Transverse cervical and great auricular nerve distribution in the mandibular area: a study in human cadavers.

The angle of the jaw is innervated by the auricular branch of the superficial cervical plexus (SCP). Cervical cutaneous nerves of the CP carry the sensation from the antero-lateral cervical skin. It is clinically relevant to identify the cervical cutaneous nerve distribution and the nerve point using superficial landmarks but published studies describing the emerging patterns and cervical cutaneous nerve branch distributions in the mandible are rare. The overlap between the cervical and trigeminal and facial nerve distributions and anastomoses is highly variable. The objective of this study was to characterize the distribution of the SCP nerves in the different parts of the mandible. Two hundred and fifty fresh and formalin-fixed human cadaver heads were microdissected to observe the distribution of the transverse cervical (TCN) and great auricular (GAN) nerves. Two main groups (G1 and G2) based on the emergence of the TCN and GAN behind the posterior edge of the sternocleidomastoid muscle and three types (T1, T2, and T3) based on their distribution in the different mandibular parts were observed. Statistical analysis showed that parameters related to the mandibular side (P = 0.307), gender (P = 0.218), and group (P = 0.111) did not influence the facial distribution of these nerves. The only parameter influencing the distribution was the type of nerve (GAN and TCN) (P < 0.001). In the face, the SCP reached the mandible in 97% of cases, its distribution and extent were subject-dependent. These results confirmed that the SCP could supply accessory innervation to the mandible through the TCN.

Assessment of the correlation between implant stability and bone density by computed tomography and resonance frequency analysis in fresh cadavers.

PURPOSE: Because of the immediate loading implant process, clinicians must consider implant primary stability issues before initiating surgery. The aim of this study was to assess the correlation between the bone density assessed by computed tomography (CT) images and the primary stability of two implant designs, as determined by resonance frequency analysis (RFA). MATERIALS AND METHODS: Sixty implants (30 NobelActive, 30 NobelSpeedy [Nobel Biocare]) were placed in five totally edentulous fresh cadaver maxillae. Before surgery, CT images were analyzed and bone densities measured. Implant primary stabilities (measured in implant stability quotient [ISQ] units) were determined along the buccolingual and mesiodistal axes by RFA. Correlations were assessed using the Pearson correlation test. RESULTS: Bone densities were similar near NobelActive and NobelSpeedy implants: 434.67 (± 220.53) versus 479.87 (± 209.05) Hounsfield Units (HU). Bone densities and NobelActive primary stabilities were highly correlated with ρ = 0.74 (P = .000) and ρ = 0.78 (P = .000) for the buccolingual and mesiodistal axes, respectively. An association was found between the 350 HU and 50 ISQ values, confirming good primary stabilities. For NobelSpeedy implants, no correlation was found regardless of the axis, with ρ = -0.07 (P = .72) (buccolingual) and ρ = -0.10 (P = .59) (mesiodistal). However, poor and good stabilities were observed in the anterior and posterior areas, respectively. CONCLUSION: This study revealed variations in primary stabilities depending on the implant design. The primary stability of conical implants with a double-lead thread design (NobelActive) seemed bone density-dependent regardless of the area of the maxilla, whereas the primary stability of nearly parallel-wall implants with a classical thread design (NobelSpeedy) seemed dependent on anatomical morphology. These results raise questions about the specific roles of the implant shape and thread design depending on the bone density and alveolar morphology.

Surgical anatomy of the preauricular anteroparotid approach for mandibular condyle surgery.

PURPOSE: The different surgical approaches used to treat mandibular condyle fractures are carried out in the periparotid skin area and can lead to facial nerve injury. We conducted a preauricular and anteroparotid surgical approach. Our main aim was to show the anatomical relationship between this approach site and the facial nerve branches, and to define cutaneous landmarks to locate the extraparotid facial nerve branches. METHOD: A 2-step dissection of 13 fresh human cadaver semi-heads was performed: a preauricular approach followed by a superficial parotidectomy to visualize the facial nerve. Its course and ramifications were studied and compared to cutaneous landmarks. The proximity of the facial nerve branches with the surgical approach site was observed. RESULTS: The approach allowed systematically visualising the zygomatic and/or buccal branches. No facial nerve branches were sectioned. In three cases (23 %), a nerve branch was visualized during the approach. The buccal and zygomatic branches were ramified in 77 % of cases. CONCLUSIONS: During our preauricular anteroparotid approach, the buccal and zygomatic branches were visualized but none was sectioned. Most often the approach was carried out between these two branches (46 % of cases). Cutaneous landmarks used were reliable to define a safe and nerve-free area for dissection. The buccal and zygomatic branches are very interesting because their high number of ramifications and anastomoses could serve as nerve relays in case of surgical lesion.

