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An American Board of Orthodontics case report: An adult nonsurgical patient whose treatment required combined dental disciplines
AMERICAN BOARD OF ORTHODONTICS CASE REPORT
An American Board of Orthodontics case report: An adult nonsurgical patient whose treatment required combined dental disciplines Steven C. Emrich, DDS, MS Columbus, Ohio This is a case report of a 27-year-old, white woman who had a Class II, Division 2 malocclusion with 100% overbite and mild skeletal mandibular retrognathia. Missing teeth were the maxillary right canine, second premolar, and second molar; the maxillary left canine and second molar; the mandibular left first premolar and second molar; the mandibular right first premolar and second molar. The maxillary first premolars were used as canines and the molars were in an Angle Class I relationship at the end of 31 months of treatment. Bonded lingual retainers were placed: a maxillary lateral incisor-to-lateral incisor, a mandibular canine-to-canine, and a maxillary Hawley retainer. Later, a fixed restoration to replace the maxillary right second premolar was completed. Included are 3-year posttreatment records. (Am J Orthod Dentofac Orthop 1996;110:163-9.)
HISTORY AND ETIOLOGY A 27-year-old, 10-month, white woman presented for orthodontic treatment. Her chief concern was that she did not like her overbite, crossbite, and missing teeth. Pertinent medical history included the removal of tonsils and adenoids at 6 years of age and an allergy to penicillin. Dental history included the extraction of palatally impacted maxillary caReprint requests to: Dr. Steven C. Emrich, 1855 E. Dublin Granville Rd., Columbus, OH 43229. Copyright © 1996 by the American Association of Orthodontists. 0889-5406/96/$5.00 + 0 8/4/72964
nines, the maxillary right second premolar, mandibular first premolars, and all second molars. She had orthodontic treatment in high school that relapsed. Habits included a history of mouth breathing and clenching.
DIAGNOSIS The concave profile was due, in part, to missing teeth and a brachycephalic skeletal pattern. Lower face height was short, and there was a fairly deep mentolabial sulcus with hypertonic lip musculature. A full smile revealed approximately 2 to 3 mm of gingiva and an asymmetrical smile (Fig. 1).
Fig. 1. Pretreatmentfacial and intraoral photographs (age 27 years, 11 months). Lateral view shows mildly retrognathic profile and mildly deep mentolabial sulcus. Frontal smiling view shows asymmetrical smile line with more gingivai display on right. Intraoral photographs show Class II, Division 2 malocclusion with 100% overbite.
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American Journal of Orthodontics and Dentofacial Orthopedics August 1996
Fig. 4. Pretreatment panoramic radiograph (age 27 years, 4 months) shows many tipped and missing teeth. Fig. 2. Pretreatment lateral cephalometric radiograph and tracing (age 27 years, 11 months) show flat mandibular plane, skeletal deep bite, and brachycephalic pattern.
skeletal deep bite as evidenced by a flat mandibular plan angle and a short lower face height. Dentally, the patient had a Class II, Division 2 malocclusion with 100% overbite. There was approximately 3 mm of maxillary anterior crowding and 3 mm of mandibular anterior crowding. The patient had mildly constricted dental arches with a crossbite of the maxillary and mandibular third molars and a deep curve of Spee. The maxillary midline was off to the right about 2 mm. The mandibular midline was off to the right about 1 mm. Therefore the dental midlines were 1 mm off in occlusion. The following teeth were missing: the maxillary right canine, second premolar, and second molar; the maxillary left canine and second molar; the mandibular left first premolar and second molar; the mandibular right first premolar and second molar (Fig. 3). On evaluation, the temporomandibular joint (TMJ) appeared normal but the patient had a history of periodic closed locking of the mandible with no pain. The panoramic radiograph showed mild anterior superior flattening of the condyles and many divergent roots at extraction sites (Fig. 4). SPECIFIC OBJECTIVES OF TREATMENT (SKELETAL AND DENTAL) No major facial esthetic changes were expected except for a more pleasing dental alignment when smiling. Skeletal change with mild mandibular advancement and "unlocking" of the anterior deep bite was possible but no major changes were anticipated because the patient was nongrowing. Dental Objectives
Fig. 3, Pretreatment study casts in habitual occlusion. Occlusal views show mildly constricted dental arches.
