ABSTRACT
Maxillary deficiency is a common feature in patients with repaired cleft lip and palate. Orthognathic surgery has been the conventional approach for the management of cleft-related maxillary hypoplasia. However, for patients with a severe maxillary deficiency, orthognathic surgery alone has many disadvantages, such as high relapse rates of 25% to 40%, instability, limited amount of advancement, and a highly invasive surgical technique. As an alternative treatment method, distraction osteogenesis has been used successfully in the distraction of the mandible, the maxilla, the entire midface, and the orbits as well as the cranial bones, with stable outcomes. The type of distraction device, either external or internal, can be chosen based on the surgical goals set for the patient. In this study, we report on the use of a rigid external distraction device for maxillary advancement in a 22-year-old woman with a repaired unilateral cleft lip and palate and severe maxillary hypoplasia. After the distraction osteogenesis, 2-jaw surgery was performed to correct the maxillary yaw deviation and the mandibular prognathism.
Subject(s)
Cleft Lip/surgery , Cleft Palate/surgery , Maxilla/abnormalities , Orthognathic Surgical Procedures/methods , Osteogenesis, Distraction/methods , Cephalometry/methods , External Fixators , Female , Genioplasty/methods , Humans , Malocclusion, Angle Class III/surgery , Maxilla/surgery , Osteogenesis, Distraction/instrumentation , Osteotomy, Le Fort/methods , Osteotomy, Sagittal Split Ramus/methods , Patient Care Planning , Prognathism/surgery , Young AdultABSTRACT
OBJECTIVE: The aims of this study were to evaluate the relationship between the detachment force and bonding resin surface are and to determine the resin bonding surface area that would provide adequate bonding strength with minimum resin volume. METHODS: One hundred and sixty human premolars were randomly divided into 4 groups of 40 teeth each. The diameter of the resin surface area in each group was as follows: group 1, 1.5 mm; group 2, 2.5 mm; group 3, 3.5 mm; and group 4, 4.5 mm. Respond Dead Soft straight (length 0.0175 inch) was used to fabricate the retainers, and Transbond™ XT was used to fix the retainers to the tooth surfaces. A pair of teeth was embedded in acrylic blocks for each specimen. Thus, each group comprised 20 samples. Fixed retainers were bonded to the teeth, and vertical force was applied at the middle of wire. The force was measured using a universal testing machine. RESULTS: The mean value of detachment force was the highest for group 4 (102.38 ± 2.92 N), followed by group 3 (63.54 ± 2.21 N), group 2 (51.95 ± 1.61 N), and group 1 (24.14 ± 1.38 N). CONCLUSIONS: The detachment force of lingual fixed retainers was significantly affected as the area of the resin bonding surface increased. Considering the minimum bonding strength of brackets, a resin bonding surface area with a diameter of 3.5 mm would provide adequate bonding strength.
