Perioperative management of oral anticoagulated patients undergoing an oral, implant, or periodontal procedure: a survey of practices of members of two dental scientific societies, the PRADICO study.

OBJECTIVES: Studies on the perioperative management of patients on direct oral anticoagulants (DOACs) receiving oral invasive procedures are sparse. Moreover, the recommendations of the scientific societies on DOACs are discordant, and the practices are highly variable. We conducted a survey of general and specialized dentists in France to compare their practices concerning the management of patients receiving vitamin K antagonists (VKAs) and DOACs. MATERIALS AND METHODS: Members of two dental surgical societies were invited to participate in the survey. One hundred forty-one practitioners answered an online questionnaire focusing on the periprocedural management of oral anticoagulated patients (participation rate, 17.8%). RESULTS: Practitioners at hospitals or mixed practices and specialists treated significantly more anticoagulated patients and more frequently performed procedures with high hemorrhagic risk than practitioners with private practice and general dentists. Greater than 90% of practitioners did not modify the treatment for patients on VKAs and controlled the International Normalized Ratio (INR) preoperatively. Regarding DOACs, 62.9% of practitioners did not change the treatment, 70.8% did not prescribe any biological tests, and 13.9% prescribed an INR. Practitioners at hospitals and mixed practices and specialists had better training and knowledge about DOACs. CONCLUSIONS: This survey showed that anticoagulated patients were managed mostly by specialists in private or hospital care, notably when requiring oral procedures at high hemorrhagic risk. CLINICAL RELEVANCE: A growing proportion of anticoagulated patients are being treated by dentists in primary care. Consequently, they need training, especially concerning DOACs. Additionally, consensus recommendations are necessary for better coordination of stakeholders and patient safety. Trial registration on ClinicalTrials.gov : NCT03150303.

Molecular and cellular characterizations of human cherubism: disease aggressiveness depends on osteoclast differentiation.

BACKGROUND: Cherubism is a rare autosomal dominant disorder of the jaws caused by mutation of the SH3BP2 gene. The bone is replaced by a fibrous granuloma containing multinucleated giant cells. Cells of the cherubism granuloma have never been systematically analyzed. Hence, the aim of this study was to characterize the cells in human cherubism granulomas, to determine the osteoclastic characteristics of the multinucleated giant cells and to investigate the potential role of TNF-α in human cherubism. RESULTS: Seven granulomas were analyzed in pathology, molecular biology and immunohistochemistry. Granulomas were composed mainly of macrophages or osteoclasts within a fibroblastic tissue, with few lymphoid cells. Myeloid differentiation and nuclear NFATc1 localization were both associated with disease aggressiveness. OPG and RANKL immunohistochemical expression was unexpected in our specimens. Five granuloma cells were cultured in standard and osteoclastogenic media. In culture, cherubism cells were able to differentiate into active osteoclasts, in both osteoclastogenic and standard media. IL-6 was the major cytokine present in the culture supernatants. CONCLUSION: Multinucleated giant cells from cherubism granulomas are CD68 positive cells, which differentiate into macrophages in non-aggressive cherubism and into osteoclasts in aggressive cherubism, stimulated by the NFATc1 pathway. This latter differentiation appears to involve a disturbed RANK-L/RANK/OPG pathway and be less TNF-α dependent than the cherubism mouse model.

Topical Review: Potential Use of Botulinum Toxin in the Management of Painful Posttraumatic Trigeminal Neuropathy.

Painful posttraumatic trigeminal neuropathy (PPTTN) is a chronic condition that is difficult to endure and has a poorly understood pathophysiology. Treatment options are limited and often unsatisfactory due to insufficient efficacy and significant adverse effects. Botulinum toxin type A (BTX-A), initially used in the management of pathologically sustained or twisting muscular contractions, has recently been advocated for treatment of neuropathic pain. Its action is not limited to the blockage of acetylcholine release at the neuromuscular junction, but also includes inhibition of exocytosis of other neurotransmitters by interfering with the SNARE complexes of synaptic membranes. When injected into the painful location, the toxin can be taken up by peripheral terminals of nociceptive afferent nerve fibers, and this action suppresses peripheral and central release of algogenic neurotransmitters such as glutamate or substance P, thus promoting analgesia. Several randomized controlled trials in humans have provided emerging evidence for the therapeutic use of BTX-A in neuropathic pain states, including trigeminal neuralgia. This evidence, in addition to its good safety profile and long-lasting effect, suggests that BTX-A could be a potential novel treatment for PPTTN.

