Reverse-sequencing chewing patterns evaluation in anterior versus posterior unilateral crossbite patients

Abstract

It is well established that patients with a unilateral posterior crossbite exhibit reverse-sequencing chewing patterns when chewing on the affected side. The aim of the study was to compare the prevalence of reverse-sequencing chewing cycles in patients with anterior versus posterior unilateral crossbite during chewing soft and hard boluses. Eighty-six children (39 boys, 47 girls) were included in the study: 26 (10.4 ± 2.7 years) with unilateral anterior crossbite, 43 (10.2 ± 4.2 years) with unilateral posterior crossbite, and 17 (10.6 ± 2 years) with normal occlusion were selected for the study. Mandibular movements were measured with a kinesiograph (K7, Myotronics Inc. Tukwila). The kinematic signals were analyzed using custom-made software. The results showed a low prevalence of reverse-sequencing chewing cycles in patients with anterior crossbite, without any significant difference between sides and with the control group, with both soft (P = 0.33) and hard (P = 0.29) bolus. The patients with posterior unilateral crossbite showed a significant higher prevalence of reverse-sequencing chewing cycles during chewing on the crossbite side with respect to the non-crossbite side (P < 0.001) and to the control group (P < 0.001). Comparing the patients with anterior versus posterior unilateral crossbite, a significant difference (P < 0.001) in the prevalence of reverse chewing cycles was demonstrated during chewing on the posterior crossbite side only with both soft and hard bolus. In conclusion, patients with anterior versus posterior unilateral crossbite show different functional characteristics depending on which dental region is involved.

Posterior scissors‐bite: masticatory jaw movement and muscle activity

“…In the present study, the jaw movement on the scissors‐bite side showed poor lateral excursion and a slow chopping‐type chewing pattern, compared with that of chewing on the non‐scissors‐bite side in the patient group and the normal group. Subjects with malocclusion show abnormal chewing patterns , a narrow and slow chewing pattern results in reduced masticatory efficiency . Scissors‐bite, labial eruption of the upper molar , lingual tipping of the lower molar or any combination of these conditions can cause occlusal interference by restricting lateral jaw movement.…”

“…Malocclusion can influence masticatory function (5)(6)(7)(8)(9)(10). In individuals with normal occlusion, the chewing pattern involves lateral deviation of the mandibular incisor towards the bolus, which is followed by medial deviation during closing (11,12).…”

Functional evaluation of orthopedic and orthodontic treatment in a patient with unilateral posterior crossbite and facial asymmetry

“…Posterior crossbite can affect the chewing pattern of patients 18,19,20,21. The difference in chewing patterns between the crossbite and non-crossbite sides is especially characterized by a reverse direction of closure, namely, reverse-sequence chewing cycles 20,21.…”

“…The difference in chewing patterns between the crossbite and non-crossbite sides is especially characterized by a reverse direction of closure, namely, reverse-sequence chewing cycles 20,21. A reverse-sequencing cycle occurs frequently whilst chewing on the crossbite side and on harder foods 19.…”

First molar cross‐bite is more closely associated with a reverse chewing cycle than anterior or pre‐molar cross‐bite during mastication

“…It has been reported that patients with unilateral posterior cross-bite often show unique masticatory jaw movement (4)(5)(6). In the frontal view, a high frequency of reverse chewing cycles on the cross-bite side was observed during mastication because of posterior cross-bite (5,6). Furthermore, we have previously found that the working condyle on the cross-bite side moved more in the medial direction during mastica-tion in patients with unilateral posterior cross-bite than in normal subjects (7).…”