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.

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.

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.

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.

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.

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.

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.

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.

Frontoethmoidal meningoencephalocele: appraisal of a craniofacial surgical teaching program in Cambodia.

OBJECTIVE The treatment of frontoethmoidal meningoencephaloceles (fMECs) in Cambodia was not possible before the development of a program that taught some Khmer surgeons (working at the Children's Surgical Centre in Phnom Penh) how to surgically correct these deformities without any foreign help. The results of that teaching program are discussed in this paper. METHODS Between 2004 and 2009, both local and visiting foreign neurosurgical and craniofacial surgeons (the visitors coming twice a year) worked together to operate on 200 patients, and a report on those cases was published in 2010. In subsequent years (2010-2016), the Khmer surgeons operated on 100 patients without the presence of the visiting surgeons. In this study, the authors compare the second case series with the previously published series and the literature in terms of results and complications. The operations were performed with limited surgical materials and equipment, using a combined bicoronal and transfacial approach in most cases. Most of the patients came from very poor families. RESULTS Organizing the postoperative follow-up of these low-income patients (mean age 12 years) was probably the most challenging part of this teaching program. Nine of the patients were lost to surgical follow-up. In the other cases, cosmetic results were judged by the surgeons as worse than the patient's preoperative appearance in 1 case, poor in 12 cases, average in 27, and good in 51-data that are significantly less encouraging than the results reported by the joint local/visiting teams in 2010 (p = 0.0001). Nevertheless, patients and parents tended to have a better overall opinion about the surgical results (rating the results as good in 84% of the 80 cases in which parent or patient ratings were available). Twenty postoperative complications were observed (the most common being temporary CSF leaks). The rate of immediate postoperative complications directly related to fMEC surgery was less than that in the previous series, but the difference was not statistically significant (20% vs 28.5%, p = 0.58). No death was noted in this case series (in contrast to the previous series). Social questionnaire results confirmed that fMEC correction partially improved the adverse social and educational consequences of fMEC in affected children. CONCLUSIONS In the current state of this program, the local surgeons are able to correct fMECs in their own country, without foreign assistance, with good results in a majority of patients. Such humanitarian teaching programs generally take years to achieve the initial aims.

Reconstruction of Cranial Vault Defect with Polyetheretherketone Implants.

OBJECT: Reconstruction of a cranial vault defect is a frequent challenge in neurosurgery. Polyetheretherketone (PEEK) is used in many types of prostheses and has been employed for 10 years in our institution (University Hospital of Toulouse, France). The objectives of this study are to describe the benefits and drawbacks of reconstructing the cranial vault defect with a PEEK prosthesis. METHODS: Clinical data of the 37 patients who received a reconstruction with a custom-made PEEK prosthesis from 2007-2015 were retrospectively analysed. Operative technique, postoperative complications, and patient's satisfaction with the aesthetic result-on a scale ranging from 1 (very dissatisfied) to 5 (very satisfied)-were studied. RESULTS: Average follow-up was 4.3 years (from 2 months-9 years). The placement of the prosthesis was performed 195 days on average (from 0-1051 days, standard deviation 258 days) after the initial bone flap removal. One infection (2.7%), which required the removal of the prosthesis, was described. Six patients (16%) were reoperated by the maxillofacial surgery team to treat a lack of temporal projection related to muscle atrophy, using a fat cell autograft taken from the abdominal region. Overall, 30 patients (81%) answered the question about their aesthetic satisfaction, with good results on the satisfaction scale (average 4.5; from 3-5). CONCLUSION: The use of a PEEK prosthesis in cranial vault defect reconstruction is a reliable technique with a high patient satisfaction rate and few complications. Corrections of the temporal muscle atrophy by fat grafting may be performed in addition, without increasing the rate of complications.

Does the Eyebrow Sag with Aging? An Anthopometric Study of 95 Caucasians from 20 to 79 Years of Age.