Opiorphin levels in fluids of burning mouth syndrome patients: a case-control study.

OBJECTIVES: Idiopathic Burning mouth syndrome (iBMS) is a poorly understood affection characterized by persistent pain in the oral cavity without any clinical or biological abnormality. Opiorphin is a natural inhibitor of enkephalin-inactivating ectopeptidases, mainly produced by salivary glands, that has demonstrated analgesic properties. The objective of the present case-control study was to test the hypothesis of a decrease in opiorphin levels in iBMS patients. MATERIALS AND METHODS: Twenty-one iBMS patients and 21 matched controls subjects were included between 2011 and 2013. Submandibular and sublingual salivary, blood, and urinary opiorphin levels of iBMS patients were compared to controls. RESULTS: Results are expressed as mean values ± SD and compared using the Wilcoxon Signed Rank test. Correlations were analyzed with Spearman coefficient. The level of significance was fixed at p < 0.05. Opiorphin levels in iBMS and controls were respectively (in ng/ml) in basal saliva: 37.8 ± 42.5 and 67.6 ± 188.9 (p = NS); stimulated saliva: 28.8 ± 25.3 and 31.1 ± 29.1 (p = NS); blood: 4.6 ± 5.4 and 1.9 ± 1.4 (p < 0.05); and urines: 68.5 ± 259.8 and 8.9 ± 6.2 (p = NS). CLINICAL RELEVANCE: In conclusion, the lack of significative difference in salivary opiorphin levels between iBMS and controls does not favor a direct local role for opiorphin in the etiopathogeny of iBMS. However, higher blood opiorphin levels may reflect a systemic dysregulation in iBMS. Trial registration NCT02686359 https://clinicaltrials.gov/ct2/show/NCT02686359.

Defining a new aggressiveness classification and using NFATc1 localization as a prognostic factor in cherubism.

Cherubism is a rare genetic disease characterized by bilateral giant cell reparative granuloma of the jaws consisting of a fibrotic stroma with giant multinucleated cells (GMCs) and osteoclastic features. Cherubism severity is highly variable, and recurrence after surgery is the most important risk. Currently, there are no prognostic indicators. The aims of this study were to evaluate the osteoclastogenesis phenotype by histologic examination of nuclear factor of activated T cells 1 (NFATc1) localization and tartrate-resistant acid phosphatase (TRAP) activity and to correlate the results to disease aggressiveness to define prognostic indicators. Based on cherubism evolution 1 year after surgery, 3 classes of cherubism aggressiveness were identified: mild (group A), moderate (group B), and severe (group C). Histologically, in grade A and B cherubism lesions, GMCs were negative for both TRAP activity and NFATc1 nuclear localization. In contrast, in grade C cherubism lesions, GMCs were all positive for TRAP activity and NFATc1 nuclear localization and displayed osteoclast-like features. Other histopathologic findings were not different among the 3 groups. Our results establish that TRAP activity and NFTAc1 nuclear localization are associated with aggressive cherubism and therefore could be added to routine pathologic examination to aid in prognosis and management of the disease. The finding of NFATc1 nuclear localization in aggressive tumors supports the addition of anticalcineurin treatment to the therapeutic arsenal for cherubism.

Management of dental extraction in patients undergoing anticoagulant oral direct treatment: a pilot study.

