Computed tomographic features of bilateral coronoid process hyperplasia with special emphasis on patients without interference between the process and the zygomatic bone

The Spatial Relationship Between Coronoid Process and Zygomatic Complex After Reduction Malarplasty

BACKGROUND

Reduction malarplasty presents challenges in terms of postoperative complications, particularly limited mouth opening. Excessive inward displacement of the zygomatic complex can impinge on the coronoid process resulting in restricted mouth opening. This study aimed to assess the spatial relationship between the coronoid process and the zygomatic complex after reduction malarplasty.

METHODS

A retrospective study was conducted, including consecutive patients underwent reduction malarplasty. Radiological measurements were performed before surgery and during the final follow-up, including the coronoid-condylar index, distance between the coronoid process and zygomatic complex, and thickness and density of the temporal and masseter muscles. Clinical and radiographic data were recorded and analyzed.

RESULTS

A total of 159 female patients were included with an average age of 28.1 years and a mean follow-up of 6.7 months. The mean coronoid-condylar index was 1:1.4, ranging from 1:0.6 to 1:2.6. Following surgery, the distances between the coronoid process and the anterior zygoma decreased by approximately 1 mm. Additionally, the postoperative distance between the highest point of the coronoid process and the zygomatic arch decreased by around 4 mm horizontally and changed approximately 1 mm vertically. No significant changes were observed in the thickness and density of the temporal and masseter muscles after surgery.

CONCLUSIONS

Reduction malarplasty led to a slight decrease in the distance between the coronoid process and the zygoma. The operation generally resulted in proximity between the highest point of the coronoid process and the zygomatic arch. However, we believe that common reduction malarplasty rarely leads to osseous impingement.

LEVEL OF EVIDENCE IV

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Morphological characteristics of coronoid process and revisiting definition of coronoid hyperplasia

The aim of this study was to assess the morphological characteristics of the coronoid process (CP) and define coronoid hyperplasia (CH) using cadaveric mandibles of a Caucasian population. A sample of 151 adult dry cadaveric mandibles (302 CPs) was acquired. Three distances were measured, which included the width, height, and length of CP. The surface area measurements involved area A: above the width distance line; area B: between incisura mandibulae-Alveolar ridge line and width distance line; area C: between distance lines of width and height. Finally, angulations of the CP and gonial angles were identified. Both length and surface area A + B acted as hyperplastic indicators. Based on the selection criteria, a sample of 197 CPs was included. The hooked shape (59%) was most commonly observed. No significant difference existed between left and right sides (p > 0.05). The mean values of length and surface area A + B were 2.2 ± 0.3 cm and 3.3 ± 0.8 cm2, and any values above 2.7 cm (n = 5 CPs- 2.5%) and 5.0 cm2 (n = 9 CPs- 4.6%) were described as hyperplastic, respectively. The presented data could act as quantitative reference for differentiating between normal and hyperplastic conditions.

Remarkably Elongated Coronoid Processes: A Cadaveric Case Report

An elongated coronoid process (ECP) can lead to impingement of the coronoid process on the body or arch of the zygomatic bone when opening the mouth. The etiology of ECP is unclear, but several theories have been postulated. We present a case of an ECP found in a 63-year-old in a Caucasian cadaveric specimen. The length of the coronoid process was 26.6 mm on the left side and 26.3 mm on the right side. To our knowledge, this is the longest coronoid process reported in the extant literature. The details of this case and the clinical significance are discussed.