BACKGROUND: It is commonly assumed that a progressive sagging of the eyebrow occurs with the facial aging process. Only a few studies have analyzed this modification, and the findings are disparate and inconclusive. This study, based on reproducible and validated data, aimed to quantify the modifications of eyebrow position that may occur with aging. Also analyzed were the effects of these eyebrow position changes on the upper eyelid and on frontal muscle activity. METHODS: The study included 95 Caucasian adults divided in three groups: 20 to 39, 40 to 59, and 60 to 79 years of age. Photographic portraits were made using a standardized photograph protocol. Eyebrow position was evaluated from the intercanthal line to four points along the upper margin of the eyebrow. The upper eyelid height, the lid sulcus height, and the upper iris coverage were measured. Severity of the forehead lines was analyzed using a validated scale. Reliability and validity of all measures were controlled beforehand. RESULTS: No significant differences were found when comparing eyebrow height above the medial canthus, the pupil, the lateral sclero-corneal limbus, and the lateral canthus between groups (p > 0.5). In addition, results suggested an increase of dermatochalasis when eyebrow height decreased. Also demonstrated was a significant increase of frontal muscle activity with aging. CONCLUSIONS: In contrast to conventional descriptions, this study demonstrated the stability of the eyebrow position with aging. This results from a physiological state of muscular compensation and may help explain the questionable results of eyebrow surgery.

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.

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.

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.

Frontoethmoidal meningoencephalocele: appraisal of 200 operated cases.

OBJECT: Frontoethmoidal mengingoencephaloceles (fMECs) are frequently observed in Cambodia, especially in poor families. The authors describe issues related to the surgical treatment of fMECs in Cambodia at the end of a humanitarian program that provided surgery free of charge to patients and their families. METHODS: The authors reviewed 257 cases of fMEC involving patients who presented to their institution, the Children's Surgical Center in Phnom Penh, between 2004 and 2009. They treated 200 of these patients surgically (108 males, 92 females; 89% younger than 18 years) using a "low-cost" management plan with no routine pre- or postoperative investigations. Initially, surgery was performed by visiting foreign surgeons who taught the procedures to resident surgeons. Patients were not charged for consultations or treatment and received at least 1 follow-up examination 6 months postoperatively. RESULTS: The nasoethmoidal type was the most frequent fMEC encountered (69%). Many patients had associated ophthalmological issues (46% of cases). Only 1 familial case was detected. Combined neurosurgical and facial procedures were successfully standardized and learned by surgeons initially unfamiliar with fMEC management. A neurosurgical approach avoided the need for a facial incision in 42 cases, improving cosmetic results. The most common postoperative issues were a temporary CSF leak (24 cases [12%]) and/or infection (28 cases [14%]). There were 3 deaths directly related to the operations. Cosmetic results were good in 145 cases, average in 27, poor in 7, and worse than preoperative appearance in 6 patients. Fifteen patients were lost to follow-up. The parents of 87% of the children were rice farmers. Questionnaire results confirmed that fMEC has important social and educational consequences for the affected children and that these consequences can be partially improved by fMEC correction. CONCLUSIONS: This experience in fMEC management demonstrates that local surgeons can treat these malformations with limited surgical materials and in a nonspecialized infrastructure after principles of treatment have been learned and if they are carefully respected. Surgery for fMEC can thus be more accessible to a larger number of patients in developing countries. Moreover, local treatment facilitates better postoperative and follow-up care.

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.

Seasonal variations in frontoethmoidal meningoencephalocele births in Cambodia.

OBJECT: Frontoethmoidal meningoencephalocele (fMEC) is relatively common in many Southeast Asian countries, with devastating aesthetic and social consequences for affected children. No cause has been detected to date. Among other factors, the authors of this paper attempt to identify a statistically significant difference in the spread of fMEC births throughout the year compared with other births. This seasonal variation in the incidence of fMEC births may provide clues to the causes of this condition. METHODS: From a group of 175 children with fMEC who underwent surgery at the authors' humanitarian institution (Children's Surgical Centre) in Phnom Penh between 2004 and 2008, 86 children were studied. These children were born at full term and had an accurately recorded date of birth. The birth dates of this fMEC group were compared with a group of > 15,000 other live births at one of the main maternity units in Phnom Penh in 2005 and 2006. RESULTS: Seasonal variation in incidence of fMEC by month of birth was highly statistically significant (p < 0.001), with the peak of births occurring in the dry season (between March and May). This is in contrast to the control group, in which there was an equal distribution of births throughout the year. More than 85% of the parents of children with fMEC who the authors treated were farmers, but this figure reflects the composition of the Cambodian population. CONCLUSIONS: Uneven spread in the incidence of fMEC births throughout the year suggests that a seasonal factor during the wet season may be suspected in the pathogenesis of fMEC in Cambodia.