Reverse-sequencing chewing cycles in a family unit with bilateral posterior crossbite
PURPOSE: Reverse chewing cycles are dyskinetic masticatory pattern highly represented in crossbite patients. The aim of this study was to analyze the prevalence of reverse-sequencing chewing cycles in a family (41-year-old father, 41-year-old mother, 10.8-year-old daughter, 7-year-old son), affected by crossbite, to evaluate the functional aspects of an inherited malocclusion. Material and methods: All the family components underwent orthodontic evaluation and chewing cycles recorded with a Myotronics K6-1 kinesiograph.
RESULTS: The results showed that the father, who previously corrected a right posterior crossbite, did not develop reverse chewing cycles (0% on the right side and 0% on the left side). The mother and the boy, affected by a bilateral posterior symmetric crossbite, developed significant reverse chewing cycles on both sides (89% on the right side, 75% on the left side, the mother and 70% on the right side, 90% on the left side, the boy); the girl, affected by a bilateral posterior crossbite with a greater number of teeth in crossbite on the left side, developed significant reverse chewing cycles on the left side only (5% on the right side and 100% on the left side).
CONCLUSION: The prevalence of the reverse chewing cycles resulted in agreement with the crossbite, mirroring the dental characteristics. These results suggest that not only the bone structure and the dental assessment, but also the function might be inherited. As a consequence, the evaluation of the family history might be an important diagnostic data to early intercept the malocclusion.