Régine Glineur

Dentocraniofacial Morphology of 21 Patients with Unilateral Cleft Lip and Palate: A Cephalometric Study:

Objective To assess the skeletal and dental craniofacial proportions of unilateral cleft lip and palate patients who were operated upon using the Malek technique, and compare them with a normal group to highlight the effect of surgical correction on craniofacial development during growth. Design Retrospective. Methods The cleft palate was closed using the Malek technique in a single operation at 3 months for 11 patients (complete closure of lip and palate) and in a two-stage operation for 10 patients (soft palate at 3 months, lip and hard palate at 6 months). Comparisons were made with a normal control group. Angular and linear measurements of anterior and posterior dimensions of the upper and lower compartments of the face were measured in the 7th and 12th years. Results and Conclusion No significant differences were observed between the two groups of palate technique repair, although significant differences were observed between craniofacial dimensions of normal versus cleft lip and palate patients. At a skeletal level, the maxilla and mandible were retrusive relative to the cranial base in the cleft lip and palate group. In fact, there was a backward rotation of the palatal plane with repercussions on the maxillo-mandibular complex position. Furthermore, the maxilla was shorter than in normal patients, whereas the mandible was normally shaped. The upper incisors were retroclined and they locked the lower incisors in linguoversion. There was a posterior skeletal deficit of the respiratory compartment, compensated by more marked posterior maxillary alveolar growth. Facial growth in cleft lip and palate patients followed the same pattern, but was delayed compared with normal patients.

L’expression de la caspase 3 et la protéine p53 au cours de l’apoptose physiologique et induite par 3 agents tératogènes au cours du développement crâniofacial précoce de l’embryon de souris

The neural crest-derived mesectoderm gives rise to physiologic apoptosis areas in early vertebrate embryos. Certain teratologic agents increase this phenomenon. The purpose of this work was to detect caspase 3 (which is associated with the apoptosis cascade) and p53 in cell death areas, both during physiological apoptosis and during apoptosis induced by three agents (retinoic acid, methyl-triazene, irradiation). Antibody revelation was performed using the aBC peroxidase kit. Quantifications were also performed on histological sections. We observed caspase 3 uptake on some apoptotic and preapoptotic cells in control embryos, and in the embryos exposed to the three teratogens. Immunoreactivity generally preceded the development of cytological features of apoptosis. However, p53 was expressed only in the embryos exposed to ionizing radiation and methyl-triazene (an alkylating agent), but not significantly in embryos exposed to retinoic acid. The present results throw some light on apoptosis mechanisms in several teratologic conditions.Resume Le mesectoderme derive des cretes neurales est le lieu de developpement de sites d’apoptose physiologique chez les jeunes embryons de vertebres. Divers agents teratogenes sont connus pour amplifier le phenomene apoptotique. Le but du present travail est la detection de l’expression de la caspase 3 (qui intervient dans la cascade de l’apoptose) et de p53 dans ces sites d’apoptose physiologique et induite par 3 agents teratogenes (acide retinoique, methyl-triazene et irradiation). La revelation s’est operee par immunohistochimie a l’aide du systeme ABC peroxydase. Des quantifications ont ete realisees sur les coupes histologiques. Les resultats nous demontrent une fixation de la caspase 3 sur certaines cellules apoptotiques et en voie d’apoptose chez les embryons temoins et dans les trois modeles teratologiques. L’expression precede en general l’apparition des stigmates cytologiques de mort cellulaire. En revanche, p53 s’exprime chez les embryons irradies et soumis au methyl-triazene (qui est un agent alkylant), mais non chez ceux qui ont ete soumis a l’acide retinoique. Les presents resultats nous paraissent etre en mesure de preciser certains mecanismes de declenchement de l’apoptose dans diverses situations teratologiques, et, partant, de mieux comprendre ceux-ci.

