CASE REPORT
A n American Board of Orthodontics case report R. Thomas Rocke, DDS, MS Westville, Ind. A case report of a Class II, Division 1 malocclusion with a deep overbite and severe overjet. The case was treated with the extraction of four first premolars and differential force mechanics. No adjuncts such as functional appliances, headgear, or surgery, were used. [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 ORTHO[~ DENTOFAC ORTHOP 1991 ;100:84-90.)
CASE REPORT Diagnosis The patient was a 10V2-year-old girl with a severe Class H, Division 1 malocclusion (Fig. 1). There was an overjet of 10 mm, with the lower incisors occluding into the palate. The four second deciduous molars were present, and the upper canines were unerupted and crowded labially. The lower arch had an arch length--tooth mass discrepancy of - 4 mm (Fig. 2). Skeletally, the patient had a high mandibular plane angle (FMA 37 °) with a large apical base discrepancy (ANB angle + 7.5°), and the Wits analysis showed a + 4 mm. The patient's lips were quite protrusive because of the malocclusion, and the perioral musculature showed strain on lip closure. Poor or insufficient mandibular growth was evidenced by an SNB angle of 72 ° (Fig. 3).
History and clinical picture The patient was healthy and of normal height and weight for her age. Her medical history was not significant except 8/4t14491
that she was allergic to penicillin. Her tonsils and adenoids were present, and she had been bottle-fed in infancy. There was no history of TMJ dysfunction, and both temporomandibular joints appeared normal. No history of thumb-sucking or tongue-thrusting habits was mentioned by the patient or the parents. Oral hygiene was excellent, with no periodontal involvement. However, the teeth were mottled and had a brownish cast. It was thought that tetracycline staining might have been the cause. Caries was not a problem; only a few small restorations were present.
Etiology The cause of the malocclusion appeared to be genetic. The patient had a poor mandibular growth pattern (more downward than forward) as evidenced by an NS-Gn angle of 71.5 °, and a steep mandibular plane angle (NS-MPA of 43°).
Treatment plan The treatment plan called for the creation of a Class I occlusion with reduction of the overbite and overjet, elimi-
Fig. 1. Pretreatment facial views, The patient was a 101A-year-old girl with a Class II, Division 1 malocclusion,
84
Volume tO0 Number 1
Case report
Figs. 2. A, Pretreatment study models. Note crowding and midltne discrepancy.
Fig. 2. B, Panoramic radiograph.
Fig. 3. Cephalometric tracing showing poor facial characteristics and skeletal discrepancy.
85
86
Rocke
Am. d. Orthod. Demofiw. Orthop. July 1991
iili
;" /,r ',e
, ':" :,.
-/,
Fig. 4. Posttreatment study models.
Fig. 5. Posttreatment facial views.
nation of the anterior crowding, and placement of the anterior teeth over the basal bone. These dental changes should also reduce the patient's lip protrusion and should obtain pleasing dental and facial features. To accomplish these objectives, the four first premolar teeth were extracted. Care would be taken to prevent both extrusion of the upper anterior teeth during retraction and downward and backward rotation of the mandible as the bite opened. This was a particular concern because of the patient's high mandibular plane angle. For optimum facial esthetics, emphasis was placed on positioning the incisal edge of the lower incisor I mm forward of the APo line and establishment of good upper incisor torque (I_ - SN 103°).
Begg appliances were chosen to allow use of differential force mechanics. Treatment would proceed without the need for headgear or bite planes, Depression would be delivered to the upper anterior teeth by means of high-tensile Australian 0.016-inch arch wires, with strong bite opening bends mesial to the maxillary first molars. Very light Class II elastics (1 to 2 ounces) would be used to prevent extrusion of the upper anterior teeth during retraction. The three stages of Begg mechanics would be followed. After treatment, a tooth positioner would be placed to bc followed by retainers, if necessary, to finish and retain the correction. Prognosis for the patient's treatment results was fair to
Volume 100
Number
Case report
1
i"
Fig. 6. Superimposed cephalometric tracings illustrate dental and facial changes after completion of active treatment,
I
1
Fig. 7. A, Study models 4 years after treatment.
