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Mandibular advancement and reduction genioplasty
American Journal oj ORTHODONTICS and DENTOFACIAL ORTHOPEDICS Volume 98 Number 6
Founded in 1915-Seventy-five years of continuous publication
December 1990
Copyright © 1990 by Mosby-Year Book, inc.
CASE REPORT
Mandibular advancement and reduction genioplasty Gary Schuberth, DDS,· Timothy Shaughnessy, DDS, MS, and David Timmis, DDS Atlanta, Ga. This case report is presented in accordance with the specifications of the American Board of Orthodontics. Before treatment, the patient had a unilateral transverse discrepancy and dentoskeletal Class II malocclusion. Clinically, however, the profile was acceptable. She was treated with an orthodontic and orthognathic surgical approach. Interesting treatment-planning considerations included the existence of an eight-unit bridge and incisor periapical pathosis. (AM J ORTHOD DENTOFAC ORTHOP 1990;98:481-7.)
CASE REPORT History, clinical findings, and diagnosis
A 59-year-old woman was referred by her dentist to the Emory Oral Surgery Department for evaluation of a colored area on the inside of her left cheek. The surgeon noted a
From Emory University School of Postgraduate Dentistry. *Staff Resident, Department of Orthodontics. **Assistant Professor of Orthodontics. ***Assistant Professor of Oral and Maxillofacial Surgery. 8/1/13241
mucosal varix; this was followed clinically, but there were no sequelae. At the first examination, however, the surgeon noted a significant maxillomandibular skeletal discrepancy and referred the patient to the Emory Orthodontic Department for further evaluation. The patient reported that she had always had a problem with her "bite" and could chew only or the left side. No one had previously informed her that her bite could be corrected. Clinical evaluation revealed a unilateral right complete maxillary buccal crossbite, an 8 mm overjet, and a 6 mm overbite (Figs. 1 and 2), Despite the increased overjet and
Fig. 1. Pretreatment patient photographs.
481
482
Am. J. Orthod. Dentofac. Orthop. December 1990
Schuberth, Shaughnessy, and Timmis
Fig. 1. (Cont'd). Pretreatment intraoral photographs.
Class II buccal segments, the facial profile appearance was acceptable. Frontal facial characteristics were also unremarkable except for an accentuated mentolabial fold. The patient had an 8-unit maxillary bridge, which was esthetically pleasing and restoratively sound, between her right and left first premolars. A mild degree of marginal gingival inflammation was associated with the bridge abutment teeth. Functional examination showed that the patient did not chew on the right side because of the transverse incompatibility. Bilateral early and late reciprocal clicking were detectable; however, the patient reported no pain or other symp-
symptoms. Maximum voluntary opening and lateral excursions were within normal limits at 49 mm and 10 mm, respectively. Analysis of the diagnostic models (Fig. 2) indicated that the right unilateral crossbite had a large mandibular dental contribution. The mandibular right posterior teeth appeared to be severely lingually inclined. There was mild crowding in the mandibular anterior segment and a measurable toothsize discrepancy (4.6 mm mandibular Bolton! excess) caused by the narrow maxillary bridge pontics. The panoramic radiograph (Fig. 3, A) showed several
Volume 98 Number 6
Case report
Fig. 2. Pretreatment views of the diagnostic models. A, Frontal. B, Right buccal. C, Left buccal. D, Right buccal, inferior view. E, Right buccal, posterior view.
Fig. 3. A, Pretreatment panoramic radiograph illustrates maxillary 8-unit bridge and mandibular incisor radiolucency. B, After treatment.
483
Am. J. Orthod. Dentofac. Orthop. December 1990
484 Schuberth, Shaughnessy, and Timmis
Fig. 4. A, Pretreatment cephalometric radiograph. B, Posttreatment cephalometric radiograph.
