The temporomandibular joint (TMJ) plays a critical role in essential functions such as mastication, swallowing, speech, and airway maintenance. Constantly subjected to mechanical loading, it also serves as a growth center during childhood. In advanced stages of joint pathology, total joint replacement (TJR) with a customized prosthesis may represent the only viable therapeutic approach, particularly when restoring anatomical structure and function, or correcting esthetic deformities such as posterior vertical deficiency, often in conjunction with orthognathic surgery indicated for functional or esthetic purposes¹.

Indications for total TMJ replacement include congenital malformations, severe osteoarthritis, ankylosis, severe inflammatory disease such as rheumatoid arthritis, and idiopathic condylar resorption, trauma, neoplasms, and failed prior reconstructions. These conditions may present with a constellation of symptoms, including chronic pain, restricted mandibular mobility, progressive deviation of the dental midline, and persistent headaches, all of which significantly compromise quality of life^2-4.

Early diagnosis of temporomandibular disorders (TMDs) is feasible, but it is often underperformed due to the subtlety of initial clinical signs. However, advanced disease is typically characterized by limited mouth opening, reduced lateral excursions, pain on jaw function (JF), and mandibular deviation or progressive mandibular retrusion. Magnetic resonance imaging (MRI) aids in the evaluation of soft tissue and internal joint derangements, while cone-beam computed tomography (CBCT) remains the gold standard for precise assessment of osseous structures⁵.

Initial management of TMD typically involves conservative strategies such as pharmacological therapy, physiotherapy, and occlusal splints. In refractory cases, surgical interventions, including arthrocentesis, arthroscopy, arthroplasty, or TJR, may be required. Among these, TJR has demonstrated high safety and efficacy, with advantages such as decreased morbidity, elimination of donor-site grafts, shorter operative time, and a lower risk of postoperative resorption⁵. These benefits translate into improved pain control, mandibular function, and overall patient well-being^6,7. Recent advances in three-dimensional imaging and computer-aided surgical planning have enabled the development of patient-specific prostheses, enhancing surgical precision and prosthetic adaptation⁸.

This clinical case series aims to present the functional and clinical outcomes observed in patients with severe TMJ pathology treated with TJR using customized prosthetic devices. Particular consideration is given to postoperative changes in mandibular range of motion, functional performance, dietary intake (DI), and pain levels.

Functional outcomes at 24 months postoperatively are summarized in Table 2. All evaluated clinical parameters demonstrated notable improvement:

• IMO: Postoperative mean measurements were 32 mm passively and 33 mm with gentle force. Preoperative values were not consistently documented, limiting direct comparison.

• JF: Median score improved from 6.5 preoperatively to 3.5 postoperatively.

• DI: Median score improved from 8.0 to 1.5.

• Pain (VAS): Median score decreased from 7 to 2.

All patients exhibited favorable postoperative courses without major complications. One case required surgical revision at six months due to screw displacement; however, this did not result in any functional impairment.

TMD in older adults, particularly those over 65, frequently present as degenerative joint disease⁹. Radiographic evidence suggests that between 45% and 70% of individuals in this age group show degenerative changes in the TMJ, although most remain minimally symptomatic. In cases with clinical manifestations, the disease course is often self-limiting, with symptoms resolving within 5-8 years after the initial diagnosis, while approximately 15% of patients experience progression of the degenerative process. A higher prevalence among females has been consistently reported, a trend reflected in our case series, where all patients were women with a mean age of 56.5 years⁹.

Patient-reported outcomes related to JF and DI were evaluated using the LTPS, as described by Bhargava et al.¹⁰. In our cohort, JF improved by 3 points (from 6.5 to 3.5), and DI improved by 6.5 points (from 8 to 1.5). These outcomes are in line with Bhargava¹¹, who reported a 4.2-point (54.5%) improvement in JF and a 5.6-point (55.6%) improvement in DI. Similarly, Wolford et al.¹² documented comparable functional gains following total TMJ replacement.

Pain, assessed using the VAS, showed a 5-point reduction, mirroring findings by Gonzalez-Perez et al.¹³, who reported a decrease from 5.9 to 1 over a five-year follow-up. Bhargava¹¹ described a 75% reduction in postoperative pain, while Wolford et al.¹² noted a statistically significant 3-point decrease (P<0.001). These data support the sustained analgesic benefits associated with total TMJ replacement.

