Three-dimensional evaluation of the danger zone of ethmoidal foramens on the frontoethmoidal suture line on the medial orbital wall

celik, servet/0000-0002-1102-4417WOS: 000361640400006PubMed: 25613792It is clear that the importance of the ethmoidal foramen (EF) is based on its vascular contents. The frontoethmoidal suture (FS) line is recommended as more reliable navigational landmark for identifying the EF. The vertical orientation between the EF and the FS line was studied in 188 orbits using a computer software program. 146 anterior EFs (77.7 %) and 42 anterior EFs (22.3 %) were situated in the FS line as intrasutural and extrasutural, respectively. 146 posterior EFs (77.25 %) and 8 posterior EFs (4.25 %) were presented as intrasutural and extrasutural, respectively. Although accessory EFs were detected in 25.5 % specimen exhibited an extrasutural location. Majority of the EFs (1-4 EFs) were situated on the FS line. The mean distances from the FS and the anterior EF, the posterior EF and the accessory EF were measured as 2.1 +/- A 0.5, 2.0 +/- A 1.5 and 2.3 +/- A 1.2 mm, respectively. The range of the distances from the FS to the anterior EF, posterior EF and accessory EF were -1.2 to 3.32 , -1.02 to 5.76 and -1.1 to 3.65 mm, respectively. The ranges of EF changed within 1-6 mm. As the FS is not a single point, it is more suitable to make the incision 7 mm above the suture line. The data from this study to help the orbital surgeons explain and avoid unexpected hemorrhage during the orbital procedures such as posttraumatic orbital reconstruction, orbital tumor resections, anterior skull base reconstruction, and orbital decompression surgery

Computer-guided technique evaluation of the bony palate for planning individual implant placement

WOS: 000402126000006PubMed ID: 27783198Objective Different clinical problems may require a surgical approach to the dental arch, such as dentofacial orthopedics, implant-supported dental prothesis, maxillary orthodontics protraction, removable appliances, and post-traumatic dental reconstruction. The aim of this study is to analyze the dental arch size and type for supporting individual dental protheses. Materials and methods In this study, the reference measurements on the length of the bony palate, maxillary intercanine width, maxillary intermolar width, and the ratio of the maxillary to the palatinal surface were studied in 120 bony palates using a computer software program. Results The average length of the bony palate, maxilla, and palatine was measured as 104.4 +/- 30.3, 40.05 +/- 4.05, and 15.00 +/- 3.03 mm, respectively. The right and left sides of average width of intermaxillary distances were measured as 13.75 +/- 1.50 and 12.51 +/- 1.50 mm, respectively. The average width of intermolar distance was calculated as 19.82 +/- 1.61 mm (right side) and 18.89 +/- 1.69 mm (left side), respectively. The maxillary dentitions were classified as square (17%), round-square (63.5%), round (14.4%), and round V-shaped arches (5.1%). The round-square ones showed no prominent principal component. Among the maxillary arches, the round arches were characterized by small values and round V-shaped ones with the largest values. Asymmetry between the right and the left bony palate was observed. The areas with equal bony palate on both sides were present in 64.4% of the cases, and in 33.1% of the cases, bony palate was dominant on the right. Conclusions The primary principle in reconstructive treatment should be describing geometrical forms and mathematical details of the bony palate. Three-dimensional reference values relative to the dental arch may increase the success of individual treatment of surgical procedures and reduce possible complications. With the help of certain software, this research has made possible to investigate the variability of the dental arch and calculate the variety in measurements and thereby determining the most appropriate implant position, optimizing the implant axis and defining the best surgical and prosthetic solution for the patient

Computerized analysis of the greater palatine foramen to gain the palatine neurovascular bundle during palatal surgery

