OBJECTIVE Frontal ventriculostomy is one of the most frequent and standardized procedures in neurosurgery. However, many first and subsequent punctures miss the target, and suboptimal placement or misplacement of the catheter is common. The authors therefore reexamined the landmarks and rules to determine the entry point and trajectory with the best hit rate (HtR). METHODS The authors randomly selected CT scans from their institution's DICOM pool that had been obtained in 50 patients with normal ventricular and skull anatomy and without ventricular puncture. Using a 5 × 5-cm frontal grid with 25 entry points referenced to the bregma, the authors examined trajectories 1) perpendicular to the skull, 2) toward classic facial landmarks in the coronal and sagittal planes, and 3) toward an idealized target in the middle of the ipsilateral anterior horn (ILAH). Three-dimensional virtual reality ventriculostomies were simulated for these entry points; trajectories and the HtRs were recorded, resulting in an investigation of 8000 different virtual procedures. RESULTS The best HtR for the ILAH was 86% for an ideal trajectory, 84% for a landmark trajectory, and 83% for a 90° trajectory, but only at specific entry points. The highest HtRs were found for entry points 3 or 4 cm lateral to the midline, but only in combination with a trajectory toward the contralateral canthus; and 1 or 2 cm lateral to the midline, but only paired with a trajectory toward the nasion. The same "pairing" exists for entry points and trajectories in the sagittal plane. For perpendicular (90°) trajectories, the best entry points were at 3-5 cm lateral to the midline and 3 cm anterior to the bregma, or 4 cm lateral to the midline and 2 cm anterior to the bregma. CONCLUSIONS Only a few entry points offer a chance of a greater than 80% rate of hitting the ILAH, and then only in combination with a specific trajectory. This "pairing" between entry point and trajectory was found both for landmark targeting and for perpendicular trajectories, with very limited variability. Surprisingly, the ipsilateral medial canthus, a commonly reported landmark, had low HtRs, and should not be recommended as a trajectory target.

Objectives To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function. Materials and methods All consecutive patients who had undergone tooth autotransplantation between 2000 and 2018 were invited to a clinical and radiographic follow-up examination. First, survival rates were calculated on the basis of a phone inquiry. A clinical follow-up examination allowed for the calculation of the success rate, i.e., absence of any potentially adverse clinical and radiographic findings of the autotransplanted teeth. Moreover, the effect of demographic, dental, and surgical variables on survival/success was analyzed statistically. Results Thirty-eight teeth in 35 patients were transplanted during the study period. Three teeth in 3 patients were excluded due to missing records. All other patients were successfully contacted and interviewed by phone. Out of these 35 transplants, 32 were still in function, and 3 had been extracted, yielding a 91.4% survival probability after a median follow-up of 3.4 years. Of the 32 teeth qualifying for the success analysis, 20 (62.5%) showed absence of potentially adverse findings, while 3 (9.4%) required root canal treatment (RCT). Out of the 9 mature, root-end resected transplants, 4 exhibited ongoing pulp canal obliteration, all with a single root canal. Postoperative and potentially adverse findings or failures were found more frequently in the group of mature transplants (55.6%) than immature transplants (30.4%) and for molars (72.7%) than premolars (17.6%) or canines (25%). None of the potential predictors had a statistically significant effect on survival or success. Conclusion Autotransplanted teeth yielded a satisfying midterm survival rate regardless of their stage of development. An additional, extraoral root-end resection of mature transplants may lead to rates of revascularization and postoperative pulp canal obliteration higher than the data reported on unmodified mature transplants. Clinical relevance Extraoral root-end resection of mature teeth shows promising outcomes for transplants especially with a single root canal and uncomplicated root morphology.

Objectives To evaluate the long‐term effectiveness of 6 mm implants in various indications with a micro‐rough surface after 4.6–18.2 years in function and to assess key factors associated with implant survival, success, and biologic/technical complications. Materials and methods Fifty‐five patients with seventy‐four 6 mm implants placed from 2000 to 2013 attended the re‐examination assessing well‐established clinical and radiographic parameters, biologic and prosthetic complications, and patient‐reported outcome measures. Results Five implants were lost after a mean follow‐up period of 9.1 years resulting in a survival rate of 93.2%. All losses occurred in free‐end situations in the mandible. Smoking habit significantly reduced implant survival (hazard ratio 36.25). Two implants exhibited a history of peri‐implantitis, and one implant showed progressive marginal bone loss (MBL) resulting in a success rate of 89.2%. The mean MBL amounted to 0.029 mm. Increased MBL was found for implants placed in the maxilla (0.057 mm) and for implants with a diameter of 4.1 mm (0.043 mm). Soft tissue thickness (1.39 mm) and width of keratinized mucosa (1.91 mm) had no effect on MBL. Patient‐reported outcome measures showed high satisfaction (mean VAS scores 88%) and high quality of life (mean OHIP‐G14 score 2.2). Conclusion The present study demonstrated survival and success rates of 93.2% and 89.2% for 6 mm implants used in various indications. A factor leading to higher implant failure was smoking, whereas modulating factors increasing annual MBL included implants placed in the maxilla and implants with a diameter of 4.1 mm compared to 4.8 mm.

No abstract