Contemporary CBCT diagnostics-discovery of a new artery with possible impact on surgical planning: the anterior superior palatal alveolar artery.

PURPOSE: An ongoing clinical trial regarding intra- and post-surgical morbidity in maxillary apicoectomies showed significant higher morbidity for upper canines and palatal roots of upper 1st premolars. Analysis of available presurgical cone beam computed tomography (CBCT)-scans revealed the existence of an unknown bone-canal branching off from the bone-canal or groove of the anterior superior alveolar artery (asaa). Aim of the study was the determination of the contents of this newly found bone canal in human cadaver heads, its prevalence as possible standard anatomical structure and its automatized detection with a contemporary high-resolution TRIUM-CBCT-device in vivo. METHODS: 35 human cadaver heads were dissected, the prevalence of the bone-canal determined and its contents analyzed by histology. 835 consecutive routine high-resolution TRIUM-CBCT-scans from routine patients were analyzed by an automatized detection- and tracing-algorithm for in vivo-determination of prevalence of this bone canal. Automatized detection and additional manual tracing were statistically evaluated by SSPS 20.0 software. RESULTS: The bone-canal was found in 96% of the anatomical specimens, its content identified as artery not described until now and named after the first finder "Arteria Kurrekii". Automatized tracing of TRIUM-CBCT-scans with additional manual tracing revealed an in vivo prevalence of this newly found artery of 95% (p ≤ 0.05). CONCLUSIONS: The newly found anterior superior palatal alveolar artery (aspaa-"Arteria Kurrekii") might have the same clinical impact for surgical procedures in the maxilla as the posterior superior alveolar artery (psaa). Its first detection was enabled by high-resolution TRIUM-CBCT devices and prevalence as standard anatomical structure proven in vivo by automatized CBCT-scan analysis.

Schneiderian membrane detachment using transcrestal hydrodynamic ultrasonic cavitational sinus lift: a human cadaver head study and histologic analysis.

PURPOSE: Recent studies have suggested the osteogenic layer of the periosteum at the base of the sinus membrane to play a key role in bone regeneration after sinus lift procedures. Thus, atraumatic detachment of the sinus membrane with an intact periosteum seems mandatory. The present histologic study of fresh human cadaver heads investigated the detachment behavior and histologic integrity of the detached periosteum after application of the transcrestal hydrodynamic ultrasonic cavitational sinus lift (tHUCSL-INTRALIFT). MATERIALS AND METHODS: A total of 15 sinuses in 8 fresh human cadaver heads were treated using tHUCSL-INTRALIFT. After surgery, they were checked macroscopically for damage to the sinus membrane and then processed for histologic inspection under light microscopy. A total of 150 histologic specimens, randomly selected from the core surgical sites, were investigated using hematoxylin-eosin (HE), Azan, and trichrome staining. RESULTS: None of the 150 inspected specimens showed any perforation or dissection of the periosteum from the subepithelial connective tissue and respiratory epithelium and were fully detached from the bony antrum floor. The connecting Sharpey fibers revealed to be cleanly separated from the sinus floor in all specimens. CONCLUSIONS: The results of the present study suggest tHUCSL-INTRALIFT should be used to perform predictable and safe detachment of the periosteum from the bony sinus floor as a prerequisite for undisturbed and successful physiologic subantral bone regeneration.

Hydrodynamic ultrasonic sinus floor elevation--an experimental study in sheep.