WOS: 000394975100008PubMed ID: 27177906Investigation of the computerized dimensional anatomic location of the greater palatine foramen (GPF) and lesser palatine foramens (LPF) is important indicating site to collect palatal donor tissue, reconstructioning the orofacial area of the oncology patient and applying the greater palatine nerve block anesthesia. The aim of this study is to determine a patient-friendly landmark and to specify the precise location of the GPF in order to standardise certain anatomical marks of safe neurovascular bundle. 120 bony palates were examined to detect the position of the GPF and the LPF related to adjacent anatomical landmarks using a computer software program. The GPF was assessed regarding the position, the diameter and the distances between each foramen and the midline maxillary suture (MMS), the inner border of alveolar ridge (AR), posterior palatal border (PBB), and incisive foramen (IF). The GPF was identified as single in 81 %, double in 16 %, triple in 2 % and absent in 2 % of the specimens. The mean distances between the GPF and the MSS, the GPF and the AR, the GPF and the PPB, the GPF and the IF were 16, 4, 4, and 40 mm, respectively. In majority of the cases, the GPF was seen between the distal surfaces of the third maxillary molar (78 %). Single LPF was observed in 53.45 % of the skulls, two LPF were observed in 31 % of the skulls bilaterally and five LPF were rare in 2.1 % of the specimens. The LPF was most commonly at the junction of the palatine bone and the inner lamella of the pterygoid plate (71.9 %). This study made possible to investigate the variability of the GPF and the feasibility of the greater palatine neurovascular bundle, and to calculate the lengths of some parameters with the help of certain software. To collect the donor tissue of the neurovascular greater palatine network, each distance among the AR-GPF-PPB were equal to 4 mm. To estimate the possible length of the graft, the incision was made along the third and the second molar to the IF as 4 cm. The data we obtained within this study have been presented to help the surgeons avoid unexpected hemorrhage during the palatinal procedures such as posttraumatic dental reconstruction, maxillofacial tumor resections, palatal micro-implants, and dentofacial orthopedic surgery

Computer-assisted analysis of anatomical relationships of the ethmoidal foramina and optic canal along the medial orbital wall

celik, servet/0000-0002-1102-4417WOS: 000361540600055PubMed: 25367707Typically, the medial orbital wall contains an anterior ethmoidal foramen (EF) and a posterior EF, but may also have multiple EFs transmitting the arteries and nerves between the orbit and the anterior cranial fossa. The aim of this study is to determine a patient-friendly landmark of the medial orbital wall and to specify a precise location of the ethmoidal foramens (EF) in order to standardize certain anatomical marks as safe ethmoidal arteries. Orientation points on the anterior ethmoidal foramen (AEF), posterior ethmoidal foramen (PEF) and middle ethmoidal foramen (MEF) were investigated in 262 orbits. Using a software program, distances between each foramen and the midpoint of the anterior lacrimal crest (ALC), the optic canal (OC), and some important angles were measured. The EFs were identified as single in 0.8 %, double in 73.7 %, triple 24,4 % and quadruple in 1.1 % specimens. The mean distances between ALC and AEF, ALC and PEF and ALC and MEF were 27.7, 10.6, and 12.95 mm, respectively. The distances from ALC-AEF, AEF-PEF, and PEF-OC were 27.7 +/- A 2.8, 10.6 +/- A 3.3, 5.4 +/- A 1 mm. The angles from the plane of the EF to the medial border of the OC were calculated as 13.2A degrees and 153A degrees, respectively. The angle from the AEF to the medial border of the OC was based on the plane between the ALC and AEF was 132A degrees. The occurrence of multiple EF with an incidence of 25 % narrows the borders of the safe region in the medial orbital wall. Safe distance of the ALC-EF was measured as 22.1 mm on medial wall. The line of the location of the EF was calculated 16.2 mm. In this study, it was possible to investigate the variability of the orbital orifice of the EF and the feasibility of the EA, to observe various angles of the orbital wall bones and to calculate the lengths of some parameters with the help of certain software

Navigational area of the cranio-orbital foramen and its significance in orbital surgery

WOS: 000345298000004PubMed ID: 24744137The cranio-orbital foramen (COF) is located on the lateral wall of the orbit. It is a potential source of hemorrhage during deep lateral orbital dissection, since it functions as an anastomosis between the lacrimal artery and the middle meningeal artery. The aim of this study was to guide and facilitate the surgical procedures in the orbit, so as to determine a navigational area and the precise location of the COF and to standardize certain anatomical marks. The navigational area of the COF and topographical features were studied in 75 craniums with presented COF. 33 bilateral main COFs, 41 (18 on the right, 23 on the left) unilateral main COFs at the main cranium and 19 accessory COFs were studied for their navigational features on the orbit. The distances between the COF and the fronto-zygomatic suture, supraorbital notch, lateral angle of the superior orbital fissure (SOF) and Whitnall's tubercle were measured. The mean distance of the COF from the fronto-zygomatic suture, supraorbital notch, lateral angle of the SOF and Whitnall's tubercle was 26.3, 37.3, 92 and 27.1 mm, respectively. For the navigational area signs of the COF, areas of the orbit that form the transversal and vertical lines are generated on the reference points. Whilst the upper outer area of the orbit contains a potential bleeding risk, the bottom section of the outer column is identified as safe for the surgical operations of the lateral orbital wall. The fronto-zygomatic suture and Whitnall's tubercle are recommended as the most reliable navigational landmarks for identifying the COF. Hence, the transversal and vertical orientation of the COF should be mastered by the surgeons reconstructing the anterior base of the skull and the orbit

Redesign and treatment planning orbital floor reconstruction using computer analysis anatomical landmarks

