Coronoid hyperplasia: A review

Is panoramic radiography adequate for diagnosing coronoid process hyperplasia? A case series

INTRODUCTION

The objective of this study was to compare the length ratios obtained on panoramic radiography and computed tomography (CT) to verify whether the former is adequate for diagnosing coronoid process hyperplasia.

METHODS

A case series of patients with coronoid process hyperplasia was investigated. Length ratios between the coronoid process and condyle were measured on panoramic radiographs by using the Levandoski method and on CT scans by using the methods described by Tavassol et al. and Stopa et al. The mean length ratios obtained using the three measurement methods were compared.

RESULTS

The mean length ratio measured with the Levandoski method was significantly lower than that measured with the method described by Stopa et al. (1.09 [0.09] vs. 1.21 [0.09]; P = 0.0001) and lower than that measured with the method described by Tavassol et al. (1.09 [0.09] vs. 1.34 [0.44]; P = 0.013).

CONCLUSION

Panoramic measurement of the coronoid process by using the Levandoski method tended to underestimate the length ratio, emphasizing the importance of using a scanographic measurement method at the slightest doubt to confirm the diagnosis of coronoid process hyperplasia.

Management of Limited Mouth Opening After Open Reduction and Fixation of Mandibular Coronoid Fractures

Mandibular coronoid process fractures are relatively rare and generally treated conservatively. This paper reports a case of limited mouth opening and pain after open reduction and fixation of the mandibular coronoid fracture. After the loose titanium screws, plates, and absorbed coronoid fracture fragments were removed, the patient's mouth opening was restored immediately. The authors believe that open reduction and fixation for coronoid process fractures can cause postoperative limited mouth opening and pain. Conservative treatment of coronoid process fractures is more beneficial for patients.

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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Endoscopically Assisted Intraoral Coronoidectomy for Treatment of Coronoid Hyperplasia

Hyperplasia of the coronoid process of the mandible is a rare condition defined as an abnormal and progressive elongation of the coronoid process (unilateral or bilateral). Jacob disease is the name given to a pseudo-joint formation between the coronoid process and the zygomatic bone. The main clinical finding is a progressive, painless difficulty in opening the mouth, due to contact of the coronoid process with the posterior surface of the zygomatic bone or the medial surface of the zygomatic arch. To restore the mouth opening in a stable manner, resection of the elongated coronoid process followed by physiotherapy is the only effective treatment. Surgery (coronoidetomy or coronoidectomy) can be performed through intraoral or extraoral access. Intraoral coronoidectomy is the best surgical choice for most of the cases. However, in some cases, the intraoral surgical field prevents an adequate visualization of the osteotomy line. The authors present 5 consecutive clinical cases of hyperplasia of the coronoid process treated with an endoscopically assisted coronoidectomy using ultrasound bone-cutting instruments.

Arthrogryposis multiplex congenita: dental and maxillofacial phenotype - A scoping review

INTRODUCTION

Arthrogryposis multiplex congenita (AMC) is a heterogeneous group of disorders associated with decreased fetal movement, with a prevalence between 1/3000 and 1/5200 live births. Typical features of AMC include multiple joint contractures present at birth, and can affect all joints of the body, from the jaw, and involving the upper limbs, lower limbs and spine. The jaws may be affected in 25 % of individuals with AMC, with limited jaw movement and mouth opening. Other oral and maxillofacial deformities may be present in AMC, including cleft palate, micrognathia, periodontitis and delayed teething. To our knowledge, oral and maxillofacial abnormalities have not been systematically assessed in individuals with AMC. Therefore, this scoping review was conducted to identify, collect, and describe a comprehensive map of the existing knowledge on dental and maxillofacial involvement in individuals with AMC.

METHODOLOGY

A scoping review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. The PRISMA guidelines for scoping reviews were followed and databases were searched for empirical articles in English and French published until October 2022. We searched MEDLINE, Embase, Web of Science and ERIC databases. Two authors independently reviewed the articles and extracted the data.

