The Influence of Pediatric Dental Trauma on Temporomandibular Joint Disorders: A Retrospective Clinical and Radiological Analysis

Introduction: Temporomandibular disorders (TMDs) encompass a range of pathological conditions affecting the temporomandibular joint (TMJ) and related structures, with a notably high incidence in children and adolescents that increases with age. While the overall prevalence in pediatric populations is estimated at around 16%, it is significantly lower among children under ten years old. Trauma-particularly from falls or direct impacts to the jaw-is a major initiating factor, often causing acute TMD that may progress to chronic dysfunction. In children, post-traumatic pain assessment is challenging due to difficulties in localizing or describing discomfort, making early diagnosis more complex. The orofacial region's dense sensory and motor innervation adds to the complexity of TMD-related pain. These disorders primarily affect the masticatory muscles and/or TMJ, with their onset and progression influenced by initiating, predisposing, and sustaining factors. Mandibular trauma frequently involves the condylar region, further complicating functional outcomes. Currently, no single gold standard exists for comprehensive TMJ assessment, particularly in cases of direct trauma. Clinical evaluation should emphasize non-invasive, standardized protocols such as joint auscultation, palpation for pain, assessment of maximum painless mouth opening, and evaluation of mandibular lateral and protrusive movements. Pain scoring during these assessments can provide valuable insights into functional abilities. Radiological imaging is essential for diagnosis, with modalities including panoramic radiography, CT, MRI, ultrasound, and cone-beam computed tomography (CBCT). CBCT offers high-resolution, three-dimensional imaging with lower radiation doses compared to conventional CT, enabling precise measurement of condylar morphology, joint space, and structural changes. It is especially effective in detecting erosive alterations and evaluating TMJ biomechanics. Standardized CBCT protocols enhance diagnostic consistency across clinical settings. Clinically, TMDs are characterized by orofacial pain, restricted or asymmetrical jaw movement, and joint sounds during function-symptoms that can impair speech, mastication, swallowing, and overall quality of life. Physical examination may be complemented by tools such as pressure algometry, which objectively quantifies muscle tenderness; however, it is most effective when used in conjunction with other diagnostic methods. This retrospective study investigates structural and symptomatic TMJ alterations in pediatric patients with a history of dental trauma by integrating clinical findings with CBCT-based joint space measurements. An orthodontically balanced control group was included for comparison. By correlating morphometric CBCT data with clinical symptoms-an approach rarely applied systematically in pediatric trauma-the study underscores the importance of early detection, timely intervention, and preventive strategies to mitigate long-term functional impairment in growing patients. Material and Methods: This retrospective study was approved by the Ethics Committee of Dicle University Faculty of Medicine, Diyarbakır, Turkey (Decision No: Ethical Comitee: 03.05.2013/576). A priori power analysis was conducted using G\*Power software, assuming a medium effect size (Cohen's d = 0.5), 80% statistical power, and a significance level of 0.05 (α = 0.05), indicating a minimum sample size of 33 participants to achieve statistical validity. The study group (Group 1) included 42 pediatric patients (17 females, 25 males; mean age: 12.54 ± 1.74 years) who were diagnosed with complicated crown-root fractures resulting from dental trauma between 2008 and 2023. Inclusion was restricted to cases presenting within one month post-trauma to ensure diagnostic consistency and minimize bias related to healing. All patients exhibited similar trauma severity, thereby maintaining sample homogeneity. Clinical records were reviewed to extract data on trauma-related symptoms and the presence of spontaneous jaw pain. In this cohort, cone-beam computed tomography (CBCT) was employed as a diagnostic necessity to evaluate potential temporomandibular joint (TMJ) alterations secondary to trauma. Given the limitations of clinical examination in detecting subclinical or asymptomatic TMJ changes-especially in children undergoing craniofacial development-CBCT offered a three-dimensional assessment of joint morphology to support accurate diagnosis and treatment planning. As noted by Tomina et al. CBCT offers superior 3D visualization of the condylar-glenoid fossa and is valuable for pediatric TMJ evaluation under proper clinical indications. In this study, CBCT allowed detection of displacements or trauma-related asymmetries not visible with conventional imaging. Group 2 (Control Group) consisted of 25 pediatric patients (9 girls and 