American Journal of ORTHODONTICS and DENTOFACIAL ORTHOPEDICS Founded in 1915
Volume 100 Number 2
August 1991
Copyright © 1991 by the American Association of Orthodontists
CASE REPORT
American Board of Orthodontics case report Steven A. Dugoni, DMD, MSD,* and Jetson S. Lee, DDS, MSD** South San Francisco, Calif.
A case of a Class I malocclusion with a bimaxillary protrusion and an anterior crossbite is presented. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.] (AM J ORTHOD DENTOFACORTHOP 1991 ;100:99-105.)
CASE REPORT Diagnostic summary The patient (Fig. l) had a Class I molar and canine relation with a Class III tendency on the right side (Figs. 2 and 3). The overjet and overbite were normal at the upper right central incisor to the lower right central incisor and lateral incisor; however, there was an anterior crossbite of the upper and lower left incisors and canines. The mandibular midline was 3 mm off to the left side, and the mandibular arch was asymmetric "in arch form. A bidental protrusion From the Department of Orthodontics. Universityof the Pacific. *Associate Clinical Professor. **Assistant Clinical Professor. 814124685
existed with approximately 5 mm of anterior crov~ding on the maxillary arch and approximately 3 mm of crowding in the mandibular arch. A small pontic was present in place of the missing upper right first premolar. The lower left second molar was also missing.
History and general clinical picture The patient was a 34-year-old Hispanic man in good health with no history of serious diseases or trauma. Clinical examination revealed normal color and texture of the tissues of the cheeks, the tongue, and the hard and soft palates. The patient had chronic generalized gingivitis and localized periodontitis at the upper right first and second molars. Oral hygiene was average. The patient had a high caries index with amalgam, gold, or porcelain restorations on most of the
Fig. 1. Pretreatment facial photographs. 99
100
Dugoni and Lee
Am. J. Orthod. Dentofiw. Orthop. Aug tst 1991
Fig. 2. Pretreatment intraoral photographs.
Fig. 3. Pretreatment study models.
Volume I00 Number 2
Case report
101
Fig. 4. Pretreatment intraoral radiographs.
posterior teeth. The upper left first and second molars were abutted together to prevent supraeruption of the upper left second molar. Facial form and esthetics The patient had a mesocephalic facial type with a balance of the upper and lower facial height, and a good harmony of the forehead, nose, and upper lip (Fig. I). The tooth to lip relationship was normal when smiling. Intraoral radiographic survey A normal bony trabecular pattern was found, with slight generalized interproximal bone loss evident (Fig. 4). The upper right first premolar and the lower left second molar were missing. Root canal fillings were present in the upper right first molar and upper left second premolar. Restorations were present on all maxillary posterior teeth and most of the mandibular posterior teeth. Cephalometric analysis An SNA angle of 87 °, an SNB angle of 85 °, and an NPoFIt angle of 92 ° suggested maxillary and mandibular protrusion (Fig. 5 and Table I). The vertical relationship of the upper to the lower face was within normal limits. The upper incisors to SN relationship of 35 ° and 11 mm indicated protrusion of the maxillary incisors. An IMPA angle of 96 ° and a lower incisor to NB relationship of 33 ° and I0 mm revealed lower incisor protrusion. The Holdaway ratio of I 0 : - 3 confirmed the mandibular anterior protrusion. Likewise, the acute interincisal angle of 111 ° indicated procumbent incisors.
