Indeed, it occurs three times more often in the mandible, especially at angle level and the ramus, followed by locations in the area first and second molars and more anterior locations.At the headquarters of the maxillary keratocyst is a little earlier in the prémolomolaire region and the canine and exceptionally the anterior region.Because of this early development, they constitute one of the first noticeable symptoms of the disease and confirm the place of choice for dentistry in the diagnosis of this syndrome.Their volume is more variable, ranging from a few millimeters to a flooding of a hemi-mandible (18). According to his "theory of the two mutational events', the first mutation is responsible for the malformation syndrome and predispose to the occurrence of tumors and the second would lead to the appearance of tumors.According to Cohen, so that a tumor suppressor gene is inactivated, two phenomena are required.The second phenomenon is the loss of the other allele, known as the loss of heterozygosity (LOH or).A loss of heterozygosity was demonstrated for basal cell carcinomas, odontogenic keratocysts and medulloblastoma, which are three of the main characteristics Gorlin syndrome.Thus, in the familial forms Gorlin syndrome, the first mutation may be present at conception and is found in all body cells.This first mutational event, generating a predisposition to develop basal cell nevus syndrome in offspring, is transmitted in dominance.This event remains latent and only exposes that if a second incident occurs on chromosomehomologous at the same locus, resulting in the appearance Gorlin syndrome.In familial cases, the individual needs only a single mutational step (since inherited the first of its genetic material).By against the appearance Gorlin syndrome in an individual with no family historyrequires the occurrence of two successive mutational events in the same individual.The PTCH gene is the human homologue of patched gene in Drosophila.This gene is a segmentation of the Drosophila gene (or polarity) occurring in the path oftransduction patched / sonic hedgehog that is involved in the control of embryonic development and cell proliferation.It functions as a cell cycle regulator by stopping cell division in the absence of ligand and activating soon as the connection is made with the ligand.Gorlin syndrome causes damage to the brain, ribs, vertebrae, members ... Patched is expressed throughout these tissues.Actors transduction pathway patched / sonic hedgehog:Although great progress has been made in recent years in understanding the operation of the signaling pathway patched / sonic hedgehog, manyuncertainties still need to be clarified in the future.- The Patched phenylthiocarbamide or protein encoded by the PTCH gene is a glycoprotein consisting of 1447 amino acids with twelve transmembrane domains,two large extracellular loops required for binding of the ligand SHH, a wide intra-cellular loop, an intracellular amino-terminal domain and a carboxy-terminal intracellular domain as well.It is found mutated in basal cell nevus syndrome but also in basal cell carcinomas, and rare cases of medulloblastoma.Most mutations are nonsense mutations that result in the synthesis of a truncated protein.- The sonic hedgehog protein (SHH), encoded by the gene located in 7q36 shh.This 45kDa protein is cleaved into two domains: an amino-terminal domain of 20 kDa Zn having a hydrolase activity and a carboxy-terminal domain of 25 kDa autocatalytic endowed withThe role of cholesterol in this signaling pathway is not fully known but it could play a role in limiting the spread of SHH molecule and distribution- Finally, the Smoothened protein (SMO), encoded by the gene located in the 7q31-32 Smoothened.It is a protein of 115 kDa, composed of 787 amino acids belonging to the family of serpentine receptors coupled to G proteins (which shows homology to the family Wnt receptors).The latter has an extracellular amino-terminal domain, a carboxy-terminal intracellular domain, and two areas (the third intracellular loop and the seventh transmembrane domain) involved in signaling.The transduction pathway of patched operating / Sonic Hedgehog:In the absence of SHH, SMO Patched and form an inactive complex.When SHH comes bind to Patched, the latter is then inactivated and SMO is free to transmit the signal within the cell.Several mechanisms have been proposed to explain the activation of SMO and signal transduction:- In a first hypothesis, Patched and Smo form a complex.SHH binding ligand to its receptor Patched result in a conformational change of the latter and therefore dissociation of Patched / SMO complex.SMO would then free to transmit the signal within the cell.- More recently, a second hypothesis proposes a non-stoichiometric regulation by Patched.Indeed, tests showed that the binding of SHH a result diminutionde Patched and increased GOS in the cell membrane.atched and SMO would be non-stoichiometric, ie that would regulate the Patched 16SMO change but do not constitute a real complex with it (there would be no physical interaction between the two).SMO is activated and can perform the signal transduction to the nucleus.The precise signal transduction pathway via GOS is not yet known, however it is known that the final target is represented by the activation of the transcription factor GLI (Cubitus interruptus homologue or Ci Drosophila).In cells unexposed to SHH GLI tétramétrique form a complex with other proteins such as Costal-2 (COS2) Fused (Fu) and Suppressor of Fused factor (SUFU).In this form, GLI can be cleaved into a 75 kDa amino terminal fragment that can translocate to the nucleus and repress target genes in the latter.In the presence of SHH ligand, the complex dissociates and whole plays its role GLI transcriptional activator (happening in the core and allows the expression of target genes).