16 boys) with a mean age of 12.60 ± 1.04 years. These patients exhibited no symptoms of temporomandibular joint pain. They were selected retrospectively from the records of individuals who presented to the Orthodontic Clinic for Class I orthodontic treatment between 2008 and 2023. The control group consisted of Class I malocclusion patients without TMJ symptoms, selected based on their skeletal harmony and the availability of diagnostic CBCT data. This group was chosen as a suitable clinical baseline for structural comparison instead of being a random sample of the general population. CBCT scans in the control group were not acquired for this study but retrospectively analyzed from orthodontic records. In Class I malocclusion cases, CBCT is often clinically indicated when conventional imaging is inadequate for evaluating craniofacial symmetry or TMJ morphology. Thus, no additional radiation was administered for research purposes. Following the ALADA (As Low As Diagnostically Acceptable) principle, CBCT imaging was used only when clinically justified, ensuring optimal image quality for accurate assessment while reducing radiation exposure in both the study and control groups. Informed consent was obtained from the patients' parents at the time of their initial treatment. The data used in this study were derived from patient examination forms completed during the initial assessment and follow-up forms recorded after treatment. In the study group, patient data had been previously collected by a single clinician to ensure standardization in data collection and treatment procedures. Similarly, the control group consisted of patients treated by a single orthodontist, maintaining consistency in patient selection and evaluation. In addition, all participants underwent comprehensive physical, oral, and radiological examinations as documented in their clinic records. Pain assessment occurred during palpation and mandibular movements (opening and closing). Palpation involved applying pressure to the temporomandibular joint (TMJ) area with both hands while facing the patient. Pain scoring was determined by the side of the joint where the patient felt discomfort. Pain levels were recorded using a standard pain scale to assess changes before and after treatment. For palpation and mandibular movements, pain intensity was scored using a four-level classification system: No Pain, Mild Pain, Moderate Pain, and Severe Pain. The area of joint pain was classified into four categories: No Pain, Pain in the Right TMJ, Pain in the Left TMJ, and Bilateral Pain. This scoring system allowed for the assessment of TMJ involvement and facilitated comparisons of pain distribution among participants. Cone-beam computed tomography (CBCT) was used for radiological evaluation to assess structural changes in the TMJ, providing detailed imaging of joint morphology and potential trauma-related alterations. CBCT images were obtained and evaluated before and after dental trauma treatment. In Group 2, CBCT images were obtained before treatment for patients with Class 1 orthodontic anomalies to ensure that previous interventions did not influence the assessment. In patients from group 2, evaluation was made only on CBCT images taken before the initiation of orthodontic treatment. All images in Group 1 and Group 2 were acquired using an ICAT 3D imaging system (I-CAT, Model: 17-19, Imaging Sciences International, Hatfield, PA). The scans were obtained through a 360-degree rotation at 120 kV, 5.0 mA, and a scanning duration of 9.6 seconds, with a voxel size of 0.3 mm. Image analysis was conducted using the proprietary software from I-CAT. Following the methodology described by Ikeda and Kawamura (2009), predefined anatomical landmarks were identified, and linear measurements were conducted to assess the condylar-glenoid fossa gap. The True Horizontal Line (THL) served as the reference plane for measurement. The criteria for measurement included evaluating the distances between the medial wall of the glenoid fossa and the outer side of the condyle at three specific points (anterior, superior, and posterior), while the mandible was in a closed rest position. The superior joint space was defined as the distance from the superior condylar point to the superior aspect of the glenoid fossa along the THL. Likewise, the anterior and posterior joint spaces were established by measuring the distances from the anterior and posterior condylar points to their respective aspects of the glenoid fossa. Statistical analyses were conducted to evaluate differences in joint space measurements and pain scores both within and between groups. The Mann-Whitney U test was utilized for comparisons of joint space measurements both within and among groups. For categorical pain score comparisons, the Chi-Square test was used. In this study, a p-value of ≤0.05 was considered statistically significant. All statistical analyses were performed using the SPSS software package (Version 21.0, IBM Corp., Armonk, NY, USA).