Cranio-facial dysmorphism: experimental study in the mouse, clinical applications

To obtain a better understanding of mandibulo-facial dysostosis and hemicraniofacial microsomia in man, the authors carried out a histologic and scanning electron microscope study of the facial malformations produced in mouse embryos by retinoic acid and methyl-triazene. The administration of 400 mg/kg 13 cis-retinoic acid (RA) to pregnant C57BL mice on day 9 of gestation produced anomalies of the cephalic extremity in the embryos resembling human mandibulo-facial dysostosis. The 64 embryos collected presented hypoplasia of the branchial arches or the snout in 79% of cases, auricular anomalies in 47% and ophthalmic anomalies in 12.5%. Fourteen NMRI mice on day 10.5 of gestation were treated with 1.5 mg (0.5 mg/kg) methyl-triazene (Methyl). The 126 embryos collected had developed a very high percentage of micromandibles and anomalies of both embryonic ears (94.6% to 100%). Finally, although the facial anomalies produced by retinoic acid resemble the human mandibulo-facial dysostosis syndrome, no correlation was found between hemicraniofacial microsomia and the administration of methyl-triazene.

Expansion maxillaire assistée par distracteur tranpalatin et ostéotomie de Le Fort I d’impaction postérieure, en un seul temps

Introduction Le distracteur palatin (TPD®, transpalatal distractor, Surgi-Tec, Bruges, Belgium) est un appareil a support osseux dont les effets d’expansion transversale sont bien connus chez les adolescents en fin de croissance et chez les adultes. L’expansion maxillaire est habituellement realisee avant la phase de traitement orthodontique. Le gain transversal se manifeste essentiellement au niveau anterieur et permet d’eviter, dans certains cas, les extractions de premolaires. La correction d’un deficit transversal posterieur important est difficilement realisable par cette technique et les patients presentant une dysmorphose complexe doivent beneficier, en fin de preparation orthodontique, d’une deuxieme phase chirurgicale visant a corriger les anomalies verticales et sagittales. Observation Les auteurs decrivent un cas clinique d’expansion chirurgicale transversale posterieure associee a une impaction posterieure du maxillaire, en une etape, en fin de preparation orthodontique. Les osteotomies, le positionnement du distracteur et l’appareillage orthodontique ont permis de moduler l’expansion transversale palatine selon la necessite. Discussion Les avantages et les limites de cette technique therapeutique sont discutes.

Impact of the mandibular divergence on the position of the inferior alveolar nerve and mylohyoid nerve: a computed tomography study and its relevance to bilateral sagittal split osteotomy

PurposeBilateral sagittal split osteotomy (BSSO) is the most common procedure used to treat mandibular deformities. BSSO procedures include the Epker technique and the Dal Pont technique which are the most frequently used. Because of the intramandibular pathway of the inferior alveolar nerve (IAN), neurosensory disturbance of the lower lip and chin is the most common complication of BSSO. This study performed quantitative measurements from computed tomographic (CT) data obtained on dry human mandibles. The main aim of the study was to evaluate if mandibular divergence can predict the position of the IAN and the mylohyoid nerve (MHN) to prevent nerve injury.MethodsAfter CT and 3D reconstruction of 65 dry mandibles, 30 measurements were made on 3 planes for each hemi-mandible. This allowed analysis of the IAN and MHN pathways. Three groups of hemi-mandibles were created depending on their divergence, and a statistical analysis was performed.ResultsEight out of the 30 measurements showed a significant difference among the 3 groups. There was no significant difference for the remaining 22 measurements.ConclusionsThe IAN seems to have a more superior position in the groups of mandibular hypo- and hyper-divergence. Orthognathic surgeons should use a more superficial retromolar bone incision in these cases. Finally, the Epker technique would be safer for preserving the MHN in normo- and hypo-divergent patients.

Effects of irradiation and methyl-triazene on craniofacial development in mouse embryos: a semiautomated morphometric analysis.

