Stefan Rupperti1, P Winterhalder2, I Rudzki3, G Mast4, C Holberg3. 1. Numerisches Biomechanik Labor, Ludwig-Maximilians University of Munich, Geschwister-Scholl-Platz 1, 80539, Munich, Germany. S.Rupperti@campus.lmu.de. 2. Department of Oral and Maxillofacial Surgery, RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany. 3. Numerisches Biomechanik Labor, Ludwig-Maximilians University of Munich, Geschwister-Scholl-Platz 1, 80539, Munich, Germany. 4. Department of Oral and Maxillofacial Surgery, Ludwig-Maximilians University of Munich, Lindwurmstr. 2a, 80337, Munich, Germany.
Abstract
OBJECTIVES: To investigate the correlation between soft- and hard-tissue changes after mandibular orthognathic surgery, to generate precise prognostic values for the esthetic treatment outcome of the facial profile. MATERIAL AND METHODS: In this retrospective study, sagittal changes in the facial soft tissue profile in relation to surgical changes in hard structures after mandibular osteotomy were examined. The sample population included 144 reported adult patients aged 17-50 years who had received combined mandibular orthognathic surgery and orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. Both mandibular advancement and mandibular setback cases in monognathic and bignathic osteotomy procedures were included. All subjects had undergone rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed, and the correlations between hard-tissue and soft-tissue change ratios were evaluated using a bivariate linear regression analysis. RESULTS: The lower lip, represented by the landmark Labrale inferius (Li), followed the lower incisor (Ii) by 77%. The soft-tissue B-point (B') followed the B-point (B) by 97% and the soft-tissue Pogonion (Pg') followed the Pogonion (Pg) by 97% in a linear correlation. CONCLUSION: The scatterplots show a distinct linear correlation and no significant difference in the direction of the movement. A wider spread for the lower lip (Li/Ii) indicates a lower predictability of the expected lip position, whereas a narrow spread of the chin values (B'/B and the Pg'/Pg) reveals a very good predictability of the postoperative chin position. CLINICAL RELEVANCE: This study contributes valid data for the soft-tissue profile prediction in orthognathic surgery.
OBJECTIVES: To investigate the correlation between soft- and hard-tissue changes after mandibular orthognathic surgery, to generate precise prognostic values for the esthetic treatment outcome of the facial profile. MATERIAL AND METHODS: In this retrospective study, sagittal changes in the facial soft tissue profile in relation to surgical changes in hard structures after mandibular osteotomy were examined. The sample population included 144 reported adult patients aged 17-50 years who had received combined mandibular orthognathic surgery and orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. Both mandibular advancement and mandibular setback cases in monognathic and bignathic osteotomy procedures were included. All subjects had undergone rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed, and the correlations between hard-tissue and soft-tissue change ratios were evaluated using a bivariate linear regression analysis. RESULTS: The lower lip, represented by the landmark Labrale inferius (Li), followed the lower incisor (Ii) by 77%. The soft-tissue B-point (B') followed the B-point (B) by 97% and the soft-tissue Pogonion (Pg') followed the Pogonion (Pg) by 97% in a linear correlation. CONCLUSION: The scatterplots show a distinct linear correlation and no significant difference in the direction of the movement. A wider spread for the lower lip (Li/Ii) indicates a lower predictability of the expected lip position, whereas a narrow spread of the chin values (B'/B and the Pg'/Pg) reveals a very good predictability of the postoperative chin position. CLINICAL RELEVANCE: This study contributes valid data for the soft-tissue profile prediction in orthognathic surgery.
Authors: Stephan Christian Möhlhenrich; Florian Kötter; Florian Peters; Kristian Kniha; Sachin Chhatwani; Gholamreza Danesh; Frank Hölzle; Ali Modabber Journal: Head Face Med Date: 2021-04-14 Impact factor: 2.151
Authors: S Rupperti; P Winterhalder; S Krennmair; S Holberg; C Holberg; G Mast; I Rudzki Journal: J Orofac Orthop Date: 2021-04-21 Impact factor: 2.341