Treatment of a Class III Malocclusion with Anterior Crossbite and Deepbite, Utilizing Infrazygomatic Crest (IZC) Bone Screws as Anchorage
Shih YH, Lin JJ, Roberts WE.
Malocclusions with anterior crossbite are a major esthetic and functional concern for patients and their parents. A 14-year-old boy was diagnosed as a Class III malocclusion, combined with anterior crossbite, deepbite, concave pro le, and inadequate maxillary incisor exposure. There was functional shift on closure, and the mandible could be manipulated to an edge-to-edge incisal occlusion, when the condyles were positioned in centric relation. The Discrepancy Index (DI) was 24. A passive self-ligation appliance, with infrazygomatic crest (IZC) bone screw anchorage, and Class III intermaxillary elastics were used to correct this severe malocclusion in only 10 months to a Cast-Radiograph Evaluation (CRE) score of 18. The IZC bone screws were installed buccal to the alveolar process between the upper 1st and 2nd molars. They provided reliable anchorage for intermaxillary elastics to retract the lower incisors and increase the vertical dimension of occlusion. The malocclusion was corrected with a relatively short treatment time, but the maxillary incisors were excessively ared. Long term follow up is required to monitor the potential for late mandibular growth to produce a skeletal Class III relationship. (Int J Orthod Implantol;40:2-14)
Key words:Class III deep bite malocclusion, functional shift, passive self-ligation appliance, IZC bone screws, extra-alveolar bone screw anchorage
Asymmetric Crowded Class II with Missing First Molars: Space Closure or Implants?
Lu SW, Chang CH, Roberts WE.
A 30-year-old female presented with a Class II malocclusion complicated with severe maxillary anterior crowding, moderate deep- bite and the asymmetric loss of two permanent rst molars: lower right ( #30) and upper left ( #14). The adjacent second molars were rotated and tipped mesially. A third molar was present on the lower right side ( #32), but the third molar was missing from the upper left quadrant ( #16). The Discrepancy Index (DI) for this asymmetric malocclusion was 16 points. Orthodontics treatment with a full xed, passive self-ligating (PSL) appliance resulted in closure of the lower right space (area #30), but the missing third molar ( #16) required opening space for an implant to replace the missing #14. After aligning the dentition, closing all mandibular space, and opening the implant site, cone-beam computer tomography (CBCT) imaging was utilized to evaluate bone distribution. A titanium xture was installed in the palatal aspect of the #14 area, with a apless surgical procedure. Thirteen months after xture placement, orthodontic treatment was completed and an implant-supported prosthesis was delivered. The overall duration for the entire interdisciplinary treatment was 29 months. Multiple outcome assessment scores documented an excellent result: cast-radiograph evaluation (CRE) 22, dental esthetics 3, implant position 0, and abutment transition 1. (Int J Orthod Implantol;40:18-41)
Key words:Class II canine relationship, missing rst molars, molar-incisor hypomineralization, space management, crowding, deep bite, implant-supported prosthesis, apless implant surgery
Nonsurgical Treatment of Anterior Open Bite Malocclusion
Chang MJ, Chang CH, Roberts WE.
This case report describes the nonsurgical treatment of a 31-years-old female presenting with a chief complaint of anterior open bite malocclusion. A clinical exam revealed that there were spaces between her lower anterior teeth. Orthodontics was indicated to align and level the maxillary dentition and close the mandibular spaces. Anterior early light short elastic (2 oz) was used to solve the open bite problem. Miniscrews in the infrazygomatic crests was applied to retract the upper and lower dentition and intrude the upper posterior segment. It improved her lip pro le and reduced the mandibular angle. Class III elastics were used to correct the negative overjet and continuous intermaxillary elastics were prescribed to settle the nal occlusion. A marked improvement in anterior open bite correction and occlusal function was achieved. (Int J Orthod Implantol;40:44-63)
Key words:Anterior open bite malocclusion, early light short elastics, Angle Class I molar relationship, mandibular midline shifted, Damon self-ligating brackets, OrthoBoneScrew, extra-alveolar miniscrews, infrazygomatic crests (IZC), class III elastics, negative overjet, continuous intermaxillary elastics.
Skeletal Class III Malocclusion with Canine Transposition and Facial Asymmetry
Wei MW, Chang CH, Roberts WE.
Simple Mechanics to Upright Horizontally Impacted Molars with Ramus Screws
Lin SY, Chang CH, Roberts WE.
Simplified mechanics are reported for uprighting horizontally impacted mandibular molars with ramus bone screws. A 27-year-old male presented with a chief complaint of food impaction and problematic occlusion of his posterior teeth. The panoramic radiograph revealed multiple impacted molars: both upper third molars, and all lower second and third molars. Orthodontic treatment was indicated to improve occlusal function by aligning the posterior segments. The treatment plan was to extract the upper second molars and lower third molars, then upright the lower second molars, and allow the upper third molars to spontaneously erupt. The deeply impacted lower second molars were uprighted in only ~4 months with superiorly positioned ramus bone screws. (Int J Orthod Implantol;40:84-92)
Key words:Horizontally impacted second molars, molar uprighting, ramus bone screws
Charles J. Burstone (1928-2015)
Burstone Biomechanics: a Living Legacy
Charles Justin Burstone (CJB) is best known for his tenure at the University of Connecticut (UCONN), but the epicenter for biomechanics was at Indiana 1922, and graduated with a DDS from Washington University, St. Louis (Wash U) in 1946. He specialized in Oral Pathology, and was subsequently appointed University (IU). CJB contributed substantially to the expression of his passion, and to the subsequent development of the bioengineering group at Indiana University and Purdue University at Indianapolis (IUPUI). Charlie’s contributions to orthodontics were profound, and in addition he had broad interests in photography, art and music. He was particularly fond of Wagner’s operas.