[Feasibility of Delaire cephalometric analysis to predict the ideal sagittal position of the maxilla and chin for surgery-first patients in orthognathic surgery]

OBJECTIVE

There is no universally accepted method for determining the ideal sagittal position of the maxilla in orthognathic surgery. The purpose of this study was to compare how well the Delaire's cephalometric analysis correlated with postoperatively findings in patients who underwent orthognathic surgery planned using other cephalometric analyses, as well as to evaluate the feasibility of the Delaire's cephalometric analysis in predicting the ideal sagittal position of the maxilla and chin.

METHODS

In the study, 35 patients with skeletal Class III malocclusion were involved and met the criteria. Treatment plans were developed using photographs, 3-D photographs, radiographs, and standard cephalometric measurements. The Delaire's cephalometric analysis data, like the phase measurements (∠C1-L1 and ∠C1-L2) of the sagittal positions of the maxillary and the chin separating the reference line (L1) of NP point and the reference line (L2) of Me point, were analyzed using Dolphin Imaging software. At the same time, the analyses on standard measurements were also performed. Four orthognathic doctors, 4 orthodontic doctors and 4 college students from non-medical majors were selected as aesthetic evaluators to assess the patients' profile aesthetic by visual analogue scale (VAS). The results through the Delaire's cephalometric analysis were statistically compared with that through standard methods.

RESULTS

The mean of ∠C1-L1 was 83.93°±2.99° and∠C1-L2 was 89.08° ±2.48° for males postoperatively, and 85.67° ±3.60° and 88.30° ±4.20° for females postoperatively. Compared with the reference values of Chinese goodlooking people, there was no significant difference of NP point, whereas there was a significant difference of Me point. The postoperative aesthetic scores were: the mean was 6.71±0.25 of upper jaws, 6.81±0.30 of chins and 6.90±0.29 of the overall for males; and 7.19±0.22, 7.26±0.34 and 7.39±0.29 for females. Compared with preoperative scores, there was a significant improvement. Furthermore, the scores of chins and the overall scores were related to the sagittal position of the chins.

CONCLUSION

Compared with standard cephalometric analysis, the Deliare's cephalometric analysis well unravel the preoperative deformity and the final esthetic sagittal positions of maxillary and chin in the present sample, and could be a useful tool for the planning of surgery-first approach in orthognathic surgery.

[Establishment of three-dimensional measurement methods of nasolabial soft tissue for patients with maxillary protrusion]

OBJECTIVE

To establish a series of three-dimensional measurement methods of nasolabial soft tissue for maxillary protrusion patients by using 3dMD camera, and to evaluate preoperative and postoperative changes of the nasolabial soft tissue.

METHODS

Three-dimensional facial photos of 30 female patients with maxillary protrusion [average age, (27.33±2.54) years] were taken by 3dMD camera preoperatively and at the end of postoperative 6 months or more. Then, 3dMD patient software was used to locate the selected landmarks at nasolabial region on the three-dimensional photos. Ten measurements, including soft tissue line distance, angle, curve distance and postoperative three-dimensional volume changes were measured twice with one week interval by 3 investigators, respectively. A standard consistency test calculated by the correlation coefficients (ICC) was performed between two sets of data (including all of the 10 measurements) for each investigator and among the three investigators to verify the repeatability.

RESULTS

The average maxillary incisor retraction distance of the 30 subjects was (5.13±0.99) mm, and the average follow-up time was (11.07±5.11) months. The standard consistency test was performed between the two sets of data for each investigator, and the correlation coefficients (ICC) of the 10 measurements were all over 0.8 for each investigator (P>0.05). The standard consistency test was performed among the three surveyors, with the result that the ICC of the width of the bilateral inner canthus, the height of the nose, the height of nasal tip, nasolabial angle, philtrum length, the curve height of upper vermilion and the height of upper lip were greater than 0.8 (P>0.05), and the ICC of the distance between SbalSbal, length of nasal dorsum and three-dimensional volume change of upper lip were 0.680, 0.627 and 0.528, respectively (P>0.05).

CONCLUSION

3dMD camera and 3dMD patient software can be used to measure and analyze the three-dimensional morphology of the nasolabial soft tissue for patients with maxillary protrusion preoperatively and postoperatively, and it is relatively accurate and reliable. However, the repeatability of three-dimensional positioning of the nasal tip point and the Sbal is slightly worse resulting in the lower value of the ICC of the distance between SbalSbal and length of nasal dorsum, as well as the upper lip three-dimensional volume change after the operation.

[Establishment of three-dimensional measurement methods of nasolabial soft tissue for patients with maxillary protrusion]

OBJECTIVE

To establish a series of three-dimensional measurement methods of nasolabial soft tissue for maxillary protrusion patients by using 3dMD camera, and to evaluate preoperative and postoperative changes of the nasolabial soft tissue.

METHODS

Three-dimensional facial photos of 30 female patients with maxillary protrusion [average age, (27.33±2.54) years] were taken by 3dMD camera preoperatively and at the end of postoperative 6 months or more. Then, 3dMD patient software was used to locate the selected landmarks at nasolabial region on the three-dimensional photos. Ten measurements, including soft tissue line distance, angle, curve distance and postoperative three-dimensional volume changes were measured twice with one week interval by 3 investigators, respectively. A standard consistency test calculated by the correlation coefficients (ICC) was performed between two sets of data (including all of the 10 measurements) for each investigator and among the three investigators to verify the repeatability.

RESULTS

The average maxillary incisor retraction distance of the 30 subjects was (5.13±0.99) mm, and the average follow-up time was (11.07±5.11) months. The standard consistency test was performed between the two sets of data for each investigator, and the correlation coefficients (ICC) of the 10 measurements were all over 0.8 for each investigator (P>0.05). The standard consistency test was performed among the three surveyors, with the result that the ICC of the width of the bilateral inner canthus, the height of the nose, the height of nasal tip, nasolabial angle, philtrum length, the curve height of upper vermilion and the height of upper lip were greater than 0.8 (P>0.05), and the ICC of the distance between SbalSbal, length of nasal dorsum and three-dimensional volume change of upper lip were 0.680, 0.627 and 0.528, respectively (P>0.05).

CONCLUSION

3dMD camera and 3dMD patient software can be used to measure and analyze the three-dimensional morphology of the nasolabial soft tissue for patients with maxillary protrusion preoperatively and postoperatively, and it is relatively accurate and reliable. However, the repeatability of three-dimensional positioning of the nasal tip point and the Sbal is slightly worse resulting in the lower value of the ICC of the distance between SbalSbal and length of nasal dorsum, as well as the upper lip three-dimensional volume change after the operation.