Outpatient orthognathic surgery: a prospective study of predictive factors for the length of hospital stays.

OBJECTIVES: Transitioning from non-outpatient orthognathic surgery to outpatient surgery is a new challenge, and it is essential to target the eligible population as precisely as possible. Several authors describe series of outpatient orthognathic surgery but do not include the reasons for their success or failure. The main aim of this study was to identify the factors significantly associated with "successful" outpatient orthognathic treatment. The secondary objective was to determine the factors significantly associated with prolonged hospital stays (≥ 2 nights). MATERIALS AND METHODS: A prospective cohort study including patients undergoing orthognathic surgery was conducted over a period of 1 year. We recorded the prognostic factors that contributed to successful outpatient treatment and prolonged hospital stays. These factors were evaluated by bivariate and multivariate analysis. RESULTS: A total of 102 patients were included, and the success rate of treatment was 65%. The variables that were isolated by multivariate analysis were: patients over the age of 22, procedures ending before 1 pm, brief operations, the absence of both postoperative vomiting and the administration of morphine. CONCLUSION: Patient selection, organisation of outpatient facilities and anaesthetic protocols contribute to the development of outpatient orthognathic surgery. These initial considerations provide a framework for our practice, but the considerations that predict the failure of outpatient surgery will need to be clarified. CLINICAL RELEVANCE: Orthognathic surgery can be performed on outpatient basis in selected cases. Age, the operative time, procedure end time, postoperative vomiting and the administration of morphine are associated with the success of outpatient care.

Quantification of global orbital shape variation.

The complex anatomy of the orbit generates a complex orbital shape that can only be quantified approximatively by classic linear measurements such as maximum width and height. There is no global three-dimensional quantification of variations in orbital shape. The purpose of this study was to develop a method to quantify a global three-dimensional orbital shape variation in a healthy population and to test a series of explanatory factors. We investigated the hypotheses that orbital shape is related to gender(H1), orbital size(H2) and/or age(H3). Medical computed tomography(CT) images of 60 adult individuals were studied. The study sample consisted of 30 males and 30 females with a mean age of 25.1 years. Four anatomical landmarks and 140 semi-landmarks were measured on both positive and negative 3D reconstructed orbits and analyzed with geometric morphometrics. A principal component analysis(PCA) was computed to define a morphological space. Shape variation was visualized using vector distance maps and diagrams. The greatest variation was seen in the length of the superior orbital fissure. There was a gradient in terms of orbital shape ranging from short, wide orbits to tall, narrow orbits. The analysis did not highlight any significant age-, gender- or size-related impact in terms of orbital shape variation. Future avenues to explore include the study of other potential explanatory factors such as the different embryological origins of the orbital bones, the passage of vessels and nerves, and ethnic origins. This method can also be applied to the study of pathological orbits.

Fibula free flap perforasomes: vascular anatomical study and clinical applications.

PURPOSE: This study assesses the anatomical features of the cutaneous fibular perforators and perforasomes of fibular free flap to determine the clinical implications therein. METHODS: This anatomical study was performed with 16 fresh cadavers after selective arterial injections of inked serum. The numbers of perforators, diameter, location of the perforasome center, perforator course, the distance between perforator origin and tibiofibular division, and the perforasome area were all documented. RESULTS: Thirty-one lower legs were dissected. Eighty-eight cutaneous perforators were found, averaging 2.8 per leg (1-4). The mean diameter was 1.7 mm and decreased from proximal to distal (p < 0.001). The centers of the perforasomes were aligned on an oblique projection from proximal to distal and anterior to posterior. Seventeen perforators (19%) were musculocutaneous, all in the proximal half of the leg, whereas 71 perforators were septocutaneous (81%), including 18 in the proximal half of the leg. Six of the uppermost perforators originated from the fibular artery less than 10 mm from the tibiofibular division. The mean area perforasome was 37.2 cm2 (7.9-106 cm2) and decreased from proximal to distal (p < 0.01). CONCLUSION: Distal and proximal fibular flap perforasomes sported different features. Large skin paddles supplied by large and often intramuscular perforators were found in the proximal half of the leg. Distal skin paddles were smaller, more posterior, and featured septocutaneous perforators. These factors should be considered in the skin paddle choice during the fibular free flap harvest.

Multicentre evaluation of the interest in planned surgery for mandibular reconstruction with fibula free flap: a retrospective cohort study.