A systematic review of treatment and outcomes in patients with mandibular coronoid process hyperplasia

Treatment of mandibular coronoid process hyperplasia (MCPH) has been described and explored in the literature. This systematic review aims to provide a comprehensive overview of the surgical and non-surgical treatment options for MCPH in pediatric and adult populations. Three databases were searched for treatment of MCPH patients (MEDLINE, Embase, and Web of Science). Two reviewers selected case reports and case series based on titles and abstracts. Finally, 55 studies reporting a total of 127 cases were included for qualitative synthesis and data extraction. The mean age at symptom onset was 15.6 years, while the mean age at diagnosis was 23.5 years. Of the included cases, 83.7% were male, and the condition was bilateral in more than 81% of the cases. Coronoidectomy was performed in 82.7% of the included cases, while coronoidotomy was performed in 3.9% of the cases. In 85.0% of the surgically treated cases, the approach was intraoral. The mean maximal intraoperative mouth opening was 38.1 mm compared with 16.5 mm at diagnosis. The mean maximal postoperative mouth opening was 35.3 mm, and the mean follow-up period was 16.3 months. Maximum mouth opening was achieved intraoperatively, and non-surgical treatment after surgery aims to reduce the risk of relapse. Additional research with a higher level of evidence is necessary to confirm these findings.

Investigation of coronoid process hyperplasia using Levandoski analysis on panoramic radiographs

BACKGROUND

The diagnosis of coronoid process hyperplasia (CPH) is usually based on symptoms and radiological imaging. Because of its similar symptoms, it can be confused with temporomandibular joint diseases. Therefore, an objective and reproducible way of diagnosis should be determined.

AIM

To investigate CPH using Levandoski analysis on panoramic radiographs to determine its prevalence.

METHODS

A total of 300 panoramic radiograph images (600 coronoid processes) were examined. Having measured the Condyle-Gonion (Cd-Go) and Coronoid-Gonion (Cor-Go) distances, the Cor-Go:Cd-Go ratio was calculated for the left and right sides of each image.

RESULTS

There was a statistically significant difference in Cd-Go and Cor-Go distances between male and female participants (P < 0.001). There was no statistically significant relationship between Cor-Go:Cd-Go ratios and gender (P > 0.05).

CONCLUSION

Cd-Go and Cor-Go distances were statistically significantly increased in males on both the left and right sides. The ratio of Cor-Go:Cd-Go was preserved in both genders. The prevalence of CPH was found to be 0.3%.

Bilateral elongated mandibular coronoid process in an Anatolian skull

Elongation or hyperplasia of coronoid process of mandible is rare condition characterized by abnormal bone development which cause malocclusion and the limited mouth opening. In this study, in an Anatolian skull, a case of bilateral elongation of mandibular coronoid process was presented. Levandoski panographic analysis was performed on the panoramic radiographie to determine the hyperplasia of the coronoid process. The right condylar process was exactly hyperplastic. The measurements of Kr-Go/Cd-Go were 95.10 mm/79.03 mm on right side and 97.53 mm/87.80 mm on left side. The ratio of Kr-Go/Cd-Go on the right side was 1.20. Elongated coronoid process is one of the factors cause mandibular hypomobility, it as reported here might lead to limited mouth opening. The knowledge of this variation or abnormality can be useful for the radiologist and surgeons and prevent misdiagnosis.

Temporomandibular joint ankylosis contributing to coronoid process hyperplasia

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±5.00mm in the case group and 14.86±2.67mm 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.

Mandibular Movement Restoration in a Child with Bilateral Coronoid Hyperplasia: A Case Report

BACKGROUND:

Coronoid process hyperplasia is an uncommon finding, characterized by an enlargement of the coronoid process, causing a mechanical obstacle by its interposing in the posterior portion of the maxilla or zygomatic arch.

CASE PRESENTATION:

The article presents a case report of a bilateral coronoid process hyperplasia in a 3-year-old girl demonstrated with inability to open the mouth and restricted jaw movement. Panoramic x-ray and 3-dimensional computed tomographic reconstruction showed bilateral elongation of the coronoid processes associated with deformation of the mandibular condyle with no involvement of the articular space. A coronoid resection by intraoral approach was done, followed by an aggressive physiotherapy. A considerable improvement in mouth opening of 30 mm was achieved. We strongly suggest early surgical treatment of coronoid hyperplasia to recover morphology and function consequently to reduce skeletofacial deformities in young patients.