Fig. 7. B, Panoramic radiograph 4 years after treatment, The occlusion has remained stable.
87
88
Rocke
Am. J. Orthod. Dentofac. Orthop. duly 1991
Fig. 8. Facial views of patient 4 years after active treatment at age 17. Facial appearance has continued to improve.
17 yrs,
3 mos.
Fig. 9. Superimposed cephalometric tracing showing changes, mainly due to growth, from end of treatment to postretention.
good, depending on the amount and direction of growth, appliance manipulation, and patient cooperation.
necessary for mesiodistal root uprighting. Stage IIl lasted 1t months, making the total treatment time 25 months.
Progress of treatment
Results achieved
The first stage of treatment progressed well, with correction of the overbite and overjet to an edge-to-edge incisal relationship within 4 months. At that time, stage I1 mechanics were started, with the patient wearing light 2-ounce intramaxillary space-closing elastics full time and Class lI elastics only if the overhite and overjct recurred. Stage II lasted 8 months. After a 2-month pre-stage III adjustment to engage and level the second premolars, the patient entered stage Ill with 0.020-inch base arch wires. An auxiliary applied torque to the upper central incisors and spring pins were used where
Through a combination of maxillary anterior retraction and mandibular growth, the overbite and overjet were reduced to normal values. All crowding was eliminated, the upper incisors were well torqued, and the lower incisors were positioned upright over the basal bone. Good root parallelism was obtained, and the extraction spaces were tightly closed (Fig. 4). Efficiency of anchorage preservation with the Begg technique was well illustrated by the significant reduction in lip protrusion, despke the tact that no headgear was used. A1-
Volume 100
Case report
89
Number 1
t
......
17
yrS.
3 mos,
Fig. 10. Superimposed cephalometric tracings show overall treatment changes from age 10 to 17.
Fig. 11. Facial and intraoral views taken 4 years after treatment,
though the patient's profile appeared somewhat flat at the time the finish records were taken (Fig. 5), with continued growth and maturation, the facial features became quite pleasing (Fig. 8). Cephalometric analysis shows the T-APo was a near optimal + 0 . 5 mm. The ANB angle was reduced from 7.5 ° to 5 ° during treatment and subsequently to 3.5 ° after treatment. A similar reduction in the Wits values from + 4 mm to +2.5
mm to + 1 mm also occurred. The high mandibular plane angle decreased during treatment from 37 ° to 36° , with no opening of the Y axis (Table I). Superimposition showed the patient experienced good downward and forward growth, The upper incisors were retracted without extrusion, Without treatment, eruption of the upper incisors would be expected because of normal alveolar growth and tooth eruption. The lower incisors were depressed
90
Rocke
Am, J.
Table I. S u m m a r y c e p h a l o m e t r i c m e a s u r e m e n t s
SNA SNB AN]3 SN-MPA NPo-FH IMPA FMA T-APo (ram) I-NA 1-NA (mm) T-NB T-NB (ram) Intercisal angle NS-GN _I-NS Wits (ram)
82 80 2 31 87 --,+3 90 25 1~ 2 22 4 25 4 135 67 103 0 -+ 2
79.5 72.0 7.5 43 78.5 88.5 37 0.5 23.5 5.0 23.0 5,5 125.5 71.5 103.5 4.0
78.5 73.5 5.0 42 80.0 95,5 36 0.5 20 0 30.0 4.5 125.0 71.5 98.5 2.5
78.0 74.5 3.5 39.5 81.0 92,5 33.5 1.0 23.5 2.5 26.5 4.5 127.0 70,0 101.5 1.0
All measurements are in degrees, unless otherwise indicated.
while the molars were slightly elevated as the result of treatment and growth (Fig, 6).
only and is now wearing it only occasionally. No retainers were used.