- Wingless (Wg) encoding members of the WNT family in vertebrates,- Decapentaplegic (DPP) encoding bone morphogenic protein (BMP) and TFG betaThese genes are essential for normal embryonic development and differentiation of certain tissues.The wingless gene codes for a family of glycoproteins involved in developmental processes such as differentiation, migration, cell proliferation and polarity.Deregulated expression of this gene is responsible for developmental abnormalities and oncogenesis.The decapentaplegic gene plays a small role on the transmission of information to the dorsoventral differentiation of the embryonic ectoderm.a Hedgehog signaling pathway plays an important role in the development of stem cells in a variety of tissues.embryonic development and in adults, suggesting that it continues to have a role during the postnatal period.Experimental models that express inappropriately any component of the hedgehog signaling pathway reveal significant developmental anomalies.The similarity between these abnormalities and those characteristics Gorlin syndrome implies that excessive activation of this signaling pathway can be the cause of developmental abnormalities and tumors found in lacnaevomatose basal cell.Patched regulates the transmission of the signal delivered by SHH, signal involved in several embryonaux processes such as the formation of the ventral neural tube, parts of the brain, limbs or dental development ...Indeed, the basal cell nevus syndrome can not be attributed to a single mutation.According to patients, there are nonsense mutations, missense, inversions, deletions ... which can be distributed over the entire coding sequence of the PTCH gene.The majority of mutations lead to the creation of a stop codon which leads to the synthesis of a truncated protein.These mutations are concentrated for the most on the wide intra-cellular loop, the wide extracellular loop and the amino terminal region of the PTCH gene.No correlation could be established between the location of the mutation in the gene and the phenotype observed in different patients Gorlin syndrome.One feature of this syndrome is the lack of genotype / phenotype correlation.For individuals carrying the same mutation, the clinical pictures can be very variable.This suggests the possibility of the influence of other factors, such as environmental or genetic factors in the development of the disease.GENERAL EVENTS IN DETAIL, THE Basal Cell Nevus SyndromeBasal cell nevus are one of the main signs of basal cell nevus syndrome such that in the absence of these nevi;They are among the major criteria for the disease, in the same way that odontogenic keratocysts.They have a large evolutionary potential of malignant degeneration in basal cell carcinomas.They are found in over 90% of cases in Gorlin syndrome.It has been estimated that 200 patients with basal cell carcinoma or more is reached Gorlin syndrome.More basal cell carcinoma diagnosis is made, the sooner this proportion increases.Considering that approximately one in five patients with basal cell carcinoma before the age of 20 years is suffering from basal cell nevus syndrome.Basal cell carcinomas, as part Gorlin syndrome, appear at an earlier age than in the normal population.They may be present at birth or develop during childhood.Most often, their occurrence begins at puberty and by the age of forty, 90% of patients affected by this disease have developed at least one basal cell carcinoma.Number: The number of basal cell carcinoma is highly variable.Although clinical cases have been observed with a single carcinoma, in most cases, the number is between twenty and several thousand.The location of these tumors can be done both on sun-exposed areas (and thus ultraviolet rays) than the unexposed areas.The eyelids, nose, cheeks and forehead are the most affected sites but the neck, trunk and axilla are also often affected.By cons, scalp and limbs are, most of the time spared.Clinical appearance: Basal cell nevus can take variable clinical aspects.- Appearance evoking the molluscum contagium is a contagious skin condition and inoculated under certain conditions.It is caused by a virus and is characterized by small elevations of a matt white or rose the size of a pearl and the top has widened by a depression in the umbilicus.- Appearance evoking the classical basal cell carcinoma.Nevus then appears as a small smooth surfaced tumor translucent.Its coloration is variable, usually that of the normal skin, sometimes pale pink or gray.Consistency is much stronger than would be expected appearance but the base is not infiltrated.If any of these lesions increased in size or starts to bleed or become covered with a crust, malignant transformation is suspected.Basal cell carcinomas appearing within the basal cell nevus syndrome can not be clearly distinguished from those appearing in an unaffected by this syndrome patient.The only characteristic element Gorlin syndrome is their occurrence in large numbers and at an early age and their location, which is not necessarily on sun-exposed areas.The clinical appearance of these tumors is highly variable ranging from flesh colored papules brown or ulcerative plaques.The histological appearance of basal cell nevus is that of an intradermal proliferation of epithelial cells, forming well defined ranges, often with peripheral palisade sitting.The histological appearance of basal cell carcinoma patients Gorlin syndrome is not different from those found in non-syndromic patients.When nevi becomes basal cell carcinoma, one notices larger and clearer cells, increased number of mitoses, an inflammatory character of the infiltrate.Deep penetrations, ulcers or invasions can occur with lymphocytic infiltration.They can be pigmented in the mass or in the periphery.A study suggests that patients with basal cell nevus syndrome would present increased sensitivity to ultraviolet rays.This is supported by the fact that only 14% of patients with Gorlin syndrome in north-west England develop basal cell carcinomas, against 47% in Australia.It stresses the importance of prenatal diagnosis (when one parent is reached) or the earliest possible diagnosis (for cases appeared de novo) to limit UV exposure upon diagnosis positive.Another study, carried reports that 88% of basal cell carcinomas in women and 86% among men in the general population occur on body areas exposed to the sun against 59% among women and 65% among male carriers of the basal cell nevus syndrome .He concluded that the anatomical distribution of lesions suggests that the sun is not an essential factor in the development of basal cell carcinomas.Only about 40% of African Americans with Gorlin syndrome develop basal cell carcinomas against 90% of Caucasians.
In some patients the skull is abnormally large prominence with frontal bossing and parietal-temporal.

Geodes are well demarcated, round or oval, of varying sizes.

The noble elements such as the neurovascular bundle of the inferior alveolar canal are, in turn, always respected, but can be turned back (and very rarely cause paraesthesia).The odontogenic keratocysts also have a very high recurrence rate. Their peak incidence is between the third and fourth decades.
They represent the most frequent radiological sign. Le diagnostic anténatal est possible par échographie et par analyse ADN des cellules foetales, obtenues par amniocentèse ou par biopsie du trophoblaste.Le diagnostic différentiel principal inclut le syndrome de Bazex, le trichoépithélium multiple et le syndrome de Muir-Torre (voir ces termes).La prise en charge requiert une approche multidisciplinaire. This examination consists of the content analysis and cystic walls is obtained after complete resection of the cyst or after taking a fragment of it during his or her marsupialisation drainage.