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Summary Introduction The 3 Noffel signs, “Ramal height”, “Smiling chin”, and “B-line space”, often present in class II division 2, are called “danger signs” for aesthetics, when they are strongly marked and absolutely need to be taken into account in the therapeutic strategy. The main objective was to assess whether the three measurements associated with Noffel signs (Gonion/Articulare distance, Cutaneous Pogonion/Na-B, and B-line space) were pathognomonic of class II division 2. The secondary objective was to determine whether there was a correlation between the severity of Noffel signs and the sagittal and/or vertical skeletal severity of class II division 2. Materials and methods In this comparative, mono-centric study based on a retrospective cohort, lateral cephalograms of all the growing patients who were treated at the CSERD between 2012 and 2018 and had normodivergent and hypodivergent profiles, were analysed. Results The logistic regression analysis showed that only “Total chin” and “B-line space” were significantly related to class II division 2 (P = 0.00199; P = 0.00778, respectively). The three signs were related to the severity of the hypodivergence, but not to the severity of skeletal class II. Conclusion Only “Total chin” and “B-line space” are pathognomonic of class II division 2. The correlation between the severity of Noffel's three signs and skeletal severity exists only in the vertical dimension.

Summary Introduction Unilateral posterior crossbite (UPCB), often from dysfunctional and para-functional causes, leads to positional mandibular asymmetries that can develop at a very young age into skeletal mandibular deviation; hence the interest of early maxillary expansion. The purpose of this retrospective study was to compare the impact of maxillary expansion by Quad Helix (QH) on mandibular skeletal asymmetry correction before and after 7 years of age. Materials and methods All children with UPCB and skeletal mandibular asymmetry, who were treated by QH in the orthodontic department of Montpellier between February 2017 and August 2018 and had a radiography file at baseline (T0) and 12 months later (T1) were retrospectively included. The patients were divided into two groups according to age: under 7 years of age with QH adjusted on second primary molars (early group G1) and over up to 13 years old with QH adjusted on first permanent molars (late group G2). The differences between the right and left sides of the mandible in corpus length ΔL (main eligibility criterion) and ramus height ΔH (secondary criterion) were compared between groups. X2 test, Fisher's exact test and Wilcoxon rank-sum tests were used for baseline comparisons. A multifactorial analysis allowing adjustment on possible confounding factors was used with R software. Results Out of 67 patients files only 40 were completed and analysed: 13 in G1 and 27 in G2. These groups were comparable at baseline except for the age parameter. Taking into account the initial severity of asymmetry, the analysis of covariance showed a significant intergroup difference with higher correction in the early group of the corpus asymmetry (+1.0; P = 0.008). On the contrary, no significant differences were observed between the groups in the ramus asymmetry correction. Conclusions Within the limits of this retrospective study, the early unilateral posterior occlusion correction by QH can better reduce both positional and contour mandibular asymmetries in patients under 7 years of age.