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

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

BACKGROUND

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.

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

Forty-three fetuses (median gestational age 26 weeks (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).

CONCLUSION

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.

Overjet in Infants: A Cross-Sectional Study

OBJECTIVE

The purpose of this study was to determine the normal ranges for overjet in healthy infants under 12 months of age.

DESIGN

A cross sectional study of consecutive patients below 12 months of age.

SETTING

The study was conducted at a private practice in Tampa, FL that specializes in pediatric craniomaxillofacial disorders.

PATIENTS

All patients under the age 12 months were considered for entry into the study. Patients were excluded if they had temporomandibular joint pathology, sleep disordered breathing, facial trauma, or were diagnosed with a craniofacial anomaly.

INTERVENTIONS

Measures of overjet, defined as the distance between the anterior surfaces of the alveolar ridges when in centric relation, were obtained.

MAIN OUTCOME MEASURE

The primary study outcome was the overjet of the enrolled patients.

RESULTS

A total of 152 infants were included in this study. Of these, 51 were female, and 40 were born prematurely (ranging from 32-37 weeks of gestation). In neonates below 1 month of age, the mean overjet was 2.25 mm (95% CI 1.31-3.19). Multivariate linear regression analysis showed overjet to significantly decrease with age, at a mean rate of approximately 0.1 mm per month (coefficient of -0.09, 95% CI -1.61 to -0.02, p = 0.01). When controlling for potential confounders, average overjet was not shown to vary significantly between the sexes, with prematurity, with race, or with primary diagnosis at presentation.

CONCLUSION

This paper establishes normative values for overjet in infants below 12 months of age.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Pediatric anterior larynx: presentations, associations and a review of the literature

OBJECTIVE

The literature on the entity of the anterior larynx (AL) is restricted to little evidence on the difficulty encountered in exposing the larynx for intubation, perioperative morbidity and mortality, and scant reports on its prevalence in general adults and children. We here describe the prevalence of AL in a series of children presenting with aerodigestive symptoms and explore its association with functional abnormalities, congenital and structural anomalies or conditions.

SETTING

Tertiary pediatric center METHODS: we conducted a retrospective case-control study. Using a prospectively collected surgical database we identified patients diagnosed with AL (grades IIb-III-IV Modified Cormack-Lehane scale) and sex and age matched controls who had undergone full airway endoscopy for aerodigestive symptoms. We collected the demographics, presentations, associated diagnoses, and investigations. We compared the proportion of patients with large airway abnormalities and dysmorphism and estimated the prevalence of AL.

RESULTS

over a 5.5-year period, 58 children with AL (28 females, mean age 0.38 years) were matched with 58 controls (mean age 0.42 years). Although both groups presented with permutations of stridor, respiratory failure, cyanotic spells, swallowing and feeding difficulties and SDB, AL presented much more with swallowing and feeding problems (33 vs 20, p<0.05). There were significantly more children with dysmorphism in the AL group (29 vs 9, P < 0.05). The prevalence of AL was 4.9% (SE 0.0063).

CONCLUSIONS

AL was detected in 4.9% of a sample of children who had undergone airway exam for aerodigestive symptoms. It is significantly associated with dysmorphism, and swallowing difficulties that warrant instrumental evaluation.