Etiology Hereditary factors are the most likely cause of the malocclusion. However, the familial history was not available. The patient's daughter had a similar type of malocclusion. Plan of treatment Extraction of the lower first premolars, removal of the pontic at the upper right first premolar area, and extraction of the upper left second premolar was the extraction pattern chosen. Removal of the lower first premolars would relieve the lower anterior crowding and allow for the retraction of the protrusive lower incisors also necessary to correct the anterior crossbite. The removal of the pontic and the nonvital upper left second premolar would relieve the crowding in the upper arch and allow retraction of the protrusive incisors. Since the anterior crossbite occurred on the left, this extraction pattern works in our favor to minimize retraction of the upper incisors on the left while allow!ng the lower incisors to be retracted to a greater extent. The patient was also referred to a periodontist for a complete periodontal evaluation and was seen every 3 months for root planing and curettage. The treatment objectives were as follows: 1. Maintenance of a good profile balance. 2. Correction of the anterior crossbite. 3. Establishment of an ideal overjet and overbite relationship. 4. Reduction of the maxillary and mandibular dentoalveolar protrusion by movement of the maxillary right central and lateral incisors lingually and movement of the lower incisors lingually.
102
Dugoni attd Lee
Am. ]. Orthod. Dentofac. Orthop. August 1991
Table I. S u m m a r y o f c e p h a l o m e t r i c measurements
Measurement
Fig. 5. Pretreatment cephalometric tracing (stage A).
I Ref. nor,,,. [ 09183
SNA SNB ANB SN-MPA FMA NPo-FH IMPA LI-APo (mm) LI-NB (mm) LI-NB (degrees) U I-NA (mm) U I-NA (degrees) U1-L1 E plane (mm) Wits (ram) Holdaway ratio (mm)
80 78 2 32 25 87 90 0 4 25 4 22 131 -2 - 1 4:4
87 85 2 31 23 92 96 10 10 33 lI 35 111 0
10186 87 85 2 31 23 92 90 5 6 27 7 24 127 -7
-4
-4
10:3
6:2
Fig. 6. Posttreatment facial photographs.
5. Correction of the midline discrepancy. 6. Correction of the mandibular arch asymmetry. Progress of treatment The maxillary and mandibular first molars were banded with an 0.022 × 0.028-inch edgewise appliance and the incisors, canines, and premolars were bonded directly. Class III elastics were used for approximately 6 months during the initial leveling and aligning to minimize forward tipping of the lower incisors. Class II elastics were later used on the left side to facilitate midline correction and to maintain a Class I canine relation. After leveling with maxillary 0.0175inch and mandibular 0.0215-inch braided arch wires, maxillary 0.018-inch and mandibular 0.020-inch multiloop arch wires were placed. Maxillary and mandibular 0.019 ×
0.025-inch rectangular arch wires were placed for torque control during en masse retraction of the incisors and canines, after correction of the anterior crossbite. A midline elastic was used for-8 months. The upper and lower right second molars were banded after the extraction spaces were closed on the right side. The Class II elastics were worn on the left side for 6 months. During the 25 months of active treatment, there was one cancelled appointment and two missed appointments. The appointments were scheduled at 3 to 4 week intervals. RESULTS ACHIEVED Facial form and esthetics A good profile balance was maintained during treatment, with the lower lip showing slightly less protrusion (Fig. 6).
Volume 100 Number 2
Case report
Fig. 7. Posttreatment intraoral photographs.
Fig, 8. Posttreatment study models.
103
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Am. J. Orthod. Dentofac. Orthop. August 1991
Dugoni and Lee
Fig. 9. Posttreatment intraoral radiographs.
34.10--
^
7
)
..-
Fig. 10. Posttreatment cephalometric tracing (stage B).
Fig. 11. Superimpositions of tracings from pretreatment (34.1 O, solid line) to posttreatment (37.11, dashed lines).
The upper and lower facial height was balanced, and there was good facial symmetry. The patient had a pleasing smile with a good tooth-to-lip relationship. No decalcification was evident.
rected, and the dental midlines were aligned. Clinical observations showed no discrepancy between centric relation and centric occlusion. Canine rise existed in lateral excursions, and no balancing interferences were detectable.
Dental assessment
Intraoral radiographs
A normal overjet and overbite relationship existed, with the posterior occlusion well seated (Figs. 7 and 8). The arch form had been appropriately altered in the mandible and the asymmetry had improved. The anterior crossbite was cot-
Root parallelism had been achieved with only slight blunting of the upper incisor roots (Fig. 9). There was a normal trabecular pattern with slight generalized interproximal bone loss.