PURPOSE: The aim of this study was to determine the impact and cost-effectiveness of virtual surgical planning during fibula free flap mandibular reconstruction on peri- and postoperative data. METHODS: We conducted a retrospective cohort study from January 2012 to December 2016 in four French university centres. RESULTS: Three hundred fibula free flaps for mandibular reconstruction were performed in 294 patients. Surgeries were planned in 29.7% of cases (n = 89). There was no significant difference in the rate of negative-margins excision, median length of hospital stay, operative time, and early complications between planned and non-planned surgeries. Morphological analysis revealed a higher rate of centred occlusion in planned patients (satisfactory alignment of interincisal points: Planned 65.5% vs Non-Planned 33.3%, p = 0.006). CONCLUSION: In mandibular reconstruction by fibula free flap, the additional cost generated by virtual surgical planning does not seem to be balanced by savings resulting from a shorter operative course, a reduced hospital stay, or a reduction in postoperative complications. However, virtual surgical planning may provide a higher rate of centred occlusion. Long-term benefits should be assessed by further studies.

The specific branches leading to the genioglossus muscle: three-dimensional localisation using skin reference points.

INTRODUCTION: Supra-selective stimulation of the branches destined for the horizontal part of genioglossus muscle (GGh) could be a target of choice in the treatment of mild-to-severe obstructive sleep apnea syndrome. The main aim of our study was to assess a percutaneous method for the three-dimensional localisation of the terminal branches destined to GGh. MATERIALS AND METHODS: Twenty cadaveric hypoglossal nerves were dissected and included in the injection protocol. The distance between the posterior edge of the mandibular symphysis and the hyoid bone on the sagittal midline as the approximated distance of the geniohyoid muscle (dGH) was measured before any dissection. Methylene blue mixed with a thickening agent, was injected. The injection point was defined in relation to dGH, in an orthonormal coordinate system. For each dissection, we recorded the theoretical and the real (X, Y, Z) coordinates of GGh motor points and measured their distance to each other. RESULTS: X was accurately estimated. Y and Z were overestimated by + 5.34 ± 5.21 mm ([Formula: see text]) and + 4.79 ± 3.99 mm ([Formula: see text]) on average, respectively. We found a more significant difference between the theoretical and real Y and Z coordinates in the subgroup BMI < 25 kg/m2 (8.6 ± 4.5 mm and 6.9 ± 2.5 mm, respectively, p = 0.0009), and of Z in subgroup with dGH ≥ 50 mm (6.89 ± 3.26 mm, p = 0.0494). CONCLUSIONS: X can be estimated accurately using the relationship [Formula: see text]. Y seems to be related to BMI and Z may be estimated with the relationship [Formula: see text]. This three-dimensional localisation could be very helpful to facilitate placement of cuff electrodes to manage refractory sleep apnea.

Ultrasound-Guided Versus Landmark-Based Approach to the Distal Suprascapular Nerve Block: A Comparative Cadaveric Study.

PURPOSE: To compare the accuracy of distal suprascapular nerve (dSSN) blockade performed with the use of ultrasound-guided regional anesthesia (USRA) versus with a landmark-based approach (LBA). A secondary aim was to describe the anatomic features of the sensory branches of the dSSN. METHODS: USRA and LBA were performed in 15 shoulders each from 15 cadavers (total of 30 shoulders). Then, 10 mL of methylene blue‒infused ropivacaine 0.75% was injected into the dSSN. Simultaneously, 2.5 mL of red latex solution was injected to identify the position of the needle tip. The division and distribution of the sensory branches originating from the SSN were described. RESULTS: The tip of the needle was identified at 1.3 cm (range, 0-5.2 cm) and 1.5 cm (range, 0-4.5 cm) with USRA and the LBA, respectively (P = .90). Staining diffused past the origin of the most proximal sensory branch in 27 cases. The most proximal sensory branch arose 2.5 cm from the suprascapular notch. Among the 3 failures that occurred in the USRA group, the sensory branches also failed to be marked. All 30 dSSNs gave off 3 sensory branches, which innervated the posterior glenohumeral capsule, the subacromial bursa, and the coracoclavicular and acromioclavicular ligaments. CONCLUSIONS: An LBA is as reliable and accurate as US guidance for anesthetic blockade of the dSSN. Marking of the suprascapular nerve must be proximal to the suprascapular notch to involve the 3 sensory branches in the anesthetic blockade. CLINICAL RELEVANCE: The present study demonstrates that a landmark-based approach to anesthetic blockade of the distal suprascapular nerve is accurate and can be performed by orthopaedic surgeons lacking experience in ultrasound-guided anesthetic techniques.