PURPOSE: The aim of the present study was to evaluate the pressure forces appearing to elevate the sinus membrane by comparing the hydraulic and pneumatic pressure. Also, the relation between the time and volume of the applied liquid and the achieved lift-volume were determined. MATERIALS AND METHODS: A total of 190 fresh, half sheep heads were used for the present investigation. An ultrasound surgical device (Piezotome; Acteon, Bordeaux, France) was tested to evaluate the pressure increase at different flow rates. The elevation volume at different flow rates and activation times of the ultrasound hand piece were measured. RESULTS: To detach the sinus membrane pneumatically from the sinus floor, a mean average pressure of 29.54 millibars was required. Using the hydraulic technique, a mean average pressure of 19.8 millibars was determined. Comparing the different flow rates, the elevated volume increased to 0.52 mL when a flow of 60 mL/minute was used. Using an activation time of 20 seconds, a lifted volume of 3.92 mL could be measured on average. If the flow was set to a maximum of 60 mL/minute, the created volume increased to 5.58 mL. A comparison using the chi(2) test showed a significant correlation (P = .03) between the application time and the created sinus lift volume. Even at high flow rates of 60 mL/minute of the activated Piezotome for a 20-second period, no rupture of the sinus membrane of the sheep heads occurred in 190 experiments. CONCLUSION: From these results, we have concluded that hydrodynamic ultrasound could be used as an alternative method for sinus floor elevations of any size and volume with a mere 3-mm-diameter transcrestal approach, if findings from clinical investigations confirm the results of the present animal study.

Primary implant stability in augmented sinuslift-sites after completed bone regeneration: a randomized controlled clinical study comparing four subantrally inserted biomaterials.

Implant-Insertion-Torque-Value (ITV) proved to be a significant clinical parameter to predict long term implant success-rates and to decide upon immediate loading. The study evaluated ITVs, when four different and commonly used biomaterials were used in sinuslift-procedures compared to natural subantral bone in two-stage-implant-procedures. The tHUCSL-INTRALIFT-method was chosen for sinuslifting in 155 sinuslift-sites for its minimal invasive transcrestal approach and scalable augmentation volume. Four different biomaterials were inserted randomly (easy-graft CRYSTAL n = 38, easy-graft CLASSIC n = 41, NanoBone n = 42, BioOss n = 34), 2 ccm in each case. After a mean healing period of 8,92 months uniform tapered screw Q2-implants were inserted and Drill-Torque-Values (DTV) and ITV were recorded and compared to a group of 36 subantral sites without need of sinuslifting. DTV/ITV were processed for statistics by ANOVA-tests. Mean DTV/ITV obtained in Ncm were: Control Group 10,2/22,2, Bio-Oss 12,7/26,2, NanoBone 17,5/33,3, easy-graft CLASSIC 20,3/45,9, easy-graft CRYSTAL 23,8/56,6 Ncm, significance-level of differences throughout p < 0,05. Within the limits of this study the results suggest self-hardening solid-block-like bone-graft-materials to achieve significantly better DTV/ITV than loose granulate biomaterials for its suspected improvement of vascularization and mineralization of the subantral scaffold by full immobilization of the augmentation site towards pressure changes in the human sinus at normal breathing.

Rupture length of the sinus membrane after 1.2 mm puncture and surgical sinus elevation: an experimental animal cadaver study.

OBJECTIVES: To evaluate the rupture length of the sinus membrane after applying a defined 1.2 mm defect comparing 3 different techniques: Summers lift, balloon-assisted technique (BASL), and hydrodynamic ultrasonic cavitational sinus lift (HUCSL). STUDY DESIGN: Thirty fresh sheep heads (60 maxillary sinuses) were investigated. The sinus membrane was ruptured using a 1.2 mm pilot drill. Then Summers lift, BASL, and HUCSL were each performed on 20 sinuses, creating a 5 mm vertical lift of the sinus membrane. The length of the ruptured sinus membrane was measured before and after the experiment. The results of the different sinus lift techniques were compared using t tests. RESULTS: The t test showed that the Summers lift leads to a significantly higher rupture length (P = .05) than BASL. The comparison between Summers lift and HUCSL showed a significantly higher rupture length with the Summers lift (P < .005). The same significance (P < .005) was found when BASL was compared with HUCSL. Comparing the increasing rupture length of the sinus membrane during the experiment, the t test showed a significantly greater rupture using BASL or the Summers lift compared with HUCSL. CONCLUSIONS: The HUCSL technique yielded the lowest increase of rupture length compared with BASL and Summers lift. The technique therefore shows the lowest risk of a growing rupture of the sinus membrane in case of an iatrogenic puncture during preparation of the transcrestal approach.