clinical case
Wojciech Pawlak¹, Krzysztof Klasicki², Barbara Warych¹, Henryk Kaczkowski¹
Skeletal Class III Dentofacial Deformity
with an Open Bite Treated by Orthodontics
and Orthognathic Surgery – a Case Report
Leczenie ortodontyczno-chirurgiczne wady szkieletowej III klasy
z towarzyszącym zgryzem otwartym – opis przypadku
¹ Department of Maxillofacial surgery, Wroclaw Medical University, Poland ² Private Practice
Abstract
The class iii skeletal deformity with open bite may be due to a horizontal excess of the mandible, an antero-posterior deficiency of the maxilla, or both. in most cases, there is a antero-posterior vertical maxillary excess that creates the anterior open bite. Treatment of open bite deformities is known to be difficult and results are not always pre-dictable. Growth modification and orthodontic camouflage not only can compromise the aesthetics but also can jeopardize the stability of the results. in such cases the combined surgical – orthodontic correction is considered the best treatment modality. simultaneous mobilization of the maxilla and mandible is often needed to correct severe class iii dentofacial deformities with accompanying open bite. in the treatment of these malformations it has been shown that the composed approach is very important to achieve high-quality functional and aesthetical results. The authors present a case of 18-year-old female patient with a class iii dentofacial deformity with an open bite interdisciplinary treated using orthodontics and orthognathic surgery. They demonstrate the stages of plan-ning and discuss surgical techniques and results obtained (Dent. Med. Probl. 2010, 47, 2, 237–244).
Key words: skeletal class iii malocclusion, open bite, orthognathic surgery, interdisciplinary treatment.
Streszczenie
Wady szkieletowe klasy iii z towarzyszącym zgryzem otwartym mogą być spowodowane nadmiernym doprzed-nim wzrostem żuchwy, niedorozwojem szczęki lub być kombinacją obu tych zaburzeń. W większości przypadków przyczyną zgryzu otwartego przedniego jest nadmierny pionowy wzrost tylnego odcinka szczęki. leczenie zgryzu otwartego jest trudne, a wyniki nie zawsze przewidywalne. Modyfikacja niekorzystnego wzorca wzrostu lub kamu-flaż ortodontyczny może mieć niekorzystny wpływ na estetykę i być przyczyną nawrotu. W tych przypadkach metodą z wyboru jest zespołowe leczenie ortodontyczno-chirurgiczne. Zabiegi chirurgiczne korygujące złożone wady szkieletowe klasy iii z towarzyszącym zgryzem otwartym wymagają często jednoczasowego uruchomienia szczęki i żuchwy. W leczeniu tych zniekształceń wykazano, że tylko ścisła współpraca chirurga szczękowego i orto-donty może zapewnić trwałą poprawę funkcji i estetyki. autorzy przedstawiają przypadek 18-letniej pacjentki leczonej zespołowo z powodu złożonej wady szkieletowej klasy iii z towarzyszącym zgryzem otwartym. U pacjent-ki zastosowano skojarzone leczenie ortodontyczno-chirurgiczne. Przedstawiono etapy planowania zabiegu oraz omówiono techniki operacyjne i wyniki leczenia (Dent. Med. Probl. 2010, 47, 2, 237–244).
Słowa kluczowe: wada szkieletowa klasy iii, zgryz otwarty, chirurgia ortognatyczna, leczenie zespołowe.
Dent. Med. Probl. 2010, 47, 2, 237–244
issn 1644-387X © copyright by Wroclaw Medical University and Polish Dental society
skeletal class iii anomalies involve mandibu-lar prognathism, maxilmandibu-lary retrusion, or combina-tion of both [1, 2]. The class iii dentofacial defor-mity with an accompanying open bite is a complex musculoskeletal deformity that exhibits skeletal abnormalities in all three planes. Vertically there
is inferior rotation of the posterior maxilla that creates the anterior open bite by a clockwise ro-tation of the mandible. The vertical discrepancy also affects anterio-posterior jaw relationship [3, 4]. The growth of the mandible rotates down and back and masks the true magnitude of the
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cessive mandibular length. in addition, excessive face height is noted (long face), and a transverse maxillary constriction with a posterior crossbite, is variably present. Bailey et al. wrote that prima-ry distiguishing characteristic of the long-face is a large total facial height that is manifested almost entirely in elongation of the lower third [3]. Prog-nathic mandible and retrogProg-nathic maxilla with accompanying anterior open bite result in a typi-cal concave profile, flatness of the paranasal areas and cheeks, angle class iii malocclusion and in-creased lower face height.
