zygoma.2,13 Our histopathologic findings are consistent with the formation of a pseudojoint between the coronoid process and the zygoma. This pseu-
321
CHOI ET AL
dojoint is characterized by reactive new bone on the surface of the coronoid process and a fibrocartilaginous cap, probably as a consequence of traumatic injury with chronic friction between the 2 bones.
References 1. Langenbeck B: Angeborene Kleinert der Unterkiefer. Langenbecks Arch 1:451, 1861 2. Jacob O: Une cause rare de constriction permanente des machoires. Bull Mem Société Anatomique Paris 1:917, 1899 3. Sreeramaneni SK, Chakravarthi PS, Krishna Prasad L, et al: Jacob’s disease: Report of a rare case and literature review. Int J Oral Maxillofac Surg 40:753, 2011 4. D’Ambrosio N, Kellman RM, Karimi S: Osteochondroma of the coronoid process (Jacob’s disease): An unusual cause of restricted jaw motion. Am J Otolaryngol 32:52, 2011 5. Thota G, Cillo JE Jr, Krajekian J, et al: Bilateral pseudojoints of the coronoid process (Jacob disease): Report of a case and review of the literature. J Oral Maxillofac Surg 67:2521, 2009 6. Hernández-Alfaro F, Escuder O, Marco V: Joint formation between an osteochondroma of the coronoid process and
7.
8. 9.
10.
11.
12.
13.
the zygomatic arch (Jacob disease): Report of case and review of literature. J Oral Maxillofac Surg 58:227, 2000 Emekli U, Aslan A, Onel D, et al: Osteochondroma of the coronoid process (Jacob’s disease). J Oral Maxillofac Surg 60: 1354, 2002 Meyer RA: Osteochondroma of coronoid process of mandible: Report of case. J Oral Surg 30:297, 1972 Ramon Y, Horowitz I, Oberman M, et al: Osteochondroma of the coronoid process of the mandible. Oral Surg Oral Med Oral Pathol 43:692, 1977 Peacock ZS, Chapman PH, Gupta R, et al: Replication of ancient Egyptian osteotomies of the facial skeleton: Insights into the mummification process. Int J Oral Maxillofac Surg 40:1301, 2011 Roychoudhury A, Gupta YK, Parkash H, et al: Jacob disease: Report of a case and review of the literature. J Oral Maxillofac Surg 60:699, 2002 Akan H, Mehreliyeva N: The value of three-dimensional computed tomography in diagnosis and management of Jacob’s disease. Dentomaxillofac Radiol 35:55, 2006 Asaumi J, Kawai N, Honda Y, et al: Comparison of threedimensional computed tomography with rapid prototype models in the management of coronoid hyperplasia. Dentomaxillofac Radiol 30:330, 2001
Bilateral Coronoid Process Hyperplasia With Pseudocartilaginous Joint Formation: Jacob Disease James G. Choi, BSc,* Sang Yoon Kim, DMD, MD,† Antonio R. Perez-Atayde, MD,‡ and Bonnie L. Padwa, DMD, MD§ The first description of coronoid process enlargement was by Langenbeck1 in 1853, but the French anatomist Jacob2 is credited with documenting the first report of an osteochondroma of the coronoid process forming a pseudojoint between the coronoid process and the zygomatic arch in 1899. Since then, there have been 50 reported cases, but only 39 had histologic evidence of a pseudojoint.3 There is a predilection toward male patients (63%) and involvement of the left coronoid process. The mean age at diagnosis is 30 years, with a range of 5 to 73 years.3 The most common clinical feature in this condition is a significant reduction in maximal incisal opening. Treatment requires resection of the coronoid process, and recurrence is rare.4,5 We report 2 cases of bilateral coronoid process hyperplasia consistent with Jacob disease with pseudocartilaginous joint formation between the coronoid process and zygoma. One patient had recurrent coronoid processes hyperplasia with lim-
itation of opening 3 years after bilateral coronoidectomies.
Case 1 A healthy 13-year-old boy presented with a 9-month history of progressive reduction in incisal opening. He had no history of pain or trauma to the temporomandibular joints (TMJs). On physical examination, there was no evidence of facial asymmetry. The patient’s maximum incisal opening was 15 mm without a click, a pop, pain, or deviation. His excursive movements were 10 mm to the left, 9 mm to the right, and 7 mm protrusive. A computed tomography (CT) scan showed the right and left coronoid processes extending above the zygomatic arch to the level of the mid orbit (Fig 1). A magnetic resonance imaging (MRI) scan confirmed normal disc position and no intra-articular pathology. Bilateral coronoidectomies were performed (Fig 2) through an intraoral approach, and at the end of the procedure, the patient’s incisal opening was 45 mm. At the latest visit, 4 months postoperatively, his maximal incisal opening was 40 mm with 8-mm excursive movements. Histopathologically, the surface of the coronoid process showed new (woven) bone formation and a fibrocartilaginous cap (Fig 3).