OBJECTIVE: The main goal of this study was to compare the incidence of postoperative bleeding events after dental extractions between patients treated with direct oral anticoagulants (DOACs) and those treated with vitamin K antagonists (VKAs) without withdrawal of oral anticoagulant therapy (OAT). Our second objective was to evaluate the risk factors affecting postoperative hemorrhage after tooth extraction in patients taking DOACs. STUDY DESIGN: This prospective observational study included 51 patients who were being treated with oral anticoagulants and required dental extractions. They were divided into two groups: 31 patients receiving a DOAC and 20 control patients taking VKA with an international normalized ratio between 2.0 and 3.0. In both groups, extractions were performed under continued OAT, and the same local hemostatic measures were applied. All procedures were performed in an outpatient facility. A bleeding event was defined as persistent oozing or marked hemorrhage over 20 minutes after tooth extraction despite local hemostasis procedures or all bleeding episode occurring during the first postoperative week. RESULTS: Five patients taking DOACs had seven bleeding episodes, and four patients receiving VKAs had five bleeding episodes during the postoperative follow-up period. The difference in the number of bleeding events between the two groups was not statistically significant (adjusted odds ratio = 0.77; 95% confidence interval 0.19-3.19; P = .723). Eleven (91.67%) bleeding events were mild and controlled by mechanical compression with gauzes, and one (8.33 %) was managed with a revision of the wound, application of fibrin glue, and resuturing. No bleeding required hospitalization or blood transfusion. All bleeding episodes occurred during the first 3 postoperative days. CONCLUSIONS: According to our preliminary outcome data, dental extractions can be performed safely in an outpatient facility in patients treated with DOAC by applying local hemostatic measures, without interrupting or modifying OAT.

Randomized Clinical Trial of Intraosseous Methylprednisolone Injection for Acute Pulpitis Pain.

INTRODUCTION: The present study reports the results of a randomized clinical trial comparing local intraosseous methylprednisolone injection and emergency pulpotomy in the management of acute pulpitis on efficacy, safety, and efficiency end points. METHODS: After providing prior informed written consent, 94 patients consulting for acute irreversible pulpitis pain at university-affiliated teaching hospital dental clinics in Dakar, Senegal were randomly assigned to either the methylprednisolone treatment group (n = 47) or the pulpotomy treatment group (n = 47). Patients were followed up at 1 week and assessed 6 months later to evaluate the therapeutic outcome of their treatment. RESULTS: At day 7 the patients in the methylprednisolone group reported less intense spontaneous and percussion pain in the day 0-day 7 period than the patients in the pulpotomy group. Methylprednisolone treatment took approximately 7 minutes (4.6-9.3) less to accomplish than pulpotomy (or about half the time). No difference in the therapeutic outcome was found between the 2 treatment groups at 6 months (all credible intervals span 0). CONCLUSIONS: This study establishes that methylprednisolone injection for acute pulpitis is relieved by a minimally invasive pharmacologic approach more effectively than by the reference pulpotomy and conserves scarce dental resources (ie, endodontic equipment and supplies, dental surgeon's time).

The calcineurin inhibitor tacrolimus as a new therapy in severe cherubism.

Cherubism is a rare genetic disorder characterized by extensive growth of a bilateral granuloma of the jaws, resulting in facial disfigurement. Cherubism is caused by gain-of-function mutations in the SH3BP2 gene, leading to overactivation of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1)-dependent osteoclastogenesis. Recent findings in human and mouse cherubism have suggested that calcineurin inhibitors might be drug candidates in cherubism medical treatment. A 4-year-old boy with aggressive cherubism was treated with the calcineurin inhibitor tacrolimus for 1 year, and clinical, radiological, and molecular data were obtained. Immunohistologic analysis was performed to compare preoperative and postoperative NFATc1 staining and tartrate resistant acid phosphatase (TRAP) activity. Real-time PCR was performed to analyze the relative expression levels of OPG and RANKL. After tacrolimus therapy, the patient showed significant clinical improvement, including stabilization of jaw size and intraosseous osteogenesis. Immunohistologic analyses on granuloma showed that tacrolimus caused a significant reduction in the number of TRAP-positive osteoclasts and NFATc1 nuclear staining in multinucleated giant cells. Molecular analysis showed that tacrolimus treatment also resulted in increased OPG expression. We present the first case of effective medical therapy in cherubism. Tacrolimus enhanced bone formation by stimulating osteogenesis and inhibiting osteoclastogenesis.

Specificity of paediatric jawbone lesions: tumours and pseudotumours.