Final evaluation The patient's occlusion remained stable (Fig. 7), and her facial appearance continued to improve between the time final records and postfinish records were taken 4 years later at the age of 17 years (Fig. 8). Superimposition of the maxilla and mandible showed negligible dental changes, while continued downward and forward growth was observed (Fig. 9). Overall changes from the start of treatment at the age of 10 years 9 months to the age of 17 3'ears 3 months are seen in Fig. 10. It is significant that this high-angle Class II case was successfully treated without the use of headgear to control the vertical dimension, retract anterior teeth, or supplement anchorage. No unfavorable downward and backward rotation of the mandible or extrusion of the upper incisors occurred. The extremely light (ll/z ounce) Class II elastics corrected the anteroposterior discrepancy without overpowering the instrusive force delivered to the upper incisors by the arch wire. The result achieved was made possible by light balanced forces and excellent patient cooperation. The patient has a pleasing smile, marred only by her tetracycline-stained teeth, which she plans to have corrected with porcelain veneers (Fig. 10),
Retention The patient wore a tooth positioner to finish the treatment and retain the correction. Initially, the positioner was worn 3 hours a day and all night, The positioner-wearing time was gradually reduced to nights only over the next 4 months, For the next 2 years, the patient wore the tooth positioner at night
Orthod. Dentofac. Orthop. July 1991
Reprint requests to: Dr. R. Thomas Roeke Orthodontic Center Westville, IN 46391
AAO MEETING CALENDAR
1992--St. Louis, Mo., May 9 to 13, St. Louis Convention Center 1993--Toronto, Canada, May 16 to 19, Metropolitan Toronto Convention Center 1994--Orlando, Fla., May 1 to 4, Orange County Convention and Civic Center 1995--San Francisco, Calif,, May 7 to 10, Moscone Convention Center 1996--Denver, Colo., May 12-15, Colorado Convention Center
A n American Board of Orthodontics case report R. Thomas Rocke, DDS, MS Westville, Ind. A case report of a Class II, Division 1 malocclusion with a deep overbite and severe overjet. The case was treated with the extraction of four first premolars and differential force mechanics. No adjuncts such as functional appliances, headgear, or surgery, were used. [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 ORTHO[~ DENTOFAC ORTHOP 1991 ;100:84-90.)
CASE REPORT Diagnosis The patient was a 10V2-year-old girl with a severe Class H, Division 1 malocclusion (Fig. 1). There was an overjet of 10 mm, with the lower incisors occluding into the palate. The four second deciduous molars were present, and the upper canines were unerupted and crowded labially. The lower arch had an arch length--tooth mass discrepancy of - 4 mm (Fig. 2). Skeletally, the patient had a high mandibular plane angle (FMA 37 °) with a large apical base discrepancy (ANB angle + 7.5°), and the Wits analysis showed a + 4 mm. The patient's lips were quite protrusive because of the malocclusion, and the perioral musculature showed strain on lip closure. Poor or insufficient mandibular growth was evidenced by an SNB angle of 72 ° (Fig. 3).
History and clinical picture The patient was healthy and of normal height and weight for her age. Her medical history was not significant except 8/4t14491
that she was allergic to penicillin. Her tonsils and adenoids were present, and she had been bottle-fed in infancy. There was no history of TMJ dysfunction, and both temporomandibular joints appeared normal. No history of thumb-sucking or tongue-thrusting habits was mentioned by the patient or the parents. Oral hygiene was excellent, with no periodontal involvement. However, the teeth were mottled and had a brownish cast. It was thought that tetracycline staining might have been the cause. Caries was not a problem; only a few small restorations were present.
Etiology The cause of the malocclusion appeared to be genetic. The patient had a poor mandibular growth pattern (more downward than forward) as evidenced by an NS-Gn angle of 71.5 °, and a steep mandibular plane angle (NS-MPA of 43°).