Case 2 *Dental Student, University of Pennsylvania School of Dental Medicine, Philadelphia, PA. †Chief Resident, Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Massachusetts General Hospital, Boston, MA. ‡Associate Professor of Pathology, Harvard Medical School, Children’s Hospital Boston, Boston, MA. §Associate Professor, Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Boston, MA, and Chief, Section of Oral and Maxillofacial Surgery, Children’s Hospital Boston, Boston, MA. Address correspondence and reprint requests to Dr Padwa: Department of Plastic and Oral Surgery, Children’s Hospital Boston, 300 Longwood Ave, Boston, MA 02115; e-mail: bonnie.padwa@ childrens.harvard.edu
A healthy 13-year-old boy presented with a 6-month history of progressive limitation in jaw opening. He denied having pain, a click, a pop, bruxism, or trauma to the TMJ. On physical examination, the patient had no facial asymmetry, his maximal incisal opening was 20 mm, and he had lateral excursive movements within the normal range at 10 mm. A panoramic radiograph showed the coronoid processes extending well above the zygomatic arch to the mid portion of the lateral orbit bilaterally (Fig 4). On a CT scan (Fig 5), there was no evidence of bony or fibrous ankylosis of the TMJ, and the MRI scan showed no intra-articular pathology, with normal disc morphology and position. The patient had bilateral coronoidectomies through an intraoral approach (Fig 6). The interincisal distance measured at the end of the procedure was 50 mm. Histopathologic examination showed peripheral new (woven) bone formation over pre-existing lamellar bone and a fibrocartilaginous cap mimicking an osteochondroma of the coronoid process (Fig 7). Six months after the operation, the patient’s maximal incisal opening was 45 mm with 10-mm excursive movements. Three years postoperatively, at the age of 16 years, the patient returned complaining of recurrent limitation of
© 2013 American Association of Oral and Maxillofacial Surgeons
0278-2391/13/7102-0$36.00/0 http://dx.doi.org/10.1016/j.joms.2012.05.029
316
317
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FIGURE 1. A, B, Axial CT images showing pseudoarticulation between the coronoid process and zygomatic arches bilaterally in case 1. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
opening, and his maximal incisal opening measured 15 mm. A panoramic radiograph showed that the coronoid processes were elongated and above the zygomatic arch. Bilateral coronoidectomies were repeated through an in-
traoral approach, and the patient’s incisal opening was 45 mm at the end of the operation. One year later, his maximal incisal opening was 42 mm with 8-mm excursive movements.
FIGURE 2. Panoramic radiograph 2 weeks after bilateral coronoidectomies in case 1. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
318
BILATERAL CORONOID PROCESS HYPERPLASIA
FIGURE 3. A, B, Osteochondroma-like overgrowth of the coronoid process with reactive (woven) bone at the base and a well-developed cartilaginous cap (asterisks) in case 1. Under polarized light (B), the absence of lamella in the reactive bone is noticeable. C, D, Images at higher magnification without (C) and with (D) polarized lenses. Reactive bone is shown between the arrowheads. Figures are of H&E (hematoxylin and eosin) stained sections. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
FIGURE 4. Panoramic radiograph showing coronoid hyperplasia in case 2. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
CHOI ET AL
319
Discussion Patients with Jacob disease usually have a painless progressive reduction in mouth opening. The etiology of limitation in oral opening can be from extra- or intra-articular pathology. Extra-articular causes of limited opening are myofascial pain disorder and coronoid hyperplasia. Intra-articular reasons include internal derangement, intra-articular pathology (tumor, etc.), and TMJ ankylosis. One of the hallmarks of an extra-articular etiology is normal excursive movements. The absence of pain helps differentiate between myofascial pain and FIGURE 6. View of medial aspect of right and left mandibular coronoid processes in case 2. Both are curved laterally at the superior portion that articulated with the zygoma. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
FIGURE 5. Axial (A) and lateral (B) 3D CT scans show the close proximity between the coronoid process and zygoma and extension of the coronoid process above the zygomatic arch in case 2. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
coronoid hyperplasia. Patients who have limitation of opening from an intra-articular source often have limitation in excursive movements as well as incisal opening. In addition to the history and physical examination, radiographic imaging can also help the clinician in making the diagnosis. A screening panoramic radiograph shows enlargement of the coronoid processes, and an MRI scan will rule out internal derangement and joint pathology. A CT scan confirms that there is no TMJ ankylosis and will clearly show the coronoid enlargement, as well as the temporal fossa, and the articulating relationship between the coronoid process and zygoma. The majority of surgeons favor an intraoral approach (49%) for coronoidectomy, although many surgeons prefer an extraoral approach (40%) and some use a combined intraoral and extraoral approach (11%).3 The intraoral approach offers direct access without the risk of facial nerve injury or scars on the face,6,7 but herniation of the buccal fat pad into the surgical site can be annoying when the dissection is carried too far superiorly and medially.8 If the exostosis is bulbous and large, an extraoral approach may be necessary.9 Peacock et al10 recently reported a study of ancient Egyptian intraoral osteotomies of the facial skeleton that involved removal of a portion of the zygoma and zygomatic process to provide excellent access to the infratemporal fossa for coronoidectomy. Sreeramaneni et al3 documented the ages of the patients with Jacob disease reported in the literature. Further analysis of these data shows that the majority of patients were diagnosed before the age of 20 years (35%), followed by 20 to 30 year olds (25%), and 30 to 40 year olds (18%). Both of our
320
BILATERAL CORONOID PROCESS HYPERPLASIA
FIGURE 7. A, B, Osteochondroma-like overgrowth of the coronoid process with reactive (woven) bone at the base and a well-developed cartilaginous cap (asterisks) in case 2. In this case the base of reactive bone and the cartilaginous cap are thinner than in case 1. Areas of pre-existing lamellar (remodeled) bone under polarized lenses (B) are indicated by arrows. C, D, Same features without (C) and with (D) polarized light, at higher magnification. The arrowheads indicate new bone (woven) formation, and the arrows show pre-existing lamellar bone. Figures are of H&E (hematoxylin and eosin) stained sections. Choi et al. Bilateral Coronoid Process Hyperplasia. J Oral Maxillofac Surg 2013.
