A radiographic analysis of the mandibular canal of the edentulous mandible in different racial and gender groups

Studies on the mandibular canal in the edentulous mandible have rarely been correlated with mandibular canal position, mandibular body width, mandibular canal width, thickness of bony plates, gender and race. The aim of this investigation was to examine the above parameters by studying the bucco-lingual relationship of the mandibular canal in dry edentulous mandibles of Black and White, males and females (n = 13 in each group), of similar age (mean 58, 17 yrs). The mandibles were radiographed cross-sectionally. The position of the mandibular canal in relation to the buccal and lingual cortical plates, and the widths of the mandibular canal and mandibular body, measured at selected distances, were recorded and the values statistically analysed. Race and gender do not seem to influence the position of the mandibular canal in the bucco-lingual plane. The location of the canal is predominantly closer to the lingual cortex in the bucco-lingual plane. It was found that the widths of the left and right halves of the mandibular body are not statistically significantly different but widths of the left and right mandibular canal are significantly different.     

Mandibular fracture after endosseous implant placement in conjunction with inferior alveolar nerve transposition: a patient treatment report

A patient with a severely atrophic right posterior mandible had three endosseous implants placed in conjunction with transposition of the inferior alveolar nerve. Three weeks following implant placement surgery, the patient experienced a spontaneous fracture of the mandible involving the two anterior implants. The two implants were removed, and the fracture was treated with open reduction and fixation with titanium mesh. The fracture healed, and the posterior implant integrated. This report suggests that the buccolingual and superior-inferior position of the mandibular canal can increase the possibility of mandibular fracture by increasing the size of the buccal cortical plate that is removed to expose the nerve during surgery.     

Interpretation of linear and computed tomograms in the assessment of implant recipient sites

Tomography is a radiographic process that produces cross-sectional images of bony structures within the body. The purpose of this study was to evaluate the accuracy of diagnostic measurements made by dental implant team members from linear tomograms of human cadaver mandibles. Five partially edentulous cadaver mandibles were radiographed using linear tomography (LT) and computer-assisted tomography (CT). From the tomograms, each of four team members traced the perceived outer circumference of the mandible and the inferior alveolar canal. Tomogram tracings were compared to each other and to the equivalent CT cross-sectional image to determine the precision of the measurements. One mandible was sectioned to verify the accuracy of the CT images. Repeated measures analysis of variance of the measurements made from the LT and CT scans showed significant statistical differences between team members. Multiple cross-sectional views facilitated identification of the inferior alveolar canal in the majority of CT scans, whereas image blurring inherent to LT resulted in the inability of team members to identify the canal in 14% to 50% of the images. Volume averaging within the CT slice aperture was found capable of producing a magnification error of short dense objects. CT and LT must both be interpreted cautiously because of innate technique objects. CT and LT must both be interpreted cautiously because of innate technique pecularities that can lead to measurement errors. The wide variation in interpretation of the linear tomograms and frequent inability to identify the inferior alveolar canal made this technique less valuable than the reformatted CT when planning dental surgical procedures.     

Short-term effects of particulate air pollution on respiratory morbidity in asthmatic children

OBJECTIVE: The aim of this study was to quantify the effect of mandibular angulation, position, and shape of an edentulous mandible on the distortion of its image in panoramic radiographs. STUDY DESIGN: Five edentulous dry mandibles varying in size from small to wide and equipped with metal bars in and on top of the mandible were used. The mandibles were radiographed at nine different positions by tilting the mandible posteriorly around a transversal axis, using an orthopantomograph. RESULTS: The length of the images of the bars on top of the mandible increased significantly by tilting the mandibles from +20 degrees to -20 degrees. The magnification factor of the images of the intrabony bars in the mandible was the largest at 0 degrees and decreased significantly by both decreasing or increasing the inclination. The size of the mandible was not related to the magnification factor. CONCLUSION: For both diagnostic and evaluation purposes of the edentulous mandible, the panoramic radiograph is not a reliable radiographic technique unless meticulous precautions are taken for reproducible positioning of the patient in the apparatus.     