The mild mandibular retrognathia was confirmed by a 6 ° ANB angle and a 72 ° SNB angle (Table I and Fig. 2). A-point might have been more forward than normal because of very upright central incisors. The patient also had a
l. Maxillary molars: Maximum anteroposterior anchorage, mild expansion with a transpalatal appliance, maintain vertical. 2. Maxillary incisors: Moderate intrusion, lingual root torque of the central incisors. 3. Mandibular molars: Moderate anteroposterior anchorage, mild exmasion expected with leveling. 4. Mandibular incisors: Moderate intrusion with leveling of the curve of Spee. 5. Finish the occlusion with a Class I molar relationship.
American Journal of Orthodontics and Dentofacial Orthopedics Volume 110, No. 2
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Fig. 5. Posttreatment facial and intraoral photographs (age 30 years, 10 months). Note improved gingival display on frontal smiling photograph and asymmetrical smile line. Mildly improved profile view with increased lower face height. Hawley retainer was inadvertently left in place for photographs. Intraoral frontal photograph shows persistent midline discrepancy. Maxillary and mandibular bonded lingual O.0215-inch Wildcat wires can be seen in occlusal views.
6. Position the maxillary first premolars in the canine position, right and left. 7. Open the deep bite by intrusion of maxillary and mandibular incisors. 8. Smooth anterior guidance by correcting the torque of the incisors. 9. Correct crossbites of third molars. 10. Prepare for restoration of the maxillary right second premolar.
TREATMENT PROGRESS A straight wire appliance with brackets that have a 0.022 x 0.028-inch slot was used. Maxillary appliances were placed on all teeth, including the third molars with full arch wire (0.0155 inch Respond, Ormco Corp., Glendora, Calif. ) engagement to begin anterior bite opening. A transpalatal appliance was inserted into the lingual sheaths of the maxillary first molars and activated for mild expansion and rotation. The transpalatal appliance was positioned approximately 2 mm off the palate to help maintain the vertical. Mandibular first and third molars were banded, and light sectional arch wires were placed to begin mandibular arch leveling. Severe anterior bracket interference was avoided. The rest of the mandibular appliances were placed with mild
Fig. 6. Posttreatment lateral cephalometric radiograph and tracing (age 30 years, 10 months). anterior bracket interference 4 months later. This "bite plane effect" unlocked the occlusion and improved the effectiveness of the Class II mechanics. Elastics were worn from the maxillary first premolars to the mandibular first molars, but not to the mandibular third molars, to help prevent lower molar extrusion. Eventually, 0.018x0.025-inch stainless steel arch wires with significant bite opening curves to finish
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American Journal of Orthodontics and Dentofacial Orthopedics August 1996
Fig. 8. Postretention panoramic radiograph (age 33 years, 10 months) shows paralleled roots, bonded lingual retainers, and completed fixed restoration in maxillary right posterior quadrant.
Fig. 7. Posttreatment study casts show good Class I molar relationship and normalized overbite and overjet. Occlusal views show improved maxillary and mandibular arch forms.
