Coronoid Process Hyperplasia and Mandibular Function

Coronoid process hyperplasia is a rare developmental anomaly characterised by excessive growth of the coronoid processes of the mandible, often leading to mechanical hindrance of mandibular movements. As the enlarged processes impinge on the zygomatic arch or posterior maxilla, the infratemporal space required for smooth rotation and translation of the mandible is compromised, resulting in progressive, usually painless, limitation of mouth opening and lateral excursion. The condition most commonly presents in adolescents and young adults, with a male preponderance, and is frequently bilateral. Clinically, it may be mistaken for temporomandibular joint dysfunction or muscular disorders, delaying appropriate management. Imaging—initially panoramic radiography but preferably three-dimensional modalities—confirms the diagnosis by quantifying coronoid length and its spatial relationship to adjacent osseous landmarks. Treatment ranges from conservative physiotherapy to surgical coronoidectomy, with postoperative rehabilitation critical to restoring and maintaining function. A deeper understanding of coronoid morphology, growth patterns and biomechanical effects on the mandible underpins improvements in diagnosis, classification and patient-centred therapeutic strategies.

Research from Nature Portfolio

Recent studies have employed large-scale morphological analyses of adult dry mandibles to establish quantitative thresholds for coronoid process hyperplasia. By measuring linear dimensions and surface areas on hundreds of specimens, researchers have identified length and area values above which hyperplastic change is reliably indicated, and have described the predominant hooked shape of the process. These data offer objective reference standards to distinguish normal variation from pathological overgrowth and facilitate more consistent diagnostic criteria across clinical and research settings. Three-dimensional morphometric techniques have also been applied to refine angular measurements, linking coronoid orientation to masticatory biomechanics and potential impingement risk during mouth opening.

Coronoid Process Hyperplasia and Mandibular Function publication trend

The graph below shows the total number of articles in coronoid process hyperplasia and mandibular function across all publications each year (not limited to Nature Index journals).

Technical terms

Coronoid process: the triangular eminence projecting from the anterior aspect of the mandibular ramus.

Coronoid process hyperplasia: abnormal volumetric enlargement of the coronoid process, leading to impingement on adjacent structures and restricted mandibular movement.

Infratemporal space: the anatomical region between the mandible and cranial base necessary for unobstructed mandibular rotation and translation.

Coronoidectomy: surgical removal of the coronoid process, performed to relieve mechanical limitation of jaw opening.

Cone-beam computed tomography (CBCT): a three-dimensional imaging modality that provides high-resolution volumetric data of craniofacial structures.

Panoramic radiography: a two-dimensional dental imaging technique offering a broad overview of the jaws but with potential measurement distortions.

References

1. Morphological characteristics of coronoid process and revisiting definition of coronoid hyperplasia. Scientific Reports (2023).
2. Mandibular Coronoid Process Hypertrophy: Diagnosis and 20-Year Follow-Up with CBCT, MRI and EMG Evaluations. Applied Sciences (2021).
3. Is panoramic radiography adequate for diagnosing coronoid process hyperplasia? A case series. Journal of Stomatology Oral and Maxillofacial Surgery (2023).