Limits...
Validity of a manual soft tissue profile prediction method following mandibular setback osteotomy.

Kolokitha OE - Eur J Dent (2007)

Bottom Line: To test the validity of the manual method the prediction tracings were compared to the actual post-operative tracings.Comparison between manual prediction tracings and the actual post-operative profile showed that the manual method results in more convex soft tissue profiles; the upper lip was found in a more prominent position, upper lip thickness was increased and, the mandible and lower lip were found in a less posterior position than that of the actual profiles.Comparison between computerized and manual prediction methods showed that in the manual method upper lip thickness was increased, the upper lip was found in a more anterior position and the lower anterior facial height was increased as compared to the computerized prediction method.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.

ABSTRACT

Objectives: The aim of this study was to determine the validity of a manual cephalometric method used for predicting the post-operative soft tissue profiles of patients who underwent mandibular setback surgery and compare it to a computerized cephalometric prediction method (Dentofacial Planner). Lateral cephalograms of 18 adults with mandibular prognathism taken at the end of pre-surgical orthodontics and approximately one year after surgery were used.

Methods: To test the validity of the manual method the prediction tracings were compared to the actual post-operative tracings. The Dentofacial Planner software was used to develop the computerized post-surgical prediction tracings. Both manual and computerized prediction printouts were analyzed by using the cephalometric system PORDIOS. Statistical analysis was performed by means of t-test.

Results: Comparison between manual prediction tracings and the actual post-operative profile showed that the manual method results in more convex soft tissue profiles; the upper lip was found in a more prominent position, upper lip thickness was increased and, the mandible and lower lip were found in a less posterior position than that of the actual profiles. Comparison between computerized and manual prediction methods showed that in the manual method upper lip thickness was increased, the upper lip was found in a more anterior position and the lower anterior facial height was increased as compared to the computerized prediction method.

Conclusions: Cephalometric simulation of post-operative soft tissue profile following orthodontic-surgical management of mandibular prognathism imposes certain limitations related to the methods implied. However, both manual and computerized prediction methods remain a useful tool for patient communication.

No MeSH data available.


Related in: MedlinePlus

Coordinate system construction.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2609908&req=5

f1-0010202: Coordinate system construction.

Mentions: The pre-operative and post-operative lateral cephalograms of each patient were traced on acetate paper. The objective was to estimate the exact amount and direction of maxillomandibular repositioning that took place after the operation. For this reason, a coordinate reference system consisting of horizontal and vertical planes into which all cephalometric landmarks could be located as x and y values was constructed (Figure 1). A line parallel to the Frankfort Horizontal through Sella was used as the best estimate for the horizontal plane and a line perpendicular to this plane through Sella represented the vertical plane. Pre- and post-operative tracings of each patient were superimposed on SN and by means of the coordinate system aided by a millimetre grid the exact amount and direction of the actual operative jaw repositioning was assessed. Thus, the exact backward movement of mandibular incisors as a result of the surgical setback was also calculated in millimetres. The method used has already been described in a previous study.21


Validity of a manual soft tissue profile prediction method following mandibular setback osteotomy.

Kolokitha OE - Eur J Dent (2007)

Coordinate system construction.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2609908&req=5

f1-0010202: Coordinate system construction.
Mentions: The pre-operative and post-operative lateral cephalograms of each patient were traced on acetate paper. The objective was to estimate the exact amount and direction of maxillomandibular repositioning that took place after the operation. For this reason, a coordinate reference system consisting of horizontal and vertical planes into which all cephalometric landmarks could be located as x and y values was constructed (Figure 1). A line parallel to the Frankfort Horizontal through Sella was used as the best estimate for the horizontal plane and a line perpendicular to this plane through Sella represented the vertical plane. Pre- and post-operative tracings of each patient were superimposed on SN and by means of the coordinate system aided by a millimetre grid the exact amount and direction of the actual operative jaw repositioning was assessed. Thus, the exact backward movement of mandibular incisors as a result of the surgical setback was also calculated in millimetres. The method used has already been described in a previous study.21

Bottom Line: To test the validity of the manual method the prediction tracings were compared to the actual post-operative tracings.Comparison between manual prediction tracings and the actual post-operative profile showed that the manual method results in more convex soft tissue profiles; the upper lip was found in a more prominent position, upper lip thickness was increased and, the mandible and lower lip were found in a less posterior position than that of the actual profiles.Comparison between computerized and manual prediction methods showed that in the manual method upper lip thickness was increased, the upper lip was found in a more anterior position and the lower anterior facial height was increased as compared to the computerized prediction method.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.

ABSTRACT

Objectives: The aim of this study was to determine the validity of a manual cephalometric method used for predicting the post-operative soft tissue profiles of patients who underwent mandibular setback surgery and compare it to a computerized cephalometric prediction method (Dentofacial Planner). Lateral cephalograms of 18 adults with mandibular prognathism taken at the end of pre-surgical orthodontics and approximately one year after surgery were used.

Methods: To test the validity of the manual method the prediction tracings were compared to the actual post-operative tracings. The Dentofacial Planner software was used to develop the computerized post-surgical prediction tracings. Both manual and computerized prediction printouts were analyzed by using the cephalometric system PORDIOS. Statistical analysis was performed by means of t-test.

Results: Comparison between manual prediction tracings and the actual post-operative profile showed that the manual method results in more convex soft tissue profiles; the upper lip was found in a more prominent position, upper lip thickness was increased and, the mandible and lower lip were found in a less posterior position than that of the actual profiles. Comparison between computerized and manual prediction methods showed that in the manual method upper lip thickness was increased, the upper lip was found in a more anterior position and the lower anterior facial height was increased as compared to the computerized prediction method.

Conclusions: Cephalometric simulation of post-operative soft tissue profile following orthodontic-surgical management of mandibular prognathism imposes certain limitations related to the methods implied. However, both manual and computerized prediction methods remain a useful tool for patient communication.

No MeSH data available.


Related in: MedlinePlus