Postoperative IMO reached mean values of 33 mm, although preoperative records were unavailable, precluding a direct comparison. Nonetheless, these values fall within the functional range reported in the literature. For example, Bhargava¹¹ observed a mean increase of 30.48 mm in patients with severe ankylosis; Gonzalez-Perez et al.¹³ documented a 0.7 cm (20%) increase; and Wolford et al.¹² reported an improvement from 25.8 mm to 36.2 mm.

Concerning surgical history, a systematic review by Johnson et al.¹⁴ found that patients with two or fewer prior arthrotomies achieved a 63.1% subjective improvement in parameters such as pain, JF, and DI, compared to those with multiple prior surgeries. The number of previous interventions was proposed as a prognostic factor for treatment outcomes. In our series, three patients had a history of prior TMJ surgeries, yet no apparent correlation with poorer outcomes was observed, likely attributable to the limited sample size.

Regarding prosthetic design, all patients received customized prostheses. Although stock devices are more readily available, they are associated with higher risks of instability, dislocation, and inadequate adaptation to host bone, especially in anatomically complex cases. Custom-made prostheses offer superior integration with residual bone structures, a critical advantage in patients with compromised bone quality or multiple failed reconstructions. These devices reduce the risk of mechanical failure and enhance functional outcomes by addressing the anatomical limitations inherent in standard prosthetic designs¹⁴. In line with this, alternative reconstructive approaches have also been reported. For example, Bai et al.¹⁵ described a TMJ capsule suspension technique to stabilize the neocondyle during TMJ reconstruction with a free fibular flap, highlighting complementary strategies for complex joint reconstruction.

The most frequently reported complications associated with TMJ prosthetic surgery include facial nerve injury, prosthetic infection, often involving Staphylococcus aureus, heterotopic ossification, hypersensitivity reactions, and severe intraoperative hemorrhage¹⁶. In our series, only one patient experienced a complication: persistent pain at six months postoperatively. For evaluation, a CBCT of the area was requested, which revealed the displacement of the condylar screw. To resolve the condition, the screw was removed under general anesthesia using the same surgical approach previously employed. The screw was identified and extracted without complications. Subsequently, thorough irrigation of the joint was performed with 0.9% saline solution. No other clinically relevant findings were observed upon inspection. Anti-inflammatory medication and an antibiotic regimen were prescribed, along with complementary kinesiotherapy. Full functional recovery and resolution of symptoms was achieved.

A recent systematic review by Ravelo et al.¹⁷ confirmed that customized TMJ prostheses represent a reliable therapeutic option for degenerative joint disease, reporting survival rates close to 97% and consistent improvements in pain, function, and interincisal opening. Long-term follow-up studies, such as the 14-year evaluation of the TMJ Concepts patient-fitted prosthesis by Wolford et al.¹², further support the safety, effectiveness, and durability of these devices. Similarly, in a clinical analysis by Olate et al.¹⁸, patients treated exclusively with custom-made ARTFIX Implants prostheses demonstrated significant improvements in mouth opening, pain reduction, and functional outcomes, with a high success rate and no prosthetic failures reported during follow-up. In line with these findings, our case series with customized ARTFIX Implants devices also showed marked improvement in IMO, DI, JF, and VAS. Furthermore, despite using prostheses from different commercial brands, both systems share common design features; for instance, the manufacturer of CPMH Digital prostheses specifies a “titanium fossa with sintered polyethylene insert” and interchangeable locking screws for stable fixation¹⁹. These similarities in design and materials may help explain the consistent favorable outcomes in IMO, DI, JF, and VAS observed in our series.

However, this study has several limitations inherent to its design. As a retrospective case series, the small sample size, relatively limited follow-up duration, and absence of consistent preoperative data on mouth opening hinder comprehensive comparative analysis. Additionally, no statistical tests were applied to assess the significance of observed outcomes, due to the descriptive nature of the study.

For future research, we recommend expanding the sample size and extending the follow-up period to more thoroughly assess the long-term stability and clinical effectiveness of TMJ prostheses. Furthermore, implementing a standardized protocol for the measurement of interincisal opening, JF, and pain would enhance the reproducibility and objectivity of outcome assessment, contributing to a more robust evaluation of treatment efficacy.

Total TMJ replacement using customized prostheses proved to be a safe and effective treatment modality for patients with severe joint pathology. This intervention resulted in marked improvements in IMO, JF, DI, and pain perception, as reported by patients through standardized evaluation scales.

Although the small sample size limits the generalizability of these findings, the outcomes are consistent with current literature and reinforce the clinical value of this therapeutic approach. Further research involving larger patient cohorts, extended follow-up periods, and the use of standardized assessment protocols is essential to validate and expand upon these preliminary results.