INTRODUCTION: Characteristics and epidemiology of jaw tumours have been described mostly in adults. Compared with their adult counterparts, childhood jaw tumours show considerable differences. The aim of this study was to describe the different jaw tumours in children, define diagnostic tools to determine their specificity and describe optimal treatment. METHODS: All children patients with jaw lesions, excluding cysts, apical granuloma and osteitis were included in our study between 1999 and 2009. The medical records were analyzed for clinical, radiological, and pathological findings, treatments and recurrences. RESULTS: Mean patient age was 10.9 years old, ranging from 2 months to 18 years old. Of the 63 lesions, 18 were odontogenic and 45 non-odontogenic lesions. 6% of all cases were malignant tumours; the mean age of presentation was 7.25 years old, [ranging from 0.2 to 18 years old]. Approximately 80% of the tumours developed after 6 years of age. Odontogenic tumours occurred more often after the age of 6. CONCLUSION: Compared with their adult counterpart, childhood jaw tumours show considerable differences in their clinical behaviour and radiological and pathological characteristics. Clinical features of some tumours can be specific to children. Tumourigenesis is related to dental development and facial growth. Conservative treatment should be considered.

Clinical study evaluating the effect of bevacizumab on the severity of zoledronic acid-related osteonecrosis of the jaw in cancer patients.

This study aimed to evaluate the effect of bevacizumab (BVZ) on the severity of osteonecrosis of the jaw (ONJ) in a cohort of cancer patients treated with intravenous zoledronic acid (ZA). We reviewed 42 oncologic patients with ONJ between 2007 and 2010. Only patients with solids tumors and who had received ZA were included. Data analyses included age, sex, underlying disease, ZA and BVZ dosages, dental history and ONJ characteristics. Of the 42 ONJ patients treated with ZA, 10 also received BVZ. In the 10 ZA/BVZ patients, the mean duration of ZA treatment at the time of ONJ diagnosis was 12.4 months (±6.8), compared to 22.9 months (±4.8) in the 32 patients who received ZA only (p<0.05). Cox's model analysis of the delay to ONJ diagnosis confirmed the impact of BVZ on ONJ diagnosis. In the ZA/BVZ-treated group, 7 (70%) patients developed spontaneous osteonecrosis. Multiple logistic regression analysis showed that ZA/BVZ is associated with increased risk of developing spontaneous ONJ (OR 6.07; 95% CI, [1.3-28.2], p<0.05). And finally, the number of ONJ lesions was increased in the ZA/BVZ-treated group compared to the ZA group (p<0.01). Other clinical conditions as type of tumor (prostate, breast…), cancer severity or other chemotherapy drugs also could be involved in ONJ evolution. However, this study demonstrates for the first time the potential negative influence of BVZ on the incidence and severity of ONJ in patients receiving ZA. Within the study limits, our results suggest that combination ZA/BVZ treatment may possibly predispose to the development of spontaneous and earlier ONJ.

Phase III, randomized, double-blind, placebo-controlled trial of topical 2 % lidocaine for the prevention and treatment of oral mucosal pain in children.

OBJECTIVES: The aim of this study was to assess the efficacy in pain reduction of topical 2 % lidocaine compared to a placebo cream in children with oral mucosal lesions due to trauma or aphthous ulcers or in the prevention of clamp placement pain. MATERIALS AND METHODS: The design was a double-blind, randomized, placebo-controlled, four-center trial on 64 patients. Pain intensity and relief were measured using a 100-mm visual analog scale (VAS). One-tailed Student's t test and ANOVA were used for statistical analyses. RESULTS: Independent of the pain origin, application of 2 % lidocaine cream led to a mean reduction in VAS pain intensity of 19.7 mm ± 18.3, which was significantly greater than that obtained with the placebo cream (p = .025). Analyses showed a statistically significant efficacy of the 2 % lidocaine cream (p < .0001). Its efficacy was not associated to any local or systemic adverse drug reaction, as reported by the patients. As the most important population represented in our patients was children whom a rubber dam clamp was placed, we also specifically analysed this population, and we were able to demonstrate a significantly greater efficacy of the 2 % lidocaine cream on the pain caused by the rubber dam clamp placement in comparison to the placebo cream (p < .005). CONCLUSIONS: A significant reduction in pain intensity occurred after application of 2 % lidocaine cream, and the effect was significantly greater than that obtained with the placebo cream. Considering the study's limitations, this product appears safe for use in children. CLINICAL RELEVANCE: For painful benign lesions of the oral mucosa (trauma or aphthous ulcers) or for preventing painful iatrogenic procedures such as rubber dam clamp placement, it is essential to treat or prevent pain onset, especially in the pediatric population for whom a painful experience could end in refusal of dental care. Application of a topical anesthetic in this specific situation is of particular interest, as is defining its efficacy and safety.