Fig. 5. Posttreatment patient photographs.
endodontically treated teeth; missing third molars, maxillary incisors, and a mandibular right second molar; and extensive crown and bridge work. The mandibular left lateral incisor had been treated endodontically; however, a persistent periapical radiolucency was associated with this tooth. Cephalometric analysis (Fig. 4, A) substantiated the dental findings of increased overjet and overbite. Measurements
indicated that the patient's skeletal structure was Class II and deep (Table I). The maxilla was well positioned vertically and anteroposteriorly. Because of the strength of the chin and the increased thickness of the soft tissue overlying pogonion, the facial profile discrepancy did not parallel the cephalometric anteroposterior discrepancy. The list below provides a summary of the patient's problems.
Volume 98 Number 6
Case report
485
Fig. 5. (Cont'd). Posttreatment intraoral photographs.
Problem list (Patient age: 59.0 years)
Pathologic I. Periapical radiolucency mandibular left lateral incisor Developmental I. Severe unilateral right maxillary buccal crossbite (dental and skeletal) 2. Moderate dentoskeletal Class II malocclusion (8 mm OJ) 3. Moderate dentoskeletal deepbite 4. Mandibular Bolton excess (4.6 mm) 5. Mild mandibular crowding
Treatment plan
The primary objective of treatment was to enable the patient to chew on the right side. Other secondary objectives included creation of ideal overjet and overbite. The patient had no particular dental or facial esthetic concerns. To satisfy the objectives and to address all of the problems, the proposed treatment plan included extraction of the mandibular left lateral incisor' and dental decompensation, both transversely and anteroposteriorIy, followed by surgical mandibular advancement and reduction genioplasty.
Am. J. Orthod. Dentofac. Orthop. December 1990
486 Schuberth, Shaughnessy, and Timmis
Table I. Pertinent cephalometric measurements and norms Measurement ANB angle (degrees) Mandible unit length (mm) Maxilla unit length (mm) Unit difference (mm) Growth axis (degrees) FMA angle (degrees) AFH (mm) A point-nasion perpendicular
Norm
6
2
123
130
100
100
23
30
+5
o 23
14 67
72
+1
+1
(mm)
Fig. 6. Cephalometric superimpositions illustrate mandibular advancement and reduction genioplasty. Soft-tissue chin position remained approximately the same, although the mentolabial contour improved.
Surgical advancement of the mandible was necessary to correct the overjet; however, this anterior movement also facilitated correction of the crossbite. Extraction of the mandibular incisor reduced the tooth size discrepancy, resolved the mild mandibular crowding, and eliminated the cause of the periapical pathology. Treatment progress
The mandibular arch was bonded from premolar to premolar with an 0.018 x 0.025-inch straight wire appliance system. Bands were cemented on the molars, and a removable auxiliary expansion appliance was used to facilitate decompensation of the mandibular teeth transversely. No appliances were placed on the maxillary teeth before surgery. Initial mandibular dental alignment was achieved by use of an 0.016inch round nickel titanium arch wire for 2 months. Closure of the incisor extraction site and leveling were accomplished with a power chain and application of tension by means of an 0.016-inch round, stainless steel arch wire for 6 months. An 0.016 x 0.022-inch stainless steel wire was placed 4 months before surgery, and surgical lugs were added 1 week before surgery. Complete diagnostic records were obtained I month before surgery. It became obvious during the model surgery that a maxillary right posterior osteotomy would also be required to complete the transverse correction. This was the only modification of the proposed treatment plan. The mandible was advanced 6 mm and rotated in a clockwise direction. The chin was set back 5 mm so that the soft tissue chin position and profile appearance would remain the same. The patient underwent intermaxillary fixation for 6 weeks and functioned with the surgical splint in place for an addi-
tional4 weeks. Bonded buttons were then placed on the facial surface of selected maxillary posterior teeth, an 0.016 x 0.022-inch TMA wire was set in place, and settling elastics were used for one month. The appliances were removed 4 months after surgery and a mandibular Hawley retainer that extended back to the molars was set in place. No retainer was used in the maxillary arch. Active treatment time was 16 months. Treatment results
The overall facial appearance did not change dramatically with treatment. The mandible was advanced to correct the dental discrepancy, and the chin was set back to maintain the original profile (Figs. 4, B and 6). The mentolabial fold became more shallow and more esthetic. Intraoral analysis showed complete closure of the incisorextraction site, with good dental alignment. The panoramic radiograph revealed good root parallelism at the extraction site and throughout the dentition (Fig. 3, B). Ideal overbite and overjet were achieved with the canines and molars in Class I occlusion bilaterally (Fig. 5). The functional occlusion was canine-protected with incisal guidance. Most important, the patient could now chew with the right side of her jaw as well as with the left. SUMMARY
Several interesting points should be emphasized in this case report. 1. A 59-year-old patient with good medical and dental health can be an excellent candidate for orthodontic treatment and/ or surgery. 2. One should not assume that an "older" patient with a dentoskeletal discrepancy is not interested in the correction of such a discrepancy. This patient, for example, had never been counseled regarding her problem or its possible correction. 3. Patients requiring orthodontic treatment who have fixed bridgework mayor may not need to have the prosthesis removed. Each case must be evaluated on
Volume 98 Number 6
Case report
its own merit, with consideration for such things as the quality of the prosthesis, esthetics, and occlusion. 4. Extraction of a single mandibular incisor is not very common, but it may be particularly useful when there is a substantial tooth size discrepancy and/ or mandibular incisor pathosis. A diagnostic setup should always be obtained before extraction of such a tooth.