Recombinant coagulation factors

Sometimes, preoperative planning in dental implantology, based on sufficient alveolar height, cannot be verified due to transversal deficiencies. A total of 102 bony mandibles and 95 maxillae were analysed after classification of atrophy, simulating implant insertion at 518 standardised edentulous cross sections with regard to anterior/posterior, mandible/maxilla and class of atrophy. Furthermore, the relation of alveolar height to possible implant length in 86 patients was evaluated retrospectively. Implant length reduction compared with alveolar height was necessary in 10% (mandibles) and 7.5% (maxillae) of the bony-jaw sections and 52.5% (mandibles) and 41.5% (maxillae) of the patients' implant regions. In this respect, the class of atrophy of the bony jaws was more important than the region of simulation. However, the highest differences were observed between mandibles and maxillae, both clinically and experimentally: simulation was possible in all mandibles and 42.5% of the maxillae, but clinical implantation was only possible in 86% of 62 mandibles and 0% of 24 maxillae, mostly due to reduced alveolar height. Alveolar ridge width primarily affected the possible implant lengths. Nevertheless, in four (two mandibular and two maxillary cases) of 58 patients (7%) with sufficient height, a surgical procedure that had already been started had to be stopped. It is expected that cross-sectional radiographical techniques of implantation planning, including ridge-width determination, will gain importance in the future.     

Usefulness of panoramic radiography in the diagnosis of postmenopausal osteoporosis in women. Width and morphology of inferior cortex of the mandible

OBJECTIVES: To evaluate the usefulness of width and morphology of the inferior cortex of the mandible on panoramic radiographs in the diagnosis of postmenopausal osteoporosis. METHODS: The width and morphology of the mandibular inferior cortex on panoramic radiographs were compared with trabecular bone mineral density (TBMD) of the 3rd lumbar vertebrae (L3) measured by dual energy quantitative computed tomography in 29 premenopausal and 95 postmenopausal women. RESULTS: There was a significant negative correlation between the width (Kendall's tau = -0.36, p < 0.001) and morphology (Kendall's tau = -0.49, p < 0.001) of the mandibular inferior cortex and the L3 TBMD. Regression analysis showed that significant linear relationships were observed between the L3 TBMD and age (p < 0.001), cortical width (p < 0.05), morphology (p < 0.05), controlling body mass index, number of teeth present and menopausal status (R2 = 0.42). CONCLUSION: Our results suggest that panoramic radiography could be reliable in screening for osteoporosis.     

Position of the mental foramen in adult black Zimbabwean mandibles: a clinical anatomical study

OBJECTIVE: To provide some anatomical information on the shape, size, and position of the mental foramen among Black Zimbabweans that could be used as reference material by dental and other health practitioners during clinical practice in Zimbabwe. DESIGN: Cross sectional anatomical study. SETTING: Department of Anatomy, Faculty of Medicine, University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe. SUBJECTS: 32 mandibles derived from adult Black Zimbabweans. MAIN OUTCOME MEASURES: The shape of the mental foramen, its relation to the lower teeth and its position in relation to the mandibular symphysis, the posterior border of the ramus of the mandible, the lower border of the mandible, and the alveolar margin. RESULTS: The shape of the mental foramen was round in 14 out of 32 mandibles (43.8%) and was oval in the remaining 18 (56.3%). The percentage of occurrence of the mental foramen was highest below the lower second premolar tooth on the right side (position 4) and posterior to it on the left side (position 5). In the vertical plane, the mental foramen lay slightly below the midpoint of the distance between the lower border of the mandible and the alveolar margin (44.1% and 45.5% for the right and left sides respectively). In the horizontal plane, it lay approximately one quarter (27.3% for the right and 27.4% for the left sides) of the distance from the mandibular symphysis to the posterior border of the ramus of the mandible. CONCLUSION: The percentage distribution of the mental foremen in relation to the lower teeth in the adult Black Zimbabwean mandible was at variance with that of other population groups. However, the quantitative position of the mental foremen was bilaterally symmetrical in the adult Black Zimbabwean mandible. The latter observation is of clinical significance to dental and other health practitioners in Zimbabwe with regards to the achievement of effective mental nerve block anaesthesia and the prevention of damage to the mental nerve during surgical procedures on the lower jaw.     

