Three-dimensional evaluation of the alar cinch suture after Le Fort I osteotomy.

Orthognathic surgery has an influence on the overlying soft tissues of the translated bony maxillomandibular complex. Improvements in both function and facial appearance are the goals of surgery. However, unwanted changes to the soft tissues, especially in the nose region, frequently occur. The most common secondary change in the nasolabial region is widening of the alar base. Various surgical techniques have been developed to minimize this effect. The purpose of this study was to evaluate the changes in the nasal region due to orthognathic surgery, especially the alar width and nasal volume, using combined cone beam computed tomography (CBCT) and three-dimensional (3D) stereophotogrammetry datasets. Twenty-six patients who underwent a Le Fort I advancement osteotomy between 2006 and 2013 were included. From 2006 to 2010, no alar base cinch sutures were performed. From 2010 onwards, alar base cinch sutures were used. Preoperative and postoperative documentation consisted of 3D stereophotogrammetry and CBCT scans. 3D measurements were performed on the combined datasets, and the alar base width and nose volume were analyzed. No difference in alar base width or nose volume was observed between patients who had undergone an alar cinch and those who had not. Postoperatively the nose widened and the volume increased in both groups.

Three-dimensional changes in nose and upper lip volume after orthognathic surgery.

Orthognathic surgery aims to improve both the function and facial appearance of the patient. Translation of the maxillomandibular complex for correction of malocclusion is always followed by changes to the covering soft tissues, especially the nose and lips. The purpose of this study was to evaluate the changes in the nasal region and upper lip due to orthognathic surgery using combined cone beam computed tomography (CBCT) and three-dimensional (3D) stereophotogrammetry datasets. Patients who underwent a Le Fort I osteotomy, with or without a bilateral sagittal split osteotomy, were included in this study. Pre- and postoperative documentation consisted of 3D stereophotogrammetry and CBCT scans. 3D measurements were performed on the combined datasets and analyzed. Anterior translation and clockwise pitching of the maxilla led to a significant volume increase in the lip. Cranial translation of the maxilla led to an increase in the alar width. The combination of CBCT DICOM data and 3D stereophotogrammetry proved to be useful in the 3D analysis of the maxillary hard tissue changes, as well as changes in the soft tissues. Measurements could be acquired and compared to investigate the influence of maxillary movement on the soft tissues of the nose and the upper lip.

One year postoperative hard and soft tissue volumetric changes after a BSSO mandibular advancement.

In this study, cone beam computed tomography (CBCT) and three dimensional (3D) stereophotogrammetry are used to compare the 3D skeletal and soft tissue changes caused by a bilateral sagittal split osteotomy (BSSO) 1 year after a mandibular advancement. Eighteen consecutive patients with a hypoplastic mandible were treated with a BSSO according to the Hunsuck modification. Preoperatively and 1 year postoperatively, a CBCT scan was acquired and a 3D photograph. The pre- and postoperative CBCT scans were matched using voxel based registration. After registration, the mandible could be segmented in the pre- and postoperative scans. The preoperative scan was subtracted from the postoperative scan, resulting in the hard tissue difference. To investigate the soft tissue changes, the pre- and postoperative 3D photographs were registered using surface based registration. After registration the preoperative surface could be subtracted from the postoperative surface, resulting in the overall volumetric difference. As expected, a correlation between mandibular advancent and volumetric changes of the hard tissues was found. The correlation between advancement and soft tissues was weak. The labial mental fold stretched after surgery. This study proved that using 3D imaging techniques it is possible to document volumetric surgical changes accurately and objectively.

[Clinical results of bone anchors for orthodontic anchorage; the indications and surgical complications]. / Zygoma-ankers voor orthodontische verankering. Indicaties en chirurgische complicaties.

In order to make teeth-movement possible, orthodontic anchorage is necessary. Neighbouring teeth, a headgear, dental implants and bone anchors can be used. During the period 2002-2007 158 bone anchors have been placed in 84 patients by an oral surgeon after referral by an orthodontist in order to achieve anchorage for orthodontic treatment. The bone anchor consists of a titanium osteosynthesis-plate ending in a round neck perforating the soft tissue and a cylinder attached to it. The indications for placement, results and complications were registered. 15 anchors (9,5%) were lost prematurely and in 13 cases (8,2%) complications needing surgical intervention were reported. It is concluded that zygoma-bone anchor is a good alternative for orthodontic anchorage and the number of complications is acceptable, though there is room for improvement.