Characteristics of pain assessed with visual analog scale and questionnaire in burning mouth syndrome patients: a pilot study.

AIMS: To test the validity of the use of the Douleur Neuropathique en 4 Questions (DN4) questionnaire for burning mouth syndrome (BMS) patients, and to differentiate patients by measuring the time course of the pain in BMS patients over a period of 7 days with a visual analog scale (VAS). METHODS: Patients completed the DN4 questionnaire and a VAS every hour for 7 days. The data were expressed as mean ± SEM. Correlations were searched using the Spearman correlation test with a significance level at P < .05. RESULTS: Data were fully analyzed for the 22 patients (21 females, 1 male, mean [± SEM] age 62.7 ± 2.3 years) for the DN4 and 17 patients for the VAS. DN4 scores ranged from 2 to 7 (mean score: 3.9 ± 0.3), and 59% of the patients had a DN4 score ≥ 4. Burning was found in all the patients, followed by pricking pain (pins and needles) and allodynia (pain on brushing) (both 68%), tingling (45%), numbness (32%), itching (27%), and electrical discharges (23%). Monitoring the hourly time-course of the pain led to the identification of two groups with intermittent or constant pain. In the latter, averaging the VAS for 7 days enabled plotting a curve, the slope of which could be calculated. The range of the slopes was 0.00 to 0.59, and a regular increase of pain during the day was seen for the majority of the patients. CONCLUSION: The findings support the use of DN4 as a tool for screening BMS and reinforce the view that BMS is a clinical manifestation of a neuropathic disease. The methodology of this study can be used for a better description of the patients and the identification of subgroups.

Osteonecrosis of the jaw and nonmalignant disease: is there an association with rheumatoid arthritis?

OBJECTIVE: To review cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) occurring in association with benign disease and to describe and compare the clinical course and outcome for patients with BRONJ and rheumatoid arthritis (RA) or osteoporosis. METHODS: We retrospectively reviewed observations of all patients referred for treatment and followup for BRONJ from January 2007 to December 2011. Only patients with malignant disease were excluded. Demographic data, medical history, maxillofacial findings, BRONJ treatment, and followup were reviewed for each case. RESULTS: Over a 5-year period, we diagnosed 112 patients with BRONJ. Among these patients, 15 received bisphosphonate (BP) treatment for nonmalignant disease (mean age 65.7 ± 19.8 yrs, 80% women). Patients received BP for a variety of reasons: 8 (53%) to prevent osteoporosis in association with underlying RA; 6 (40%) to prevent idiopathic osteoporosis; and 1 (7%) to treat ankle algodystrophy. The mean oral BP exposure period was 48.4 months (median 36 mo). In 13 cases (86.6%), BRONJ was diagnosed following dental extraction. Of the 8 patients with RA, 5 (62.5%) were taking prednisone at the time of the discovery of BRONJ. Major surgery, sequestrectomy, or alveolectomy was performed in 9 patients (60%), all of whom healed within 3 to 36 months (mean 11.5 mo). Comparative analysis of all the variables showed no statistically significant differences between patients with RA and others. CONCLUSION: ONJ is a rare adverse effect of BP therapy, especially when administered orally. Within the limits of our study, we were unable to demonstrate a difference in BRONJ disease spectrum, clinical course, or outcome between patients with and those without RA.

PTCH1 mutation and local aggressiveness of odontogenic keratocystic tumors in children: is there a relationship?

Keratocystic odontogenic tumors (KCOTs) are locally aggressive jaw lesions that may be related to PTCH1 mutations in isolation or in association with nevoid basal cell carcinoma syndrome. We sought to clarify the role of PTCH1 mutation in KCOT aggressiveness. We assessed cyst pathological characteristics, Ki-67 immunostaining, and somatic and germinal PTCH1 mutation in 16 KCOTs from 10 unrelated patients. Ten PTCH1 mutations were identified in 16 tumors. All tumors with PTCH1 mutations presented the criteria of pathological aggressiveness. We also noted the presence of a chorionic epithelial structure apparently acting as a secondary germinal center in these same tumors. Ki-67 immunostaining was not associated with PTCH1 mutation. KCOTs harboring the mutation display a chorionic epithelial structure that acts as a secondary germinal center. Genetic and microenvironmental factors might interact to propel tumor development.

