title: Breakage of internal maxillary distractor: considerable complication of maxillary distraction osteogenesis.
abstract: Maxillary distraction osteogenesis using intraoral distractors is now one of the standard treatments of maxillary retrusion. This report shows 2 cases of breakage of this internal maxillary distractor in patients with cleft lip and palate; one was observed during the distraction period and the other was during the retention period. The first case required a rotational movement of the distraction segment, and this movement caused the laterally dislocation of the posterior part of the distractor, where the distractor suffered some mechanical forces by mouth opening. In the latter case, breakage of distractor was observed on the radiographs taken 3 months after distraction and this complication may have been caused by mechanical force by occlusion and mastication. Both breakages were found at the joint of the anchorage plate and the extension rod, which has some flexibility for adjusting the plate to the bone surface. Therefore, surgeons should pay special attention for this mechanical weak area in this distractor not only during the advancement period, but also during the retention period and should avoid unnecessary frequent bending for adopting the bone surface, which directly weakens the joint.
authors.affiliation: First Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Tomonao
authors.initials: T
authors.lastname: Aikawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Iida
authors.forename: Emiko T
authors.initials: ET
authors.lastname: Isomura
authors.forename: Mari
authors.initials: M
authors.lastname: Namikawa
authors.forename: Yudai
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: Chiaki
authors.initials: C
authors.lastname: Yamada
authors.forename: Taku
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yoko
authors.initials: Y
authors.lastname: Takigawa
mesh_terms: D000328:Adult; D001732:Bite Force; D002508:Cephalometry; D002971:Cleft Lip / Q000150:complications; D002972:Cleft Palate / Q000150:complications; D003762:Dental Instruments / Q000009:adverse effects*; D003799:Dental Stress Analysis; D004867:Equipment Design / Q000009:adverse effects; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000209:etiology / Q000601:surgery*; D008409:Mastication; D008437:Maxilla / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000009:adverse effects* / Q000295:instrumentation; D019857:Osteogenesis, Distraction / Q000009:adverse effects* / Q000295:instrumentation*; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000295:instrumentation; D063173:Retrognathia / Q000209:etiology / Q000601:surgery