We suggest that an early introduction of bottlefeeding, indicating a pattern of low-impact muscular activity, may interfere with the normal development of alveolar ridges and hard palate, and hence lead to posterior crossbite.

No abstract

The findings show that children with SBDT display a characteristic facial appearance at an early age. Since the condition has an effect on growth, it needs to be prevented by controlling morphology and function at the preschool age.

The severity of lesions in the temporomandibular joint (TMJ) area and their association with age at onset, the various forms of juvenile rheumatoid arthritis (JRA), and certain serologic tests for rheumatoid factor (RF), antinuclear antibodies (ANA), and human leukocyte antigen (HLA)‐B27 were determined in 15‐yr‐old children. The series comprised 121 JRA children, 78 girls and 43 boys, in whom an analysis had recently been made of the relation of TMJ lesions to jaw movement and occlusal status. The mean age at onset was 7.3 yr, the girls contracting JRA earlier than the boys. Also, the girls with lesions in the TMJ area were significantly younger than those with no lesions. TMJ abnormalities were found in 50% of cases with a pauciarticular or systemic onset, but in 72% of those representing the polyarticular subtype. Flattened condyles and grave lesions were equally represented in all subgroups and in both sexes. A crossover from onset type to present diagnosis was found in 30% of the cases, mostly from pauciarticular to polyarthritis, which also increased the risk of TMJ lesions from 50 to 60%. RF, ANA, or HLA‐B27 alone did not seem to be associated with a risk of TMJ abnormalities. Maximal opening capacity is more restricted in patients with early onset or a polyarticular mode of JRA. Since the TMJ is affected in more than half of JRA children, regular measurements of maximal movements of the mandible or roentgenologic examinations of the TMJ are essential for their optimal treatment.

While there are numerous investigations on hormonal control of long bone epiphyseal growth, corresponding knowledge is sparse concerning the condylar cartilage. We investigated the distribution of growth hormone (GH) and insulin-like growth factor I (IGF-I) receptors in the temporomandibular joint (TMJ), especially the condyle, and compared the findings with information of long bone epiphyseal plates. The localization of the receptors was examined in vivo by immunohistochemical methods in one- to 21-day-old rats. GH receptors were detected in various components of the TMJ, but not in the fibrous articular surface or in the cartilage layers of the condyle. IGF-I receptors were found in the fibrous articular surface of the condyle and particularly in the superior and posterosuperior regions of the condylar cartilage, the depth of the labeled cell layer increasing significantly with age. It is evident that the expression of GH and IGF-I receptors is area-specific in the TMJ. Early post-natal growth and development of the mandibular condylar cartilage seem to be IGF-I-dependent but not directly dependent on GH.