patients were boys in whom limitation of opening developed at the age of 13 years. They both reported a large skeletal growth spurt that began approximately 6 months before the onset of symptoms. One of our patients had recurrence at age 16 years requiring another operation to remove the enlarged coronoid processes. In the other patient, it has only been 6 months since the operation was performed, and to date, he has no limitation of opening. Thota et al5 reported a 15-year-old patient who had regrowth of the coronoid process above the zygomatic arch 14 months after coronoidectomies. At the time of the report, the patient had no significant limitation in incisal opening. The age of onset for our patients and those of Thota et al is early in the pubertal growth spurt, and perhaps this is responsible for the recurrence.
The pathogenesis of Jacob disease is not known, but several theories have been proposed to explain the pseudojoint formation. Roychoudhury et al11 hypothesized that as the coronoid process enlarges, it compresses against the zygoma, and with function, the zygoma resorbs and remodels, forming a pseudojoint. Akan and Mehreliyeva12 have suggested that there is direct contact between the hyperplastic coronoid process and the posterior wall of the maxilla and/or zygomatic arch that occurs either by the coronoid process impinging on a concavity formed on the zygomatic arch6 or by a concavity on the coronoid process that is caused by new bone formation on the medial surface of the zygoma.2,13 Our histopathologic findings are consistent with the formation of a pseudojoint between the coronoid process and the zygoma. This pseu-
321
CHOI ET AL
dojoint is characterized by reactive new bone on the surface of the coronoid process and a fibrocartilaginous cap, probably as a consequence of traumatic injury with chronic friction between the 2 bones.
References 1. Langenbeck B: Angeborene Kleinert der Unterkiefer. Langenbecks Arch 1:451, 1861 2. Jacob O: Une cause rare de constriction permanente des machoires. Bull Mem Société Anatomique Paris 1:917, 1899 3. Sreeramaneni SK, Chakravarthi PS, Krishna Prasad L, et al: Jacob’s disease: Report of a rare case and literature review. Int J Oral Maxillofac Surg 40:753, 2011 4. D’Ambrosio N, Kellman RM, Karimi S: Osteochondroma of the coronoid process (Jacob’s disease): An unusual cause of restricted jaw motion. Am J Otolaryngol 32:52, 2011 5. Thota G, Cillo JE Jr, Krajekian J, et al: Bilateral pseudojoints of the coronoid process (Jacob disease): Report of a case and review of the literature. J Oral Maxillofac Surg 67:2521, 2009 6. Hernández-Alfaro F, Escuder O, Marco V: Joint formation between an osteochondroma of the coronoid process and
7.
8. 9.
10.
11.
12.
13.
the zygomatic arch (Jacob disease): Report of case and review of literature. J Oral Maxillofac Surg 58:227, 2000 Emekli U, Aslan A, Onel D, et al: Osteochondroma of the coronoid process (Jacob’s disease). J Oral Maxillofac Surg 60: 1354, 2002 Meyer RA: Osteochondroma of coronoid process of mandible: Report of case. J Oral Surg 30:297, 1972 Ramon Y, Horowitz I, Oberman M, et al: Osteochondroma of the coronoid process of the mandible. Oral Surg Oral Med Oral Pathol 43:692, 1977 Peacock ZS, Chapman PH, Gupta R, et al: Replication of ancient Egyptian osteotomies of the facial skeleton: Insights into the mummification process. Int J Oral Maxillofac Surg 40:1301, 2011 Roychoudhury A, Gupta YK, Parkash H, et al: Jacob disease: Report of a case and review of the literature. J Oral Maxillofac Surg 60:699, 2002 Akan H, Mehreliyeva N: The value of three-dimensional computed tomography in diagnosis and management of Jacob’s disease. Dentomaxillofac Radiol 35:55, 2006 Asaumi J, Kawai N, Honda Y, et al: Comparison of threedimensional computed tomography with rapid prototype models in the management of coronoid hyperplasia. Dentomaxillofac Radiol 30:330, 2001