- Email: [email protected]
Changes in nasal and labial soft tissues after surgical repositioning of the maxilla
Scientific Poster Session
Changes in Nasal and Labial Soft Tissues After Surgical Repositioning of the Maxilla Norman J. Betts, DDS, Univ. of Michigan, Dept. of OMS, Rm. Bl-104, Box 0018,150O E. Medical Ctr. Dr., Ann Arbor, MI 48109 (Fonseca, R.J., Vig, P.S., Dryland-Vig, K. W., Spalding, P.M.) To accurately predict the esthetics in function of the soft tissues of the nose and upper lip, it is essential to understand the relationship between movements of the maxilla with its dentoalveolar component and the changes in the nasal soft tissues and the upper lip. Previous studies have employed lateral cephalometric analysis and standardized full facial photographs in this assessment. Both of these techniques are insufficient because they attempt to quantify a three dimensional change with two dimensional figures. It would be advantageous to accurately measure soft tissue changes on a three dimensional model. A group of thirty-two patients who underwent LeFort I osteotomies, some with concomitant mandibular procedures had standardized lateral cephalograms taken pre-, post-operatively and one year later. The same patients also had pre-operative and one year post-operative alginate impressions of the nose and upper lip converted to stone models. The three cephalograms were compared using an X-Y coordinate system based on th SN line in order to assess surgical, soft tissue change, and relapse. The hard tissue points were ANS, PNS, A pt., maxillary incisal edge and mesiobuccal cusp of the maxillary first molar. The soft tissue points were pronasale, subnasale, labrale superius, stomion superius, nasolabial angle, and nasolabial depth. The pre-operative and one year postoperative nasolabial casts were assessed by comparing the greatest alar width, alar base width, nares width, philtral width and height, columella height, alar height, nasal tip protrusion, nasolabial angle and nasal tip angle. The data was analyzed using a multiple stepwise regression with the cephalometric measurements acting as the independent variable and the nasolabial cast measurements as the dependent variable, taking account of age, sex, alar cinch suture, V-Y closure, and contouring of the anterior nasal spine. The results showed a widening of the greatest alar width and alar base width in all patients regardless of the type of movement. An associated shortening of the columella height, alar height and nasal tip protrusion was seen in most cases. Several other significant associations are discussed. Account was taken of measurement error in the lateral cephalogram tracings and nasolabial casts. It appeared the soft tissue changes were consistent, and were more affected by the position of the soft tissue incisions and method of closure than by the hard tissue change.
Dann, J.J., Fonseca, R.J. and Bell, W.H.: Soft tissue changes associated with total maxillary advancement: A preliminary study. J Oral Surg. 34 (1):19-23, 1976 142
Phillip, C., Devereux, J.P., Camille-Tulloch, J.F. and Tucker, M.R.: Full-faced soft tissue response to surgical maxillary intrusion. Intl J. Adult Ortho and Orthognathic Surg April, 1986,299-304 Departmental funding provided
Pterygomaxillary Separation Without the Use of Osteotome: 426 Cases David S. Precious, DDS, MSc, Dalhousie Univ., Dept. of OMS, Dental Bldg., Room 5 132, Halifax, Nova Scotia, B3H 355 (Ricard D., Morrison, A.) Introduction: In order to completely mobilize the maxilla during LeFort I osteotomy it is necessary to effect a clean, precise separation of the maxilla from the pterygoid process of the sphenoid bone. When this manoeuver is accomplished using a pterygomaxillary osteotome the following complications have been reported: (a) pterygoid plate fracture and comminution; (b) severe hemorrhage and; (c) nerve damage. Studies of strain distribution and osteotome design modification indicate that accidental fractures of the pterygoid plates are likely to occur regardless of the type of osteotome used. The purpose of this study was to evaluate, at surgery, the anatomy of pterygomaxillary separation in 426 patients who underwent LeFort I osteotomy in which no osteotome was used to achieve this separation. Materials and Methods: The study population consisted of 426 patients (age x=22.1, (11.856 yrs.) sex: 65%F, 35%M, who underwent LeFort I osteotomy for correction of dento-skeletal deformity, during 1985-1988 inclusive. Excluded from the study were patients with cleft lip/palate anomalies and syndromes such as hemifacial microsomia. In each case the osteotomy was carried out in conventional fashion except that bilateral Tessier separating forceps, placed in the osteotomy at the region of the anterior maxillary pillar, were used to inferiorly mobilize the maxilla. No osteotome was used in the region of the pterygomaxillary junction and final separation accomplished using either posterior engagement of the Tessier separator or maxillary mobilization forceps. The specific anatomic characteristics of the pterygomaxillary separation were noted at surgery. Results: Two principal types of separation were noted. 1. A complete clean separation of the maxilla from the pterygoid process in which the tuberosity was intact and in which the pyramidal process of the palatine bone remained with the pterygoid plates. Type 1 separation occurred in 83% of the study population. 2. A complete clean separation as in 1 but in which a part of the pyramidal portion of the palatine bone remained attached to the horizontal plate. The tuberosity was intact and separate from the pterygoid plates. Type 2 separation occurred in 17% of the study population. Neither age nor sex altered the frequency of type of separation. AAOMS .
