Jaw Index Research Articles

Predicting the Difficult Neonatal Airway in Fetuses WithMicrognathia, Oropharyngeal or Neck Mass Lesions: Two-Center Experience With Fetal MRI.

Neonatal airway compromise requiring intubation, due to micrognathia or a mass lesion obstructing the fetal airway, remains difficult but important to predict prenatally. We aimed to validate MR predictors of difficult neonatal airway (DNA) in a multicentre retrospective cohort of fetuses with micrognathia and oropharyngeal/neck masses. The radiology databases of two large Australian maternal-fetal medicine centers were searched for subjects meeting inclusion criteria: Pregnancies of > 18weeks' gestation evaluated with prenatal ultrasound and MRI between 2007 and 2022 where either fetal micrognathia or a fetal cervical, oral or oropharyngeal mass was identified on prenatal ultrasound and MRI, and details of delivery/postnatal course were available including: nature of delivery, need for the fetal airway to be secured at delivery, degree of difficulty in airway securement, survival > 24h postnatally. Imaging predictors of a difficult neonatal airway (DNA) were assessed blinded to these neonatal outcomes. Twenty-six fetuses met the inclusion criteria. Oropharyngeal and neck mass location with polyhydramnios was 100% sensitive and 82% specific for DNA. JI<5th centile with polyhydramnios was 83% sensitive and 70% specific. JI<5th centile with polyhydramnios was associated with DNA in 80% of cases delivered by ex utero intrapartum (EXIT) delivery and none with non-EXIT delivery mode. A cervical or oropharyngeal mass with polyhydramnios predicted a difficult neonatal airway. Polyhydramnios with jaw index < 5th centile was less sensitive and less specific for a difficult neonatal airway.

Comparison of best landmarks for calculating fetal jaw measurements by ultrasound and MRI in micrognathia.

Micrognathia can be diagnosed in utero with ultrasound by measuring the jaw index and/or inferior facial angle, though it can be challenging due to fetal positioning. The jaw index can be measured with magnetic resonance imaging (MRI) using the masseter muscle, but indistinct margins can lead to inaccuracy; the easily visualized posterior teeth buds may be a better landmark. We aimed to evaluate inter-reader variability, agreement with ultrasound, and association with postnatal outcomes using MRI to measure the inferior facial angle, jaw index by masseter muscle, and jaw index by posterior teeth buds. A single-institution retrospective review was performed of singleton pregnancies with prenatally diagnosed micrognathia by ultrasound or MRI from September 2013-June 2022. Ultrasound measurements were obtained by a maternal-fetal medicine specialist and MRI measurements by two radiologists to evaluate inter-reader variability. Intraclass correlation coefficients (ICC) and Bland-Altman analysis were used to assess agreement between imaging methods and logistic regressions and ROC curves to assess associations with postnatal outcomes. Forty-three fetuses (median gestational age 26weeks (IQR 22-31); 47% male (20/43)) were included. Ultrasound measurements could not be obtained for jaw index in 15/43 (35%) fetuses and inferior facial angle in 11/43 (26%); MRI measurements were obtained by at least one reader in all cases. Jaw index by teeth buds demonstrated lowest inter-reader variability (ICC = 0.82, P < 0.001) and highest agreement with ultrasound (bias -0.23, 95% CI -2.8-2.2). All MRI measurements, but not ultrasound, predicted need for mandibular distraction (inferior facial angle P = 0.02, jaw index by masseter muscle P = 0.04, jaw index by teeth buds P = 0.01). Fetal MRI measurements, particularly jaw index measured by posterior teeth buds, demonstrate low inter-reader variability and high agreement with ultrasound, and may predict need for mandibular distraction postnatally.

Prospective cohort study on facial profile changes in infants with Robin sequence and healthy controls

