Inferior Facial Angle Research Articles

Normal mandibular growth and diagnosis of micrognathia at prenatal MRI.

The aim of this article is to present reference data for fetal mandibular growth on magnetic resonance imaging, enabling the diagnosis of micrognathia. Retrospectively, on 355 magnetic resonance scans of apparently facially normal fetuses [gestational age (GA), 20-36 weeks], mandibular anterior-posterior diameter (APD = mandibular size), inferior facial angle (IFA = mandibular position), and jaw index (APD normalized to biparietal diameter) were correlated with GA by Pearson correlation. APD-age relationship was modeled. A receding chin was subjectively determined. Ten fetuses with mandibular anomalies were compared with normal fetuses. For GA, APD showed high correlation (r = 0.850; P < 0.001), IFA (r = 0.086; P = 0.119) no correlation, and jaw index (r = -0.139; P = 0.018) weak correlation. APD-age relationship was expressed by the following: APD = 0.281 + 0.989 * GA (r(2) = 0.723). A receding chin was identified in 7/10 abnormal fetuses. APD, IFA, and jaw index of abnormal and normal fetuses were significantly different (P < 0.001). In 10/10 abnormal fetuses, IFA was <50.0°; in 7/10, jaw index was less than the fifth percentile (micrognathia); in 3/10, jaw index was at low normal range (retrognathia). Subjective identification of micrognathia may be limited. Reference data provide quantitative evaluation of mandibular size and position. An IFA <50° reflects micrognathia or retrognathia; a jaw index less than the fifth percentile suggests micrognathia.

Fetal MRI as a complement to US in the evaluation of cleft lip and palate

The aim of our study was to investigate the role of fetal magnetic resonance imaging (MRI) as a complement to ultrasound (US) in the evaluation of cleft lip and palate (CLP), whether isolated or in association with syndromic conditions. We enrolled 24 pregnant women (27 fetuses) (mean gestational age 23.7 weeks) with a level-two US diagnosis of cleft lip (CL) or CLP with or without associated central nervous system (CNS) or facial-bone anomalies. All individuals underwent a fetal MRI examination to study the facial skeleton, CNS and fetal body. For each fetus, the main anatomical facial landmarks and biometric parameters [anteroposterior diameter (APD), biparietal diameter (BPD), inferior facial angle (IFA), frontomaxillary angle (FMA), bi-orbital diameter (BOD), intraorbital diameter (IOD)] were measured. Twenty-five of 27 fetuses had a US diagnosis of CL or CLP. MRI confirmed the diagnosis in 16/25 fetuses and added information about the extent of the cleft and the degree of involvement of the anterior and posterior palate in 8/25 fetuses. MRI ruled out the diagnosis in 1/25 fetuses and identified an alteration of the parameters IFA, FMA and IOD in 6/24 fetuses. In the study of CLP fetal, MRI is able to define the degree of involvement of the posterior palate and the lateral extent of the cleft with higher diagnostic accuracy than US. Furthermore, MRI provides a complete study of the fetal head and biometric development of the facial bones, thus enabling early detection of potential syndromic conditions.

Fetal micrognathia: objective assessment and associated anomalies on prenatal sonogram

To determine the accuracy and characteristics of prenatally detected fetal micrognathia. A retrospective analysis of all pregnancies with the suspicion of fetal micrognathia was performed. The affected fetuses were reassessed by estimation of the inferior facial angle (IFA) and the frontal nasomental angle on stored gray scale images to objectively establish the diagnosis. Of the 28.935 ultrasounds (USs) reviewed, 58 cases were eligible and 4 were excluded because of inconclusive data. The mean values for IFA and frontal nasomental angle were 44.8° and 123.3°, respectively. In 33 cases, the pregnancy was terminated. Four fetuses died sub partu or immediately after birth, five were stillborn. Invasive testing in 40/54 cases revealed aneuploidies in 35%. Associated anomalies comprised musculoskeletal disorders (43%) and non-skeletal anomalies (15%). Less than one fifth (9/54) were alive beyond postnatal period. Four fetuses had an isolated micrognathia, one of which was found to have a cleft palate postnatally. The diagnosis of micrognathia has a crucial impact on both prenatal and postnatal outcomes of affected individuals due to its association with additional abnormalities. A detailed sonographic survey using objective criteria for defining micrognathia is mandatory. Once the diagnosis is confirmed, an intensive interdisciplinary counseling of the parents is needed.

OP18.04: Degree of micrognathia by inferior facial angle (IFA) differentiates primary mandibular dysostoses from secondary involvement

OP18.04: Degree of micrognathia by inferior facial angle (IFA) differentiates primary mandibular dysostoses from secondary involvement

Fetal micrognathia: almost always an ominous finding

Fetal micrognathia: almost always an ominous finding

The fetal mandible: a 2D and 3D sonographic approach to the diagnosis of retrognathia and micrognathia.

To define parameters that enable the objective diagnosis of anomalies of the position and/or size of the fetal mandible in utero. Fetuses at 18-28 gestational weeks were examined by two- and three-dimensional ultrasound. The study included normal fetuses and fetuses with syndromes associated with known mandible pathology: Pierre Robin sequence or complex (n = 8); hemifacial microsomia (Treacher-Collins syndrome, n = 3); postaxial acrofacial dysostosis (n = 1). Fetuses with Down syndrome (n = 8) and cleft lip and palate without Pierre Robin sequence or complex (n = 18) were also studied. Retrognathia was assessed through the measurement of the inferior facial angle, defined on a mid-sagittal view, by the crossing of: 1) the line orthogonal to the vertical part of the forehead at the level of the synostosis of the nasal bones (reference line); 2) the line joining the tip of the mentum and the anterior border of the more protruding lip (profile line). Micrognathia was assessed through the calculation of the mandible width/maxilla width ratio on axial views obtained at the alveolar level. Mandible and maxilla widths were measured 10 mm posteriorly to the anterior osteous border. In normal fetuses, the inferior facial angle was constant over the time span studied. The mean (standard deviation) value of the inferior facial angle was 65.5 (8.13) degree. Consequently, an inferior facial angle value below 49.2 degree (mean - 2 standard deviations) defined retrognathism. All the fetuses with syndromes associated with mandible pathology had inferior facial angle values below the cut-off value. Using 49.2 degree or the rounded-up value of 50 degree as a cut-off point, the inferior facial angle had a sensitivity of 1.0, a specificity of 0.989, a positive predictive value of 0.750 and a negative predictive value of 1.0 to predict retrognathia. In normal fetuses, the mandible width/maxilla width ratio was constant over the time interval studied. The mean (standard deviation) value was 1.017 (0.116). Consequently, a mandible width/maxilla width ratio < 0.785 defined micrognathism. Mandible width/maxilla width ratio values were below this cut-off point in eight and in the normal range in four fetuses with syndromes associated with mandible pathology. Retrognathia and micrognathia are conditions that can be separately assessed. The use of inferior facial angle and mandible width/maxilla width ratio should help sonographic recognition and characterization of fetal retrognathic and micrognathic mandibles in utero.