487
REFERENCES I. Bolton W. Dishannony in tooth size and its relation to the analysis and treatment of malocclusion. Angle Orthod 1958;28:113. 2. Kokich V, Shapiro P. Lower incisor extraction in orthodontic treatment. Angle Orthod 1984;54:139.
Reprint requests to:
Timothy Shaughnessy, DDS, MS 3823 Roswell Rd., Suite 308 Marietta, GA 30062
We are gratefUl to Nell McDonald for preparation of the manuscript.
BOUND VOLUMES AVAILABLE TO SUBSCRIBERS
Bound volumes of the AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS are available to subscribers (only) for the 1990 issues from the Publisher, at a cost of $44.00 ($54.00 international) for Vol. 97 (January-June) and Vol. 98 (July-December). Shipping charges are included. Each bound volume contains a subject and author index and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby-Year Book, Inc., Circulation Department, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; telephone (800)325-4177, ext. 7351.
Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular Journal subscription.
Founded in 1915-Seventy-five years of continuous publication
December 1990
Copyright © 1990 by Mosby-Year Book, inc.
CASE REPORT
Mandibular advancement and reduction genioplasty Gary Schuberth, DDS,· Timothy Shaughnessy, DDS, MS, and David Timmis, DDS Atlanta, Ga. This case report is presented in accordance with the specifications of the American Board of Orthodontics. Before treatment, the patient had a unilateral transverse discrepancy and dentoskeletal Class II malocclusion. Clinically, however, the profile was acceptable. She was treated with an orthodontic and orthognathic surgical approach. Interesting treatment-planning considerations included the existence of an eight-unit bridge and incisor periapical pathosis. (AM J ORTHOD DENTOFAC ORTHOP 1990;98:481-7.)
CASE REPORT History, clinical findings, and diagnosis
A 59-year-old woman was referred by her dentist to the Emory Oral Surgery Department for evaluation of a colored area on the inside of her left cheek. The surgeon noted a
From Emory University School of Postgraduate Dentistry. *Staff Resident, Department of Orthodontics. **Assistant Professor of Orthodontics. ***Assistant Professor of Oral and Maxillofacial Surgery. 8/1/13241
mucosal varix; this was followed clinically, but there were no sequelae. At the first examination, however, the surgeon noted a significant maxillomandibular skeletal discrepancy and referred the patient to the Emory Orthodontic Department for further evaluation. The patient reported that she had always had a problem with her "bite" and could chew only or the left side. No one had previously informed her that her bite could be corrected. Clinical evaluation revealed a unilateral right complete maxillary buccal crossbite, an 8 mm overjet, and a 6 mm overbite (Figs. 1 and 2), Despite the increased overjet and
Fig. 1. Pretreatment patient photographs.
481
482
Am. J. Orthod. Dentofac. Orthop. December 1990
Schuberth, Shaughnessy, and Timmis
Fig. 1. (Cont'd). Pretreatment intraoral photographs.
