Search

The purpose of this study was to investigate the association between coronoid process hyperplasia and temporomandibular joint (TMJ) ankylosis and to analyze the pathological mechanism and clinical significance of coronoid process hyperplasia. Forty-four patients treated for TMJ ankylosis between January 2007 and December 2014 were studied retrospectively; 176 patients with normal TMJs served as controls. The original DICOM data were used to reconstruct the jaw, and a three-dimensional cephalometric analysis (SimPlant Pro software version 11.04) was performed to assess the association between the severity of TMJ ankylosis and the height of the coronoid process. The height of the coronoid process was 20.41 ± 5.00 mm in the case group and 14.86 ± 2.67 mm in the control group; there was a significant difference between the two groups ( P < 0.001). Long-standing TMJ ankylosis contributes to coronoid process hyperplasia. Therefore, attention should be drawn to the coronoid process in patients with TMJ ankylosis. A coronoidectomy together with arthroplasty is recommended in patients with TMJ ankylosis. [ABSTRACT FROM AUTHOR]

Abstract: Fractures of the coronoid process are uncommon and can easily be missed. The purpose of this study was to classify the fracture patterns and explore the treatment options. This retrospective study included 39 patients with fractures of the mandibular coronoid process. Treatment protocols were developed based on the time of fracture, degree of mouth opening, location of the coronoid fracture, types of fracture, and other concomitant fractures. All patients were followed up for 12–60 months. Sixteen patients underwent conservative management and four of these patients developed progressive trismus, which improved significantly after removal of the coronoid process. Twenty-three patients underwent open reduction and internal fixation (ORIF) via the modified retromandibular approach. Follow-up data showed significant improvement in maximum mouth opening and symptoms (diet and pain) compared to their preoperative status. In summary, conservative management is first recommended for fractures of the coronoid process with minimal displacement or restriction of mouth opening. For patients with significant fracture displacement and limited mouth opening, or with concomitant fractures of the zygoma, zygomatic arch, or mandibular ramus, ORIF via the modified retromandibular approach through the anterior border of the parotid gland is an alternative treatment method. [Copyright &y& Elsevier]

Abstract: Although the precise prediction of the results before distraction is important, performing three-dimensional (3D) simulations for all distraction osteogenesis patients is not practical. Formulating general guidelines based on the factors affecting the 3D results of distraction treatment is recommended. This study was performed on a 3D mandible based on a finite element method. Three surgical cuts (oblique, vertical and horizontal) were made in the right side of the mandible. The amount and direction of movement of proximal and distal segments were evaluated after simulation of 15mm of distraction. In the distal segment, the maximum displacement in the pogonion occurred in the vertical cut. In the proximal segment, the maximum displacement occurred in the coronoid process in horizontal and oblique cuts in a superior direction. The condylar process rotated in the clockwise direction when the vertical cut was used and the coronoid process moved inferiorly. To make the gonial angle more prominent the vertical cut should be used. A horizontal cut is used to lengthen the ramus. Vertical and oblique cuts can be used in patients with long anterior facial height, but all other conditions being equal horizontal cuts are better used in short faced patients. [Copyright &y& Elsevier]

Abstract: Impingement of the enlarged coronoid processes against the medial surfaces of the zygomatic arches and posterior surfaces of the body of the zygomatic bones results in mechanical restriction of the mouth opening. The authors introduce a helpful tool for easy assessment and estimatation of the length of the coronoid process, measured on the CT scans of 40 patients (20 adults, 20 adolescents) and report a case of a 13-year-old boy suffering from restricted mouth opening caused by bilateral hyperplasia of the coronoid process. The CT based analysis resulted in a mean length of the coronoid process of 13.02mm in adults and 12.43mm in adolescents. The 13-year-old boy had a length of nearly 2cm. For comparison, a coronoid/condyle ratio was developed. This ratio showed a value of 0.78 for all patients compared with a value of about 2.0 for the boy. The literature review revealed comparable results to the reported case. Most of the patients were adolescent, male and presented a median history of 2years until correct diagnosis. [Copyright &y& Elsevier]

Abstract: Jacob''s disease is a rare condition consisting of pseudojoint formation between enlarged coronoid process and the inner surface of the zygoma. The authors report a 45-year-old female patient who presented with limited mouth opening (5mm) and swelling of the left zygoma. No temporomandibular joint disease was diagnosed. 3D computed tomography images showed a mushroom-shaped coronoid growth with pseudojoint formation medial and superior to the zygomatic arch. Under general anaesthesia, coronoidectomy was carried out through a combined extraoral and intraoral approach. Histopathological examination revealed normal trabecular bone covered with hyaline cartilage. To the best of the authors’ knowledge this case is the fifth typical mushroom-shaped Jacob''s disease; only four similar cases have been reported. A review of the literature revealed only 39 histologically proved cases of Jacob''s disease cases up to 2010. Aggressive physical treatment was given to improve function and maximum mouth opening, which had increased to 40mm at 3 months follow-up. The literature concerning this condition''s aetiology, pathogenesis, clinical characteristics, diagnosis, and treatment is reviewed. [Copyright &y& Elsevier]

Abstract: Sagittal application of a titanium mini screw in the coronoid process at the time of coronoidotomy is a very efficient method for easy removal. [Copyright &y& Elsevier]

Abstract: A benign tumour of osseous and cartilaginous origins, osteochondroma generally develops in osseous tissue and is frequently found near the end of long bones. It is relatively rare in the oral and maxillofacial region but is common in the mandibular condyle and coronoid process in the pediculate form. This is a report on a rare case of osteochondroma in soft tissue near the mandibular angle without pedicle to the bone. [Copyright &y& Elsevier]