Residents’ journal review

Soft-tissue changes in skeletal Class III orthodontic/orthognathic correction

Verdenik M, Ihan Hren N. Differences in three-dimensional soft tissue changes after upper, lower, or both jaw orthognathic surgery in skeletal class III patients. Int J Oral Maxillofac Surg 2014;43:1345-51

Three surgeries are generally recommended for skeletal Class III patients: bilateral sagittal split osteotomy setback of the mandible, maxillary LeFort I advancement osteotomy, or a combination of both. The goals of this study were to analyze and contrast soft-tissue changes over the entire face after these surgeries. Eighty-three patients were examined with an Artec 3D scanner before and 6 months after surgery using the “best fit” approach. The patients were similar with regard to age, body mass index, and Wits appraisal. In the bilateral sagittal split osteotomy group, the greatest changes occurred in the lower lip and chin; in the LeFort I group, the greatest changes occurred in the nose, cheek, and upper lip; in the combination group, the greatest changes occurred in the lower lip, chin, nose, cheek, and upper lip. The changes were greatest near the midline and smaller on the lateral aspects of the face. Changes were also seen at sites distal to the surgical procedure (although usually smaller, <1.5 mm; in certain cases, this could be significant). Smaller changes were seen in the nose, cheek, and upper lip regions with a bilateral sagittal split osteotomy. Changes were seen in the lower lip and chin regions with a LeFort I, but they were not significant. Vertical changes were seen in all groups but were significant only in the combination group. The conclusion that should be drawn from this study is that soft tissues indisputably act as a unit. One must understand the complexity of facial structure to provide good esthetics and understand the limitations of surgery.

Reviewed by Jessica Fuller

Resorbable fixation in mandibular advancement

Yu S, Bloomquist D. Can resorbable screws effectively be used in fixating bilateral sagittal split osteotomies for mandibular advancement? A randomized controlled trial. J Oral Maxillofac Surg 2014;72:2273-7

Metal rigid fixation has become the standard in orthognathic surgery, craniofacial surgery, and maxillofacial surgery after trauma. The use of biodegradable fixation (polylactate material) is an interesting alternative that theoretically mitigates postoperative complications that would require removal of a nonresorbable implant. The purpose of this study was to compare titanium and resorbable fixation in bilateral sagittal split osteotomies. One hundred one patients with retrognathic mandibles were enrolled in this prospective randomized trial. Those eligible for the study had isolated mandibular deficiency treated with a bilateral sagittal split osteotomy. Patients were randomly assigned into 2 groups: group 1 (n = 51) received titanium screws, and group 2 (n = 50) received resorbable screws. In both groups, 4 bicortical screws were placed for fixation: 2 were placed superior to the mandibular canal, and 2 were placed inferior to the mandibular canal. The findings demonstrated greater use (48% in the resorbable group vs 20% in nonresorbable group) of elastics to correct a Class III open-bite tendency during the initial postoperative phase in the resorbable group. The open-bite tendency was noticed within the first 1 to 2 weeks. These authors attributed this to a higher incidence of rotation around the resorbable positional screws secondary to mechanical looseness resulting from the requirement to tap the bone before screw placement. The study showed no statistical differences in the rates of relapse, postoperative infection or inflammation, having to reoperate, or maximal incisal opening. The study suggests that resorbable screws can effectively be used for fixation with some possible postoperative elastics wear as indicated. Further studies are needed to assess the long-term outcomes of resorbable vs metal fixation in maxillofacial surgeries.

Reviewed by Julie Wees

Resorbable fixation in mandibular advancement

Yu S, Bloomquist D. Can resorbable screws effectively be used in fixating bilateral sagittal split osteotomies for mandibular advancement? A randomized controlled trial. J Oral Maxillofac Surg 2014;72:2273-7

Metal rigid fixation has become the standard in orthognathic surgery, craniofacial surgery, and maxillofacial surgery after trauma. The use of biodegradable fixation (polylactate material) is an interesting alternative that theoretically mitigates postoperative complications that would require removal of a nonresorbable implant. The purpose of this study was to compare titanium and resorbable fixation in bilateral sagittal split osteotomies. One hundred one patients with retrognathic mandibles were enrolled in this prospective randomized trial. Those eligible for the study had isolated mandibular deficiency treated with a bilateral sagittal split osteotomy. Patients were randomly assigned into 2 groups: group 1 (n = 51) received titanium screws, and group 2 (n = 50) received resorbable screws. In both groups, 4 bicortical screws were placed for fixation: 2 were placed superior to the mandibular canal, and 2 were placed inferior to the mandibular canal. The findings demonstrated greater use (48% in the resorbable group vs 20% in nonresorbable group) of elastics to correct a Class III open-bite tendency during the initial postoperative phase in the resorbable group. The open-bite tendency was noticed within the first 1 to 2 weeks. These authors attributed this to a higher incidence of rotation around the resorbable positional screws secondary to mechanical looseness resulting from the requirement to tap the bone before screw placement. The study showed no statistical differences in the rates of relapse, postoperative infection or inflammation, having to reoperate, or maximal incisal opening. The study suggests that resorbable screws can effectively be used for fixation with some possible postoperative elastics wear as indicated. Further studies are needed to assess the long-term outcomes of resorbable vs metal fixation in maxillofacial surgeries.

Reviewed by Julie Wees

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Apr 6, 2017 | Posted by in Orthodontics | Comments Off on Residents’ journal review
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