The class iii open bite deformities may create both aesthetic concerns and functional problems including masticatory insufficiency, periodontal disease, speech problems and temporomandibular joints dysfunctions [5, 6]. The psychosocial impact of a dentofacial deformity on an individual is well known. such a deformity can profoundly affect the quality of life and often leads to discrimina-tion in social interacdiscrimina-tions [7, 8].
etiology of class iii skeletal deformities in-clude hereditary environmental factors. The rela-tive contribiution of genetic factor to class iii malocclusions has been the subject of a number of previous studies [7, 9–1]. among environmental factors which have been suggested as contributory to the development of class iii open bite defor-mities are enlarged adenoids, nasal blockage, hor-monal disturbances, posture and trauma [7].
Generally, skeletal class iii open bite deformi-ties are difficult to correct and maintain. its treat-ment outcome is less stable than surgical cases without skeletal open bites [2, 4, 12].
in patients with a severe class iii open bite skeletal deformities, growth modifications and orthodontic camouflage do not lead to a satisfac-tory functional and aesthetic results. The tendency of anterior teeth to relapse towards their pretreat-ment vertical and horizontal relationship follow-ing treatment is well recognized [3, 12]. in such cases the combined surgical-orthodontic correc-tion is the best treatment modality.
a primary goal of presurgical orthodontic treatment is to eliminate all existing dental com-pensation. The teeth are aligned in their optimal positions in arch so that an acceptable occlusion can be produced at surgery [1, 13].
after preoperative orthodontic preparation surgery is performed to re-align the jaw bases. in the past, most patients were treated by mandibular procedures but experience had shown that the cor-rection of skeletal open bite by lower jaw surgery as an isolated procedure is considered to induce considerable relapse due to clockwise rotation of the mandibular body with lengthening of the su-prahyoid muscles and stretching the
ptreygomas-seteric sling. currently, the best surgical results are achieved through bimaxillary procedures. The bilateral sagittal ramus osteotomy (BssO) and le Fort i osteotomy are the most frequently used methods for surgical correction of skeletal class iii open bite discrepancies. Maxillary intrusion is used to close an open bite and to obtained the cor-rect face height, and mandibular osteotomies are used to adjust the horizontal position of the lower jaw [2, 4].
Following surgical aligment of the jaws, the fin-ishing treatment are applied to the teeth through postoperative orthodontics. This may involve simple aligments or more extensive compensation for minor relapse or overcorrections. This process usually requires from six to twelve months [13].
in this report we present a case of 18-year-old female patient with a class iii dentofacial defor-mity with an open bite interdisciplinary treated using orthodontics and orthognathic surgery. We demonstrate the stages of planning and discuss surgical techniques and results obtained.
Case Report
a female patient aged 17 years and 8 months presented to the Maxillofacial clinic of Wroc-law Medical University with a chief complaint of “too prominent lower jaw, flat appearance of her midface and chewing problems”. The patient was referred by her orthodontist asked for surgical correction of class iii open bite dentofacial defor-mity. The abnormal forward growth of the lower jaw was first noted at the age of 8 years and had become gradually worse. The patient’s mother and grandfather had similar prognathous deformity. Her medical history was noncontributory.
