Osteochondroma of the right coronoid process (Jacob disease): a case report

Jacob's Disease: Case Series, Extensive Literature Review and Classification Proposal

Jacob's disease is a rare entity consisting of the formation of a pseudojoint between an abnormal coronoid process of the mandible and the inner surface of the zygomatic bone. First described by Jacob in 1899, its diagnosis and definition have never been entirely univocal. In this paper, we present three emblematic cases and an extensive review of the literature on Jacob's disease. Given the variability observed in the presentation of the disease, we have developed a proposal for the classification, here reported.

Osteochondroma of the coronoid process: A case report and review of the literature

Osteochondroma (OC) is considered the most common tumor of the axial skeleton, although it is relatively uncommon in the craniofacial region. The present study describes an atypical case of OC of the coronoid process. A 34-year-old woman presented with severely limited mouth opening (5 mm) and swelling of the right zygoma. Cone-beam computed tomography (CBCT) revealed a mushroom-shaped outgrowth from the coronoid process to the inner surface of the zygomatic arch, forming a pseudojoint. The patient was treated with coronoidectomy via an intraoral approach. Histopathological examination revealed features suggestive of OC. Subsequently, the patient was able to open their mouth, and there was no evidence of recurrence or post-operative complications in the 21-month follow-up. A review of the literature revealed only 38 histologically proven cases of coronoid OC in the past 30 years (1989-2018). The incidence of the disease was higher in men compared with that in women (male:female, 2.17:1), and the median age at onset was 28.7 years, with a range of 5-57 years. Gradual limitation of mouth opening and facial asymmetry are the most noticeable symptoms. Water's view and submentovertex projection of the zygomatic arch may be useful in identifying the tumor and its association with the zygoma, while CT and CBCT permit a detailed visualization of the location and density of the tumor. Coronoidectomy is the preferred treatment option, and the prognosis is excellent, with no evidence of recurrence or malignant transformation.

Osteochondroma of maxillofacial region: Tumor arising from two different developmental bones

Osteochondromas are benign bony tumors which are commonly believed to originate by the proliferation of epiphyseal cartilage into the surrounding tissues. However, this hypothesis cannot explain the occurrence of this tumor in the intramembranous bones and soft tissue. Since most of the craniofacial bones have intramembranous origin, the occurrence of this lesion in this territory is considered rare. Contrary to the above hypothesis, Lichtenstein proposed that this entity arises from the metaplastic changes in the periosteum which explains the occurrence of this tumor in endochondral as well as intramembranous bones and also in soft tissues. Complying with Lichtenstein's hypothesis, the authors are presenting two cases of osteochondromas with one arising from the endochondral bone (the coronoid process of the mandible) and the other from an intramembranous bone (lateral pterygoid plate of the sphenoid).

One-stage treatment to osteochondroma of the coronoid process and secondary facial asymmetry with coronoidectomy and reduction malarplasty: a case report and literature review

PURPOSE

This study summarizes the literature concerning osteochondroma of the mandibular coronoid process and presents a case of 1-stage treatment for this condition and concomitant facial asymmetry.

MATERIALS AND METHODS

A 20-year-old man presented with osteochondroma of the mandibular coronoid process. Radiologic images showed a mushroom-shaped coronoid growth inside the zygomatic arch with outward expansion. Coronoidectomy and reduction malarplasty were performed in 1 stage. The literature on osteochondroma of the mandibular coronoid process since 1943 was reviewed concerning etiology, pathogenesis, clinical characteristics, diagnosis, and treatment.

RESULTS

At 20-month follow-up, the patient achieved markedly improved joint function and a symmetric facial appearance after excision of the osteochondroma.

CONCLUSION

Coronoidectomy combined with simultaneous reduction malarplasty could be an alternative and promising method to treat osteochondroma of the coronoid process with secondary facial asymmetry.