CONCLUSIONS:

The article presents a clinical and surgical case of bilateral coronoidectomy in a 3-year-old girl, with retrognathic mandible. The diagnosis of bilateral coronoid process hyperplasia was confirmed, and the surgical treatment was under general anesthesia, with nasotracheal intubation guided by a nasofiber endoscope, using an intraoral approach.

Surgical Intervention for Masticatory Muscle Tendon-Aponeurosis Hyperplasia Based on the Diagnosis Using the Four-Dimensional Muscle Model

OBJECTIVES

The surgical target of Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is the masseter or temporal muscle. In our clinic, the 4-dimentional muscle model (4DMM) has been used to decide if we should approach to the masseter or temporal muscle. The aim of this study is validate the clinical usefulness of 4DMM on the basis of the surgical results.

METHODS

The 4DMM was constructed from the digital data of 3D-CT and 4-dimentional mandibular movements of the patients. It made us to able to visually observe the expansion rate of masticatory muscles at maximum mouth opening comparing to their length at closed mouth position. Fifteen patients were applied the 4DMM before the surgical treatment and 2 healthy volunteers were enrolled as control group.

RESULTS

The expansion rate of temporal muscle at the maximum mouth opening in the patient group was significantly less than that in the control group (P < 0.05). On the other hand, the masseter muscles of all patients were expanded as same as the control group. Therefore the main cause of limitation of mouth-opening was suggested to be a contracture of the temporal muscle. Consequently, we performed successful bilateral coronoidectomy with no surgical intervention to the masseter muscles in all patients.

CONCLUSION

The present 4DMM would be valuable modality to decide the target muscle of surgical treatment for patients with MMTAH. In this pathology, contracture of the temporal muscle seems to be main cause of limited mouth opening.

Bilateral coronoid hyperplasia (Jacob disease on right and elongation on left): report of a case and literature review

A case is reported of bilateral coronoid hyperplasia. The literature is reviewed concerning this condition's etiology, pathogenesis, clinical characteristics, diagnosis, and treatment. Jacob disease and coronoid elongation are both clinical features of coronoid hyperplasia. It is usually accompanied by restricted opening. The etiology and pathogenesis of coronoid hyperplasia are unclear. The condition can be diagnosed by panoramic radiographs and with 3-dimensional reconstructions from computerized tomography image data sets. Hyperplasia of the coronoid processes can be treated using an intraoral approach for coronoidectomy and dynamic laser physiotherapy after surgery. Although hyperplasia of the coronoid processes is uncommon in clinic, it can be found through careful examination and proper radiographic study. A 39-year-old female patient was referred for coronoid hyperplasia (Jacob disease on right and elongation on left). The histologic diagnosis for the right condylar condition was osteochondroma.

Hyperplasie des Processus coronoideus: Diagnose und Therapie

STUDY GOAL

As it is an unusual and infrequent clinical entity, hyperplasia of the coronoid process is often overlooked or diagnosed too late. The aim of this study was to characterize the morphology, etiology, and clinical picture of coronoid hyperplasia as well as to discuss its diagnosis and treatment.

MATERIALS AND METHODS

All cases of histologically confirmed hyperplasia of the coronoid process treated in our center between 1995 and 2004 were analyzed. Patient data were evaluated with respect to age, gender, clinical symptoms, diagnostic work-up, and treatment. The extracted data were compared to those found in the literature.

RESULTS

The study included 14 new cases and 101 cases already published: 96 with bilateral and 19 with unilateral hyperplasia. At the time of diagnosis, the subjects' mean age was 23.7 years. The patients in Bonn were all treated by coronoidectomy and appropriate physiotherapy. An improvement in mouth opening could be achieved in 86% of our patients.

CONCLUSIONS

In comparison to the somewhat disappointing results of previously published studies with regard to mouth opening and mandibular mobility, our treatment concept seems to offer the possibility for improvement. Our study emphasizes the significance of three-dimensional CT techniques for diagnosis and surgical planning, the superiority of coronoidectomy over coronoidotomy, and the importance of dynamic physiotherapy to prevent postoperative scar formation.