RESULTS

Of a total of 997 studies that were identified, 96 met the inclusion criteria and were subsequently included in this scoping review. These 96 studies collectively provided insights into 167 patients who exhibited some form of oral and/or maxillofacial involvement. Notably, 25 % of these patients were within the age range of 0-6 months. It is worth highlighting that only 22 out of the 96 studies (22.9 %), had the primary objective of evaluating dental and/or maxillofacial deformities. Among the patients studied, a prevalent pattern emerged, revealing that severe anomalies such as micrognathia (56 %), high-arched palate (29 %), cleft palate (40 %), limited mouth opening (31 %), and dental anomalies (28 %) were frequently observed. Importantly, many of these patients were found to have more than one of these anomalies. Even though these maxillofacial impairments are known to be associated with dental problems (e.g., cleft palate is associated with oligodontia, hypodontia, and malocclusion), their secondary effects on the dental phenotype were not reported in the studies.

CONCLUSION

Our findings have uncovered a notable deficiency in existing literature concerning dental and maxillofacial manifestations in AMC. This underscores the need for interdisciplinary collaboration and the undertaking of extensive prospective cohort studies focused on AMC. These studies should assess the oral and maxillofacial abnormalities that can impact daily functioning and overall quality of life.

[Bilateral hyperplasia of the coronoid process in an adolescent patient. case report]

Hyperplasia of the coronoid process is a rare alteration that is characterized by the exaggerated and progressive development of said process over periods of months or years, both in height and volume, which finally causes mandibular hypomobility. It is important to highlight the importance of imaging for the correct diagnosis and treatment of said entity, taking into consideration the great variety of differential diagnoses that can occur. In this sense, conventional radiographs constitute a basic and indispensable tool for approaching the diagnosis. However, it is actually the CT scan that offers the greatest precision. The case of a 14-year-old male patient is presented, with no contributing medical history, who was referred for presenting progressive opening limitation since childhood, for which, after clinical and imaging evaluation, he was treated with total bilateral coronoidectomy, postoperative follow-up was performed. for a year in which recurrence of said entity could be observed. This case demonstrates the importance of correct diagnosis, as well as postoperative control and the rehabilitation scheme carried out by the patient.

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.

Congenital mandibular coronoid process hyperplasia and associated diseases

Coronoid process hyperplasia (CPH) is an oral and maxillofacial surgical disease that can result in restricted jaw movement due to an enlarged and elongated mandibular coronoid process. It is characterized by the painless progressive restriction of unilaterally or bilaterally mouth opening. Clinically, unexplained bilateral CPH is less common and therefore often overlooked or misdiagnosed, and coronoidectomy can be very effective on improving mouth opening. Currently, the exact etiology and mechanism of congenital CPH have not yet been fully understood, but it is generally believed to be genetically related. In this paper, the relationship of the congenital mandibular CPH with the related diseases was examined based on cases collected in our clinic and literature review for the clinical diagnosis and treatment of patients with restricted mouth opening associated with CPH.

TGFB3 gene mutation associated with mandibular coronoid process hyperplasia: a family investigation

OBJECTIVE

Coronoid process hyperplasia (CPH) of the mandible can lead to restricted mouth opening and maxillofacial deformities, which have been hypothesized to be closely associated with genetics. This study investigated the relationship between congenital CPH and TGFB3 mutation in a family of patients with CPH.

STUDY DESIGN

A limited mouth opening proband with CPH underwent whole-exome gene sequencing in November 2019, and the results confirmed compound heterozygous mutations in the TGFB3 gene. Subsequently, clinical imaging and genetic testing were performed on 10 other individuals in his family.

RESULTS

A total of 9 people in this family have CPH. Among them, 6 have the same exon compound heterozygous mutation sites of the TGFB3 gene (chr14-76446905 and chr14-76429713), accompanied by homozygous or heterozygous mutations in the 3'untranslated region (3'UTR) of the TGFB3 gene (chr14:76429555). The other 3 individuals have a homozygous mutation in the 3'untranslated region of the TGFB3 gene.