Volume IOO Number 2
Cephalometric findings The overall superimposition on sella and anterior cranial base revealed a 4 m m to 5 m m retraction of the lower lip (Figs. 10 and 11). Maxillary superimposition revealed slight intrusion of the upper incisor with 4 mm of retraction and 5 mm of slippage of the posterior anchorage. The mandibular superimposition showed that the lower incisors were retracted 4 mm, and the molars came forward 4 mm. The molars did not extrude during orthodontic treatment. The upper and lower incisor protrusion was reduced during treatment. There was an improvement in the relationship of the upper incisors to NA from 35 ° and 11 m m to 24 ° and 7 mm (Table I). The relationship of the loffer incisors to NB improved from 33 ° and 11 m m to 27 ° and 7 mm with an improvement of the Holdaway ratio from 10: - 3 to 6 : - 2 . The IMPA also improved from 96 ° to 90 °, and the interincisal angle is close to ideal with a 16 ° change from 111 ° to 127 °.
C a s e report
opening of the extraction site. A maxillary anterior elastic retainer was placed and a fixed lower canine-to-canine retainer was bonded lingually. The patient wore the maxillary retainer on a full-time basis for 1 year. During the second year of retention, the retainer was worn on a nighttime basis. During the third and fourth years of retention, the retainer was worn 3 nights a week. The mandibular fixed retainer was worn for 5 years. A slight space between the upper right central and lateral incisors tended to develop when the maxillary retainer was not worn.
FINAL EVALUATION The anterior crossbite was successfully corrected, and the upper and lower incisor protrusion was reduced. There was an ideal overjet and overbite relationship, and the midlines were now coincident. Treatment objectives were obtained with substantial cooperation from the patient. Reprint requests to:
Secondary treatment Supracrestal fiberotomy was performed on the upper incisors 4 months before band removal, and excess gingival tissue at the extraction site was removed to help prevent re-
105
Dr. Steven Dugo'ni 1131 Mission Rd. South San Francisco, CA 94080
Volume 100 Number 2
August 1991
Copyright © 1991 by the American Association of Orthodontists
CASE REPORT
American Board of Orthodontics case report Steven A. Dugoni, DMD, MSD,* and Jetson S. Lee, DDS, MSD** South San Francisco, Calif.
A case of a Class I malocclusion with a bimaxillary protrusion and an anterior crossbite is presented. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.] (AM J ORTHOD DENTOFACORTHOP 1991 ;100:99-105.)
CASE REPORT Diagnostic summary The patient (Fig. l) had a Class I molar and canine relation with a Class III tendency on the right side (Figs. 2 and 3). The overjet and overbite were normal at the upper right central incisor to the lower right central incisor and lateral incisor; however, there was an anterior crossbite of the upper and lower left incisors and canines. The mandibular midline was 3 mm off to the left side, and the mandibular arch was asymmetric "in arch form. A bidental protrusion From the Department of Orthodontics. Universityof the Pacific. *Associate Clinical Professor. **Assistant Clinical Professor. 814124685
existed with approximately 5 mm of anterior crov~ding on the maxillary arch and approximately 3 mm of crowding in the mandibular arch. A small pontic was present in place of the missing upper right first premolar. The lower left second molar was also missing.
History and general clinical picture The patient was a 34-year-old Hispanic man in good health with no history of serious diseases or trauma. Clinical examination revealed normal color and texture of the tissues of the cheeks, the tongue, and the hard and soft palates. The patient had chronic generalized gingivitis and localized periodontitis at the upper right first and second molars. Oral hygiene was average. The patient had a high caries index with amalgam, gold, or porcelain restorations on most of the
Fig. 1. Pretreatment facial photographs. 99
100
Dugoni and Lee
Am. J. Orthod. Dentofiw. Orthop. Aug tst 1991
Fig. 2. Pretreatment intraoral photographs.
Fig. 3. Pretreatment study models.