Clinical Examination
clinical examination revealed the following: 1) extraoral – frontal view: increased chin prominence, decreased exposure of upper lip ver-milion, deficient paranasal areas, increased lower facial height (Fig. 1a),
2) extraoral – profile view: increased chin prominence with obtuse labio-mental fold, con-cave profile, stretched lower lip to compensate in-creased lower facial height (Fig. 1c),
3) intraoral – molar and canine class iii mal-occlusion on both sides, anterior open bite, retro-clined lower incisors and proretro-clined upper incisors, crowding with blocked out the left upper canine with gingival recession, narrow maxillary dental arch, deviation of mandibular dental midline to the left 1 mm in relation to the maxillary dental
mid-line and the patient’s facial midmid-line, good oral hy-giene and sound periodontal support (Fig. 1D–H),
4) functional: interincisal opening was 42 mm and there were not limitations in protrusive and and lateral movements. The temporomandibular joints functioned without any signs and symptoms,
5) Pantomographic X-ray revealed a full com-plement of teeth with partially impacted both up-per wisdom teeth and right lower wisdom tooth. The left lower first molar was endodontically treated,
6) lateral cephalometric X-ray revealed class iii skeletal relationship, maxillary antero-posteri-or deficiency, mandibular antero-posteriantero-posteri-or excess, anterior open bite (Fig. 5a, Tab. 1).
Problem list included: vertical excess of the lower face associated with an anterior open bite, retrognathic maxilla, concave profile, long mandi-ble with steep mandibular plane, excessive lingual inclination of the mandibular incisors with crow-ding, excessive forward inclination of maxillary anterior teeth with crowding.
The aims of treatment were: to reduce excessive anterior facial height, to correct the sagittal skeletal discrepancy between the maxilla and the mandible, to correct profile concavity, to closure of an open bite, to leveling and alignment of the dental arches.
Treatment Plan
To correct a skeletal class iii open bite defor-mity the following treatment plan was proposed:
1. Removal of all wisdom teeth.
2. Presurgical orthodontics to level and align of the dental arches with elimination of dental compensations.
3. simultaneous bimaxillary osteotomies: le Fort i maxillary osteotomy to advance and supe-riorly repositioned the maxilla (to allow the man-dible to autorotate and close an open bite) and bi-lateral sagittal split ramus osteotomy to set back the mandible.
4. Postsurgical orthodontic treatment to refine the occlusion and retention after debanding.
Fig. 1. Pretreatment facial (a–c) and occlusal (D–H) photographs Ryc. 1. Fotografie twarzy (a–c) i zgryzu (D–H) przed leczeniem
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Treatment Progress
all wisdom teeth were removed and fixed ap-pliances were placed to start preoperative ortho-dontics. The maxillary and mandibular arches were leveled with continuous archwires, starting with .016-in nickel-titanium (ni-Ti) and working up to .017x.025-in ni-Ti. after proper buccolin-gual inclination in the posterior teeth had been achieved and all anterior dental compensations had been eliminated by proclination of mandibular incisors and retroclination of maxillary incisors, .017x.025-in stainless steel (ss) archwires were ap-plied before the surgery. Both dental arches were leveled and aligned and compatibility of the arches was established (Fig. 2D–H, Fig. 5B).
at the age of 19 years 8 months corrective bi-maxillary surgery was performed. The maxilla was osteotomized and advanced 5 mm by the conven-tional le Fort i procedure [14]. at the same time the maxilla was superiorly repositioned 2 mm an-teriorly (to establish ideal tooth-upper lip relation-ship) and 5 mm posteriorly (to allow the mandible to autorotate and close an open bite) (Fig. 6a–c). The occlusal splint constructed during mock sur-gery on the articulator was applied to determine the position of the maxilla. The maxilla was fixed in new position with four titanium miniplates and sixteen monocortical screws. 7 mm of mandibu-lar set back was performed using a bilateral sagit-tal ramus osteotomy [15] and osteotomized frag-ments were fixed with one titanium miniplate and 4 monocortical titanium screws on each side. Max-illomandibular fixation was maintained for 14 days after surgery and then was changed to elastics.
six weeks after surgery, the surgical stabilizing arch wire was replaced by .017x.025-in active arch wire and vertical elastics were applied to settle the occlusion. after 6 months post surgery, the patient was debonded. The retention appliances used were a maxillary removable retainer and a mandibular canine-to-canine bonded retainer.
Results Achieved
The posttreatment extraoral photographs, tak-en 6 months (Fig. 3a–c) and 2 years and 8 months post surgery (Fig. 4a–c) reveal a favorable and stable improvement in the frontal and profile facial views. The lip competency, tooth-to-lip at rest, and at smile was significantly improved. The soft facial profile improved with reduced chin and lower lip prominence and increased paranasal fulness. The excessive vertical facial dysplasia was reduced, and most of the cephalometric values were brought into the normal range (Tab. 1). The intraoral post-treatment photographs reveal stable class i canine and molar relationships on both sides and normal overjet and overbite (Fig. 3D–H, Fig. 4D–H). all the functional movements of the mandible were without symptoms. The patient was very satisfied with the results of treatment.