the anterior bite opening and to improve the interincisal relationship were placed. Class II elastics were continued as described previously with slightly heavier elastics on the left side to help correct the midline discrepancy. The patient's cooperation was optimal, and the appliances were removed 31 months after the start of treatment; estimated treatment time was 32 months. RESULTS ACHIEVED Facial changes observed (Fig. 5) were mild lip fullness in profile and mild arch width increase of the maxillary anterior teeth on smiling. The patient showed an ideal amount of tooth structure in the frontal full smile and, because of an asymmetrical smile line, a mild amount of gingiva on the right side only. Because of molar extrusion, there was a mild lower face height increase (Fig. 6). With leveling of the occlusion and Class II mechanics, the molar extrusion caused a mild mandibular retrusion with a bite opening rotation of the mandible. The brachyfacial pattern, the transpalatal arch, and the short Class II elastics all
helped to keep the vertical molar eruption to a minimum. The mandible did not come forward with the "unlocking" of the anterior deep bite. The maxillary molars were maintained in their anteroposterior and vertical positions during anterior torque and bite opening. There was a 3.5 mm width increase. There was favorable lingual root torque with mild intrusion of the maxillary incisors. The mandibular molars moved mesially with mild extrusion and 3.5 mm width increase to a Class I position. The mandibular third molars were uprighted and moved out of crossbite. The mandibular incisors were intruded significantly and there was labial crown torque. All treatment goals were satisfied (Fig. 7). The postretention panoramic radiograph showed all spaces closed with parallel roots except for the space created by the premature extraction of the maxillary right second premolar. The bone level and the periodontal condition remained good (Fig. 8). RETENTION Because of the severity of the malocclusion, bonded, lingual maxillary lateral-to-lateral and mandibular canine-to-canine retainers were placed with a light-cured resin. The 0.0215-inch twist "Wildcat" wires (GAC International Inc., Central Islip, N.Y.) were formed to casts made from impressions taken a week before removal of the appliance. The patient was advised to wear the bonded lingual wires indefinitely. She was shown how to maintain good oral hygiene with floss threaders and correct angulation of the toothbrush. To maintain the maxillary posterior arch width and the pontic space for the missing maxillary right second
Emrich
American Journal of Orthodontics and Dentofacial Orthopedics Voh~me 110, No. 2
Fig. 9. Postretention facial and intraoral photographs (age 33 years, 10 months). Completed fixed restorations can be seen.
Table I. C e p h a l o m e t r i c s u m m a r y
I Analysis Jarabak
Pretreatment
Norm
Saddle angle (°) Artieulare angle (°) Gonion angle (°) GO-GN-SN (°) Anterior cranial base (ram) Posterior cranial base (ram) Upper gonion angle (°) Lower gonion angle (°) Ramus height (ram) Ratio PCBL/RH (%) Mandibular body length (mrn) SNA (°) SNB (°) ANB (°) Posterior face height (ram) Anterior face height (nun) Posterior FH/Anterior FH (%) Interincisor angle (o) Convexity (ram) ANS-menton (ram) Nasion-menton (rrun) ANS-Menton/Nasion-Menton (%)
137.0 138.1 116.0 31.2 75.0 33.4 50.5 65.5 48.4 69,0 77.7 78.0 71.9 6.1 76.5 117.1 65.3 175.6 4.6 62.3 117.l 53.2
123.0 143.0 130.0 32.0 70.3 32.0 53.5 72.5 44.0 80.0 72.4 82.0 80.0 2.0 83.1 130.6 62.0 130.0 0.9 62.1 112.4 55.0
Clinical development 2,8** -0,8 -2,0* -0.2 1.6" 0.5 -I.0 -2.3** 0.9 -1.1" 1.1" -1.3" -2.7** 2.0** -1.3" -2.l** 0.8 7.6*** 1.9" 0.0 0.8 -0.6
Posttreatment 138.3 138.5 116.1 33.0 74.9 32.7 49.8 66.4 47.9 68.2 77.3 76.0 71.1 4.9 75.6 118.3 63.9 133.1 3.8 63.8 118.3 53.9
Postretention 138.2 138.0 118.1 34.3 74.7 33.0 50.9 67,2 45,9 72,0 77.7 75.5 71.0 4.5 73.8 118.3 62.4 130.7 3.1 63.9 118.3 54.0
167
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t
Fig. 10. Superimposition of pretreatment (solid line) and posttreatment (dashed line) tracings. Note mild bite opening mandibular rotation and change in incisor position and torque.
Fig, 11. Postretention lateral cephalometric radiograph and tracing (age 33 years, 10 months) show stable result.
premolar, a Hawley retainer was fabricated. The tient wore this retainer full-time for 2 years until bridgework was completed. After the restoration, maxillary retainer was adjusted to fit around bridgework and was to be worn only at night.
pathe the the
FINAL EVALUATION
Because of the patient's excellent cooperation, a significant improvement in the dental relationship was achieved, even though the final occlusion was unconventional. The health of the TMJ may have been improved by normalizing the anterior guidance and by unlocking the severe deep bite. The patient has had no TMJ dysfunction since the posttreatment records.