Treatment plan The treatment plan called for the creation of a Class I occlusion with reduction of the overbite and overjet, elimi-
Fig. 1. Pretreatment facial views, The patient was a 101A-year-old girl with a Class II, Division 1 malocclusion,
84
Volume tO0 Number 1
Case report
Figs. 2. A, Pretreatment study models. Note crowding and midltne discrepancy.
Fig. 2. B, Panoramic radiograph.
Fig. 3. Cephalometric tracing showing poor facial characteristics and skeletal discrepancy.
85
86
Rocke
Am. d. Orthod. Demofiw. Orthop. July 1991
iili
;" /,r ',e
, ':" :,.
-/,
Fig. 4. Posttreatment study models.
Fig. 5. Posttreatment facial views.
nation of the anterior crowding, and placement of the anterior teeth over the basal bone. These dental changes should also reduce the patient's lip protrusion and should obtain pleasing dental and facial features. To accomplish these objectives, the four first premolar teeth were extracted. Care would be taken to prevent both extrusion of the upper anterior teeth during retraction and downward and backward rotation of the mandible as the bite opened. This was a particular concern because of the patient's high mandibular plane angle. For optimum facial esthetics, emphasis was placed on positioning the incisal edge of the lower incisor I mm forward of the APo line and establishment of good upper incisor torque (I_ - SN 103°).
Begg appliances were chosen to allow use of differential force mechanics. Treatment would proceed without the need for headgear or bite planes, Depression would be delivered to the upper anterior teeth by means of high-tensile Australian 0.016-inch arch wires, with strong bite opening bends mesial to the maxillary first molars. Very light Class II elastics (1 to 2 ounces) would be used to prevent extrusion of the upper anterior teeth during retraction. The three stages of Begg mechanics would be followed. After treatment, a tooth positioner would be placed to bc followed by retainers, if necessary, to finish and retain the correction. Prognosis for the patient's treatment results was fair to
Volume 100
Number
Case report
1
i"
Fig. 6. Superimposed cephalometric tracings illustrate dental and facial changes after completion of active treatment,
I
1
Fig. 7. A, Study models 4 years after treatment.
Fig. 7. B, Panoramic radiograph 4 years after treatment, The occlusion has remained stable.
87
88
Rocke
Am. J. Orthod. Dentofac. Orthop. duly 1991
Fig. 8. Facial views of patient 4 years after active treatment at age 17. Facial appearance has continued to improve.
17 yrs,
3 mos.
Fig. 9. Superimposed cephalometric tracing showing changes, mainly due to growth, from end of treatment to postretention.
good, depending on the amount and direction of growth, appliance manipulation, and patient cooperation.
necessary for mesiodistal root uprighting. Stage IIl lasted 1t months, making the total treatment time 25 months.
Progress of treatment
Results achieved
The first stage of treatment progressed well, with correction of the overbite and overjet to an edge-to-edge incisal relationship within 4 months. At that time, stage I1 mechanics were started, with the patient wearing light 2-ounce intramaxillary space-closing elastics full time and Class lI elastics only if the overhite and overjct recurred. Stage II lasted 8 months. After a 2-month pre-stage III adjustment to engage and level the second premolars, the patient entered stage Ill with 0.020-inch base arch wires. An auxiliary applied torque to the upper central incisors and spring pins were used where
Through a combination of maxillary anterior retraction and mandibular growth, the overbite and overjet were reduced to normal values. All crowding was eliminated, the upper incisors were well torqued, and the lower incisors were positioned upright over the basal bone. Good root parallelism was obtained, and the extraction spaces were tightly closed (Fig. 4). Efficiency of anchorage preservation with the Begg technique was well illustrated by the significant reduction in lip protrusion, despke the tact that no headgear was used. A1-
Volume 100
Case report
89
Number 1
t
......
17
yrS.
