Nonsurgical treatment of skeletal maxillary protrusion with gummy smile using headgear for growth control, mini-implants as anchorage for maxillary incisor intrusion, and premolar extractions for incisor retraction

Introduction

An adolescent girl, aged 12 years 11 months, was evaluated for orthodontic treatment. Her chief complaints included a difficulty with keeping her lips passively closed and excessive gingival exposure upon smiling. Her treatment plan included (1) restriction of maxillary growth with cervical headgear, (2) extraction of the maxillary first premolars to reduce the maxillary protrusion and the mandibular second premolars to facilitate Class II dental correction, and (3) management of maxillary incisor intrusion via anchoring with mini-implants. When indicated, even in the absence of large space discrepancies, extractions can be beneficial to the patient. The final results showed an attractive smile, passive lip seal, and a more esthetic and balanced facial profile. Retention records confirmed the stability of the treatment. The 5-year follow-up visit revealed that the treatment results were quite stable.

Highlights

  • The performed treatment resulted in large improvements in facial and smile esthetics.

  • Treatment results remained stable at 5 years after active orthodontic treatment.

  • Gingival smile—“gumminess”—improved with intrusion of maxillary incisors.

  • Extractions assisted in achieving occlusal and facial planned treatment objectives, even in the absence of a large tooth size–arch length discrepancy.

The degree of perceived improvement of facial esthetics is closely related to a patient’s approval and satisfaction of the completed orthodontic treatment. Therefore, current orthodontic treatments put a major focus on improving facial balance because it is one of the leading reasons for which patients seek treatment. An increased facial convexity caused by maxillary anterior teeth protrusion resulting in upper lip projection associated with a retruded mandible is a common characteristic of orthodontic patients with a skeletal Class II pattern and is considered to be esthetically unpleasant. Frequently, these patients request orthodontic treatment to improve their facial appearance and consequently their self-esteem and quality of life.

The smile is also an element of significant importance in facial esthetics and commonly becomes one of the main aspects considered in a patient’s evaluation of how successful their orthodontic treatment was. The amount of gingival exposure at smiling influences attractiveness, and both lay people and dentists consider enlarged gingival display to be an unpleasant esthetic feature.

The objective of this case report was to present the orthodontic treatment of an adolescent patient with skeletal Class II gummy smile (GS) and lip incompetence. The reasoning for tooth extraction and the orthodontic mechanics are explained in detail.

Diagnosis and etiology

The patient, an adolescent female aged 12 years 11 months, presented for orthodontic treatment. Her chief complaints were the existence of a difficulty in keeping her lips passively closed and the presence of excessive gingival exposure upon smiling ( Fig 1 ).

Fig 1
Pretreatment photographs.

Facially, she presented with a symmetrical face including balanced and proportional facial thirds, an increased chin-lip groove with lower lip eversion, lip incompetence with forced sealing, and excessive gingival display on smile (4.5 mm). During the dental examination, a Class II, Division 1 malocclusion, exaggerated curve of Spee, a deep overbite (impinging mandibular incisors), noncoincident dental midline lines with the lower being deviated 2 mm to the left, and no significant tooth size–arch length discrepancy in the maxillary or mandibular arches were observed. In addition, an increased overjet (7 mm) was seen ( Figs 1 and 2 ). Cephalometrically, a convex face profile (Z angle: 59.5°), protruding upper and lower lips (upper lip S line: 6 mm and lower lip S line: 7 mm), acute nasolabial angle (77°), dentoalveolar extrusion (U1 stomium: 12 mm), and a short upper lip (length: 17 mm) were seen ( Fig 3 ; Table I ). The patient also presented with a skeletal Class II (ANB: 12.5° and Wits: 9.5 mm) appearance because of maxillary protrusion (SNA: 94°), with the mandible well positioned relative to the cranium base (SNB: 81.5°), a mesocephalic pattern (SN-GoGn: 31° and FMA: 29°), the mandibular incisors proclined and protruded in relation to the NB line (L1.NB: 38.5° and L1-NB: 10.5 mm) and also proclined in relation to the apical base (IMPA: 102°), and retroclined and retruded maxillary central incisors (U1.NA: 5.5° and U1-NA: 0.5 mm) ( Fig 3 ; Table II ). The patient showed no signs or symptoms of temporomandibular disorder, normal mouth opening extension without deviations during opening or closing, hyperactivity of the elevator muscles of the upper lip, and healthy periodontal tissues ( Fig 1 ).

