Condylar bony change and craniofacial morphology in orthodontic patients with temporomandibular disorders (TMD) symptoms: A pilot study using helical computed tomography and magnetic resonance imaging

Abstract

The present study was performed to investigate how condylar bony changes related to craniofacial morphology. Twenty‐nine subjects (an average age of 18.8) with condylar bony changes were selected from orthodontic patients who had undergone both helical computed tomography (CT) and magnetic resonance imaging (MRI) to evaluate suspected temporomandibular joint (TMJ) internal derangement and condylar bony changes. Craniofacial morphology was assessed with lateral and frontal cephalograms. For each patient, six linear and five angular measurements were compared with an age‐ and sex‐matched population from the Japanese standard. In the bilateral condylar bony change group (bilateral group), osteophyte formation and erosion were the common bony change and were present in adult as well as juvenile subjects. In the unilateral condylar bony change group (unilateral group), flattening was the most common feature, erosion was only present in subjects below 19 years. Disk displacement without reduction was seen in 90.6% of the bilateral group, and in 76.9% of the unilateral group. In the bilateral group, retrognathic mandible was shown. In the unilateral group, all subjects exhibited a lateral shift of the menton to the side with condylar bony changes. These findings suggested that condylar bony changes might be progressive and unstable in adults of the bilateral group as well as juveniles of the both groups. It is concluded that condylar bony changes may be related to a lateral shift of the mandible and a retrognathic mandible in orthodontic patients with temporomandibular disorders (TMD) symptoms.

Cartilage changes link retrognathic mandibular growth to TMJ disc displacement in a rabbit model

“…Severe cartilage reactions were linked to ipsilateral impairment and retrognathic direction of mandibular growth. By verifying how histological condylar cartilage reactions and subsequent ipsilateral retrognathic mandibular growth are linked sequals to surgically created nonreducing TMJ disc displacement during growth in the rabbit model; the present experimental study might contribute to the understanding of the reported clinical association between facial as ymmetry and non-reducing TMJ disk displacement in humans 8,10,20,21,23,25 [ ( ) T D $ F I G ] Table 1.…”

“…The condylar cartilage is a biologically unique articular cartilage with an exceptional capacity for adaptive modelling in response to external stimuli 24 . The cellular activity of the cartilage is regulated by various local growth factors 22 and changes in the cartilage's biophysical environment, such as altered articulating function, triggers or impairs their endogenous expression, leading to increased or decreased condylar growth 6,24 .Several clinical studies of facial asymmetry and mandibular retrognathia, have reported an association with coexisting non-reducing TMJ disc displacement in adults as well as in children and adolescents 8,10,20,21,23,25 . Whether the adverse craniofacial growth predisposed for displacement of the TMJ disc or vice versa was clinically unclear, but cause and effect has been established in longitudinal Int.…”

“…Several clinical studies of facial asymmetry and mandibular retrognathia, have reported an association with coexisting non-reducing TMJ disc displacement in adults as well as in children and adolescents 8,10,20,21,23,25 . Whether the adverse craniofacial growth predisposed for displacement of the TMJ disc or vice versa was clinically unclear, but cause and effect has been established in longitudinal Int.…”

“…Several clinical studies of facial asymmetry and mandibular retrognathia, have reported an association with coexisting non-reducing TMJ disc displacement in adults as well as in children and adolescents 8,10,20,21,23,25 . Whether the adverse craniofacial growth predisposed for displacement of the TMJ disc or vice versa was clinically unclear, but cause and effect has been established in longitudinal experimental studies verifying that surgically induced non-reducing TMJ disc displacement with onset during the growth period in a rabbit model, caused subsequent ipsilateral impairment of mandibular growth 13,14 , and that with bilateral joint affliction, the extent of growth impairment corresponded to the development of mandibular retrognathia in man 4 .…”

Role of Articular Disc in Condylar Regeneration of the Mandible

“…The absence of the TMj due to discectomy induces histological changes in the condylar cartilage [11]. several clinical studies on facial asymmetry and mandibular retrognathia in children and adolescents have reported an association of these conditions with coexisting irreducible displacement of the TMj disc [7,15,17,19,20,22]. in animal experiments, TMj disc displacement was shown to induce histological changes in the condylar cartilage and exert a substantial influence on mandibular growth [1].…”