OBJECTIVE The purpose of the present study was a 2D-semiautomated morphometric analysis of craniofacial growth in nuclear magnetic resonance imaged (NMRI) mouse embryos. METHODS The NMRI mouse embryos were exposed in utero to either a single dose of 2 Gy X-irradiation on day 9 of gestation (113 embryos) or to 1.5 mg methyl-triazene administered orally to their pregnant mothers on gestational day 10.5 (124 embryos). An additional group of 108 embryos was used as controls. Digitized pictures of embryos from gestational days 14 to 17 were taken in lateral right view using a video system. Landmarks were located and digitized for computerized analysis of growth changes in relation to developmental stages of the face. RESULTS The results revealed that the snout of control embryos lengthens during the developmental period considered. The snout of embryos previously submitted to methyl-triazene displayed micrognathia, and all treated fetuses exhibited macroscopic signs of microcephaly with a reduced mandible. The snouts of irradiated embryos appeared shortened at the 14-day stage and continued to shorten as development proceeded. A shortening of the midface was detected macroscopically in 83% of the cases. CONCLUSION The results of this morphometric analysis enabled us to trace the developmental progression of the induced dysmorphosis and to assess the differences compared with normal development.

Effect of sleep bruxism duration on perceived sleep quality in middle-aged subjects

Sleep-related bruxism may directly impact sleep quality. This study aims to evaluate potential relationships between sleep bruxism events and related daytime symptoms. We investigated 22 patients (42.1 ± 11.6 yr of age) with sleep bruxism in comparison with 12 good sleeper control subjects of similar age (41.0 ± 11.5 yr). Sleep bruxism was visually analyzed and categorized according to sleep stage, bruxism type (tonic/phasic) and duration. Clinical instruments comprised the Epworth Sleepiness, the Brugmann Fatigue Scale, and the Hospital Anxiety and Depression Rating Scale. Sleep quality was measured using the Pittsburgh Sleep Quality Index. Controls and patients with sleep bruxism presented similar sleep architecture. However, patients with sleep bruxism displayed significantly decreased sleep efficiency and higher sleep fragmentation. Perceived sleep quality was significantly worse in patients with sleep bruxism than in control subjects. Additionally, patients presented with significantly greater fatigue intensity and more affective symptoms than controls. The cumulative durations of sleep bruxism events (phasic, tonic, and combined) were significantly correlated with deterioration of sleep quality, whereas neither the event index per hour of sleep nor the count of event types (phasic/tonic) were related to sleep quality. Patients with sleep bruxism present with higher levels of daytime fatigue and sleepiness than control subjects who experience good sleep and may also exhibit impairments of sleep quality which are related to the duration of bruxism occurrence rather than to its frequency.

In vitro evaluation of microleakage under orthodontic brackets bonded with different adhesive systems

Objective: Adhesives systems have a drawback when utilized for bonding orthodontic brackets: they shrink during photopolymerization creating microleakage. The aim of this study was to assess the stability of different orthodontic adhesives around brackets and enamel. Materials and Methods: Sixty noncarious mandibular premolars extracted for orthodontic reasons were randomly divided into six groups of adhesives used for bonding brackets to dental enamel: NeoBond® Light Cure Adhesive Kit, Transbond™ Plus Self-Etching, Victory V-Slot APC PLUS® + Transbond™ MIP, Rely-A-Bond® Kit, Light Cure Orthodontic Adhesive Kit (OptiBond®), and Transbond™ MIP. Following bonding, all teeth underwent 2500 cycles of thermal cycling in baths ranging from 5°C to 55°C before being immersed in 2% methylene blue for 24 h. All samples were examined under a binocular microscope to assess the degree of microleakage at the “bracket-adhesive” and “adhesive-enamel” interfaces in the gingival and occlusal regions of the bracket. Results: A significant difference was found at the “occlusal bracket-adhesive” interface. The highest microleakage values were found in the occlusal region, although no significant. Microleakage was observed in all groups. Conclusion: Group 2 had the highest microleakage values whereas Group 6 had the lowest values.