Dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients

Abstract

Objective: To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite. Materials and Methods: This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test. Results: The mean treatment observation time was 1.31 years (SD 5 2.03). The maxillary first molars (P 5 0.0026) and second molars (P 5 0.039) were intruded. However, the mandibular first molars (P 5 0.0004) and second molars (P 5 0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P 5 0.025 and P 5 0.044, respectively). The mandibular plane angle decreased (P 5 0.036), lower facial height decreased (P 5 0.002), and the occlusal plane angle increased (P 5 0.009). The overbite increased (P , .0001). The ANB angle decreased (P , .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes. Conclusions: Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults. (Angle Orthod. 2015;85:941-948.)

Nonsurgical treatment of skeletal anterior open bite in adult patients: Posterior build-ups

“…11,12 The maxillary molar intrusion obtained using skeletal anchorage has been found VELA-HERNÁNDEZ, LÓ PEZ-GARCÍA, GARCÍA-SANZ, PAREDES-GALLARDO, LASAGABASTER-LATORREgreater (approximately 2.6 mm) than that obtained in the present study. [13][14][15] As for skeletal changes, the present study obtained an average of 1.198 mandibular counterclockwise rotation, a finding that agrees with Aras et al, 18 who carried out extractions. In terms of mandibular plane rotation, Erverdi et al 15 obtained higher values.…”

“…Contrary to the present findings, Erverdi et al 15 and Hart et al 14 observed a clockwise rotation of the plane.…”

“…[12][13][14][15] Dental and skeletal parameters at T1, T2, and T3 were compared and the differences between times were analyzed. Regarding dental changes, overbite increased by 3.98 mm after treatment (T2), a statistically significant increase and a finding similar to the changes observed by Erverdi et al 15 and Hart et al, 14 who used skeletal anchorage (miniplates and microscrews, respectively) for molar intrusion.…”

“…[12][13][14][15] Dental and skeletal parameters at T1, T2, and T3 were compared and the differences between times were analyzed. Regarding dental changes, overbite increased by 3.98 mm after treatment (T2), a statistically significant increase and a finding similar to the changes observed by Erverdi et al 15 and Hart et al, 14 who used skeletal anchorage (miniplates and microscrews, respectively) for molar intrusion. Studies of the RMI device 13 and the multiloop technique 12 show less satisfactory results than does the present study, in which mandibular incisor average extrusion of 1.44 mm contributed to the overbite increase.…”

“…Another common approach that has been used in the past few years is skeletal anchorage devices such as miniscrews 14 or miniplates. 15 These therapies can be used for molar intrusion.…”