Download Anterior maxillary excess correction with ASMO – A case report

ISSN 0975-8437
INTERNATIONAL JOURNAL OF DENTAL CLINICS 2011:3(3):65-66
CASE REPORT
Anterior maxillary excess correction with ASMO – A case report
Joby Paulose, Rhea Mini Jayan
Abstract
Anterior maxillary excess presents with excessive gummy smile with increased over jet and deep
overbite. Surgical approach with ASMO has produced excellent treatment results. This clinical case
typically exemplifies the effect of ASMO on improving the skeletal, dental, soft tissue and over all
aesthetics of the patient.
Key Words: Anterior Maxillary Segmental Osteotomy; Maxillary Excess; Gummy Smile
Introduction
The first report of an anterior segmental
maxillary osteotomy (ASMO) was published by
Cohn Stock in 1921.(1) Currently, mainly three
variations of ASMO are used; the Wassmund,
Wunderer, and down fracture methods.(2, 3) The
usual indications for ASMO are excessive
vertical or sagittal development of the maxillary
alveolar process in patients where the
relationships between the posterior teeth are
acceptable. Anterior maxillary excess presents
with excessive gummy smile with increased over
jet and deep overbite. Surgical approach with
ASMO has produced excellent treatment results.
This clinical case typically exemplifies the effect
of ASMO on improving the skeletal, dental, soft
tissue and over all aesthetics of the patient.
Case report
A male patient aged 24 years came to
the orthodontic clinic with a chief complaint of
forwardly placed upper front teeth. On extra-oral
examination
(Fig1-8),
patient
had
a
leptoprosopic facial form with posteriorly
divergent convex profile, mild recessive chin,
deep mento-labial sulcus, severe gummy smile
(gingival exposure of 4-5 mm on smile) with
incompetent lips (hypotonic upper lip). Intra-oral
examination revealed severely proclined upper
and lower incisors, over bite of 2-3mm, over jet
of 7-8 mm, end on molar relationship on right
and class I on left (Fig 1-8).
Discolouration observed on 21, but the
tooth was vital with no periapical pathology.
Cephalometric evaluations (Table 1) revealed a
class II skeletal pattern with a prognathic maxilla
and mild retrognathic mandible with an anterior
maxillary excess, average growth pattern. As the
patient was 16years, surgical mode of treatment
was considered.
Fig 1-8: Pre - treatment extra oral and intra oral photographs of the patient, Fig 9-11: Intra-oral view after lower
anterior retraction - prior to surgery, Fig 12-14: Mock surgery performed on study model, Surgery correction (AMO&
advancement genioplasty) Fig 15-17: Post-surgical intra-oral view, Fig 18-20: mild intrusion in upper anteriors post
surgically, Fig 21-28: Extra oral and intra oral photographs of the patient after treatment, Fig 29-30: Profile change, pre
and post treatment.
©INTERNATIONAL JOURNAL OF DENTAL CLINICS
VOLUME 3 ISSUE 3 JULY- SEPTEMBER 2011
65
ISSN 0975-8437
Parameter
INTERNATIONAL JOURNAL OF DENTAL CLINICS 2011:3(3):65-66
Pre - Rx
Post - Rx
Skeletal
1.
SNA
860
820
2.
SNB
790
800
3.
ANB
70
20
4.
N Perp to Pt. A
6 mm
2mm
5.
N Perp to Pog
-8mm
-3mm
6.
GoGn to SN
320
330
7.
UAFH
52 mm
46 mm
8.
LAFH
48 mm
54 mm
9.
AO ahead of BO
7 mm
3 mm
Dental
10.
U1 to NA (Angle, 400, 12mm
230, 5mm
Linier)
11.
L1 to NB (Angle, 410, 13mm
240, 5mm
Lenier)
12.
U1 to SN
1280
1040
13.
L1 To Mand Plane 1140
930
0
14.