Volume I00 Number 2
Case report
101
Fig. 4. Pretreatment intraoral radiographs.
posterior teeth. The upper left first and second molars were abutted together to prevent supraeruption of the upper left second molar. Facial form and esthetics The patient had a mesocephalic facial type with a balance of the upper and lower facial height, and a good harmony of the forehead, nose, and upper lip (Fig. I). The tooth to lip relationship was normal when smiling. Intraoral radiographic survey A normal bony trabecular pattern was found, with slight generalized interproximal bone loss evident (Fig. 4). The upper right first premolar and the lower left second molar were missing. Root canal fillings were present in the upper right first molar and upper left second premolar. Restorations were present on all maxillary posterior teeth and most of the mandibular posterior teeth. Cephalometric analysis An SNA angle of 87 °, an SNB angle of 85 °, and an NPoFIt angle of 92 ° suggested maxillary and mandibular protrusion (Fig. 5 and Table I). The vertical relationship of the upper to the lower face was within normal limits. The upper incisors to SN relationship of 35 ° and 11 mm indicated protrusion of the maxillary incisors. An IMPA angle of 96 ° and a lower incisor to NB relationship of 33 ° and I0 mm revealed lower incisor protrusion. The Holdaway ratio of I 0 : - 3 confirmed the mandibular anterior protrusion. Likewise, the acute interincisal angle of 111 ° indicated procumbent incisors.
Etiology Hereditary factors are the most likely cause of the malocclusion. However, the familial history was not available. The patient's daughter had a similar type of malocclusion. Plan of treatment Extraction of the lower first premolars, removal of the pontic at the upper right first premolar area, and extraction of the upper left second premolar was the extraction pattern chosen. Removal of the lower first premolars would relieve the lower anterior crowding and allow for the retraction of the protrusive lower incisors also necessary to correct the anterior crossbite. The removal of the pontic and the nonvital upper left second premolar would relieve the crowding in the upper arch and allow retraction of the protrusive incisors. Since the anterior crossbite occurred on the left, this extraction pattern works in our favor to minimize retraction of the upper incisors on the left while allow!ng the lower incisors to be retracted to a greater extent. The patient was also referred to a periodontist for a complete periodontal evaluation and was seen every 3 months for root planing and curettage. The treatment objectives were as follows: 1. Maintenance of a good profile balance. 2. Correction of the anterior crossbite. 3. Establishment of an ideal overjet and overbite relationship. 4. Reduction of the maxillary and mandibular dentoalveolar protrusion by movement of the maxillary right central and lateral incisors lingually and movement of the lower incisors lingually.
102
Dugoni attd Lee
Am. ]. Orthod. Dentofac. Orthop. August 1991
Table I. S u m m a r y o f c e p h a l o m e t r i c measurements
Measurement
Fig. 5. Pretreatment cephalometric tracing (stage A).
I Ref. nor,,,. [ 09183
SNA SNB ANB SN-MPA FMA NPo-FH IMPA LI-APo (mm) LI-NB (mm) LI-NB (degrees) U I-NA (mm) U I-NA (degrees) U1-L1 E plane (mm) Wits (ram) Holdaway ratio (mm)
80 78 2 32 25 87 90 0 4 25 4 22 131 -2 - 1 4:4
87 85 2 31 23 92 96 10 10 33 lI 35 111 0
10186 87 85 2 31 23 92 90 5 6 27 7 24 127 -7
-4
-4
10:3
6:2
Fig. 6. Posttreatment facial photographs.