Comparison between the rigidity of bicortical screws and a miniplate for fixation of a mandibular setback after a simulated bilateral sagittal split osteotomy

PURPOSE: This investigation compared the biomechanical stability of three bicortical screws with that of a single four-hole miniplate after 5-mm mandibular setback after a bilateral sagittal split osteotomy (BSSO) in cadaver mandibles. MATERIALS AND METHODS: Thirty human cadaver hemimandibles underwent BSSO followed by two different rigid fixation techniques. All specimens had no third molar, bony pathology, or evidence of mandibular fracture, and there was no history of renal disease or hyperparathyroidism. The specimens were randomly divided into two groups. In group I, three bicortical screws were placed at the superior border, and in group II, one four-hole miniplate was secured on the external oblique ridge with four monocortical screws. The bony height of the mandible was recorded. Maximum resistance load (MRL), the greatest load recorded just before a sudden decrease in load level (bone or fixation failure), was recorded when the mandibles were tested in a compression machine. Multiple regression analysis was used to evaluate the differences in bone height and the MRL between groups I and II. RESULTS: The mean bone height in groups I and II were 28.64 +/- 2.50 mm and 28.72 +/- 4.08 mm, respectively. The mean MRL in group I (20.49 +/- 7.22 kg) was greater than in group II (17.41 +/- 7.81 kg). The multiple regression analysis showed no significant difference in the bone height and the MRL between group I and group II (beta = 2.3492, P = .4114). CONCLUSION: There was no statistically significant difference in stability provided the two techniques.     

Long time follow-up of flexor tendons of the hand after reconstructive operations. Part 1. Monitoring method

OBJECTIVE: To assess whether it is possible to make accurate vertical measurements of the jaws from panoramic radiographs. METHODS: Five dry skulls were shifted 5 mm forwards and backwards and tilted 5 degrees up and down in the sagittal plane. Panoramic radiographs of each skull were obtained in nine different positions. In the maxilla, three reference lines were used and vertical measurements were made at the distal surfaces of the first premolar and first molar and in the midline. In the mandible, measurements were made at the distal surfaces of the first premolar and first molar, and at the mental foramen on both sides, and in the midline. The points and lines were marked manually and the radiographs were digitized, magnified and measured. RESULTS: Sagittal shifting and tilting had only a slight effect on measurements in the mandible. Sagittal tilting of the head had the greatest effect on all the measurements made from the line between the articular eminences to the alveolar crest, as well as measurements in the maxillary midline. CONCLUSIONS: The line between the articular eminences is unsuitable as a reference line for measurements of the tooth-bearing areas. A slight misalignment of the head does not significantly affect the vertical measurements in the mandible or of the posterior maxilla if the reference lines are in the same vertical plane as the teeth.     

Diagnosis and management of tuberculosis

PURPOSE: To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla. METHODS: Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a work-station as panorama and cross-sectional views of the mandible or maxilla. RESULTS: The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated. CONCLUSION: Dental-MRT promises to provide a new tool for visualization and detection of dental diseases.     

An evaluation of torque (moment) on implant/prosthesis with staggered buccal and lingual offset

The supposition that staggered buccal and lingual implant offset is biomechanically advantageous was examined mathematically. The method of evaluation utilized a standard hypothetical geometric configuration from which implants could be staggered buccally and/or lingually in both arches. Torque (moment) values were calculated at the gold screw, abutment screw, and 3.5 mm apical to the head of the implant. Comparisons were made in percentages of change from the hypothetical standard to the buccal and/or lingual implant offset. In the maxillary arch, buccal offset decreased the torque (moment) while lingual offset increased it. If more lingually offset implants were present in the maxillary restoration, the total torque would be greater than if they were all in a straight line. Staggered buccolingual implant alignment often requires abutment reangulation. The resultant line of force produced by occlusal anatomy usually results in buccal inclination in the maxillary arch and lingual inclination in the mandibular arch. As a result, mandibular implant/prostheses are greatly favored over similar maxillary configurations because the mandibular resultant line of force usually passes lingually, closer to the components and supporting bone and considerably less torque is produced. Therefore, the concept of staggered offset for multiple implant-supported prostheses can be utilized on the mandible but is not recommended for the maxilla where maximum uniform buccal implant orientation is advised.     