BackgroundVarious conservative and surgical approaches exist to treat Robin sequence (RS), but their effects on facial profile and mandibular catch-up growth are unclear. A functional treatment concept, used in our centre for 25 years, includes an individualized palatal plate with a velo-pharyngeal extension and intensive feeding training.MethodsWe performed a prospective study to objectively describe facial profiles in infants with RS treated with the above concept. Infants with isolated RS were admitted to our tertiary perinatal and national referral centre for craniofacial malformations between May 2018 and Nov 2019. Infants with RS received 3D-photographs during clinically indicated visits. Healthy controls were recruited from Dec 2018 to Sep 2019 and received 3D-photographs every 3 months. The digitally measured jaw index (JI), defined as alveolar overjet (O) x maxillary arch (U)/mandibular arch (L), and the soft tissue reference points A’-point, Nasion’, B’-point angle (ANB’), describing the relative position of maxilla to mandible, were evaluated. Linear mixed models were used to examine time trajectories in JI and ANB’.ResultsA total of 207 3D images, obtained in 19 infants with RS and 32 controls, were analysed. JI and ANB’ decreased over time in both groups [for JI − 0.18 (95% CI − 0.25 to − 0.10); for ANB’: − 0.40° per month [(95% CI − 0.48 to − 0.32)]] but remained lower in controls [for JI − 2.5 (95% CI − 3.2 to − 1.8); for ANB’-1.7° (95% CI − 2.4 to − 1.0)]. Also, the ANB’ model showed a significant effect of the interaction term diagnosis x age.ConclusionsBased on longitudinal 3D images, we describe changes in objective parameters of facial profile in infants with and without RS during the first year of life. Our findings indicate catch-up growth in infants treated for RS.4YQYEi2Zb5vMP7WQ-MbtxwVideo

Prenatal Diagnosis of Pierre Robin Sequence and Its Prognosis: A Retrospective Cohort Study.

This study aimed to explore the efficiency of ultrasound (US) in prenatal diagnosis and prognosis of Pierre Robin sequence (PRS) of 18 cases. A total of 79,305 women admitted for prenatal US examinations were recruited from January 2017 to December 2020. Eighteen cases of PRS fetuses were selected form the cohort and 40 cases of isolated micrognathia were recruited randomly as control group. All the clinical and imaging results were retrospectively reviewed. General condition, US measurements, and prognosis of fetuses were compared between groups. Cleft palate, glossoptosis, and micrognathia were found in all 18 fetuses with PRS by prenatal US. Compared with the isolated micrognathia group, there were no significant differences in the PRS group in examination of maternal age, gestational weeks at assessment, and gender of fetuses, but significant lower measures in inferior facial angle, jaw index, and frontal nasal-mental angle (each p < 0.05). Twelve fetuses were defined to have other associated malformations. Ear malformations were the most common associated malformations with a prevalence of 44.4% (8/18). All of the18 cases were confirmed with PRS after delivery or autopsy. Two delivered infants were found bucking easily, one baby was spitting up frequently but growth showed normal. Prenatal detection of PRS with US examination is highly efficient. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period. Prenatal detection of Pierre Robin syndrome with targeted US examination is efficient in discerning characteristics of this rare syndrome. Even with the triad of malformations, isolated PRS had good outcomes following initial stabilization and management in the neonatal period. · Prenatal diagnosis of fetal PRS is of great clinical importance.. · Micrognathia has been identified as the primary feature of PRS.. · Posterior displacement of the tongue may cause acute neonatal respiratory distress.. · Even with triad malformation, isolated PRS seemed to have good outcomes..

Prospective Evaluation of Children with Robin Sequence following Tübingen Palatal Plate Therapy.

To assess the long-term functional orthodontic outcome of the Tübingen palatal plate (TPP) in children with Robin sequence (RS) in comparison to age- and sex-matched healthy controls. Between 09/2019 and 10/2020, we performed orthodontic assessments in 41 children at our Department of Orthodontics. Included were patients with RS (17 non-syndromic; four syndromic) and healthy controls (n = 22, average age in both groups 9.9 y). Facial analyses of 2D images, digital study casts and cephalometric measurements were made. The orthodontic examinations showed no statistically significant group differences regarding functional extraoral, intraoral and pharyngeal parameters, or in skeletal patterns. The relationship between the upper and lower incisors was significantly increased (overjet 4 (2-10) vs. 3 (0-9) mm; p = 0.01) with a significant deficit in the lower face proportions (Jaw Index 4.15 (1.9-9.6) vs. 2.98 (0-9); p = 0.02; Facial convexity angle 157 (149-173) vs. 159 (149-170); p = 0.01). Children with RS treated with the TPP showed normal long-term functional orthodontic outcomes, thanks to the functional adaption of the stomatognathic system. However, soft tissue growth did not completely match skeletal growth, resulting in a more convex facial profile.

Reference ranges of fetal mandible measurements: Inferior facial angle, jaw index, mandible width/maxilla width ratio and mandible length in Thai fetuses at 15 to 23 weeks of gestation.