1989
Changes in Nasal and Labial Soft Tissues After Surgical Repositioning of the Maxilla Norman J. Betts, DDS, Univ. of Michigan, Dept. of OMS, Rm. Bl-104, Box 0018,150O E. Medical Ctr. Dr., Ann Arbor, MI 48109 (Fonseca, R.J., Vig, P.S., Dryland-Vig, K. W., Spalding, P.M.) To accurately predict the esthetics in function of the soft tissues of the nose and upper lip, it is essential to understand the relationship between movements of the maxilla with its dentoalveolar component and the changes in the nasal soft tissues and the upper lip. Previous studies have employed lateral cephalometric analysis and standardized full facial photographs in this assessment. Both of these techniques are insufficient because they attempt to quantify a three dimensional change with two dimensional figures. It would be advantageous to accurately measure soft tissue changes on a three dimensional model. A group of thirty-two patients who underwent LeFort I osteotomies, some with concomitant mandibular procedures had standardized lateral cephalograms taken pre-, post-operatively and one year later. The same patients also had pre-operative and one year post-operative alginate impressions of the nose and upper lip converted to stone models. The three cephalograms were compared using an X-Y coordinate system based on th SN line in order to assess surgical, soft tissue change, and relapse. The hard tissue points were ANS, PNS, A pt., maxillary incisal edge and mesiobuccal cusp of the maxillary first molar. The soft tissue points were pronasale, subnasale, labrale superius, stomion superius, nasolabial angle, and nasolabial depth. The pre-operative and one year postoperative nasolabial casts were assessed by comparing the greatest alar width, alar base width, nares width, philtral width and height, columella height, alar height, nasal tip protrusion, nasolabial angle and nasal tip angle. The data was analyzed using a multiple stepwise regression with the cephalometric measurements acting as the independent variable and the nasolabial cast measurements as the dependent variable, taking account of age, sex, alar cinch suture, V-Y closure, and contouring of the anterior nasal spine. The results showed a widening of the greatest alar width and alar base width in all patients regardless of the type of movement. An associated shortening of the columella height, alar height and nasal tip protrusion was seen in most cases. Several other significant associations are discussed. Account was taken of measurement error in the lateral cephalogram tracings and nasolabial casts. It appeared the soft tissue changes were consistent, and were more affected by the position of the soft tissue incisions and method of closure than by the hard tissue change.
Dann, J.J., Fonseca, R.J. and Bell, W.H.: Soft tissue changes associated with total maxillary advancement: A preliminary study. J Oral Surg. 34 (1):19-23, 1976 142
Phillip, C., Devereux, J.P., Camille-Tulloch, J.F. and Tucker, M.R.: Full-faced soft tissue response to surgical maxillary intrusion. Intl J. Adult Ortho and Orthognathic Surg April, 1986,299-304 Departmental funding provided
Pterygomaxillary Separation Without the Use of Osteotome: 426 Cases David S. Precious, DDS, MSc, Dalhousie Univ., Dept. of OMS, Dental Bldg., Room 5 132, Halifax, Nova Scotia, B3H 355 (Ricard D., Morrison, A.) Introduction: In order to completely mobilize the maxilla during LeFort I osteotomy it is necessary to effect a clean, precise separation of the maxilla from the pterygoid process of the sphenoid bone. When this manoeuver is accomplished using a pterygomaxillary osteotome the following complications have been reported: (a) pterygoid plate fracture and comminution; (b) severe hemorrhage and; (c) nerve damage. Studies of strain distribution and osteotome design modification indicate that accidental fractures of the pterygoid plates are likely to occur regardless of the type of osteotome used. The purpose of this study was to evaluate, at surgery, the anatomy of pterygomaxillary separation in 426 patients who underwent LeFort I osteotomy in which no osteotome was used to achieve this separation. Materials and Methods: The study population consisted of 426 patients (age x=22.1, (11.856 yrs.) sex: 65%F, 35%M, who underwent LeFort I osteotomy for correction of dento-skeletal deformity, during 1985-1988 inclusive. Excluded from the study were patients with cleft lip/palate anomalies and syndromes such as hemifacial microsomia. In each case the osteotomy was carried out in conventional fashion except that bilateral Tessier separating forceps, placed in the osteotomy at the region of the anterior maxillary pillar, were used to inferiorly mobilize the maxilla. No osteotome was used in the region of the pterygomaxillary junction and final separation accomplished using either posterior engagement of the Tessier separator or maxillary mobilization forceps. The specific anatomic characteristics of the pterygomaxillary separation were noted at surgery. Results: Two principal types of separation were noted. 1. A complete clean separation of the maxilla from the pterygoid process in which the tuberosity was intact and in which the pyramidal process of the palatine bone remained with the pterygoid plates. Type 1 separation occurred in 83% of the study population. 2. A complete clean separation as in 1 but in which a part of the pyramidal portion of the palatine bone remained attached to the horizontal plate. The tuberosity was intact and separate from the pterygoid plates. Type 2 separation occurred in 17% of the study population. Neither age nor sex altered the frequency of type of separation. AAOMS .
1989