Interest of Mineralized Plasmatic Matrix in Secondary Autogenous Bone Graft for the Treatment of Alveolar Clefts.

The authors describe a new material termed mineralized plasmatic matrix (MPM), a combination of platelets, fibrin concentrate, and autogenous bone to repair alveolar cleft defects. Autogenous cancellous bone is widely used to this end because such bone affords the functionalities (osteogenesis, osteoinduction, and osteoconduction) required for successful outcomes. To optimize these features, autologous blood products high in platelet concentrations have recently been developed. On the basis of our experience with PRP (platelet-rich plasma) and PRF (platelet-rich fibrin), we developed MPM, which contains platelets and fibrin concentrate in a liquid state; these materials can become bound to bone particles. The filling material is easy to shape and a PRF-type membrane is also generated. Ten patients with cleft lips and alveoli, with or without cleft palates (median, or uni- or bilateral) benefited from secondary bone grafts placed using our new material. We transferred autogenous bone from the iliac crest, an abundant source of cancellous bone associated with a high success rate. The 6-month outcomes of all patients were excellent in terms of both bone graft stability and closure of the oronasal fistulae. The preparation procedure is simple and the technical requirements minimal. Upon further optimization, MPM may serve as a third-generation platelet concentrate with potential applications in various fields.

Tortuosity and other vessel attributes for arterioles and venules of the human cerebral cortex.

Despite its demonstrated potential in the diagnosis and/or staging of disease, especially in oncology, tortuosity has not received a formal and unambiguous clinical definition yet. Using idealized three-dimensional vessel models (wavy helices) with known characteristics, we first demonstrate that, among various possible tortuosity indices, the standard deviation of the curvature Ksd best satisfies i) scale invariance and ii) positive monotonic response with respect to the amplitude and frequency of vessel oscillations. Ksd can thus be considered as a robust measure of tortuosity. On the contrary, indices previously considered as tortuosity metrics, such as the distance factor metrics (DFM), are highly scale dependent and inappropriate for that purpose. The tortuosity and other vessel attributes (curvature, length-to-diameter ratio (LDR),…) of more than 15,000 cortical vessels are subsequently studied, establishing their statistical properties as a function of the vessel nature (arterioles versus venules) or topological order (hierarchical position). In particular, arterioles have a higher LDR than venules, but the two kinds of vessels have the same mean curvature and tortuosity. Moreover, the lower the order of the vessels, i.e. the nearer to the capillary network, the more curved and tortuous they are. These results provide an essential reference both for diagnosis and for a future large reconstruction of the cerebral microvascular network.

Reliability of cone beam computed tomography in scalar localization of the electrode array: a radio histological study.

Postoperative imaging plays a growing role in clinical studies concerning prognostic factors in cochlear implantation. Indeed, intracochlear position of the cochlear implant has recently been identified as a contributor in functional outcomes and radiological tools must be accurate enough to determine the final placement of the electrode array. The aim of our study was to validate cone beam computed tomography as a reliable technique for scalar localization of the electrode array. We performed therefore a temporal bone study on ten specimens that were implanted with a perimodiolar implant prototype. Cone beam reconstructions were performed and images were analyzed by two physicians both experienced in cochlear implant imaging, who determined the scalar localization of the implant. Temporal bones then underwent histological control to document this scalar localization and hypothetical intracochlear lesions. In four cases, a dislocation from scala tympani to scala vestibuli was suspected on cone beam reconstructions of the ascending part of the basal turn. In three of these four specimens, dislocation in pars ascendens was confirmed histologically. In the remaining temporal bone, histological analysis revealed an elevation with rupture of the basilar membrane. Histological assessment revealed spiral ligament tearing in another bone. We conclude that cone beam is a reliable tool to assess scalar localization of the selectrode array and may be used in future clinical studies.

Can we consider standard microsurgical anastomosis on the posterior tibial perforator network? An anatomical study.