ObjectivesTo determine the normal distribution of 1) inferior facial angles (IFA), 2) jaw index, 3) mandible width/maxilla width ratio (MD/MX ratio), and 4) mandible length (ML) in second trimester Thai fetuses.MethodsA prospective study was performed between April 1 and October 31, 2020, at the Maternal-Fetal Medicine Unit of Songklanagarind Hospital. Transabdominal ultrasonography was performed on Thai singleton pregnant women at 150/7 to 236/7 weeks of gestation to measure IFA, jaw index, MD/MX ratio and ML. All women received standard antenatal care and were followed up until delivery. The exclusion criteria were multifetal gestation, congenital anomaly, chromosomal abnormality, fetal growth restriction, abnormal amniotic fluid volume, suspected abnormality of fetal mandible, maxilla or jaws based on the proposed criteria from previous studies and suspected neonatal structural or genetic abnormalities postnatally. Quantile regression was used to estimate changes in the median, 5th and 95th percentiles of each parameter across gestational ages and to generate formulas for predicting the 5th percentile value for each parameter.ResultsThe results of 291 women were analyzed. Scatter plots and reference ranges of each parameter were generated. IFA, jaw index and ML values significantly increased, while the MD/MX ratio value significantly decreased, with increasing gestational age. The formulas calculated for predicting the 5th percentile value for each parameter were IFA = 55.12 + 0.045*(GA in days—136) jaw index = 37.272 + 0.01693*(GA in days—136) MD/MX ratio = exp(0.027–0.00110*(GA in days—136)) ML = 20.83 + 0.243*(GA in days—136).ConclusionsThe reference ranges and formulas to calculate the 5th percentile values of mandible parameters in Thai fetuses were developed.Trial registrationThis study has been reviewed and approved by the Thai Clinical Trials Registry with identification number TCTR20210602003.

Validity and reliability of new instruments for measuring patient satisfaction with removable dentures, Arabic Version

BackgroundThe psychometric properties of self-administered instruments for measuring patient satisfaction with removable dentures should be tested before inviting patients to express their opinions. This study aimed to evaluate the validity and reliability of new instruments in the Arabic language that measure patient satisfaction with all types of removable dentures.MethodsA three-step methodology was used to translate and test the instruments. In step one, the instruments were translated from tested German instruments to develop the pilot questionnaires. In step two, the face validity of the pilot questionnaires was tested through three rounds of interviews. There were 15, 13, and 15 participants per round, respectively. At the end of every round, the results of the interviews were discussed with an expert panel. The expert panel confirmed the form and the type of questionnaires’ adjustments before a new round of interviews began. At the end of step two, the final form of the questionnaires was reached. In step three, 235 questionnaires were distributed to 133 participants to estimate the construct validity of the upper jaw and the lower jaw questionnaires. After one week, the participants were asked to complete the questionnaires again. A total of 102 questionnaires were returned and used to assess the instruments’ reliability. Factor analysis was used to assess the construct validity. The intraclass correlation coefficient and Cronbach’s alpha were used to estimate the reliability and suitability of the items in the indexes.ResultsThe result of step one was two pilot questionnaires. The pilot questionnaires were adjusted in step two. At the end of step two, the questionnaires proved to have good face validity. Factor analyses in step three revealed that only one factor could be retained. The one-factor model explained 60.95% and 63.06 of the total variance of the upper jaw and lower jaw questionnaires, respectively. The items in every questionnaire shared the same cluster and could be summed to form an upper jaw index and lower jaw index that reflected patient satisfaction with removable dentures. Cronbach’s alpha values indicated excellent internal consistency and reliability for the upper jaw questionnaire (α = 0.91) and the lower jaw questionnaire (α = 0.92). Intraclass correlation coefficient values ranged from 0.72 to 0.95, which can be considered “moderate” to “excellent”.ConclusionsThe Arabic version of questionnaires and indexes assessing patient satisfaction with upper and lower removable dentures are reliable and valid self-administered instruments.