5. Correction of the midline discrepancy. 6. Correction of the mandibular arch asymmetry. Progress of treatment The maxillary and mandibular first molars were banded with an 0.022 × 0.028-inch edgewise appliance and the incisors, canines, and premolars were bonded directly. Class III elastics were used for approximately 6 months during the initial leveling and aligning to minimize forward tipping of the lower incisors. Class II elastics were later used on the left side to facilitate midline correction and to maintain a Class I canine relation. After leveling with maxillary 0.0175inch and mandibular 0.0215-inch braided arch wires, maxillary 0.018-inch and mandibular 0.020-inch multiloop arch wires were placed. Maxillary and mandibular 0.019 ×
0.025-inch rectangular arch wires were placed for torque control during en masse retraction of the incisors and canines, after correction of the anterior crossbite. A midline elastic was used for-8 months. The upper and lower right second molars were banded after the extraction spaces were closed on the right side. The Class II elastics were worn on the left side for 6 months. During the 25 months of active treatment, there was one cancelled appointment and two missed appointments. The appointments were scheduled at 3 to 4 week intervals. RESULTS ACHIEVED Facial form and esthetics A good profile balance was maintained during treatment, with the lower lip showing slightly less protrusion (Fig. 6).
Volume 100 Number 2
Case report
Fig. 7. Posttreatment intraoral photographs.
Fig, 8. Posttreatment study models.
103
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Am. J. Orthod. Dentofac. Orthop. August 1991
Dugoni and Lee
Fig. 9. Posttreatment intraoral radiographs.
34.10--
^
7
)
..-
Fig. 10. Posttreatment cephalometric tracing (stage B).
Fig. 11. Superimpositions of tracings from pretreatment (34.1 O, solid line) to posttreatment (37.11, dashed lines).
The upper and lower facial height was balanced, and there was good facial symmetry. The patient had a pleasing smile with a good tooth-to-lip relationship. No decalcification was evident.
rected, and the dental midlines were aligned. Clinical observations showed no discrepancy between centric relation and centric occlusion. Canine rise existed in lateral excursions, and no balancing interferences were detectable.
Dental assessment
Intraoral radiographs
A normal overjet and overbite relationship existed, with the posterior occlusion well seated (Figs. 7 and 8). The arch form had been appropriately altered in the mandible and the asymmetry had improved. The anterior crossbite was cot-
Root parallelism had been achieved with only slight blunting of the upper incisor roots (Fig. 9). There was a normal trabecular pattern with slight generalized interproximal bone loss.
Volume IOO Number 2
Cephalometric findings The overall superimposition on sella and anterior cranial base revealed a 4 m m to 5 m m retraction of the lower lip (Figs. 10 and 11). Maxillary superimposition revealed slight intrusion of the upper incisor with 4 mm of retraction and 5 mm of slippage of the posterior anchorage. The mandibular superimposition showed that the lower incisors were retracted 4 mm, and the molars came forward 4 mm. The molars did not extrude during orthodontic treatment. The upper and lower incisor protrusion was reduced during treatment. There was an improvement in the relationship of the upper incisors to NA from 35 ° and 11 m m to 24 ° and 7 mm (Table I). The relationship of the loffer incisors to NB improved from 33 ° and 11 m m to 27 ° and 7 mm with an improvement of the Holdaway ratio from 10: - 3 to 6 : - 2 . The IMPA also improved from 96 ° to 90 °, and the interincisal angle is close to ideal with a 16 ° change from 111 ° to 127 °.
C a s e report
opening of the extraction site. A maxillary anterior elastic retainer was placed and a fixed lower canine-to-canine retainer was bonded lingually. The patient wore the maxillary retainer on a full-time basis for 1 year. During the second year of retention, the retainer was worn on a nighttime basis. During the third and fourth years of retention, the retainer was worn 3 nights a week. The mandibular fixed retainer was worn for 5 years. A slight space between the upper right central and lateral incisors tended to develop when the maxillary retainer was not worn.
FINAL EVALUATION The anterior crossbite was successfully corrected, and the upper and lower incisor protrusion was reduced. There was an ideal overjet and overbite relationship, and the midlines were now coincident. Treatment objectives were obtained with substantial cooperation from the patient. Reprint requests to:
Secondary treatment Supracrestal fiberotomy was performed on the upper incisors 4 months before band removal, and excess gingival tissue at the extraction site was removed to help prevent re-
105
Dr. Steven Dugo'ni 1131 Mission Rd. South San Francisco, CA 94080