Comparative study of femoral diaphyseal morphometry in two male populations, in France and a French West Indies island: an example of clinical relevance of comparative anatomy for orthopedic practice.

Our aim, through a comparative study of two populations, one European and the other Afro-Caribbean, was to find out whether there were differences in radiographic measurements of femoral diaphyseal canal diameter, thickness of the medial and lateral cortex, and global diaphyseal diameter. We studied the nailed femurs of adult males in a population of 54 Europeans and 52 Afro-Caribbeans. Both populations were comparable in terms of age, height and weight. The measurements were taken with a ruler on the narrowest area of the hourglass, the isthmus, on an antero-posterior radiograph. The diameter of the femoral canal was classified into three intervals: <13 mm, 13-14 mm and >14 mm. The femoral canal diameter was significantly larger in the European patients, 14.3 (11-19) versus 13.4 (11-15.6), while the thickness of the lateral cortex was significantly larger in the Afro-Caribbean patients, 8.50 (6-12) versus 7.72 (5.4-11.5). Patient distribution according to the intervals was different in both groups: 59% of the Afro-Caribbeans were in the average interval versus 24.1% of the Europeans. For nearly 53.7% of the Europeans, the diameter of the femoral canal fell in the last interval versus 15.4% of the Afro-Caribbeans. The fact that the femoral canal is narrower in the Afro-Caribbean population may be linked to a thicker lateral cortex. The diameters of the nails used were larger in the European population, 12.6 mm (10-15) versus 12.1 mm (11-14) in the Afro-Caribbean population. The global diameters of both populations' femurs were similar (28.9 mm for the European sample vs. 29 mm). The present study may have an impact on the implants used in the orthopedic surgery (intramedullary nailing, arthroplasty implants). The range of usable implants must be complete and there must be precise pre-operative planning. A study of computed tomography scans could complement our measurements.

On two equations about brain volume, cranial capacity and age.

AIM: We decided to study the relationship between brain volume and cranial capacity and the relationship between brain volume and age on a series of CT from healthy adults. METHODS: Fifty-eight healthy volunteers (27 women, 31 men, age range 18-95 years) were examined using our imaging protocols. The volunteers had no present or past neuropsychiatric illness and no abuse of alcohol or illicit drugs. RESULTS: Mean intracranial volume was 1,384.6 cm(3) (standard deviation = 135.27, range 1,106-1,656) and mean brain volume was 1,201.0 cm(3) (standard deviation = 142.52, range 791-1,500). Linear regression between brain volume and cranial capacity yielded this formula: brain volume = 182.3 + 0.7 × cranial capacity. Multivariate analysis yielded a relationship between cranial capacity, brain volume and age as follows: brain volume = 396.5-3.5 × age + 0.7 × cranial capacity. CONCLUSION: This study could be supplemented by the collection of data such as, the size of the individuals in order to study the relationship between size of the brain and stature because this relation remains unclear.

Treatment of mandibular fractures with Michelet technique: manual fracture reduction without arch bars.

PURPOSE: In our Bordeaux maxillofacial surgery unit, we have used the Michelet technique described for 40 years: manual fracture reduction and semi-rigid miniplate osteosynthesis fixation. No maxillomandibular fixation (MMF) with arch bars or with screws was used for reduction during osteosynthesis. The aim of this work was to evaluate results of this unknown manual reduction method. MATERIALS AND METHODS: A total of 184 patients were reviewed. We recorded epidemiology of mandible fracture, clinical and radiologic evaluation before and after surgery, and treatment. Anatomic and functional manual reductions were the basic principle: manual maxillomandibular immobilization (functional) and manual fracture reduction (anatomic). In cases of condylar fractures without severe displacement, MMF with cortical bone screws was indicated (orthopedic treatment). Physiotherapy was also possible (functional treatment). RESULTS: In all, 315 mandible fractures sustained by 184 patients were reviewed into the study. Of the patients, 80% were treated by osteosynthesis: 54% by osteosynthesis treatment alone, 26% by osteosynthesis and orthopedic treatments. The average time required for osteosynthesis or osteosynthesis and orthopedic treatment was 56 minutes. We observed 0.67% of disturbed occlusion, 0.67% of pseudarthrosis, and 0.67% of bilateral temporomandibular joint internal derangement. CONCLUSIONS: Manual fracture reduction suppresses systematic MMF using arch bars during osteosynthesis of mandible fractures. Operating time and risk of complications are reduced. Functional results seem to be similar to that reported in the literature.