Pug-Headedness Anomaly in a Wild and Isolated Population of Native Mediterranean Trout Salmo trutta L., 1758 Complex (Osteichthyes: Salmonidae)

Skeletal anomalies are commonplace among farmed fish. The pug-headedness anomaly is an osteological condition that results in the deformation of the maxilla, pre-maxilla, and infraorbital bones. Here, we report the first record of pug-headedness in an isolated population of the critically endangered native Mediterranean trout Salmo trutta L., 1758 complex from Sardinia, Italy. Fin clips were collected for the molecular analyses (D-loop, LDH-C1* locus. and 11 microsatellites). A jaw index (JI) was used to classify jaw deformities. Ratios between the values of morphometric measurements of the head and body length were calculated and plotted against values of body length to identify the ratios that best discriminated between malformed and normal trout. Haplotypes belonging to the AD lineage and the genotype LDH-C1*100/100 were observed in all samples, suggesting high genetic integrity of the population. The analysis of 11 microsatellites revealed that observed heterozygosity was similar to the expected one, suggesting the absence of inbreeding or outbreeding depression. The frequency of occurrence of pug-headedness was 12.5% (two out of 16). One specimen had a strongly blunted forehead and an abnormally short upper jaw, while another had a slightly anomaly asymmetrical jaw. Although sample size was limited, variation in environmental factors during larval development seemed to be the most likely factors to trigger the deformities.

The Reproducibility of the Jaw Index in the Measurement of Healthy Newborns.

Objective:Establish the reliability of the jaw index to objectify the relationship between the maxilla and mandible in healthy newborns.Design:Cohort study.Setting:Tertiary setting.Patients:A total of 52 healthy newborns were included to detect an inter and intraclass correlation coefficient (ICC) of 0.8 with a 95% confidence interval (95% CI) of width 0.3. Inclusion criteria were children born full term without respiratory or feeding problems, and without congenital malformations or facial deformities due to birth trauma. Uncooperative patients were excluded.Interventions:The jaw index, a measuring tool for objectifying micrognathia in children suspected of having Robin sequence, was used. An ICC of greater than 0.8 was considered clinically relevant.Main Outcome Measure(s):Primary outcomes are the reliability of the jaw index expressed as interclass correlation coefficient and ICC. Secondary outcomes are the mean jaw index and mean length of the mandible, maxilla, and the alveolar overjet.Results:An interclass correlation coefficient of 0.74 (95% CI: 0.49-0.86) and an ICC of 0.81 (95% CI: 0.66-0.89) were found. The mandible had an average length of 162.6 mm (standard deviation [SD] 11.1), the maxilla 168.7 mm (SD 9.4), the alveolar overjet 2.0 mm (SD 0.60), and the mean jaw index was 2.1 (SD 0.64).Conclusion:The jaw index is a consistent instrument between different observers as well as for one observer measuring consecutively in the same child, to objectify the size of the lower jaw compared to that of the upper jaw in healthy newborns.

Mandibular growth in infants with Robin sequence treated with the T\xfcbingen palatal plate

BackgroundRobin sequence (RS) is characterized by mandibular retrognathia, glossoptosis and upper airway obstruction. Whether mandibular catch-up growth may occur in RS is yet controversial. Our functional and less invasive treatment including the Tübingen Palatal Plate (TPP), early oral feeding and orofacial stimulation may promote mandibular catch-up growth. We evaluated the effect of the Tübingen Palatal Plate on mandibular growth, expressed by the Jaw index, sleep study results and weight gain in infants admitted with isolated and syndromic RS, born at or referred to our center between 6/2015 and 5/2018.MethodsRetrospective analysis of our electronic patient database that included data on jaw index measurements, sleep study results and standard deviation (Z-)scores for weight.ResultsOf 31 patients referred for RS treatment (22 isolated, 9 syndromic), we had data on the above parameters, determined at admission, discharge and 3 months after discharge, in 20. Jaw index at admission and 3-month follow-up was 8.8 (6.3–11.3) and 2.1 (2.0–4.0), respectively (median (IQR); p < 0.0001). Mixed-obstructive apnea index (MOAI) decreased from 9.7 (4.8–24.2) to 0.0 (0–1.3; p < 0.002). No significant correlation was observed between MOAI and Jaw Index, but MOAI correlated with the Maxillary/Mandibular arch ratio (r = 0.58; p < 0.001).Z-scores for weight were similar at both time points at − 1.34 (− 1.76 – − 0.57) and − 1.50 (− 1.89 – − 0.54), while the proportion of infants requiring nasogastric tube feeding decreased from 84 to 8%. No infant had craniofacial surgery; one with syndromic RS required tracheostomy.ConclusionThese longitudinal cohort data suggest that the Tübingen Palatal Plate as used here may alleviate upper airway obstruction by promoting mandibular growth.Trial registrationN.A.

Predictive Factors for Perinatal Outcomes of Infants Diagnosed With Micrognathia Antenatally.

