[Positioning of the premaxilla in cases of bilateral cleft lip, alveolus and palate using Latham's appliance]

Defining biomechanical principles in pre-surgical infant orthopedics in a real cleft finite element model

Presurgical infant orthopedics (PSIO) is the first step in the treatment of cleft lip and palate (CLP) and is designed to approximate the cleft segments as effectively as possible before surgical reconstruction of the lip and palate. The biomechanical efficacy of different PSIO approaches in transferring molding forces to the CLP is unknown. This study aimed to define the biomechanical principles of competing PSIO techniques in a real cleft finite element (FE) model. Active intraoral (Latham), passive alveolar molding (PAM), and extraoral (DynaCleft) molding forces were virtually applied to a real cleft FE model. In the cleft region, PAM (P < 0.001) and Latham (P < 0.05) exerted significantly less stress than DynaCleft. Intraoral molding forces acted primarily at the site of the force initiation without being accompanied by high loads in the midface. PAM showed a tendency toward a better flow behavior of the molding forces than Latham. Extraoral molding transferred high stresses to the cleft, alveolar ridge, and midface. Intraoral passive molding was ultimately characterized by the highest biomechanical efficacy and showed the most favorable load distribution of all of the PSIO approaches considered in this study. Future research is needed to validate the findings against clinical data.

The impact of passive alveolar molding vs. nasoalveolar molding on cleft width and other parameters of maxillary growth in unilateral cleft lip palate

OBJECTIVE

Passive alveolar molding (PAM) and nasoalveolar molding (NAM) are established presurgical infant orthodontic (PSIO) therapies for cleft lip palate (CLP) patients. PAM guides maxillary growth with a modified Hotz appliance, while NAM also uses extraoral taping and includes nasal stents. The effects of these techniques on alveolar arch growth have rarely been compared.

MATERIAL AND METHODS

We retrospectively compared 3D-scanned maxillary models obtained before and after PSIO from infants with unilateral, non-syndromic CLP treated with PAM (n = 16) versus NAM (n = 13). Nine anatomical points were set digitally by four raters and transversal/sagittal distances and rotations of the maxilla were measured.

RESULTS

Both appliances reduced the anterior cleft, but NAM percentage wise more. NAM decreased the anterior and medial transversal width compared to PAM, which led to no change. With both appliances, the posterior width increased. The alveolar arch length of the great and small segments and the sagittal length of the maxilla increased with PAM but only partially with NAM. However, NAM induced a significant greater medial rotation of the larger and smaller segment compared to PAM with respect to the lateral angle.

CONCLUSIONS

NAM and PAM presented some significant differences regarding maxillary growth. While NAM reduced the anterior cleft and effectively rotated the segments medially, PAM allowed more transversal and sagittal growth.

CLINICAL RELEVANCE

The results of this study should be taken into consideration when to decide whether to use PAM or NAM, since they show a different outcome within the first few months. Further studies are necessary regarding long-term differences.

[Lip, jaw, and palate clefts. Analysis of unilateral cleft lip using 3-D laser topometry]

INVESTIGATION

In most cases it is not sufficient to use photographs and plaster casts to document and analyze the three-dimensional morphology of lip, jaw, and palate clefts. The aim of this study was to evaluate the applicability of surface scanning with a 3-D laser topography scanner in patients with unilateral cleft lip.

PATIENTS AND METHODS

Three-dimensional surface scans of the face were performed pre- and postoperatively in 20 patients (3-35 years of age) with a 3-D laser topography scanner. All patients were suffering from nonoperated, one-sided cleft lip, cleft lip-jaw, or cleft lip-jaw and palate. The digital data sets were metrically analyzed and expressed on the basis of quotients, independent of size factors.

RESULTS

Using this 3-D laser scanner it was possible to acquire good quality three-dimensional data sets. Measurements were in the dimension of millimeters. Based on the data sets it was possible to provide the three-dimensional cleft morphology with reproducible landmarks and analyze the data. The postoperative symmetry of the face was controlled and objectively quantified. It is disadvantageous however that numerous views need to be taken to get the full image of the face and that the scanning process takes about 2 s.

CONCLUSION

The presented 3-D laser scanner renders a precise 3-D surface analysis of the lip and nose region in cleft patients. For lively infants or uncooperative adults, the system is suitable only to a limited extent due to the time-consuming scanning process.