Septa within the sinus: effect on elevation of the sinus floor.

Elevation of the sinus floor allows the correct number and length of oral implants to be placed. The sinus membrane is dissected blindly, usually by a crestal approach, but several internal configurations of the maxillary sinus or intrasinus septa can cause problems. We studied 150 sinuses from 40 male cadavers, and 35 randomised male patients by anatomical dissection and computed tomography. Forty-six subjects (61%) had no bony septa or had septa less than 4mm. Twenty-nine (39%) had bony septa of which seven were incomplete, one had a complete bony septum in each maxillary sinus, and 20 had symmetrical bony septa. We present the results of a study of bony intramaxillary sinus septa and the potential problems they can cause during elevation of the sinus floor.

Vascular connections of the lateral wall of the sinus: surgical effect in sinus augmentation.

PURPOSE: There are several vascular vessels that supply the maxillary sinus, such as the posterior superior alveolar artery, the anterior superior alveolar artery, and the infraorbital artery (IOA). These vessels have to be taken into consideration during a sinus augmentation because of the potential risk of bleeding during the procedure. The objective of this investigation was to study variations in maxillary sinus artery connections with the potential surgical effect during a sinus floor elevation by the lateral wall. MATERIALS AND METHODS: The first part of the study was done in 32 anatomical specimens embedded in 10% formaldehyde solution and aged between 55 and 70 years (mean, 61.3 years). The second part of the study was a radiographic study using computerized tomographic (CT) scan images in 35 randomized patients treated in odontology and maxillofacial surgery departments. RESULTS: Results were recorded for 134 sinuses. In most cases, there was no vessel visible or no vessel present with a diameter less than 0.5 mm after dissection or CT-scan analysis: 120 sinuses (89.5%). In 14 cases (10.5%) there were vessels in the lower two thirds of the anterolateral wall. In 10 sinuses (71.4% of the 14 cases), there was an intraosseous or intrawall artery and in 2 sinuses (14.3%) they were in the intrasinusal position. In 8 of the 14 sinuses (57.1%, about 6% of overall sinuses) the diameter was between 1 and 2.5 mm. CONCLUSION: Knowledge of the arterial supply is essential for surgical treatment in the sinus area. A CT scan is recommended and the radiologist must be advised to search for intraosseous or extraosseous vessels in the lower two thirds of the maxillary sinus.

Anatomy and blood supply of the subgaleal fascia flap.

The subgaleal fascia (SGF) is a distinct layer in the temporal fossa situated between the superficial fascia and galea aponeurotica and the temporal fascia covering the superficial surface of the temporal muscle. The SGF is used most frequently for otologic reconstruction. Reviewing the literature, however, showed many contradictory findings about dissection of an independent SGF layer, its blood supply, and the possibility of harvesting it as part of a combined flap. Our study, carried out on ten fresh cadavers, presents a detailed view of the blood supply of the SGF to develop a safe method of harvesting an inferior-based SGF. Our systematic plane-by-plane approach, associated with a transparent grid applied on each dissection, allowed us to quantify the branches from each plane and to localize precisely their entering sites from a reference "zygomatic point." The SGF had no ascending axial vascular supply entering from its base; according to our results, therefore, the SGF could not be harvested alone as an inferior pedicled flap down to the zygomatic arch. It may be feasible, however, to harvest a SGF flap when a strip of the superficial fascia is associated with its middle third. Therefore, we suggest that an average height of 5.4 cm of superficial fascia should be included in an inferior-based pedicle of a SGF.