CONCLUSION

The heterogeneous compound mutation of the TGFB3 gene or the homozygous mutation of 3'UTR of the TGFB3 gene may be correlated with CPH. In addition, the specifically related mechanism needs to be confirmed by further genetic animal experiments.

Evaluation of Joint Formation in Coronoid Process Hyperplasia (Jacob's Disease) on CT and MR Imaging

Background

Jacob's disease is a rare pathology characterized by elongation/ enlargement of coronoid process of mandible with formation of pseudoarticulation with zygomatic arch. It presents clinically as restricted mouth opening and is often misdiagnosed as temporomandibular joint pathology.

Case Presentation

We performed cross sectional imaging and evaluation of Jacob's disease in a 14-year-old girl with restricted mouth opening, CT images including Multiplanar Reconstruction and Volume Rendered Technique revealed enlarged left coronoid process of mandible while open mouth CT images and MR images concluded the presence of joint between enlarged coronoid process and zygomatic arch.

Conclusions

Coronoid process hypertrophy and Jacob's disease are important differentials which should be considered in evaluation of restricted mouth opening. We propose that apart from CT, MR imaging should be considered in such cases for better pre-operative evaluation of joint formation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03323-7.

Shifting the Spotlight From the Mandibular Condyle to the Coronoid Process: A Report of a Unique Case of Trifid Mandibular Coronoid Process

The trifid mandibular coronoid process is an uncommon finding characterized by three projections arising from the mandibular ramus instead of a single triangular coronoid process. Previous authors reported cases of the bifid coronoid process. The authors referred to them as the bifid/second/double coronoid process. This article aims to report a unique case of a trifid coronoid process incidentally detected during radiographic evaluation for implant planning. This article also emphasizes the effectiveness of cone beam computed tomography (CBCT) volume rendering as a valuable tool in demonstrating morphological variations such as the trifid coronoid process. In addition, we discussed possible etiologies for the trifid coronoid process. To the best of our knowledge, this is the first case of the trifid coronoid process.

Effects of osseous structure based on three-dimensional reconstructive imaging evaluation in the assessment of temporomandibular joint disc position

OBJECTIVES

This pilot morphological study aimed to investigate the association between anterior disc displacement (ADD) and the status of the mandibular condyle and articular fossa.

MATERIALS AND METHODS

Thirty-four patients were divided into a normal articular disc position group and an ADD with and without reduction group. Images reconstructed were used to determine multiple group comparisons of these three different types of disc position, and the diagnostic efficacy for the morphological parameters with significant group difference was analyzed to assess.

RESULTS

The condylar volume (CV), condylar superficial area (CSA), superior joint space (SJS), and medial joint space (MJS) all exhibited obvious changes (P < 0.05). Additionally, they all had a reliable diagnostic accuracy in differentiating between normal disc position and ADD with an AUC value from 0.723 to 0.858. Among them, the CV, SJS, and MJS (P < 0.05) had a significantly positive impact on the groups by analysis of multivariate logistic ordinal regression model.

CONCLUSIONS

The CV, CSA, SJS, and MJS are significantly associated with different disc displacement types. The condyle in ADD exhibited altered dimensions. These could be promising biometric markers for assessing ADD.

CLINICAL RELEVANCE

The morphological changes of mandibular condyle and glenoid fossa were significantly influenced by the status of disc displacement, and condyles with disc displacement had three-dimensionally altered condylar dimensions, irrespective of age and sex.

Effectiveness of treatment by coronoidectomy and active rehabilitation in Langenbeck or Jacob diseases. A retrospective study of 20 cases

BACKGROUND

The objective of this study was to evaluate the mouth opening (MO) in patients with Langenbeck or Jacob diseases after a multimodal treatment combining the coronoidectomy and a self or assisted postoperative rehabilitation.

