Molar height and dentoalveolar compensation in adult subjects with skeletal open bite

Abstract

Objective: To evaluate the skeletal and dentoalveolar components in adult subjects with skeletal open bite in the presence or absence of dental compensation. Materials and Methods: The study sample included 69 adult female subjects who belonged to three groups according to skeletal vertical relationships and overbite. A total of 15 variables (5 angular, 10 linear) were evaluated. Values in the dentally compensated open bite group (COBG), the dentally noncompensated open bite group (NCOBG), and the control group with normal vertical skeletal relationships and overbite (CG) were compared by means of parametric statistics. Results: The COBG and the NCOBG showed significantly greater incisor and molar heights in both jaws than the CG. No significant difference in upper or lower molar height was found between COBG and NCOBG. Incisor height was significantly greater in COBG than in NCOBG. Elongation in the incisor region was accompanied by significant narrowing of the lower anterior alveolar process in both skeletal open bite groups. Proclination of the upper incisors was significantly smaller in the COBG than in the other groups. Conclusions: Dentoalveolar components consisting of incisor elongation and inclination play a significant role in compensating for skeletal open bite configuration in adult subjects. Increased molar height is a common finding in adults with skeletal open bite. (Angle Orthod. 2011;81:564-569.)

Anterior maxillary dentoalveolar and skeletal cephalometric factors involved in upper incisor crown exposure in subjects with Class II and III skeletal open bite

“…This is in agreement with other research, which found that the open bite group did not differ significantly from a CG in this regard. 12,23,24 The ULH was not statistically significantly different between SOBGs and CG. This makes sense as the length of the upper lip is not influenced by the sagittal skeletal malocclusion.…”

“…Burstone et al 17 found that the distance of the upper incisor edge to the PP in males was 30.5 6 2.1 mm and in females 27.5 6 1.7 mm, where larger values were considered as overeruption and smaller values as infraeruption. Also, Kucera et al 12 found that in the skeletal open bite group, the incisor height was significantly elongated compared with CG by approximately 3 mm. Our results were consistent with those of previous studies, [12][13][14][15][16][17][18][19] but they contradict those reported by Nahoum,20 who found smaller values for incisor height in patients with open bite with respect to CG.…”

“…However, anterior open bite can also occur due to posterior dentoalveolar adaptations such as increased molar extrusion. Kucera et al 12 concluded that the increased molar height is a common finding in adults with skeletal open bite. In a study using the same sample, Arriola-Guillé n and Flores-Mir 13 concluded that the skeletal open bite groups had greater molar heights than did CG.…”

“…Because of the relatively small standard deviation (62 mm), the treatment of most of these cases should focus primarily on maintaining or slightly decreasing the exposure, not necessarily implying major surgical procedures. Intrusion of the posterior teeth as the treatment of choice has been indicated by some studies, 12,13 although the long-term stability of molar intrusion is still controversial. According to Baek et al, 18 relapse occurred on an average of 23% of the amount of molar intrusion facilitated by microscrews within 3 years of the postretention period.…”

“…Kucera et al 12 concluded that incisor eruption was significantly greater in dentally compensated skeletal open bite and that UIs were significantly more retroclined in in these subjects. They did not distinguish whether their cases were Class II or III, which likely could have unique camouflage compensations.…”