Advances in fetal imaging have allowed us to identify abnormalities previously not appreciated. With this study, we hope to identify factors predicting a difficult airway at birth and review the perinatal outcomes of these patients. Sixteen patients with antenatally diagnosed micrognathia were reviewed from a tertiary care hospital database from 2011 to 2016. Jaw index (JI), amniotic fluid index (AFI), glossoptosis, gastric size, and oropharynx obliteration were assessed. The airway support required at birth, specialist team involvement, and outcomes were evaluated. Nine (56.3%) of 16 patients had JI <5th percentile, 3 (33.3%) of 9 had difficult intubation, 2 (22.2%) of 9 needed an emergency tracheostomy, and 1 (11.1%) of 9 died. Seven patients had polyhydramnios, 2 (28.6%) of 7 had difficult intubation, 2 (28.6%) of 7 required tracheostomy, and 1 (14.3%) of 7 died. Twelve patients had either JI <5th percentile or abnormal AFI, 5 (41.7%) of 12 had difficult intubation, 2 (16.7%) of 12 required tracheostomy, and 1 (8.33%) of 12 died. For the group without otolaryngology consultation, 8 (50%) of 16, 1 (12.5%) of 8 had difficult intubation and 1 (12.5%) of 8 died because airway was not secured after 45 minutes of resuscitation. Jaw index <5th percentile or abnormal AFI predicts a difficult airway. A multidisciplinary approach with otolaryngology involvement for airway intervention may be required at birth.

EP10.09: Added value of prenatal MR in the evaluation of fetal cleft lip, cleft palate and micrognathia

The aim of this study was to describe MR findings and to determine the accuracy of fetal MRI in diagnosing fetal cleft lip, cleft palate, and micrognathia, either isolated, or in association with additional abnormalities. We reviewed our fetal MRI database from March 2011 through February 2017 and searched for exams referred for cleft lip, cleft palate, and/or micrognathia. A total of 37 fetal exams were identified. 7 cases were lost to follow up, 6 patients underwent termination of pregnancy. Anatomic facial landmarks and biometric parameters were documented including evaluation of the lips, maxillary ridge, position of the tongue, presence/absence of the palate, measurement of the jaw index to evaluate for micrognathia, and binocular and intraocular diameter to evaluate for hypo/hypertelorism. A complete fetal neuroevaluation was performed to detect additional anomalies. Findings on fetal MR were correlated post delivery. In the remaining cohort of 21 fetuses, 20 cases were diagnosed with positive findings. There were 6 diagnoses of cleft lip, 7 diagnoses of cleft lip and palate, 4 isolated micrognathia, 5 micrognathia with isolated cleft palate consistent with Pierre Robin sequence. Of the 21 fetuses, the MR diagnosis was confirmed following delivery in 17 cases. Syndromes that were seen with micrognathia included Dandy Walker, Frynn's, Emanuel, and mid-face hypoplasia syndromes. There was 1 false positive case of cleft lip and palate due to a tethered frenulum. Three cases are waiting to deliver. MRI has a 95.5% degree of accuracy in diagnosing fetal facial abnormalities, including isolated cleft lip, cleft lip with cleft palate, micrognathia with cleft palate (Pierre Robin syndrome), and isolated syndromic micrognathia with additional non-palatal abnormalities.

Micrognathia and Oropharyngeal Space in Patients With Robin Sequence: Prenatal MRI Measurements

Micrognathia is the initiating feature of Robin sequence (RS) and leads to airway obstruction. Prenatal identification of micrognathia is currently qualitative and has not correlated with postnatal findings in previous studies. Oropharyngeal airway space has not been evaluated prenatally. The purposes of this study were to 1) quantitate mandibular characteristics and oropharyngeal size at prenatal magnetic resonance imaging (MRI) and 2) identify differences in fetuses with postnatal RS compared with those with micrognathia (without RS) and normal controls. This is a retrospective case-control study of fetuses with prenatal MRIs performed from 2002 through 2017 who were live born and evaluated postnatally for craniofacial findings. Postnatal findings were used to divide patients into 3 groups: 1) RS (micrognathia, glossoptosis, and airway obstruction), 2) micrognathia without RS ("micrognathia"), and 3) a gestational-age matched control group with normal craniofacial morphology ("control"). Inferior facial angle (IFA), jaw index, and oropharyngeal space (OPS) were calculated and compared among groups. Of 116 patients in this study, 27 had RS (23%), 35 had micrognathia (30%), and 54 were control subjects (47%). IFA, jaw index, and OPS were statistically significantly smaller in the RS group compared with the comparison groups (P<.0001). Prenatal MRI measurements of micrognathia and OPS are considerably different in patients with RS compared with other groups, including those with micrognathia alone. These measurements might serve as reliable prenatal predictors of RS.