Inter-incisal Angle 88
1270
Soft Tissue
15.
Nasolabial Angle
670
890
16.
S line to upper lip
6mm
-1mm
17.
S line to lower lip
3 mm
0 mm
Table 1: Pretreatment and Post - treatment Cephalometric
Measurements.
Pre-surgical phase: Extraction of 34 and
44 followed by levelling & aligning of both
arches. Retraction of lower anteriors (maximum
anchorage) was done to create sufficient over jet
to facilitate surgical correction.(Fig 9-11)
Surgical phase: Study models were
articulated and a mock surgery (Fig 12) was
performed to view the occlusion after surgery.
On table extraction of 14 and 24 was done,
followed by AMO with superior and posterior
positioning of pre-maxillary segment with a
clockwise rotation to compensate the severe
proclination of upper incisors.(Fig 13) The
clockwise rotation of pre-maxillary segment
resulted in an anterior deep bite with disocclusion in the canine region which was
corrected in post-surgical orthodontic phase. An
advancement genioplasty was done to address
the deficient chin.(Fig 14)
Post-surgical Phase: Three months after
surgery, upper arch was aligned to correct the
occlusal discrepancy (Fig 15-17) and mild
intrusion was done in upper anteriors to correct
the deep bite and to reduce the incisal exposure
during smile.(Fig 18-20)
Debonding was done after final
finishing and detailing. Hawley’s retainer was
given in both arches for retention. At the time of
appliance removal, 21 appeared to have a slight
grayish color. Examination of the radiographs
before surgery, immediately after surgery, and at
the day of appliance removal showed no
periapical pathology.
Discussion
A dramatic improvement in facial
esthetics and occlusal function was realized with
the completion of treatment.(Figure 21-28) The
lip competency, gingival exposure on smile and
facial contour was significantly improved. The
patient was very satisfied with the results of
treatment. The excessive vertical dysplasia was
dramatically reduced, and most of the
cephalometric values were brought into the
normal range.(Table 1) The anterior maxillary
excess was significantly reduced, an ideal over
jet and overbite and the chin deficiency was well
addressed.
Conclusion
This case illustrates the importance of
proper diagnosis and treatment planning. A team
approach with the orthodontist, surgeon, and
restorative dentist all having input before the
initiation of treatment is the best way to achieve
stable, functional, and esthetic results. Through
this combined approach, the patient had a
dramatic skeletal, dental, and occlusal
improvement. As an added benefit, the patient
has reported a better self-esteem and a greater
degree of pleasure related to his appearance.
Authors Affiliations: 1. Dr. Joby Paulose,M.D.S.,
Senior Lecturer, 2. Dr. Rhea Mini Jayan, Lecturer,
Mar Baselios Dental College and Hospital,
Kothamangalam, Kerala, India.
References
1. Leibold D, Tilson HB, Rask K. A subjective
evaluation of the re-establishment of the
neurovascular supply of teeth involved in anterior
maxillary osteotomy procedures. Oral Surgery,
Oral Medicine, Oral Pathology. 1971;32(4):5314.
2. Rosenquist B. Anterior segmental maxillary
osteotomy:: A 24-month follow-up. International
journal of oral and maxillofacial surgery.
1993;22(4):210-3.
3. Jayaratne YSN, Zwahlen RA, Lo J, Cheung LK.
Facial soft tissue response to anterior segmental
osteotomies: A systematic review. International
Journal of Oral and Maxillofacial Surgery.
2010;39(11):1050-8.
Address for Correspondence
Dr. Joby Paulose, M.D.S.,
Senior Lecturer,
Mar Baselios Dental College and Hospital,
Kothamangalam, Kerala, India.
Email: [email protected]
Source of Support: Nil, Conflict of Interest: None Declared
©INTERNATIONAL JOURNAL OF DENTAL CLINICS
VOLUME 3 ISSUE 3 JULY- SEPTEMBER 2011
66