Efficacy of topical 1% lidocaine in the symptomatic treatment of pain associated with oral mucosal trauma or minor oral aphthous ulcer: a randomized, double-blind, placebo-controlled, parallel-group, single-dose study.

AIMS: To determine the efficacy in pain reduction of a topical 1% lidocaine compared to a placebo cream in patients with oral mucosal lesions due to trauma or minor oral aphthous ulcer. METHODS: The design was a double-blind, randomized, placebo-controlled, six-center trial on 59 patients. Pain intensity and relief were measured using a 100-mm visual analog scale (VAS). One-tailed Student t test and ANOVA analyses were used for statistical analyses. RESULTS: Independent of the pain origin (oral mucosal trauma or minor oral aphthous ulcer), the application of the 1% lidocaine cream led to a mean reduction in VAS pain intensity of 29.4 mm ± 17.0, which was significantly greater than the decrease obtained with the placebo cream. Analysis showed a statistically significant efficacy of the 1% lidocaine cream (P = .0003). Its efficacy was not related to the type of lesion, and no adverse drug reaction, either local or systemic, was reported by any of the patients. CONCLUSION: A significant reduction in pain intensity occurred after application of 1% lidocaine cream and was significantly greater than that with the placebo cream. Taking into account the study's limitations, this product seems safe to use.

Enamel protein regulation and dental and periodontal physiopathology in MSX2 mutant mice.

Signaling pathways that underlie postnatal dental and periodontal physiopathology are less studied than those of early tooth development. Members of the muscle segment homeobox gene (Msx) family encode homeoproteins that show functional redundancy during development and are known to be involved in epithelial-mesenchymal interactions that lead to crown morphogenesis and ameloblast cell differentiation. This study analyzed the MSX2 protein during mouse postnatal growth as well as in the adult. The analysis focused on enamel and periodontal defects and enamel proteins in Msx2-null mutant mice. In the epithelial lifecycle, the levels of MSX2 expression and enamel protein secretion were inversely related. Msx2+/- mice showed increased amelogenin expression, enamel thickness, and rod size. Msx2-/- mice displayed compound phenotypic characteristics of enamel defects, related to both enamel-specific gene mutations (amelogenin and enamelin) in isolated amelogenesis imperfecta, and cell-cell junction elements (laminin 5 and cytokeratin 5) in other syndromes. These effects were also related to ameloblast disappearance, which differed between incisors and molars. In Msx2-/- roots, Malassez cells formed giant islands that overexpressed amelogenin and ameloblastin that grew over months. Aberrant expression of enamel proteins is proposed to underlie the regional osteopetrosis and hyperproduction of cellular cementum. These enamel and periodontal phenotypes of Msx2 mutants constitute the first case report of structural and signaling defects associated with enamel protein overexpression in a postnatal context.

Vitamin D and tissue non-specific alkaline phosphatase in dental cells.

Dental epithelium comprises different cell populations, including ameloblasts and stratum intermedium cells. Ameloblasts are vitamin D targets, and at least five proteins undergo specific modulation of their expression following the addition of 1alpha,25(OH)2 vitamin D3[1alpha,25(OH)2D3]. Stratum intermedium cells have not been studied in any great detail regarding vitamin D impact. Interestingly, in these cells, the tissue non-specific alkaline phosphatase (TNAP) is overexpressed. On the other hand, TNAP is a reliable bone marker of vitamin D action, similar to calbindins in kidney and intestine, previously used for studies of vitamin D activity in ameloblasts. Here, TNAP expression and activity were investigated in vivo in the microdissected epithelium and mesenchyme of mandible incisors. Physiological doses of 1alpha,25(OH)2D3 injected in control rats failed to modify TNAP activity in both dental epithelium and mesenchyme. No significant differences were observed in the steady-state levels of TNAP mRNAs of dental tissues from wild-type and vitamin D nuclear receptor (VDRnuc)-deficient mice of the same litters. These data suggest that, in contrast to ameloblasts, stratum intermedium cells are not sensitive to 1alpha,25(OH)2D3. An explanation for such a responsiveness of stratum intermedium cells to 1alpha,25(OH)2D3 is proposed based on the respective expressions of both vitamin D receptors (VDRnuc and 1,25D3-[MARRS]) and the Dlx2 homeobox gene.