PURPOSE: The main vessels in an injured leg can be spared with perforator-to-perforator anastomosis. However, supermicrosurgery is not a routine procedure for all plastic surgeons. Our objective was to establish if the diameter of the perforators of the leg could allow anastomosis with standard microsurgical procedures. METHODS: Twenty lower legs harvested from ten fresh cadavers were dissected. Arterial and venous vessels were injected with colored latex. The limbs were then dissected in a suprafascial plane. All the perforating arteries of a diameter >0.8 mm were located and their external diameter, the number and external diameter of the venae comitantes were reported. RESULTS: We found at least three tibial posterior artery perforators with diameters >0.8 mm per leg with a mean external diameter of 1.1 mm and one vena comitans in almost all cases (96 %). The vena comitans was usually bigger than the perforating artery with a mean diameter of 1.6 mm. After statistical analysis, we were able to locate two main perforator clusters: at the junctions of the upper two-thirds of the leg and of the lower two-thirds of the leg. CONCLUSION: The low-morbidity concept of perforator-to-perforator anastomosis can apply to posterior tibial artery perforators without using supermicrosurgical techniques. This is of high interest for open leg fractures where main vessels could be injured. We hope that the results of our study will incite surgeons to consider sparing of main vessels for coverage of open leg fractures whether surgical teams master supermicrosurgery or not.

Use of nasal retainers in the primary management of cleft lip: Current practices in France.

BACKGROUND: The primary surgical management of cleft lip (CL) or cleft lip and palate (CLP) aims to achieve harmonious lip and nasal symmetry while ensuring satisfactory ventilation. Postoperative nasal retainers are commonly used, though both duration of use and conformer type used vary widely. This study aimed to establish an inventory of current practices for primary cheilorhinoplasty and nasal retainer use in France. METHODS: A survey was sent to surgeons within and outside the French National Clefts and Facial Malformations (MAFACE) network. Questions focused on age when primary cleft closure is performed, retainer types used, conformation duration, and estimated patient compliance. Responses were collected March-July 2023. RESULTS: Thirty-two surgeons responded with substantial variations in practices. For isolated CL, the age for primary cleft closure was 1-6 months, with 28 % performing surgery at 3 months, 12.5 % between 3 and 6 months, 44 % at 6 months. In cases with CLP, 63 % performed simultaneous surgery at 6 months. Two surgeons (6 %) reported preoperative nasoalveolar molding and 30 surgeons (94 %) reported postoperative nasal retainer use. Retainer type used immediately after surgery varied, with equal use of commercial retainers (31 %), silicone sheets (31 %), and in-house retainers (31 %). Duration of retainer prescription was in majority 3-4 months. Notably, 44 % of surgeons reported <70 % adherence rates for the recommended conformation duration, while 25 % reported very good compliance. CONCLUSION: Primary cheilorhinoplasty and nasal conformation practices are highly diverse in France. Suboptimal patient compliance demonstrates the need for improved retainer design and strategies to enhance compliance.

Bilateral ultrasound-guided maxillary and mandibular combined nerves block reduces morphine consumption after double-jaw orthognathic surgery: a randomized controlled trial.

BACKGROUND: Double-jaw surgeries are known to be painful and to require opioids. Maxillary (V2) and mandibular (V3) nerves block could provide adequate pain management with minimal opioid-related side effects. Our main objective was to evaluate the analgesic effect of bilateral ultrasound-guided V2 and V3 combined nerves block in patients undergoing double-jaw orthognathic surgery. METHODS: In this single-blind, randomized control study, 50 patients were prospectively allocated to either bilateral ultrasound-guided V2 and V3 combined nerves block or intraoral infiltration of local anesthetic. Primary outcome was the cumulative oral morphine equivalent (OME) consumption assessed at postoperative day 1. Secondary outcomes were cumulative OME consumption and pain scores in recovery room and at postoperative day 2, intraoperative anesthetic consumption, and opioid-related side effects. Preoperative anxiety was investigated by the Amsterdam Preoperative Anxiety and Information Scale (APAIS). RESULTS: Compared with infiltration, ultrasound-guided regional anesthesia reduced cumulative OME consumption on day 1 (45.7±37.6 mg vs 25.5±19.8 mg, respectively, mean difference of -20.1 (95% CI -37.4 to -2.9) mg, p=0.023) and day 2 (64.5±60 mg vs 35.8±30.2 mg, respectively, mean difference of -28.7 (95% CI -55.9 to -1.43) mg, p=0.040). Interestingly, worst pain score and cumulative OME consumptions on day 2 were positively correlated with the APAIS (Pearson's correlation coefficient of 0.42 (p=0.003) and 0.39 (p=0.006), respectively). CONCLUSION: Bilateral ultrasound-guided V2 and V3 combined nerves block reduces postoperative opioid consumption by about 50% in patients undergoing double-jaw surgery. TRIAL REGISTRATION NUMBER: NCT05351151.