Class II buccal segments, the facial profile appearance was acceptable. Frontal facial characteristics were also unremarkable except for an accentuated mentolabial fold. The patient had an 8-unit maxillary bridge, which was esthetically pleasing and restoratively sound, between her right and left first premolars. A mild degree of marginal gingival inflammation was associated with the bridge abutment teeth. Functional examination showed that the patient did not chew on the right side because of the transverse incompatibility. Bilateral early and late reciprocal clicking were detectable; however, the patient reported no pain or other symp-
symptoms. Maximum voluntary opening and lateral excursions were within normal limits at 49 mm and 10 mm, respectively. Analysis of the diagnostic models (Fig. 2) indicated that the right unilateral crossbite had a large mandibular dental contribution. The mandibular right posterior teeth appeared to be severely lingually inclined. There was mild crowding in the mandibular anterior segment and a measurable toothsize discrepancy (4.6 mm mandibular Bolton! excess) caused by the narrow maxillary bridge pontics. The panoramic radiograph (Fig. 3, A) showed several
Volume 98 Number 6
Case report
Fig. 2. Pretreatment views of the diagnostic models. A, Frontal. B, Right buccal. C, Left buccal. D, Right buccal, inferior view. E, Right buccal, posterior view.
Fig. 3. A, Pretreatment panoramic radiograph illustrates maxillary 8-unit bridge and mandibular incisor radiolucency. B, After treatment.
483
Am. J. Orthod. Dentofac. Orthop. December 1990
484 Schuberth, Shaughnessy, and Timmis
Fig. 4. A, Pretreatment cephalometric radiograph. B, Posttreatment cephalometric radiograph.
Fig. 5. Posttreatment patient photographs.
endodontically treated teeth; missing third molars, maxillary incisors, and a mandibular right second molar; and extensive crown and bridge work. The mandibular left lateral incisor had been treated endodontically; however, a persistent periapical radiolucency was associated with this tooth. Cephalometric analysis (Fig. 4, A) substantiated the dental findings of increased overjet and overbite. Measurements
indicated that the patient's skeletal structure was Class II and deep (Table I). The maxilla was well positioned vertically and anteroposteriorly. Because of the strength of the chin and the increased thickness of the soft tissue overlying pogonion, the facial profile discrepancy did not parallel the cephalometric anteroposterior discrepancy. The list below provides a summary of the patient's problems.
Volume 98 Number 6
Case report
485
Fig. 5. (Cont'd). Posttreatment intraoral photographs.
Problem list (Patient age: 59.0 years)
Pathologic I. Periapical radiolucency mandibular left lateral incisor Developmental I. Severe unilateral right maxillary buccal crossbite (dental and skeletal) 2. Moderate dentoskeletal Class II malocclusion (8 mm OJ) 3. Moderate dentoskeletal deepbite 4. Mandibular Bolton excess (4.6 mm) 5. Mild mandibular crowding
Treatment plan
The primary objective of treatment was to enable the patient to chew on the right side. Other secondary objectives included creation of ideal overjet and overbite. The patient had no particular dental or facial esthetic concerns. To satisfy the objectives and to address all of the problems, the proposed treatment plan included extraction of the mandibular left lateral incisor' and dental decompensation, both transversely and anteroposteriorIy, followed by surgical mandibular advancement and reduction genioplasty.
Am. J. Orthod. Dentofac. Orthop. December 1990
486 Schuberth, Shaughnessy, and Timmis
Table I. Pertinent cephalometric measurements and norms Measurement ANB angle (degrees) Mandible unit length (mm) Maxilla unit length (mm) Unit difference (mm) Growth axis (degrees) FMA angle (degrees) AFH (mm) A point-nasion perpendicular
Norm
6
2
123
130
100
100
23
30
+5
o 23
14 67
72
+1
+1
(mm)
Fig. 6. Cephalometric superimpositions illustrate mandibular advancement and reduction genioplasty. Soft-tissue chin position remained approximately the same, although the mentolabial contour improved.