Favorable facial changes were seen on profile view (Fig. 9). Mild lip fullness and a slightly increased lower face height were evident. On frontal view, favorable changes were seen with increased width of the anterior teeth on full smile, which can be seen in the postretention photographs. A problem with the patient's treatment was the correction of the Class II dental relationship and the opening of the severe anterior deep bite in an adult patient with some mandibular retrognathia. The anterior bite opening needed to be achieved from incisor intrusion rather than molar extrusion. Molar extrusion would make the Class II relationship more difficult to correct as the mandible rotated down and back. The superimpositions of the pretreatment cephalometric tracing and the posttreatment tracing show some mandibular rotation with molar extrusion. Most of the bite opening, however, was due to incisor intrusion (Fig. 10).
A concern during retention was relapse of the anterior deep bite correction because it had occurred before. The "permanent" lingual retainers, the maxillary Hawley retainer, the bridgework, and a more stable position of the dentition all helped maintain the bite opening. The postretention cephalometric radiograph and tracing and the superimpositions show the stability (Figs. 11 and 12). The bridgework from the maxillary right first premolar to the maxillary right first molar has fairly good esthetics and anterior guidance but poor occlusal anatomy (Figs. 9 and 13). Taking into account the
Emrich
American Journal of Orthodontics and Dentofacial Orthopedics Volume 110, No. 2
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Fig. 12. Superimposition and pretreatment (solid line) and postretention (dotted line) tracings.
Fig. 13. Postretention mounted study casts on Panadent articular (Panadent Corp., Grand Terrance, Calif.) show favorable anterior guidance and almost no CR-CO discrepancy.
crown preparation necessary and the lingual pulpal horn of the maxillary right first premolar, this tooth could have been made to look more like a canine. Mounted, 3-year postretention casts indicate the
occlusion remained stable and that there was less then 0.3 mm CR-CO discrepancy in a horizontal and vertical direction of both condyles (Fig. 13). The mounted casts also confirm good anterior guidance.
An American Board of Orthodontics case report: An adult nonsurgical patient whose treatment required combined dental disciplines Steven C. Emrich, DDS, MS Columbus, Ohio This is a case report of a 27-year-old, white woman who had a Class II, Division 2 malocclusion with 100% overbite and mild skeletal mandibular retrognathia. Missing teeth were the maxillary right canine, second premolar, and second molar; the maxillary left canine and second molar; the mandibular left first premolar and second molar; the mandibular right first premolar and second molar. The maxillary first premolars were used as canines and the molars were in an Angle Class I relationship at the end of 31 months of treatment. Bonded lingual retainers were placed: a maxillary lateral incisor-to-lateral incisor, a mandibular canine-to-canine, and a maxillary Hawley retainer. Later, a fixed restoration to replace the maxillary right second premolar was completed. Included are 3-year posttreatment records. (Am J Orthod Dentofac Orthop 1996;110:163-9.)
HISTORY AND ETIOLOGY A 27-year-old, 10-month, white woman presented for orthodontic treatment. Her chief concern was that she did not like her overbite, crossbite, and missing teeth. Pertinent medical history included the removal of tonsils and adenoids at 6 years of age and an allergy to penicillin. Dental history included the extraction of palatally impacted maxillary caReprint requests to: Dr. Steven C. Emrich, 1855 E. Dublin Granville Rd., Columbus, OH 43229. Copyright © 1996 by the American Association of Orthodontists. 0889-5406/96/$5.00 + 0 8/4/72964
nines, the maxillary right second premolar, mandibular first premolars, and all second molars. She had orthodontic treatment in high school that relapsed. Habits included a history of mouth breathing and clenching.
DIAGNOSIS The concave profile was due, in part, to missing teeth and a brachycephalic skeletal pattern. Lower face height was short, and there was a fairly deep mentolabial sulcus with hypertonic lip musculature. A full smile revealed approximately 2 to 3 mm of gingiva and an asymmetrical smile (Fig. 1).
