Single Central Maxillary Incisor Research Articles

Sonography of fetal holoprosencephaly: a guide to recognize the lesser varieties

Background Alobar holoprosencephaly (HPE) is easily detected during a first-trimester screening examination, conversely, recognizing the lesser varieties may be difficult even in the second trimester. Objectives To describe the imaging findings of a cohort of fetuses with holoprosencephaly (HPE) and to elucidate the appearances of the different anatomical varieties. Materials and methods We reviewed medical records and stored images of pregnant women referred to our clinic because of a diagnosis or the suspicion of various forms of HPE. We reported the imaging characteristics, the presence of other associated anomalies, magnetic resonance findings, karyotype and autoptic examinations when available. Results Alobar forms show great distortion of normal brain anatomy, with a single ventricle detectable during the first trimester of pregnancy. Extracerebral, face and karyotype abnormalities are often associated. In semilobar and lobar forms the septum pellucidum is typically absent in axial planes, with fused frontal horns, while posterior fossa is often normal. At multiplanar neurosonogram, anomalies involving corpus callosum and cortex development can be detected. Face abnormalities are mild in lobar forms: receding forehead, various degrees of hypotelorism and the presence of a single central maxillary incisor are reported. Conclusions The alobar forms are detectable since the first trimester, with a peculiar single ventricle and extremely frequent extracerebral and karyotype abnormalities. The semilobar and lobar forms are more challenging and the diagnosis is easily missed in a mid-trimester screening exam unless a careful evaluation of both cavum septi pellucidi and frontal horns as well is conducted.

An unusual case of SMMCI syndrome: supernumerary midline central incisor in siblings

This is the first reported case of siblings with Solitary Median Maxillary Central Incisor (SMMCI) syndrome presenting with an erupted single symmetrical central maxillary midline incisor between normal central incisors. Usually only one central incisor is present. This case is also interesting as the tooth described could have been mistaken for a mesiodens, however, a mesiodens is not symmetrical and usually erupts between the maxillary central incisors and sits slightly to the right or left of the midline. CPD/Clinical Relevance: This case highlights the fact that SMMCI should not be considered as a simple dental anomaly because it may be associated with more complex craniofacial malformations.

Influence of resin cement shade on the color and translucency of zirconia crowns.

BackgroundZirconia crowns are highly attractive for clinicians, although have poor translucency when used as single restorations, in addition to unknown effect of resin cement shade on final cemented crown shade. This study aimed to assess effect of resin cement opacity on color replication potential of different zirconia frameworks with target tooth color, in addition to different zirconia crowns translucency evaluation. Material and MethodsTwenty-four zirconia crown restorations were fabricated to restore single central maxillary incisor for 8 patients, divided into 3 groups according to color and type of zirconia used (white Zr core, colored Zr core and monolithic HT Zrcowns). Each group was further subdivided into 2 subgroups according to resin cement shade. Using Easyshade spectrophotometer, Delta E color difference was calculated between each crown parameters using 2 different resin luting cement shades and adjacent target tooth. Translucency parameters (TP) were tested for finished crowns. ΔEs obtained were assessed based on ΔEof 1.6 which represented color difference that could not be detected by human eye and considered clinically acceptable. ResultsNo statistically significant values were found between subgroups related to different resin cement shade. Translucency parameters showed statistically significant different values. Monolithic crowns showed highest translucency parameters followed by Zr crowns on white cores then Zr crowns on colored cores. ConclusionsResin cement shade didn’t affect final color perception. Monolithic high translucency crowns usage gained advantages of high translucency and delamination prevention. Zirconia crowns could be cemented by opaque or transparent cement without affecting final color. Key words:Zirconia, resin cement, monolithic, translucency, spectrophotometer, Delta E.

Congenital nasal pyriform aperture stenosis: Elaboration of a management algorithm from 25 years of experience