Radiographic modalities for diagnosis and treatment planning in implant dentistry

Early in the development of implant technology it became apparent that conventional dental imaging techniques were limited for evaluating patients for implant surgery. During the treatment planning phase, the recipient bed is routinely assessed by visual examination and palpation, as well as by periapical and panoramic radiology. These two imaging modalities provide a two-dimensional image of mesial-distal and occlusal-apical dimensions of the edentulous regions where implants might be placed. When adequate occlusal-apical bone height is available for endosteal implants, the buccal-lingual width and angulation of the available bone are the most important criteria for implant selection and success. However, neither buccal-lingual width nor angulation can be visualized on most traditional radiographs. Although clinical examination and traditional radiographs may be adequate for patients with wide residual ridges that exhibit sufficient bone crestal to the mandibular nerve and maxillary sinus, these methods do not allow for precise measurement of the buccolingual dimension of the bone or assessment of the location of unanticipated undercuts. For these concerns, it is necessary to view the recipient site in a plane perpendicular to a curved plane through the arch of the maxilla or mandible in the region of the proposed implants. Implant dentists soon recognized that, for optimum placement of implants, cross-sectional views of the maxilla and mandible were the ideal means of providing necessary pre-operative information. Today, the two most often employed and most applicable radiographic studies for implant treatment planning are the panoramic radiograph and tomography. Although distortion can be a major problem with panoramic radiographs, when performed properly they can provide valuable information, and are both readily accessible and cost efficient. To help localize potential implant sites and assist in obtaining accurate measurements, it is recommended that surgical stents be used with panoramic radiographs. In simple cases, where a limited number of implants are to be placed, panoramic radiography and/or tomography may be used to obtain a view of the arch of the jaw in the area of interest. For complex, cases, where multiple implants are required, the CT scan imaging procedure is recommended. Because of its ability to reconstruct a fully three dimensional model of the maxilla and mandible, CT provides a highly sophisticated format for precisely defining the jaw structure and locating critical anatomic structures. The use of CT scans in conjunction with software that renders immediate "treatment plans" using the most real and accurate information provides the most effective radiographic modality currently available for the evaluation of patients for oral implants. To follow patients after implant surgery, DSR can be helpful by addressing the limitations of other radiographic modalities in detecting postoperative changes. By eliminating unchanged information, DSR allows the clinician's eye to focus on actual changes that have occurred between the recordings of two images.     

Cloning, characterization, and chromosomal localization of human superillin (SVIL)

The specific aim of this study was to determine the response of alveolar bone after it was augmented vertically using distraction osteogenesis and subsequently loaded with implant restorations. Four dogs each had four implants placed horizontally into an edentulous mandibular quadrant and, after integration, a distraction osteogenesis device was fabricated in the laboratory. An osteotomy was made to allow the crest of the alveolar ridge to be distracted vertically. After 10 mm of vertical distraction, the device was stabilized with light cured resin. Following bone fill confirmation of the distraction gap at 10 weeks, two implants were placed into the ridges, one in distracted bone and one in nondistracted bone. After 4 months for implant integration, freestanding prostheses were fabricated. Crestal bone levels were evaluated throughout the period of function. Animals were sacrificed after 1 year of loading, for histologic evaluation of the bone. The vertical ridge augmentation averaged 8.85 +/- 1.05 mm after 10 weeks of healing following distraction, without change over 1 year of implant loading. Histologic examination showed that bone had formed between the distracted segments, creating an augmented ridge. The average thickness of the labial cortex in the distraction gap was significantly thinner than the lingual cortex in distracted bone and the lingual and labial nondistracted cortical bone. The presence of the dental implant did not significantly affect cortical bone thickness. Serial sections showed that implants remained integrated and functional without soft tissue inflammation. Dental implants placed into alveolar ridges augmented with the technique of distraction osteogenesis maintained bone and were functional for the length of this study.     