Impact of obturation of palatal fistulae on speech quality and aerodynamic parameters in patients with cleft palates.

OBJECTIVES: The aim of this prospective study was to measure nasal and oral airflow during speech, before and after obturation. PATIENTS AND METHODS: Included were children aged 3-18 years with nonsyndromic clefts and palatal fistulae. The corpus used was: syllable /pi/; a sentence containing stop consonants and a nasal phoneme; and the description of a picture of a scene. Analysis criteria were: percentage of nasality; value of average flow for the explosion; perceived nasality and intelligibility; and tolerance of the proposed device. RESULTS: Only 5 children were included due to the observation of an increase in the percentage of nasality after obturation. The value of average flow for the explosion increased in all patients. A decrease in perceived nasality was noted in all but 1 patient. An improvement in intelligibility was observed in 3 out of the 5 children. The tolerance of the device was good. CONCLUSION: While the small number of patients studied does not permit firm conclusions concerning the efficiency of the obturation, the method described, as well as the introduction of 'speed of explosion' of stop consonants, offer new perspectives to prospectively study obturator effects on speech.

Characterization of labiomandibular movements induced after isolated LeFort I osteotomy in the surgical management of class III malocclusion.

INTRODUCTION: Maxillary surgery alone can be proposed for the surgical management of class III malocclusion, but anticipating outcomes for the labiomental muscle complex is challenging due to the mandibular autorotation phenomenon. The objective of this study was to quantify the mandibular and labiomental movements induced by maxillary osteotomy alone in the management of class III malocclusion according to different clinical and surgical variables. METHODS: The post-operative changes in mandibular and labiomental shapes were studied by geometric morphometry from the pre- and post-operative lateral cephalometric radiograph of 25 patients. The explanatory variables tested were maxillary advancement, maxillary rotation, and divergence. RESULTS: Soft tissues repositioning are different from postoperative mandibular repositioning after maxillary osteotomy. Neuromuscular adjustments of mandible depend on divergence and the maxillary rotation. Labiomental response only depends on divergence. CONCLUSION: The surgical procedure does not have the same bone-related and musculocutaneous effects on patients with the same class III malocclusion. It is therefore essential for surgeons to understand the effects of their procedure on musculocutaneous tissues in order to best anticipate post-operative outcomes.

Anatomic variations of the renal vessels: focus on the precaval right renal artery.

The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

Primary extra-nodal non-Hodgkin's lymphoma affecting mandibular bone: a case report.

Non-Hodgkin's lymphoma (NHL) is the second most common non-epithelial malignant tumor in the cervicofacial region. Among aggressive NHL, the most common histological type is diffuse large B cell lymphoma (DLBCL). A 44-year-old man presented himself at the oral surgery consultation for the development of isolated dental mobilities associated with mandibular osteolytic lesion. The extraoral examination showed nothing. The neurological examination did not reveal dysesthesia or hypoesthesia. The endo-buccal examination showed an erythematous gum, mobility stage 3 of teeth #42 to 35 with positive pulp sensitivity tests on teeth #34 to 47 and no increased probing depth. The X-rays found homogeneous rounded monogeodic osteolytic lesion extending from teeth #42 to 35 with thinning of the cortical layer. The anatomopathological results of a partial biopsy of the parasymphyseal region found a diffuse large B cell lymphoma of GC phenotype. The patient was referred to the department of oncohematology and treatment was only medical with R-CHOP 21 type immunochemotherapy for 6 cycles. Primary intraosseous localization of non-Hodgkin's lymphoma is rare. The clinical and radiological signs of this malignant tumor pathology are not specific and make its positive diagnosis particularly difficult. In case of uncertainty, an appropriate radiological examination combined with a partial biopsy is essential.

Correction of congenital macrostomia by double reversing Z-plasty: A technical note.