WOS: 000379255600029PubMed ID: 26242253Orbital floor fractures are one of the most commonly encountered maxillofacial fractures due to their weak anatomical structure. Restoration of the orbital floor following a traumatic injury or a tumor surgery is often difficult due to inadequate visibility and lack of knowledge on its anatomical details. The aim of this study is to investigate the locations of the inferior orbital fissure (IOF), infraorbital groove (G), and infraorbital foramen (Fo) and their relationship with the orbital floor using a software. Measurements from the inferior orbital rim (IOR) using the Fo, the IOF, G, and the optic canal (OC) were calculated in 268 orbits as reference points. The surgical landmarks from the G and the OC, the G and the IOF, the G and the intersection point were measured as 31.6 +/- A 6, 12.9 +/- A 4, and 12 +/- A 5 mm, respectively. The mean distances between the G and the IOR, the Fo and the IOF, and the Fo and the OC were found as 8.3 +/- A 2.1, 28.7 +/- A 3.5, and 53.6 +/- A 5.9 mm, respectively. The mean angles were calculated as OC-IOF-G 68.1A degrees A A +/- A 16.4A degrees; intersection-G-IOF as 61.4A degrees A A +/- A 15.8A degrees; IOF-OC-G as 19A degrees A A +/- A 5.5A degrees; OC-G-intersection as 31.5A degrees A A +/- A 11.9A degrees, G-intersection-OC as 129.5A degrees, IOF-intersection-G as 50.5A degrees. Furthermore, variable bony changes on the orbital floor which may lead to the differences at intersection point of the G and Fo were determined. In 28 specimens (20.9 %), unilateral accessory Fo (AcFo) was present. In 27 specimens, AcFo was situated supermaedially (96.4 %) on the main aperture. In one specimen, two intraorbital canals and Fo emerged from different points and coursed into different apertures. The measured mean distances of the AcFo-IOR and the AcFo-Fo were as 7 +/- A 2 and 7.3 +/- A 3.2 mm, respectively. The primary principle in the oculoplastic treatment of orbital floor reconstructions must be repositioning the herniated orbital aperture by maintaining the infraorbital artery and the nerve in the orbital floor. The IOF and the G were recommended as the more reliable oculoplastic surgical landmarks for identifying the orbital floor. To avoid pinching of the orbital floor structures, the triangle (IS-G-IOF) should be equilateral with an exigence of a 70A degrees angle within it. Among each distance of the intersection-IOF, IOF-G, G-intersection should be equal. With the help of certain software, this study made possible to investigate the variability of the orbital floor structures, observe the variety in measurements and calculate the parameters which are crucial in implementing personalized reconstruction and implanting support

The first step of patient-specific design calvarial implant: A quantitative analysis of fresh parietal bones

WOS: 000445241400004BackgroundAccurate knowledge of the fracture of cranial bone can provide insight into the prevention of skull fracture injuries and help aid the design of energy-absorbing head protection systems and safety helmets. When cranial bone needs to be removed or is lost, subsequent reconstruction of the defect is necessary to protect the underlying brain, or correct esthetic deformities, or both. Ideal reconstruction of defected bone is possible utilizing a biocompatible implant with a bone-like design individualized for the specific patient. The purpose of this study is to investigate the anatomical and mechanical characteristics of fresh frozen human parietal bones and determine compliance of polylactic acid-based personalized three-dimensional implants in terms of mechanical properties in order to replace such defective bones.MethodsParietal bone specimens were extracted from 19 fresh frozen cadavers. Morphological parameters of individual bone specimens were measured using Image J software. Three-point bend tests were performed to extract Young's modulus and tensile strength of the specimens from the measured force and displacement data by modeling the bone specimens as curved linear elastic beams. Also, three-point bend tests were performed to polylactic acid-based three-dimensional replicas mimicking geometry of the bone specimens in order to determine whether the material's Young's modulus and tensile strength properties comply with parietal bones.ResultsEntire fresh parietal specimens were observed to be comprised of a three-layered structure: external layers consisting of compact, high-density cortical bone and the central layer consisting of low-density, irregularly porous bone structure. Mean thickness of three-layered structure was 6.251.46mm. Mean Young's modulus and tensile strength of the specimens were 1.401.34GPa and 44.56 +/- 21.94MPa, respectively where no statistically significant differences among genders were detected (p>0.05). Mean Young's modulus and tensile strength of the polylactic acid-based three-dimensional implants mimicking geometry of the bone specimens were 1.8 +/- 0.7GPa and 72.8 +/- 2.5MPa, respectively.ConclusionsPolylactic acid-based three-dimensional implants can be considered as acceptable candidates for temporary replacement of parietal defects in terms of mechanical properties.Level of Evidence: Not ratable