The influence of alveolar structures on the torsional strain field in a gorilla corporeal cross-section

Anthropologists have often used mandibular torsional properties to make inferences about primate dietary adaptations. Most of the methods employed are based on assumptions related to periodontal and alveolar properties. This study uses the finite element method to evaluate some of these assumptions with a cross-section through the third molar of a gorilla. Results indicate that the properties of alveolar bone play an important role in determining the strain field. In comparison, the exact stiffness values of the periodontal ligaments seem to have a much smaller impact. Replacing the dental roots and periodontal ligaments with alveolar bone, however, has a significant influence on the strain field. It underestimates the maximum shear strain by about 28% along its periosteal aspect when alveoli are modeled as cortical bone. It overestimates the strain by a smaller amount when alveoli are modeled as trabecular bone. This study supports the assumption that primate mandibles behave like a closed-section under torsion under the limiting condition that the alveolar bone stiffness is more than half of the value of cortical bone; alveolar bone can then be modeled as cortical bone with a minimal loss of accuracy. In addition, this study suggests that the minimum cortical thickness should be considered for torsional strength. Finally, modeling accuracy can be significantly increased if both dental and periodontal structures can be realistically incorporated into mandibular biomechanical models. However, this may not be always feasible in studies of fossil mandibles. This is due mainly to the difficulties involved in estimating alveolar bone densities and in distinguishing boundaries between cortical bone, alveolar bone, periodontal ligaments, and dental roots in fossil specimens.     

Assessment of tumour invasion into the mandible: the value of different imaging techniques

In oral carcinomas close to the mandible, tumour invasion of the mandible is important in selecting segmental or marginal resection. Imaging may play a role in assessing tumour invasion. This study compares the accuracy of panoramic X-ray, CT and MR imaging in assessing invasion of the mandible in 29 patients. At histopathology, 6 patients had mandible erosion, 12 had invasion and 11 had an intact mandible. Magnetic resonance imaging had the highest sensitivity (94%), but a low specificity (73%), with 3 of 11 intact mandibles interpreted as positive. Furthermore, MR often overestimated the extent of tumour invasion. On the other hand, CT and panoramic X-ray had a lower sensitivity (64 and 63%, respectively) and a higher specificity (89 and 90%, respectively). Computed tomography (using 5-mm sections) and panoramic X-ray had a similar accuracy, and negative findings do not exclude invasion. Magnetic resonance imaging was the most sensitive technique but had more false positives and frequently overestimated the extent of tumour invasion. Because none of the radiological techniques are accurate enough, clinical examination seems at present to remain the most important modality in deciding between segmental and marginal resection. Tumour invasion at CT or panoramic X-ray is a strong argument for a segmental resection.     

Striatal dopaminergic D1 and D2 receptors after intracerebroventricular application of alloxan and streptozocin in rat

The purpose of this study was to evaluate the changes in condylar position following bilateral sagittal split ramus osteotomy with 5- and 10-mm setback in 1 symmetric human cadaver mandibles. A Plexiglas device was constructed to determine the mandibular morphology and the movements of the condyle and the proximal segments before and after surgery. There was no statistically significant relationship between mandibular morphology or the magnitude of setback and changes in condylar position postsurgery. All condyles and rami tipped in a highly variable fashion in the coronal plane. In the axial plane, the lateral pole of the condyles rotated predominantly anteriorly; the left side rotated significantly more than did the right. In the sample studied, the position of the condylar and proximal segments was altered in a highly variable and unpredictable manner, regardless of the magnitude of setback or the morphology of the mandible.     

