Bilateral open bite in dicygotic twins. A combined orthodontic-prosthetic approach.
METHODS
Dizygotic twins, male, 25 years of age, required treatment for an identical orthodontic diagnosis.


METHODS
Class III malocclusion with mesial molar relation and frontal edge-to-edge bite, lyrate upper dental arch, grouped cross-bite and bilateral open bite in the molar and bicuspid region, retention and lingual inclination respectively of the lower left second bicuspid, mesial inclination of both lower first molars. The severity of the malocclusion differed in the two brothers.


METHODS
Orthodontic treatment was successful concerning the transversal expansion and alignment of the maxillary dental arch, the functional relation of the anterior teeth, the transversally correct relation of the upper and lower dental arches and, following surgical removal of the lower second bicuspids, the reduction of crowding in the lower arch. An attempt was made to upright the molars in the mandibular arch and to close the lateral open bite by means of vertical elastics. However, the 10-month period of resistance to the therapy suggested, after a tongue protrusion habit had been ruled out, a diagnosis of ankylosis. Further orthodontic treatment was renounced and a prosthetic solution was pursued instead: the teeth in infraocclusion were treated with full ceramic overlays and, in the regions with residual gaps, with pontics (Empress II, Ivoclar, Schaan, Liechtenstein), after minimally invasive preparation (confined to removal of existing fillings).


CONCLUSIONS
This case is particularly interesting because the infrapositioned molars in both brothers were very likely due to ankylosis, suggesting a genetic cause.
Radlanski
Ralf J
RJ
Department of Experimental Dentistry/Oral Biology, Benjamin Franklin University Hospital, Free University, Berlin, Germany. ralfj.radlanski@medizin.fu-berlin.de
Freesmeyer
Wolfgang B
WB
D000328:Adult; D003131:Combined Modality Therapy; D003828:Denture, Overlay; D003830:Denture, Partial, Fixed; D004200:Diseases in Twins; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000235:genetics* / Q000628:therapy; D024343:Open Bite / Q000235:genetics* / Q000628:therapy; D009971:Orthodontics, Corrective; D014429:Twins, Dizygotic