Fig. 1. Pretreatmentfacial and intraoral photographs (age 27 years, 11 months). Lateral view shows mildly retrognathic profile and mildly deep mentolabial sulcus. Frontal smiling view shows asymmetrical smile line with more gingivai display on right. Intraoral photographs show Class II, Division 2 malocclusion with 100% overbite.
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American Journal of Orthodontics and Dentofacial Orthopedics August 1996
Fig. 4. Pretreatment panoramic radiograph (age 27 years, 4 months) shows many tipped and missing teeth. Fig. 2. Pretreatment lateral cephalometric radiograph and tracing (age 27 years, 11 months) show flat mandibular plane, skeletal deep bite, and brachycephalic pattern.
skeletal deep bite as evidenced by a flat mandibular plan angle and a short lower face height. Dentally, the patient had a Class II, Division 2 malocclusion with 100% overbite. There was approximately 3 mm of maxillary anterior crowding and 3 mm of mandibular anterior crowding. The patient had mildly constricted dental arches with a crossbite of the maxillary and mandibular third molars and a deep curve of Spee. The maxillary midline was off to the right about 2 mm. The mandibular midline was off to the right about 1 mm. Therefore the dental midlines were 1 mm off in occlusion. The following teeth were missing: the maxillary right canine, second premolar, and second molar; the maxillary left canine and second molar; the mandibular left first premolar and second molar; the mandibular right first premolar and second molar (Fig. 3). On evaluation, the temporomandibular joint (TMJ) appeared normal but the patient had a history of periodic closed locking of the mandible with no pain. The panoramic radiograph showed mild anterior superior flattening of the condyles and many divergent roots at extraction sites (Fig. 4). SPECIFIC OBJECTIVES OF TREATMENT (SKELETAL AND DENTAL) No major facial esthetic changes were expected except for a more pleasing dental alignment when smiling. Skeletal change with mild mandibular advancement and "unlocking" of the anterior deep bite was possible but no major changes were anticipated because the patient was nongrowing. Dental Objectives
Fig. 3, Pretreatment study casts in habitual occlusion. Occlusal views show mildly constricted dental arches.
The mild mandibular retrognathia was confirmed by a 6 ° ANB angle and a 72 ° SNB angle (Table I and Fig. 2). A-point might have been more forward than normal because of very upright central incisors. The patient also had a
l. Maxillary molars: Maximum anteroposterior anchorage, mild expansion with a transpalatal appliance, maintain vertical. 2. Maxillary incisors: Moderate intrusion, lingual root torque of the central incisors. 3. Mandibular molars: Moderate anteroposterior anchorage, mild exmasion expected with leveling. 4. Mandibular incisors: Moderate intrusion with leveling of the curve of Spee. 5. Finish the occlusion with a Class I molar relationship.
American Journal of Orthodontics and Dentofacial Orthopedics Volume 110, No. 2
Emrich
165
Fig. 5. Posttreatment facial and intraoral photographs (age 30 years, 10 months). Note improved gingival display on frontal smiling photograph and asymmetrical smile line. Mildly improved profile view with increased lower face height. Hawley retainer was inadvertently left in place for photographs. Intraoral frontal photograph shows persistent midline discrepancy. Maxillary and mandibular bonded lingual O.0215-inch Wildcat wires can be seen in occlusal views.
6. Position the maxillary first premolars in the canine position, right and left. 7. Open the deep bite by intrusion of maxillary and mandibular incisors. 8. Smooth anterior guidance by correcting the torque of the incisors. 9. Correct crossbites of third molars. 10. Prepare for restoration of the maxillary right second premolar.
