Influence of bad oral habits upon the development of posterior crossbite in a preschool population.

BACKGROUND: A study is made of posterior crossbite in deciduous dentition and its possible association to extrinsic factors (bad oral habits). METHODS: A total of 1168 Spanish children between 3 and 6 years of age were included in the study. Exploration of the oral cavity was performed to assess the presence of crossbite (uni- or bilateral and/or functional), and a questionnaire was administered to the parents or caregivers to determine the presence of bad oral habits and their duration. RESULTS: In occlusion, 19.7% of the cases (n = 230) presented uni- or bilateral posterior crossbite. On adopting centric relation confronting the midlines, crossbite persisted in 165 children, indicating that 65 cases were due to premature contacts (functional crossbite). The identified favoring factors were pacifier use, thumb sucking, oral breathing and tongue thrusting or immature swallowing. DISCUSSION: Most studies in the literature report a relationship between posterior crossbite and bad oral habits. The proportion of posterior crossbites identified in our study (16.6%) is consistent with the data published by authors such as Kobayashi, Limeira or Paolantonio, among others, but differs from the results of Zhifei Zhou, Peres or Germa. In coincidence with most studies, we recorded a statistically significant association between posterior crossbite and bad oral habits. CONCLUSIONS: Bad oral habits favor the appearance of posterior crossbite, and the duration of the habit, its intensity (in the case of thumb sucking) and type (in the case of pacifier use) act as influencing factors. Functional study characterized the types of posterior crossbites and identified those attributable to premature contacts. This aspect has not been addressed by previous studies, and we consider the findings to be very interesting for analyzing and identifying the features of true crossbites.

Evolution of the Terminal Plane from Deciduous to Mixed Dentition.

(1) Introduction: Correct development and growth of the dental arches and occlusion in the deciduous dentition is crucial for physiological occlusion in the permanent dentition. The present study evaluates the evolution of the terminal plane and canine occlusion class in the same children from deciduous to mixed dentition. (2) Materials and methods: The study included 257 children (164 girls and 93 boys) aged 3-5 years in the first phase and 8-10 years in the second phase. The chi-square test was used for the comparison of qualitative variables, while analysis of variance (ANOVA) or the Mann-Whitney U-test, Kruskal-Wallis test, and Wilcoxon test were used in the case of quantitative variables, as applicable. Statistical significance was considered for p < 0.05. (3) Results: The most common terminal plane in the first phase of the study was a bilateral flush plane (70%), followed by distal and mesial, with few differences between them. In the second phase, the most common terminal plane was mesial, followed by bilateral flush and distal. There were no statistically significant differences according to gender. Canine occlusion in the first phase was predominantly bilateral class I, followed by class II and class III. Similar results were recorded in the permanent dentition, except for a lesser percentage of children with canine class II. Molar occlusion in the second phase was predominantly class I, followed by half cusp class II and full cusp class II and class III. (4) Conclusions: The present study shows that knowing the age range in which maximum dental development and growth in both arches occurs may contribute to avoiding malocclusions and the possible need for orthodontic-orthopedic treatment, resulting in improved outcomes and greater stability.

Dental Malocclusion and Its Relation to the Podal System.

Background and Objective: This study analyzes the possibility that Stomatognathic and Postural systems are related by muscle chains. Malocclusion may influence the posture, contact between the foot and the ground, center of mass, footprint or vice-versa. This study aimed to verify whether there is a relationship between dental occlusion and podal system. Materials and Methods: A cross-cutting, descriptive study was carried out on 409 children (222 boys and 187 girls) between 8 and 14 years old. Dental occlusion was assessed on the sagittal plane (Angle's classification) the contact between the foot and the ground and the center of mass were evaluated using a stabilometric platform. Results: There was a statistically significant relationship between the plantigrade phase, the contact surface area and center of gravity. There was a prevalence of molar and canine Angle's class II malocclusion. In molar class II, an anterior center of gravity was predominant, in class I it was centered and in class III, it was posterior. There was significant correlation between malocclusions and the FPI (foot posture index) of the left foot and the height of the scaphoid in the right foot (P < 0.001). Conclusions: Some authors agree with our results. There is still much uncertainty in terms of showing a relationship between both systems. In addition, there is scarce scientific evidence on the topic. Some kind of relationship between the two systems has been proven. Studies that evaluate a group of subjects in a longitudinal manner are necessary to enable the changes taking place in both systems to be defined.

Do breastfeeding and bottle feeding influence occlusal parameters?

OBJECTIVE: A study was made of the influence of breastfeeding and bottle feeding on development of the dental arches and occlusion in an infant population. SUBJECTS AND METHODS: In total, 298 infants (163 girls and 135 boys) were selected from a series of 1,643 preschool children in Seville, Spain, evaluating the type of feeding received after birth (breastfeeding only or bottle feeding only), the duration of such feeding, and its influence upon the parameters that define occlusion of the dental arches. The study comprised a full exploration of the stomatognathic system of the infants and a questionnaire for the parents. SPSS Statistical Package software (SPSS, Inc., Chicago, IL) was used to analyze the results. RESULTS: In total, 109 children were exclusively breastfed (36.6%) for an average of 6.8±5.8 months, whereas 189 children were exclusively bottle fed (63.4%) for an average of 17.99±11.5 months. On comparing the occlusal parameters of the two groups, the most beneficial effects (straight terminal plane, canine class I relationship, diastemas, and primate spaces) corresponded to the infants who were breastfed. CONCLUSIONS: Breastfed infants show better development of the dental arches and a lesser incidence of dental occlusion disorders than bottle-fed infants.