Conclusions
With the advances of the orthognathic surgery techniques, patients with skeletal class iii dentofa-cial deformities can be benefited from a combined orthodontic and surgical treatment.
With proper preoperative assessment and postoperative care, the discomfort and potential complications from the surgery can be reduced to a minimum.
When evaluating patients with dentofacial de-formities, attention should be directed toward the skeletal and soft tissue aesthetic examination. it is important to keep in mind that the patient’s over-all satisfaction will be highly dependent on the aesthetic result, not on the achievement of a ce-phalometrically normal database.
Patients with class iii open bite discrepancies are best treated by a combined maxillary advance-ment with intrusion and mandibular set back pro-cedure.
Table 1. selected cephalometric measurements according to segner and Hasund analysis [16] before and after surgery Tabela 1. Wybrane przed- i pooperacyjne pomiary cefalometryczne wg analizy segnera i Hasunda [16]
Measurements
(Pomiary) Presurgery(Przedoperacyjne) norm(norma) Postsurgery(Pooperacyjne) sna snB anB Gntgoar nl-nsl Ml-nsl Ml-nl H Wits index 76.2° 82.9° –4.5° 134.0° 3.9° 36.3° 32.4° –2.7° –12.3 mm 64.8% 82.0° ± 3.0 80.0° ± 3.0 2.0° ± 2.0 122.0° ± 7.0 8.0° ± 4.0 28.0° ± 5.0 20.0° ± 7.0 9.0° ± 3.0 0.0 mm ± 2.0 80.0% ± 7.0 79.0° 80.5° –1.5° 128.4° 10.2° 34.1° 23.8° 5.4° –4.0 mm 70.0%
Fig. 2. immediate preoperative facial (a–c) and occlusal (D–H) photograph after orthodontic decompensation Ryc. 2. Przedoperacyjne fotografie twarzy (a–c) i zgryzu (D–H) po ortodontycznej dekompensacji wady
Fig. 3. Posttreatment (6 month post surgery) facial (a–c) and occlusal (D–H) photographs Ryc. 3. Fotografie twarzy (a–c) i zgryzu (D–H) po zakończeniu leczenia (6 miesięcy po operacji)
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Fig. 4. Posttreatment (2 years, 8 months post surgery recall) facial (a–c) and occlusal (D–H) photographs Ryc. 4. Fotografie twarzy (a–c) i zgryzu (D–H) w odległym badaniu kontrolnym (2 lata, 8 miesięcy po operacji)
Fig. 5. Pretreatment (a), immediate presurgery (B) and postsurgery (c) lateral cephalometric X-rays
Ryc. 5. Radiogramy profilowe głowy: (a) przed leczeniem, (B) bezpośrednio przed zabiegiem operacyjnym i (c) po
Described case illustrates the importance of proper diagnosis and treatment planning. This patient who presented with a severe skeletal class iii open bite malocclusion was successfuly treated
with combined multidisciplinary approach and satisfactory improvement was achieved regarding aesthetics, function and occlusion.
Fig. 6. intraoperative photographs of le
Fort i osteotomy: (a) using reciprocating saw the osteotomy is completed, (B) oste-otomy completed on both sides, (c) wedge of maxillary bone that was removed
Ryc. 6. Fotografie śródoperacyjne
osteoto-mii szczęki typu le Fort i: (a) osteotomia szczęki z użyciem piły wzdłużnej, (B) obu-stronnie przecięte kości szczęk, (c) usunię-ty fragment kostny szczęki
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Address for correspondence:
Wojciech Pawlak
Department of Maxillofacial surgery Wroclaw Medical University Borowska 213 50-556 Wrocław Poland Tel.: 668 32 40 27 e-mail: wpawlak@mfs.am.wroc.pl Received: 26.03.2010 Revised: 25.06.2010 accepted: 25.06.2010
Praca wpłynęła do Redakcji: 26.03.2010 r. Po recenzji: 25.06.2010 r.
