TMJ pathomorphology in patients with JIA-radiographic parameters for early diagnosis

Reliability of landmark identification for analysis of the temporomandibular joint in real-time MRI

BACKGROUND

Real-time magnetic resonance imaging (rtMRI) is essential for diagnosing and comprehending temporomandibular joint (TMJ) movements. Current methods for tracking and analysis require manual landmark placement on each acquisition frame. Therefore, our study aimed to assess the inter- and intra-rater reliability of placing cephalometric landmarks in frames from a dynamic real-time TMJ MRI.

MATERIAL AND METHODS

Four real-time MRIs of the right TMJ were taken during mandibular movement at ten frames per second. Seven dentists identified ten landmarks on two frames (intercuspal position-ICP-and maximum mouth opening-MMO) twice at a two-week interval, yielding 112 tracings. Six typical cephalometric measurements (angles and distances) were derived from these landmarks. The reliabilities of landmarks and measurements were evaluated using distance-based (dbICC), linear mixed effect model intraclass correlation (lmeICC), and standard ICC.

RESULTS

The average inter-rater reliability for the landmarks stood at 0.92 (dbICC) and 0.93 (lmeICC). The intra-rater reliability scores were 0.97 and 0.98. Over 80% of the landmarks showed an ICC greater than 0.98 (inter-rater) and over 0.99 (intra-rater). The lowest landmark ICC was observed for the orbitale and the oblique ridge of the mandibular ramus. However, the cephalometric angle and distance measurements derived from these landmarks showed only moderate to good reliability, whereas the reliability in the frames with ICP was better than those with MMO. Measurements performed in the ICP frame were more reliable than measurements in the MMO frame.

CONCLUSION

While dentists reliably localize isolated landmarks in real-time MRIs, the cephalometric measurements derived from them remain inconsistent. The better results in ICP than MMO are probably due to a more familiar jaw position. The higher error rate of the TMJ measurements in MMO could be associated with a lack of training in real-time MRI analysis in dentistry.

Prevalence of incidental findings in adult vs. adolescent patients in the course of orthodontic X-ray diagnostics

OBJECTIVE

Due to increasing numbers of adult patients presenting to orthodontic practices, an increase in incidental findings on diagnostic X‑rays, which are the cornerstone of orthodontic diagnostics, is expected. This raises the clinically relevant question of whether an age effect exists regarding prevalence, localisation and severity of incidental findings on orthodontic diagnostic X‑rays.

MATERIALS AND METHODS

The clinical, primarily retrospective study examined pathological incidental findings from 600 orthopantomograms (OPT) and lateral cephalogram (LC) images in two groups of orthodontic patients (group I: 150 children/adolescents, age 11.89 ± 2.47 years; group II: 150 adults, age 27.03 ± 10.42 years). Prevalence, localisation and severity of the findings were recorded based on a classification sheet. The assessment was done by three experienced examiners following a systematic approach along the nine locations: mandible, maxilla, dentition, paranasal sinuses, temporomandibular joint, cranial base, orbit, cervical spine, soft tissues.

RESULTS

In all, 1458 incidental findings were detected, with 66% of the findings having occurred away from the dentition. There was a significant age effect (p < 0.001) with respect to the prevalence of incidental findings (group II-adults 1026 findings-OPT: 566/LC 460 vs. group I-children/adolescents 432 findings-OPT: 221/LC 211). Regarding localisation, incidental findings in adults commonly occurred in the dentition, paranasal sinuses and mandibular regions. Furthermore, analysis of the LC images revealed significantly more incidental findings in the area of the cranial base and cervical spine in adults (p < 0.001, p = 0.003). Categorisation according to the severity of the incidental findings showed that 33% of the incidental findings needed further diagnostic investigation and possibly treatment by other specialities.

CONCLUSION

Diagnostic assessment using orthodontic diagnostic X‑rays results in a high prevalence of incidental findings away from the dentition. Particularly in adults, a large number of incidental findings outside the dental/alveolar region may be expected on orthodontic diagnostic X‑rays. Thus, a structured approach during diagnostic assessment is required to minimise the extent to which incidental findings of clinical relevance are overlooked.

Clinical and Instrumental TMJ Evaluation in Children and Adolescents with Juvenile Idiopathic Arthritis: A Case—Control Study

To investigate temporomandibular joint (TMJ) involvement signs such as muscle pain, the ratio of masseter and temporal muscle activity, mouth opening width and jaw deviation during mouth opening in children and adolescents with juvenile idiopathic arthritis (JIA), a group of 32 subjects with JIA and a control group of 32 healthy subjects were evaluated. Data were collected clinically by muscle palpation (masseters, anterior temporalis and sternocleidomastoids) and instrumental analysis (electromyography and kinesiography). Higher pain was registered in the masseter and sternocleidomastoid muscles on both sides and in the right anterior temporalis in the JIA group compared to the control group (p < 0.05). Electromyography showed no statistically significant difference in the frequency of the pathological ratio of masseter and temporal muscle activity (MM/TA < 1) both in the JIA group and in the control group. Kinesiography showed a statistically significant difference in mouth opening width and jaw deviation during mouth opening between the groups (p < 0.05): JIA subjects showed lower mouth opening values and wider deviation on mouth opening; 29 out of 32 JIA subjects showed jaw deviation towards the right side. JIA affects the TMJ, causing myalgia in the head and neck muscles, a reduction in mouth opening width and an increase in jaw deviation during mouth opening.