METHODS

This observational retrospective study included patients who had clinically impacted MO limitation. All patients underwent unilateral or bilateral coronoidectomy and then physical therapy for at least 3 months. MO measurements were compared between the preoperative time (M0), the immediate postoperative time (M1) and the last follow-up (M2). Other data regarding the surgical procedure and the postoperative rehabilitation were collected.

RESULTS

Twenty patients were included. The MO was significantly improved from 19.15 ± 7.02 mm at M0 to 38.00 ± 7.62 mm at M1 (p = 0.0002). After a mean follow-up of 21.5 ± 40.5 months, the mean MO was 32.85 ± 5.69 mm (M2). All patients underwent coronoidectomy through an intraoral approach except for one patient who was given a combined extra-oral approach for a recurrent disease. Rehabilitation protocol included assisted physiotherapy and self-rehabilitation in 7 patients as well as just self-rehabilitation in 13 patients. No patient showed worsening or stagnation of MO.

CONCLUSIONS

The multimodal treatment combining the surgical removal of the coronoid process and an active rehabilitation performed by the patient himself or assisted by a physiotherapist seems effective in Langenbeck or Jacob diseases.

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%.

The Regrowth of Mandibular Coronoid Process After Coronoidectomy: A Retrospective Analysis of 57 Cases

PURPOSE

Coronoidectomy is carried out frequently as a part of the cranial-maxillofacial surgery procedure. There are few articles on the fate of coronoid process after coronoidectomy, except that several case reports mentioned that coronoid process had regenerated. This study aimed to radiographically access the anatomic outcomes of coronoid process and investigate which factors were associated with the outcomes after coronoidectomy.

MATERIALS AND METHODS

A retrospective cohort study included patients undergoing coronoidectomy over a 7-year period. The primary outcome variable was the new coronoid process occurrence (yes/no). Secondary outcome variable was the type of the new coronoid process by evaluating its size, shape and position. Radiograph at 1-year postoperative visit was used to determine the outcomes. The predictor variables included age, sex, surgical purpose, surgical side, surgical approach and the maximal interincisal opening. Appropriate statistics were analyzed by SPSS version 22. χ² test and binary logistic regression were used to assess the association between predictor factors and anatomic outcomes (P <.05).

RESULTS

The study sample included 57 patients. In total, 96 coronoidectomies were performed. Seventy-four coronoid processes (77.1%) showed complete (n = 44, 45.8%), nonunion (n = 19, 19.8%) or partial (n = 11, 11.5%) regrowth, whereas no evidence of regeneration in 22 sites was observed radiographically at 1-year postoperative visit. Binary logistic regression showed that a young age (odds ratio 0.704; 95% confidence interval 0.562-0.882; P = .002) was significantly associated with regeneration of coronoid process.

CONCLUSIONS

Coronoid process can mostly regenerate after coronoidectomy. A young age may contribute to regrowth of coronoid process.

Trismus Due to Hyperplastic Coronoid Process: Series of Five Cases and Review of Literature

ABSTRACT

Hyperplasia of the coronoid process is a rare condition, potentially leading to a mechanical mouth opening restriction. Diagnostic workup and treatment will be discussed based on 5 cases. This article presents 5 cases of true coronoid process hyperplasia. In addition, we reviewed accessible literature on the topic with special attention to pathophysiologic theories, surgical approach, and postoperative physiotherapy. The improvement in the maximal intercuspidal opening ranged from 4 and 31 mm. Greater maximal intercuspidal opening improvement was connected to compliant patients, while poor outcome occurred in the case of a patient that neither followed the recommendations for physical therapy nor showed up for his follow up appointments. The success of the therapy is defined by a long-lasting and stable improvement of the mouth opening compared to the preoperative situation. In the presented cases, the outcome was strongly dependent on the patients' postoperative compliance. Based on the cases described, we conclude that a good outcome is accomplishable for patients using the methods presented, as long as patients cooperate well after surgery.Diagnostic workup in patients with trismus should be thorough to correctly diagnose rare entities such as coronoid hyperplasia. If treated correctly this condition has a good outcome, as long as the compliance of the patient is adequate.