The mucosal attachment at different abutments. An experimental study in dogs

The present experiment was performed to examine if the material used in the abutment part of an implant system influenced the quality of the mucosal barrier that formed following implant installation. 5 beagle dogs were included in the study. The mandibular premolars and the 1st, 2nd and 3rd maxillary premolars were extracted. Three fixtures of the Br?nemark System were installed in each mandibular quadrant (a total of 6 fixtures per animal). Abutment connection was performed after 3 months of healing. In each dog the following types of abutments were used: 2 "control abutments" (c.p. titanium), 2 "ceramic abutments" (highly sintered Al2O3), 1 "gold abutment", and 1 "short titanium abutment". This "short titanium abutment" was provided with an outer structure made of dental porcelain fused to gold. Following abutment connection a plaque control program was initiated and maintained for 6 months. The animals were sacrificed and perfused with a fixative. The mandibles were removed and each implant region was dissected, demineralized in EDTA and embedded in EPON. Semithin sections representing the mesial, distal, buccal and lingual aspects of the peri-implant tissues were produced and subjected to histological examination. The findings from the analysis demonstrated that the material used in the abutment portion of the implant influenced the location and the quality of the attachment that occurred between the periimplant mucosa and the implant. Abutments made of c.p. titanium or ceramic allowed the formation of a mucosal attachment which included one epithelial and one connective tissue portion that were about 2 mm and 1-1.5 mm high, respectively. At sites where abutments made of gold alloy or dental porcelain were used, no proper attachment formed at the abutment level, but the soft tissue margin receded and bone resorption occurred. The abutment fixture junction was hereby occasionally exposed and the mucosal barrier became established to the fixture portion of the implant. It was suggested that the observed differences were the result of varying adhesive properties of the materials studied or by variations in their resistance to corrosion.     

A dental CT study for preoperative assessment of maxillary atrophy

According to a new technology in the planning of endo-osseous implantation, based on a new CT-software for evaluation of the bone structure of the jaws, anatomico-morphological changes after the loss of teeth are measured much more accurately than with conventional methods like the panoramic intraoral x-ray or conventional tomography. 30 mandibles and 22 maxillae of 36 patients were examined. Besides the topographic course of the mandibular canal and the location of the foramen mentale, the anatomic structures as the important aspects for planning endo-osseous implants are seen more accurately. It is now possible to recognise morphological changes with paraxial reconstructions in a very short time more clearly and precisely than with former techniques.     

The dark side of dioxygen biochemistry

The aim of this study was to evaluate the clinical function and long-term prognosis of overdentures retained by a small number of implants in the maxilla and mandible using one of two different attachment systems. Included in the study were all patients referred to specialty clinics in J?nk?ping and Link?ping, Sweden, during the treatment period who needed an overdenture and could be provided with a minimum number of two bilaterally-placed implants. Excluded were patients with bone-grafted jaws, irradiated cancer patients, heavy bruxers, and patients who had lost a fixed prosthesis because of implant losses. The patients were randomly assigned to receive one retentive system, either a round 2-mm-diameter bar with clips or ball attachments (Nobel Biocare). Eighteen overdentures were placed in maxillae and 32 in mandibles, supported by a total of 115 Br?nemark implants. Of the implants placed, 86.1% were continuously osseointegrated. The cumulative implant survival rates after 7 years of loading were 75.4% in the maxillae and 100% in the mandibles. There was no difference in implant survival rate between the attachment systems. Patients with implant losses were characterized by severely resorbed maxillary ridges and inferior bone quality, together with unfavorable loading circumstances such as short implants combined with long leverages. Complications and prosthetic adjustments were mostly resolved early and easily.     

Clinical anatomy of the human mental foramen

BACKGROUND: The great diffusion of the surgical technics in oral implantology and the progress of the radiological imaging produces some interest for the clinical anatomy of the mental foramen (MF). The study, in addition to the measurements that define it, considers others anatomical features of practical utility and the variableness of them. METHODS: In the Anatomic Institute of the Bologna University, it has been made a morphometric revision of the MF on 100 dried mandibles of normal young adults (78 males, 32 females) random chosen with the complete integrity of the dental apparatus and of the mandibular bone criteria. The measurements have been made by anthropometric methods on the two sides of the same mandible (n = 200) and for everyone has been reported in the tables the medium, the maximum and the minimum values with their specific variation interval. The results are applicable to the common work conditions because they take in consideration among the specific characteristics of the MF in addition to the seat, the course of the mandibular canal, the thickness and the height of the mandibular bone. RESULTS: To the clinical and diagnostic imaging object the medium values of the anatomical measurements can be considered sufficent. To anthropometric, anesthesiologic and surgical aims it is also necessary the knowledge of the maximum and the minimum values and the variation interval. In the living man the anatomicomedical study of the MF is made by the diagnostic imaging, especially by computed tomography with specific algorithm, because it makes possible absolutely exact measurements. CONCLUSIONS: Finally, the specifications on the MF provided by the present study are important not only for an anatomical but also for a practical point of view because they are a datum point value in the patient clinical management.