[Study on the occlusal stability after three years of full-mouth occlusal reconstruction in maximum intercuspal position]

Objective: To observe the stability of vertical dimension of occlusion (VDO) and mandibular position in full-mouth occlusal reconstruction subjects by means of digital occlusal analysis. Methods: Six subjects who had completed full-mouth occlusal reconstruction by intraoral functional generated path technique for more than three years in the Department of Prosthodontics, Peking University School and Hospital of Stomatology were enrolled for follow-up observation, all six patients were male, with an age of (53.6±8.4) years. The digital dentition model and occlusal contact at baseline and three years follow-up review after restoration were recorded by intraoral laser scanning, and the changes in occlusal surface morphology, occlusal contact area and mandibular position (mandibular overall deviation and mandibular reference plane average angle deviation) were measured in reverse engineering software. The Wilcoxon signed rank test was used to statistically analyze the changes of horizontal and vertical overbite of anterior teeth and VDO of posterior teeth between baseline and three years follow-up after reconstruction. Results: The prosthesis in the 6 subjects were intact at the time of follow-up, and there was no significant change in occlusal morphology compared with that at the baseline right after restoration delivery, and the occlusal contact in maximum intercuspid position was stable. The overall deviation of the lower jaw was (0.19±0.06) mm, and the angular deviation of the mandibular reference plane was 0.72°±0.38°. The chromatic scale of occlusal contact showed that the occlusal contact in some areas was heavier during the three years post-delivery, and the overbite of anterior teeth and the VDO of posterior teeth showed no statistical difference compared with that in the baseline (P>0.05). Conclusions: This study suggests that the occlusal contact distribution and jaw position relationship can be maintained after 3 years of full-mouth occlusal reconstruction, and there is no significant change in the anterior overbite and VDO.