3 mos,
Fig. 10. Superimposed cephalometric tracings show overall treatment changes from age 10 to 17.
Fig. 11. Facial and intraoral views taken 4 years after treatment,
though the patient's profile appeared somewhat flat at the time the finish records were taken (Fig. 5), with continued growth and maturation, the facial features became quite pleasing (Fig. 8). Cephalometric analysis shows the T-APo was a near optimal + 0 . 5 mm. The ANB angle was reduced from 7.5 ° to 5 ° during treatment and subsequently to 3.5 ° after treatment. A similar reduction in the Wits values from + 4 mm to +2.5
mm to + 1 mm also occurred. The high mandibular plane angle decreased during treatment from 37 ° to 36° , with no opening of the Y axis (Table I). Superimposition showed the patient experienced good downward and forward growth, The upper incisors were retracted without extrusion, Without treatment, eruption of the upper incisors would be expected because of normal alveolar growth and tooth eruption. The lower incisors were depressed
90
Rocke
Am, J.
Table I. S u m m a r y c e p h a l o m e t r i c m e a s u r e m e n t s
SNA SNB AN]3 SN-MPA NPo-FH IMPA FMA T-APo (ram) I-NA 1-NA (mm) T-NB T-NB (ram) Intercisal angle NS-GN _I-NS Wits (ram)
82 80 2 31 87 --,+3 90 25 1~ 2 22 4 25 4 135 67 103 0 -+ 2
79.5 72.0 7.5 43 78.5 88.5 37 0.5 23.5 5.0 23.0 5,5 125.5 71.5 103.5 4.0
78.5 73.5 5.0 42 80.0 95,5 36 0.5 20 0 30.0 4.5 125.0 71.5 98.5 2.5
78.0 74.5 3.5 39.5 81.0 92,5 33.5 1.0 23.5 2.5 26.5 4.5 127.0 70,0 101.5 1.0
All measurements are in degrees, unless otherwise indicated.
while the molars were slightly elevated as the result of treatment and growth (Fig, 6).
only and is now wearing it only occasionally. No retainers were used.
Final evaluation The patient's occlusion remained stable (Fig. 7), and her facial appearance continued to improve between the time final records and postfinish records were taken 4 years later at the age of 17 years (Fig. 8). Superimposition of the maxilla and mandible showed negligible dental changes, while continued downward and forward growth was observed (Fig. 9). Overall changes from the start of treatment at the age of 10 years 9 months to the age of 17 3'ears 3 months are seen in Fig. 10. It is significant that this high-angle Class II case was successfully treated without the use of headgear to control the vertical dimension, retract anterior teeth, or supplement anchorage. No unfavorable downward and backward rotation of the mandible or extrusion of the upper incisors occurred. The extremely light (ll/z ounce) Class II elastics corrected the anteroposterior discrepancy without overpowering the instrusive force delivered to the upper incisors by the arch wire. The result achieved was made possible by light balanced forces and excellent patient cooperation. The patient has a pleasing smile, marred only by her tetracycline-stained teeth, which she plans to have corrected with porcelain veneers (Fig. 10),
Retention The patient wore a tooth positioner to finish the treatment and retain the correction. Initially, the positioner was worn 3 hours a day and all night, The positioner-wearing time was gradually reduced to nights only over the next 4 months, For the next 2 years, the patient wore the tooth positioner at night
Orthod. Dentofac. Orthop. July 1991
Reprint requests to: Dr. R. Thomas Roeke Orthodontic Center Westville, IN 46391
AAO MEETING CALENDAR
1992--St. Louis, Mo., May 9 to 13, St. Louis Convention Center 1993--Toronto, Canada, May 16 to 19, Metropolitan Toronto Convention Center 1994--Orlando, Fla., May 1 to 4, Orange County Convention and Civic Center 1995--San Francisco, Calif,, May 7 to 10, Moscone Convention Center 1996--Denver, Colo., May 12-15, Colorado Convention Center