TREATMENT PROGRESS A straight wire appliance with brackets that have a 0.022 x 0.028-inch slot was used. Maxillary appliances were placed on all teeth, including the third molars with full arch wire (0.0155 inch Respond, Ormco Corp., Glendora, Calif. ) engagement to begin anterior bite opening. A transpalatal appliance was inserted into the lingual sheaths of the maxillary first molars and activated for mild expansion and rotation. The transpalatal appliance was positioned approximately 2 mm off the palate to help maintain the vertical. Mandibular first and third molars were banded, and light sectional arch wires were placed to begin mandibular arch leveling. Severe anterior bracket interference was avoided. The rest of the mandibular appliances were placed with mild
Fig. 6. Posttreatment lateral cephalometric radiograph and tracing (age 30 years, 10 months). anterior bracket interference 4 months later. This "bite plane effect" unlocked the occlusion and improved the effectiveness of the Class II mechanics. Elastics were worn from the maxillary first premolars to the mandibular first molars, but not to the mandibular third molars, to help prevent lower molar extrusion. Eventually, 0.018x0.025-inch stainless steel arch wires with significant bite opening curves to finish
166
Emrich
American Journal of Orthodontics and Dentofacial Orthopedics August 1996
Fig. 8. Postretention panoramic radiograph (age 33 years, 10 months) shows paralleled roots, bonded lingual retainers, and completed fixed restoration in maxillary right posterior quadrant.
Fig. 7. Posttreatment study casts show good Class I molar relationship and normalized overbite and overjet. Occlusal views show improved maxillary and mandibular arch forms.
the anterior bite opening and to improve the interincisal relationship were placed. Class II elastics were continued as described previously with slightly heavier elastics on the left side to help correct the midline discrepancy. The patient's cooperation was optimal, and the appliances were removed 31 months after the start of treatment; estimated treatment time was 32 months. RESULTS ACHIEVED Facial changes observed (Fig. 5) were mild lip fullness in profile and mild arch width increase of the maxillary anterior teeth on smiling. The patient showed an ideal amount of tooth structure in the frontal full smile and, because of an asymmetrical smile line, a mild amount of gingiva on the right side only. Because of molar extrusion, there was a mild lower face height increase (Fig. 6). With leveling of the occlusion and Class II mechanics, the molar extrusion caused a mild mandibular retrusion with a bite opening rotation of the mandible. The brachyfacial pattern, the transpalatal arch, and the short Class II elastics all
helped to keep the vertical molar eruption to a minimum. The mandible did not come forward with the "unlocking" of the anterior deep bite. The maxillary molars were maintained in their anteroposterior and vertical positions during anterior torque and bite opening. There was a 3.5 mm width increase. There was favorable lingual root torque with mild intrusion of the maxillary incisors. The mandibular molars moved mesially with mild extrusion and 3.5 mm width increase to a Class I position. The mandibular third molars were uprighted and moved out of crossbite. The mandibular incisors were intruded significantly and there was labial crown torque. All treatment goals were satisfied (Fig. 7). The postretention panoramic radiograph showed all spaces closed with parallel roots except for the space created by the premature extraction of the maxillary right second premolar. The bone level and the periodontal condition remained good (Fig. 8). RETENTION Because of the severity of the malocclusion, bonded, lingual maxillary lateral-to-lateral and mandibular canine-to-canine retainers were placed with a light-cured resin. The 0.0215-inch twist "Wildcat" wires (GAC International Inc., Central Islip, N.Y.) were formed to casts made from impressions taken a week before removal of the appliance. The patient was advised to wear the bonded lingual wires indefinitely. She was shown how to maintain good oral hygiene with floss threaders and correct angulation of the toothbrush. To maintain the maxillary posterior arch width and the pontic space for the missing maxillary right second
Emrich
American Journal of Orthodontics and Dentofacial Orthopedics Voh~me 110, No. 2
Fig. 9. Postretention facial and intraoral photographs (age 33 years, 10 months). Completed fixed restorations can be seen.
