Defects and bone loss in the maxilla and mandible pose significant challenges for dental rehabilitation. This paper focuses on complex cases of bimaxillary dental rehabilitation, where traditional dental implant protocols were not feasible in at least one jaw. Four patients were examined conceptually, where conventional dental implant placement (n = 20) was combined in either the same or opposite jaw with a patient-specific subperiosteal implant (n = 5). This study evaluates aspects such as primary stability, prosthodontic restoration, complications, and soft tissue management over the observation period. None of the five patient-specific subperiosteal implants (IPS Implants^® Preprosthetic; KLS-Martin Group, Tuttlingen, Germany) experienced failure or showed any loosening of screws, with the longest observation period extending to 68 months. These implants were securely fixated away from the posts, without any biomechanical restrictions on loading from the time of insertion. Planning and manufacturing, including the initial suprastructure, followed a fully digital workflow. The number of screws required for multivector fixation ranged from 13 to 22. All dental implants placed remain functional, definitive prosthodontic restoration has been performed, and no stability loss or peri-implantitis has been observed. The IPS Implants^® Preprosthetic emerges as a valuable consideration when conventional implant dentistry protocols encounter limitations.

Introduction: Congenital mandibular hypoplasia (CMH) remains challenging because of the underlying combined hard and soft tissue deficiency. Treatment options include craniofacial distraction, orthognathic surgery, and autologous grafts, although the latter produces inadequate results after distraction and autologous grafting. Unsatisfactory long-term stability may cause relapse, necessitating reoperation. Material and Methods: We investigated the feasibility of using alloplastic total joint replacement (TJR) in growing and young adult CMH patients. The primary outcome was long-term reconstruction stability, without implant failure. Secondary outcomes were TMJ function and pain, and jaw movements achieved during surgery. Results: Three patients (age: 9–22 years) were treated by the same surgeon at one institution during 2018–2021. Anamnesis and clinical parameters were obtained from patient records. Preoperative 3D-scans were superimposed with postoperative 3D-scans and preoperative plans, including TJR-implant STL files, to measure jaw movement. All patients underwent prior reconstructive surgery. Mandibular movement of 16.4–20.1 mm in the sagittal direction was achieved. Post-TJR follow-up ranged from 24 to 42 months. No long-term complications occurred. At the latest follow-up, the maximal interincisal opening was between 21 and 40 mm, and all implants were functioning, without failure. Conclusion: In selected CMH cases, alloplastic TJR can deliver satisfactory medium-term results with predictable and stable outcomes, even in growing patients.

Open treatment of condylar head fractures (CHF) is considered controversial. In this retrospective cohort study our primary objective was therefore to assess bone resorption and remodeling as well as patients function after open treatment of CHF in a medium-term follow-up (15.1 ± 2.2 months). We included 18 patients with 25 CHF who underwent open reduction and internal fixation, between 2016 and 2021, in our analysis. The clinical data and cone-beam computed tomography (CBCT) datasets were analyzed. The condylar processes were segmented in the postoperative (T1) and follow-up (T2) CBCT scans. Volumetric and linear bone changes were the primary outcome variables, measured by using a sophisticated 3D-algorithm. The mean condylar head volume decreased non-significantly from 3022.01 ± 825.77 mm³ (T1) to 2878.8 ± 735.60 mm³ (T2; p = 0.52). Morphological alterations indicated remodeling and resorption. The pre-operative maximal interincisal opening (MIO) was 19.75 ± 3.07 mm and significantly improved to 40.47 ± 1.7 mm during follow-up (p = 0.0005). Low rates of postoperative complications were observed. Open reduction of CHF leads to good clinical outcomes and low rates of medium-term complications. This study underlines the feasibility and importance of open treatment of CHF and may help to spread its acceptance as the preferred treatment option.

Background: Sophisticated guided surgery has not been implemented into total joint replacement-surgery (TJR) of the temporomandibular joint (TMJ) so far. Design and in-house manufacturing of a new advanced drilling guide with vector and length control for a typical TJR fossa component are described in this in vitro study, and its accuracy/utilization was evaluated and compared with those of intraoperative real-time navigation and already available standard drilling guides. Methods: Skull base segmentations of five CT-datasets from different patients were used to design drilling guides with vector and length control according to virtual surgical planning (VSP) for the TJR of the TMJ. Stereolithographic models of the skull bases were printed three times for each case. Three groups were formed to compare our newly designed advanced drilling guide with a standard drilling guide and drill-tracking by real-time navigation. The deviation of screw head position, screw length and vector in the lateral skull base have been evaluated (n = 72). Results: There was no difference in the screw head position between all three groups. The deviation of vector and length was significantly lower with the use of the advanced drilling guide compared with standard guide and navigation. However, no benefit in terms of accuracy on the lateral skull base by the use of real-time navigation could be observed. Conclusion: Since guided surgery is standard in implant dentistry and other CMF reconstructions, this new approach can be introduced into clinical practice soon, in order to increase accuracy and patient safety.

This prospective observational study had two aims: (I) to assess whether a preoperative dental screening before endoprosthesis (EP) implantation with need-based dental intervention would decrease the prevalence of periprosthetic joint infection (PJI) and (II) to evaluate whether instructed orthopedic surgeons would achieve similar results in oral screening as dentists. The preoperative oral health statuses of the patients, prior to EP insertion, were either evaluated by the patients’ general dentists (Ia) or, if the patient had not visited a general dentist, by an instructed orthopedic surgeon (Ib). Both the dentist and orthopedic surgeon used standardized risk estimation (low risk, moderate risk, and high risk) for an oral-health-related infectious complication after EP insertion, including a recommendation for further management of the patient. If required, a need-based dental rehabilitation was performed. In addition, retrospective data evaluation of a comparison group (II) was performed, which had not been screened orally preoperatively. A total of 777 patients (screening group (I): n = 402, of which 229 were screened by a dentist (Ia), 173 were screened by an orthopedic surgeon (Ib); comparison group (II): n = 375) were included. No general association between early infection rate and preoperative oral screening in general was found (1% PJI in screening group (I), 1.6% PJI in comparison group (II); p = 0.455). However, screening performance (dentist vs. orthopedic surgeon) had a significant impact on the prevalence of developed PJIs (p = 0.021). Thereby, 100% of observed infections in the screening group (I) occurred in the group with previous oral screening by an orthopedic surgeon (Ib). Furthermore, the C-reactive protein (CRP) value at discharge was significantly lower when general preoperative oral screening had been performed (group I vs. group II, p = 0.03). Only preoperative oral screening by a dentist had the potential to reduce oral-focus-associated EP infections; therefore, increased attention should be paid to the further promotion of interdisciplinary work between dentists and orthopedic surgeons. Dental screenings, using objectifiable criteria, as applied in this study, seem reasonable but require further validation in larger cohorts.