Surgical advancement of the mandible was necessary to correct the overjet; however, this anterior movement also facilitated correction of the crossbite. Extraction of the mandibular incisor reduced the tooth size discrepancy, resolved the mild mandibular crowding, and eliminated the cause of the periapical pathology. Treatment progress
The mandibular arch was bonded from premolar to premolar with an 0.018 x 0.025-inch straight wire appliance system. Bands were cemented on the molars, and a removable auxiliary expansion appliance was used to facilitate decompensation of the mandibular teeth transversely. No appliances were placed on the maxillary teeth before surgery. Initial mandibular dental alignment was achieved by use of an 0.016inch round nickel titanium arch wire for 2 months. Closure of the incisor extraction site and leveling were accomplished with a power chain and application of tension by means of an 0.016-inch round, stainless steel arch wire for 6 months. An 0.016 x 0.022-inch stainless steel wire was placed 4 months before surgery, and surgical lugs were added 1 week before surgery. Complete diagnostic records were obtained I month before surgery. It became obvious during the model surgery that a maxillary right posterior osteotomy would also be required to complete the transverse correction. This was the only modification of the proposed treatment plan. The mandible was advanced 6 mm and rotated in a clockwise direction. The chin was set back 5 mm so that the soft tissue chin position and profile appearance would remain the same. The patient underwent intermaxillary fixation for 6 weeks and functioned with the surgical splint in place for an addi-
tional4 weeks. Bonded buttons were then placed on the facial surface of selected maxillary posterior teeth, an 0.016 x 0.022-inch TMA wire was set in place, and settling elastics were used for one month. The appliances were removed 4 months after surgery and a mandibular Hawley retainer that extended back to the molars was set in place. No retainer was used in the maxillary arch. Active treatment time was 16 months. Treatment results
The overall facial appearance did not change dramatically with treatment. The mandible was advanced to correct the dental discrepancy, and the chin was set back to maintain the original profile (Figs. 4, B and 6). The mentolabial fold became more shallow and more esthetic. Intraoral analysis showed complete closure of the incisorextraction site, with good dental alignment. The panoramic radiograph revealed good root parallelism at the extraction site and throughout the dentition (Fig. 3, B). Ideal overbite and overjet were achieved with the canines and molars in Class I occlusion bilaterally (Fig. 5). The functional occlusion was canine-protected with incisal guidance. Most important, the patient could now chew with the right side of her jaw as well as with the left. SUMMARY
Several interesting points should be emphasized in this case report. 1. A 59-year-old patient with good medical and dental health can be an excellent candidate for orthodontic treatment and/ or surgery. 2. One should not assume that an "older" patient with a dentoskeletal discrepancy is not interested in the correction of such a discrepancy. This patient, for example, had never been counseled regarding her problem or its possible correction. 3. Patients requiring orthodontic treatment who have fixed bridgework mayor may not need to have the prosthesis removed. Each case must be evaluated on
Volume 98 Number 6
Case report
its own merit, with consideration for such things as the quality of the prosthesis, esthetics, and occlusion. 4. Extraction of a single mandibular incisor is not very common, but it may be particularly useful when there is a substantial tooth size discrepancy and/ or mandibular incisor pathosis. A diagnostic setup should always be obtained before extraction of such a tooth.
487
REFERENCES I. Bolton W. Dishannony in tooth size and its relation to the analysis and treatment of malocclusion. Angle Orthod 1958;28:113. 2. Kokich V, Shapiro P. Lower incisor extraction in orthodontic treatment. Angle Orthod 1984;54:139.
Reprint requests to:
Timothy Shaughnessy, DDS, MS 3823 Roswell Rd., Suite 308 Marietta, GA 30062
We are gratefUl to Nell McDonald for preparation of the manuscript.
BOUND VOLUMES AVAILABLE TO SUBSCRIBERS
Bound volumes of the AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS are available to subscribers (only) for the 1990 issues from the Publisher, at a cost of $44.00 ($54.00 international) for Vol. 97 (January-June) and Vol. 98 (July-December). Shipping charges are included. Each bound volume contains a subject and author index and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Mosby-Year Book, Inc., Circulation Department, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; telephone (800)325-4177, ext. 7351.
Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular Journal subscription.