Total joint reconstruction using computer-assisted surgery with stock prostheses for a patient with bilateral TMJ ankylosis

Mandibular Condylar Head Regeneration Owing to Remodeling of the Costochondral Graft After Condylectomy for Odontogenic Myxoma

Odontogenic myxoma of the mandibular condyle is a rare tumor that requires complete surgical resection because of the tendency for recurrence. The right mandibular condyle was resected to remove the myxoma. The author performed immediate condylar reconstruction using a costochondral graft (CCG), and stable temporomandibular joint (TMJ) function and occlusion were achieved. During follow-up, the grafted CCG healed well, and a favorable bony union with the mandibular ramus was observed. Furthermore, unexpected bony remodeling was observed in the CCG; growth of the cartilaginous part resulted in the formation of a structure similar to the condylar head, and the body of the rib bone thickened similar to the mandibular subcondylar region. In conclusion, the author reported the successful removal of an odontogenic myxoma from the right mandibular condyle via condylectomy, condylar reconstruction using a CCG, and condylar head regeneration owing to CCG remodeling.

Advancements in computer-assisted orthognathic surgery: A comprehensive review and clinical application in South Korea

OBJECTIVES

Orthognathic surgery (OS) has evolved with technological advancements, notably through the implementation of computer-assisted orthognathic surgery (CAOS). This article aims to elucidate various types of CAOS and their efficiency and accuracy, supplemented by a thorough literature review focusing on their clinical applications in South Korea.

STUDY SELECTION, DATA, AND SOURCES

A comprehensive search strategy was employed, including systematic reviews, meta-analyses, randomized controlled trials, and observational studies published until December 2023 in the PubMed, MEDLINE, and Google Scholar databases. The literature search was limited to articles written in English.

RESULTS

Static CAOS demonstrated high precision, reduced operative time, and high accuracy, suggesting its potential reliability in orthognathic procedures. Dynamic CAOS presented a promising avenue for exploration, showing an accuracy comparable to that of traditional methods. The critical considerations for CAOS include accuracy, time efficiency, and cost-effectiveness. Recent studies have indicated advancements in the time efficiency of static CAOS. Static CAOS requires less equipment and is more cost-effective than dynamic CAOS.

CONCLUSIONS

CAOS offers clear advantages over conventional OS in terms of surgical convenience and accuracy in implementing the surgical plan. To achieve recognition as the gold standard method for maxillofacial deformity treatment, CAOS must overcome its limitations and undergo continuous verification via well-designed studies.

CLINICAL SIGNIFICANCE

The introduction of CAOS, mainly static CAOS with high precision and reduced surgical time, signifies a notable advancement in OS. However, rigorous studies are warranted to validate CAOS as the gold standard for treating maxillofacial deformities.

Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

BACKGROUND

This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed.

RESULTS

The output of implants was accurately implemented within the error range (- 0.03-0.03 mm), and the surgical accuracy varied depending on the measured area (range - 0.4-1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery.

CONCLUSION

To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

Total Alloplastic Temporomandibular Joint Replacement

Purpose

End-stage temporomandibular joint (TMJ) disease are not uncommon and affects quality of life. Multiple surgical procedures have been mentioned in literature for management of TMJ disease which ranges from conservative management to aggressive resection of involved joint and replacement with alloplastic total joint prosthesis. The purpose of the present paper was to provide an overview of the role of alloplastic total joint prosthesis in TMJ replacement.

Methods and results

Alloplastic total joint prosthesis is nowadays considered as a standard of care in the adult patients who require TMJ replacement. The requirement of alloplastic total prosthesis has increased in present era with the improvement in design and material of implants, surgical skills and reported victorious outcome along with improved quality of life after its use. It provides restoration of form and functions, improvement in quality of life, reduction in pain and maintenance of ramal height. Additionally, in TMJ ankylosis it reduces chances of re-ankylosis and allows facial asymmetry correction. Currently, enough evidence is however not available for replacement in skeletally immature patient.

Conclusion

The authors conclude that the total joint replacement is a standard procedure for end-stage TMJ disease. Every maxillofacial surgeon should be well-acquainted with TMJ replacement.

Alloplastic total joint replacement in management of temporomandibular joint ankylosis

Both autogenous and alloplastic material have been used in management of temporomandibular joint (TMJ) ankylosis. Second surgical site, donor site morbidity, possibility of over/undergrowth, graft fracture or resorption and increased surgical time are the disadvantages of autogenous graft. Alloplastic total joint replacement (TJR) has become a promising technique in management of adult temporomandibular joint ankylosis (TMJA). This paper intends to present the role of alloplastic TJR in management of TMJA. There is significant current evidence of the role of alloplastic TJR in the management of TMJA. Results in TMJA are excellent with sustained improvement in pain free mouth opening, correction of facial asymmetry, reduction in recurrence and improved quality of life. TMJ TJR is becoming the gold standard of care in the management of TMJA, although costs can sometime preclude access to this mode of therapy.

The use of cutting/positioning devices for custom-fitted temporomandibular joint alloplastic reconstruction: current knowledge and development of a new system

Alloplastic replacement of the temporomandibular joint (TMJ) is the treatment of choice in cases of TMJ end-stage disease. Improvements in computer-aided design/computer-aided manufacturing (CAD/CAM) translated into the possibility ongf designi very precise TMJ prostheses based on the anatomy of each single patient. Custom-made TMJ prostheses are described in the most recent literature and provide facilitations in terms of ease of placement and accuracy. Although before the era of custom-made surgical guides, they did not play a prominent role in the field of TMJ surgery, their use has become mandatory when custom-made prostheses are used. Surgical guides, generally known also as cutting guides, allow the subcondylar bone cut to be performed according to the exact shape and size of the planned prostheses. Additionally, they allow the predrilling of fixation holes in the mandible to minimize errors in prostheses positioning. However, the design of surgical guides did not evolve over time as much as prostheses did. In this paper the authors critically analysed literature on this topic and described the improvements of surgical guides over time. Moreover, based on the findings of literature research, a new cutting guide system was developed and is proposed in this article.