IntroductionCongenital nasal pyriform aperture stenosis (CNPAS) is a rare disease presenting with neonatal respiratory distress, often associated with other anomalies. Materials and methodsThis study reports the clinical and radiological characteristics of the patients managed in The Department of Pediatric Otolaryngology Head and Neck Surgery of La Timone Children's Hospital in Marseille between 1988 and 2014. Pyriform aperture (PA) widths were measured on CT-scans, obtained by using hand calipers at the largest portion of the PA in a plan parallel to the Francfort plan. Results10 patients were included. Average PA width was 6.6mm, 5/10 patients presented with single central maxillary median incisor, 6/10 patients had associated abnormalities. 8 patients underwent a surgical intervention and 2 patients were medically managed. All the patients had satisfactory nasal airway permeability on late follow-up.A management algorithm was elaborated. CNPAS should be evoked when breathing difficulties are associated with impossibility of passing fiberscope or nasogastric tube at the nasal inlet. Craniofacial CT-scanning is necessary to make the diagnosis and look for associated abnormalities. Medical treatment associating nasal wash and decongestants should be performed. Surgical intervention is necessary when failure of the medical management. Discussion and conclusionsOur results were close to those found in the literature in terms of clinical characteristics, associated abnormalities and PA width. However, no objective criterion to decide whether a surgical intervention is necessary or not, has been established so far. The algorithm we propose offers guidelines from diagnosis to treatment, but the management should be adapted based on clinical tolerance.

Managing the Challenge of Crowning the Single Central Maxillary Incisor

Managing the Challenge of Crowning the Single Central Maxillary Incisor

Congenital nasal pyriform aperture stenosis and single central maxillary incisor: preoperative evaluation with three-dimensional computed tomography.

Congenital nasal pyriform aperture stenosis (CNPAS) is an uncommon cause of nasal airway obstruction in neonates and infants. It is frequently associated with a single central maxillary incisor (SCMI). The purpose of this study was to assess whether 3-dimensional spiral computed tomography (3D spiral CT) could be used for the diagnosis of CNPAS and for detecting SCMI in CNPAS patients before tooth eruption. From January 1996 to December 2001, 16 patients (mean age, 2 +/- 3 months) with clinically suspected CNPAS and 13 normal control subjects (mean age, 28 +/- 32 months) were studied prospectively by 3D spiral CT. On the 3D CT image of each subject, the middle pyriform aperture width (MPAW), upper 1/4 PA width (UPAW), and middle internasal process width (MINPW) were measured. In addition, the ratios of MINPW to MPAW and of MINPW to UPAW were calculated. SCMI was identified as a bigger tooth with singular convexity. SCMI was diagnosed in 11 of the 16 CNPAS patients. In the CNPAS patient group, the mean MINPW (5 +/- 1 mm) was significantly shorter than the mean MPAW (9 +/- 1 mm) and the mean UPAW (8 +/- 1 mm) [p < 0.001]. However, in the normal control group, the mean UPAW (13 +/- 2 mm) was significantly shorter than the mean MPAW (16 +/- 3 mm) and the mean MINPW (16 +/- 3 mm) [p < 0.01]. In the CNPAS patients, the mean ratios of both MINPW to MPAW (0.5 +/- 0.1) and of MINPW to UPAW (0.6 +/- 0.1) were significantly lower than the corresponding mean ratios in the normal control subjects (1.0 +/- 0.1 and 1.3 +/- 0.2, respectively; both p < 0.001). Our results indicate that CNPAS is frequently associated with a SCMI and CNPAS patients have a significant reduction in the MINPW and in the ratios of MINPW to MPAW and of MINPW to UPAW. We conclude that 3D spiral CT can be used for diagnosis of CNPAS and for detecting SCMI in CNPAS patients before tooth eruption.

Extreme variability of expression of a Sonic Hedgehog mutation: attention difficulties and holoprosencephaly

Holoprosencephaly (HPE) is a clinically variable and genetically heterogeneous central nervous system (CNS) malformation. Alobar HPE, which is its most severe form, is associated with a poor prognosis. At the...

Congenital nasal pyriform aperture stenosis and single central maxillary incisor:: CT And mri findings

The authors report five cases of congenital nasal pyriform aperture stenosis (CNPAS). Four cases are presented as neonatal nasal obstruction and also have single central maxillary incisor (SCMI). Computed tomography examination indicates three of the SCMI are unerupted and one is erupted. The fifth case has an erupted SCMI and short stature. The associated SCMI in CNPAS is believed to be more than an isolated anomaly. Awareness of the associated features of CNPAS among the radiologist and otolaryngologist may help the diagnosis and treatment of the patient.

Holoprosencephaly: a family showing dominant inheritance and variable expression.

A family with probable dominant holoprosencephaly is presented with five affected subjects in two sibships, the offspring of healthy sisters who are presumed gene carriers. Of the affected children, three had cebocephaly and died shortly after birth. One had left choanal atresia, retinal coloboma, a single central maxillary incisor, microcephaly, short stature, and learning problems. Another had only a single central maxillary incisor. The occurrence of hypotelorism, microcephaly, and unilateral cleft lip and palate as minor manifestations of the gene in possible and probable gene carriers is discussed.