Fig 2
Pretreatment dental casts.

Fig 3
Pretreatment panoramic and cephalometric radiograph with the SN −7° perpendicular reference line.

Table I
Soft tissue, profile, and esthetic measurements
Variables Norm Pretreatment Posttreatment Difference
(T1) (T2) (T1−T2)
Upper lip-S line 0 mm 6 1 –5
Lower lip-S line 0 mm 7 –1 –8
Z angle 75° 59.5 75 +15.5
Nasolabial angle 102° ± 8° 77 95 18
Upper lip thickness 12 mm 14 15 1
Lower lip thickness 11 mm 13 11 –2
Gingival display <3 mm 4.5 0 –4.5
U1-stomium 2-4.5 mm 12 4 –8
1-3.0 mm
Upper lip length 20 mm 17 21 4
24 mm

Denotes female.

Denotes male.

Table II
Cephalometric measurements
Pattern Variable Norm Pretreatment Posttreatment Difference
(T1) (T2) (T1−T2)
Skeletal pattern SNA 82° 94 87 −7
SNB 80° 81.5 81 −0.5
ANB 12.5 6 −6.5
Wits 0 ± 2 mm 9.5 5 −4.5
1 ± 2 mm
SN-GoGn 32° 31 29 −2
FMA 25° 29 24 −5
Pog-NB 0 2 2
Dental pattern IMPA 90° 102 94 −8
U1.NA 22° 5.5 9.5 4
U1-NA 4 mm 0.5 0 −0.5
L1.NB 25° 38.5 25 −13.5
L1-NB 4 mm 10.5 4 −6.5
U1.L1 130° 123.5 140 +16.5

Denotes female.

Denotes male.

After panoramic radiography, no major abnormalities or pathologies were detected. The third molars were present and in the root formation stage ( Fig 3 ). The respiratory pattern was predominantly buccal, and she had allergic rhinitis, according to her mother. Menarche had not yet occurred. The cervical vertebral maturation evaluation indicated the patient was at the CS3 stage ( Fig 3 ).

Treatment objectives

Based on observations of the patient, the following items for inclusion in the treatment plan were identified:

  • 1.

    Increase the nasolabial angle, correct the lower lip eversion, and reduce the upper and lower lip protrusion to improve the facial profile

  • 2.

    Obtain a passive labial seal

  • 3.

    Improve the smile esthetics, including reducing the gingival display on smile

  • 4.

    Minimize as much as possible the anteroposterior skeletal discrepancy

  • 5.

    Correct the Class II, Division 1 malocclusion

  • 6.

    Achieve proper overbite and overjet

  • 7.

    Reduce the mandibular incisor protrusion

  • 8.

    Attempt to establish a predominantly nasal respiratory pattern and control of allergic rhinitis

Treatment plan

The following treatment plan was developed:

  • 1.

    Perform leveling and aligning of the maxillary and mandibular dental arches

  • 2.

    Manage the maxillary molars’ anteroposterior control and growth response with cervical headgear. Owing to the patient’s age, some facial growth was expected. The headgear may assist with the skeletal Class II correction.

  • 3.

    Extractions of the maxillary first premolars and mandibular second premolars to provide spaces for retraction of the incisors and as an adjunct to the correction of the Class II dental relationship.

  • 4.

    Address intrusion of the maxillary incisors and correct the everted lower lip using mini-implants

  • 5.

    Refer the patient to the otorhinolaryngologist for an evaluation of the airway and attempt to establish a predominantly nasal respiratory pattern

  • 6.

    Refer the patient to the allergist for evaluation of her allergic rhinitis

Notably, one identified limitation of the treatment plan was that orthopedic and orthodontic correction would be dependent on the collaboration, compliance, and proper use of the cervical headgear.

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Mar 9, 2020 | Posted by in Orthodontics | Comments Off on Nonsurgical treatment of skeletal maxillary protrusion with gummy smile using headgear for growth control, mini-implants as anchorage for maxillary incisor intrusion, and premolar extractions for incisor retraction
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