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.

Prevalence of temporomandibular dysfunction in children and adolescents

OBJECTIVE: To review the prevalence of temporomandibular disorders (TMD) in children and adolescents, verifying the methodological variations. DATA SOURCES: Research conducted in Medline, PubMed, Lilacs and BBO databases, including manuscripts (except reviews and case reports) published from 1990 to 2012. The descriptors were "temporomandibular joint syndrome", "temporomandibular joint dysfunction syndrome", "temporomandibular joint disorders", "prevalence studies", and "cross-sectional studies"; the words "dysfunction", "disorder", "temporomandibular", "children", "adolescents", "prevalence", "frequency", and "transversal" were used. DATA SYNTHESIS: Seventeen articles were selected, and the TMD frequency varied from 16 to 68%. Regarding the methodological criteria, only three articles (18%) reported sample size determination, three (18%) clearly described the sample selection process by stratified selection technique, and nine studies (53%) carried out the calibration of the examiners. The diagnostic criteria used in the studies were: Helkimo index (n=2; 12%), Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) (n=4; 24%), the jaw index (n=1; 6%), clinical protocols (n=10; 59%), and anamnestic questionnaires (n=6; 35%). CONCLUSIONS: The TMD prevalence in children and adolescents varies in the literature. Appropriate and standardized methods are needed to identify, with greater validity, the presence of TMD in this population, allowing a better understanding of the pathological aspects in order to address more effective preventive and therapeutic procedures.

Fetal micrognathia: almost always an ominous finding

Fetal micrognathia: almost always an ominous finding

“Outbreak” of Hand Injuries During Hajj Festivities in Saudi Arabia

Micrognathia and glossoptosis may cause severe respiratory and feeding difficulties in newborns with Pierre Robin syndrome. The growth of the mandible is alleged to more or less “catch up” during the first year of life. We could not objectify such a catch-up growth using the noninvasive and harmless measurement of the jaw index. The jaw index is defined as alveolar overjet x maxillary arch/mandibular arch. The alveolar overjet is the frontodorsal distance between the most anterior points of the upper and lower alveolar arches, whereas the maxillary arch is measured from the left tragus to the right tragus via the subnasal point, and the mandibular arch is measured from the left to the right tragus via the pogonion point. The growth of the mandible in 7 Pierre Robin patients was found to be proportionately similar to that observed in healthy control subjects age 0 months (N = 100), 6 months (N = 42), and 1 year (N = 32).

Objective diagnosis of micrognathia in the fetus: the jaw index

Objective: To provide an objective and accurate tool to diagnose micrognathia in the fetus. Methods: The anteroposterior and laterolateral diameter of the mandible were measured in 262 normal fetuses between 12 and 37 weeks’ gestation and plotted against gestational age and biparietal diameter (BPD). The jaw index (anteroposterior mandibular diameter/BPD × 100) was then tested against the usual subjective method for diagnosing micrognathia, consisting of the evaluation of the facial profile, in a population of 198 malformed fetuses, 11 of which had micrognathia at necropsy or birth. Results: The mandibular growth was linearly correlated with gestational age and BPD. Using a cutoff level of less than 23, the jaw index had a 100% sensitivity and 98.1% specificity in diagnosing micrognathia, in comparison with 72.7% and 99.2% shown by the subjective evaluation of the fetal profile. With a cutoff of 21, it yielded a positive predictive value of 100%. Conclusion: We demonstrated the linear relationship between mandibular growth and gestational age or BPD. In addition, we validated the jaw index as an objective tool for diagnosis of micrognathia in the fetus.

The jaw index: new guide defining micrognathia in newborns.

Newborns with glossoptosis due to micrognathia can suffer from life-threatening respiratory distress and severe feeding difficulties. These characteristic features are found in newborns with Pierre Robin sequence. In the relevant literature, no concensus concerning diagnosis for these children can be found. A guide defining micrognathia can be helpful in the diagnosis of glossoptosis and possible airway obstruction. The jaw index is obtained in newborns by measuring three facial dimensions. In a series of 100 healthy neonates the standard measures were defined. The average jaw index in children with Pierre Robin sequence differs significantly from the reference group and was found to be over 3.6 times the normal value. Micrognathia can be defined with the jaw index.