Congenital macrostomia is a rare congenital deformity that consists of an enlargement of the commissure of the mouth. The malformation may be unilateral or bilateral and has a polymorphic presentation. Various surgical techniques have been described to correct macrostomia, with only a few cases illustrating the expected results. The surgical repair must consider both esthetic as well as functional impacts for the patient. We here propose a technical note to refine and provide additional information for good achievement of "Double Reversing Z-Plasty" for correction of macrostomia. Our case series also reports good long-term functional and esthetic results obtained with this technique, especially in case of a minor cleft.

The corticoperiosteal medial femoral supracondylar flap: anatomical study for clinical evaluation in mandibular osteoradionecrosis.

PURPOSE: An ideal way to treat osteoradionecrosis of the jaws is to transfer an osteogenic, appropriately vascularized flap to the affected site. The corticoperiosteal femoral medial supracondylar flap is being used increasingly in the treatment of complex pseudarthrosis of long bones, but is yet to find robust indications for use in the treatment of osteoradionecrosis of the jaw, the reasons being a lack of anatomical data concerning its vascular supply and the local constraints of its routine harvest. This study presents an anatomical study and literature review to explore its potentials in clinical practice. MATERIALS AND METHODS: A total of 25 legs were dissected following vascular injection of colored neopren. The descending genicular artery (DGA) and veins were studied with particular attention paid to anatomical variations found in their branches. Calibers and length of the vessels were recorded. RESULTS: Many anatomical variations of the DGA were found and a classification proposed. The mean caliber of the DGA at the origin was 1.9 mm, and for the vein, 1.8 mm. The mean useful length of the pedicle was 7.9 cm. A case is reported. CONCLUSION: A clear anatomical knowledge (and, therefore, a sound classification system to grade flap harvesting potential) is the key first step prior to extensive clinical use of this flap. Various anatomical patterns of the pedicle are frequently encountered; branches can be elusive when raising the flap. Vascular imaging is therefore a critical step in identifying types and subtypes before surgery.

Surgical benefit of mandibular morphometric analysis: A new tool to standardize mandibular reconstruction.

PURPOSE: The gold-standard for reconstruction of large mandibular defects is the use of free flaps of vascularized autologous bone with the fibula as the preferred donor site. The use of "custom cutting guides" for this indication is becoming increasingly prevalent. But cost of the procedure averages around 2,500 dollars per patient excluding treatment and entails selection criteria. We think it is possible to standardize mandibular reconstructions from an anatomical mean. The objective of this study was to perform a mandibular morphometric analysis in order to obtain a set of "mean" measurements, which can be used by all surgeons interested in mandibular reconstruction. METHODS: We performed a morphometric analysis consisting of three-dimensional mandibular reconstructions of 30 men and 30 women. Several reference points were set and defined to evaluate specific lengths and angles of interest. We conducted an intra and inter-sexual descriptive analysis of measurements obtained. RESULTS: We did not identify any major intra-sexual differences within each group. The gonial angle is more open in women and the measurements characterizing the basilar contour are more prominent in men. We did not identify any differences in alveolar region parameters. CONCLUSION: The results of this study constitute a morphological tool for surgeons, from bone graft to free flap. These results also confirm us that the use of «custom cutting guides¼ for mandibular reconstruction may be excessive. It is pertinent to examine the value of "custom made" mandibular reconstructions since the differences observed are of the order of millimeters.

Scaling laws for branching vessels of human cerebral cortex.

OBJECTIVE: Vascular architecture, particularly of cerebral microvessels, has profound implications for both health and disease in a variety of areas, such as neuroimaging, angiogenesis and development, Alzheimer's disease, and vascular tumors. We analyzed the architecture of tree-like vessels of the human cerebral cortex. METHODS: Digital three-dimensional images of the microvascular network were obtained from thick sections of India ink-injected human brain by confocal laser microscopy covering a large zone of secondary cortex. A novel segmentation method was used to extract the skeleton and measure the diameter at every vertex. RESULTS: In this paper, we focus on the topology of the cortical tree-like vessels. Using stem-crown decomposition, power-scaling laws were shown to govern the relationships between integrated parameters, such as the distal cumulative length, volume, or normalized flow. This led us toward an experimental confirmation of the allometric equation between mass and metabolic rate. Inversely, the power-law model did not match the relationships between local parameters, such as diameter, and integrated ones. As a consequence, Murray's law did not appropriately model the architecture of cerebrovascular bifurcations. CONCLUSIONS: This study provides a unique, large database and mathematical characterization that may prove valuable for modeling the cerebral.