Table I. C e p h a l o m e t r i c s u m m a r y
I Analysis Jarabak
Pretreatment
Norm
Saddle angle (°) Artieulare angle (°) Gonion angle (°) GO-GN-SN (°) Anterior cranial base (ram) Posterior cranial base (ram) Upper gonion angle (°) Lower gonion angle (°) Ramus height (ram) Ratio PCBL/RH (%) Mandibular body length (mrn) SNA (°) SNB (°) ANB (°) Posterior face height (ram) Anterior face height (nun) Posterior FH/Anterior FH (%) Interincisor angle (o) Convexity (ram) ANS-menton (ram) Nasion-menton (rrun) ANS-Menton/Nasion-Menton (%)
137.0 138.1 116.0 31.2 75.0 33.4 50.5 65.5 48.4 69,0 77.7 78.0 71.9 6.1 76.5 117.1 65.3 175.6 4.6 62.3 117.l 53.2
123.0 143.0 130.0 32.0 70.3 32.0 53.5 72.5 44.0 80.0 72.4 82.0 80.0 2.0 83.1 130.6 62.0 130.0 0.9 62.1 112.4 55.0
Clinical development 2,8** -0,8 -2,0* -0.2 1.6" 0.5 -I.0 -2.3** 0.9 -1.1" 1.1" -1.3" -2.7** 2.0** -1.3" -2.l** 0.8 7.6*** 1.9" 0.0 0.8 -0.6
Posttreatment 138.3 138.5 116.1 33.0 74.9 32.7 49.8 66.4 47.9 68.2 77.3 76.0 71.1 4.9 75.6 118.3 63.9 133.1 3.8 63.8 118.3 53.9
Postretention 138.2 138.0 118.1 34.3 74.7 33.0 50.9 67,2 45,9 72,0 77.7 75.5 71.0 4.5 73.8 118.3 62.4 130.7 3.1 63.9 118.3 54.0
167
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American Journal of Orthodontics and Dentofacial Orthopedics August 1996
t
Fig. 10. Superimposition of pretreatment (solid line) and posttreatment (dashed line) tracings. Note mild bite opening mandibular rotation and change in incisor position and torque.
Fig, 11. Postretention lateral cephalometric radiograph and tracing (age 33 years, 10 months) show stable result.
premolar, a Hawley retainer was fabricated. The tient wore this retainer full-time for 2 years until bridgework was completed. After the restoration, maxillary retainer was adjusted to fit around bridgework and was to be worn only at night.
pathe the the
FINAL EVALUATION
Because of the patient's excellent cooperation, a significant improvement in the dental relationship was achieved, even though the final occlusion was unconventional. The health of the TMJ may have been improved by normalizing the anterior guidance and by unlocking the severe deep bite. The patient has had no TMJ dysfunction since the posttreatment records.
Favorable facial changes were seen on profile view (Fig. 9). Mild lip fullness and a slightly increased lower face height were evident. On frontal view, favorable changes were seen with increased width of the anterior teeth on full smile, which can be seen in the postretention photographs. A problem with the patient's treatment was the correction of the Class II dental relationship and the opening of the severe anterior deep bite in an adult patient with some mandibular retrognathia. The anterior bite opening needed to be achieved from incisor intrusion rather than molar extrusion. Molar extrusion would make the Class II relationship more difficult to correct as the mandible rotated down and back. The superimpositions of the pretreatment cephalometric tracing and the posttreatment tracing show some mandibular rotation with molar extrusion. Most of the bite opening, however, was due to incisor intrusion (Fig. 10).
A concern during retention was relapse of the anterior deep bite correction because it had occurred before. The "permanent" lingual retainers, the maxillary Hawley retainer, the bridgework, and a more stable position of the dentition all helped maintain the bite opening. The postretention cephalometric radiograph and tracing and the superimpositions show the stability (Figs. 11 and 12). The bridgework from the maxillary right first premolar to the maxillary right first molar has fairly good esthetics and anterior guidance but poor occlusal anatomy (Figs. 9 and 13). Taking into account the
Emrich
American Journal of Orthodontics and Dentofacial Orthopedics Volume 110, No. 2
169
Fig. 12. Superimposition and pretreatment (solid line) and postretention (dotted line) tracings.
Fig. 13. Postretention mounted study casts on Panadent articular (Panadent Corp., Grand Terrance, Calif.) show favorable anterior guidance and almost no CR-CO discrepancy.
crown preparation necessary and the lingual pulpal horn of the maxillary right first premolar, this tooth could have been made to look more like a canine. Mounted, 3-year postretention casts indicate the
occlusion remained stable and that there was less then 0.3 mm CR-CO discrepancy in a horizontal and vertical direction of both condyles (Fig. 13). The mounted casts also confirm good anterior guidance.