Correction of Anterior Open Bite and Facial Profile by Orthognathic Surgery – A Case Report

This case report describes the treatment of a severe anterior open bite, Class III malocclusion with a history of digit sucking. An 18 years-old male presented with a significant anteroposterior and vertical discrepancy of face. The patient’s face was concave with procumbent lips. He had an anterior open bite of 11 mm, a reverse overjet of 8 mm, and a transverse maxillary deficiency on right side. The orthognathic surgery was elected as an option of treatment to correct the anterior open bite with improvement of facial profile.

chewing problem.His medical and dental history was noncontributory.He had a history of digit sucking and swollen palatine tonsils.The enlarged tonsils were believed to have caused mouth breathing and compensatory anterior tongue posturing to achieve an adequate airway.On the basis of the skeletal discrepancies, a pre-surgical orthodontic treatment was discussed, but the parents deemed it too long procedure and selected an immediate treatment option without the need to wait for many years until the end of an orthodontic treatment then a surgical procedure.Thus, a surgical plan was devised to eliminate the open bite and there by, the patient's chief complaint.For surgical correction of the skeletal discrepancies the patient was referred to the oral and maxillofacial department of BSMMU and decided to work out bilaterally.

Treatment plane:
A two-phase treatment was considered.In the early intervention, to improve the facial profile Le Fort I Osteotomy in maxilla and Bilateral Saggital Splite Ramus Osteotomy in mandible followed by surgical correction of macroglossia were prescribed.To improve the minor occulusal irregularities, in the second phase of treatment, the occlusion was corrected by orthodontic treatment.The patient was discussed about the complexity of this plan and about the need for perfect compliance with procedure.
Treatment Progress:  Under general anesthesia, Le Fort I Osteotomy was done by traditional approach to reduce the vertical high of the maxilla by removing a triangular bone fragment that's base (10 mm) located on retromolar region & apex (1 mm) located to the ANS, from both side of the maxilla which made of possible to reduce the vertical height and advancement of maxilla 7-8 .Bilateral Saggital Splite Ramus Osteotomy was done by traditional approach 9 to reposition the mandible at relatively proper position which made of possible to correct the prognathism of the mandible with the occlusion of maxilla by moving the mandible upwards and backwards.

Fig.-6: Per operative photograph: Le Fort 1 Osteotomy (q), Bilateral Saggital Splite Ramus Osteotomy (r), Traditional surgical approach by a rhomboid pattern from the dorsum of the tongue(s)
The tongue was reduced by traditional surgical approach by a rhomboid pattern from the dorsum to prevent the post operative tongue thrush and post surgical relapse.Peroperatively, the miniplate osteosynthesis was done to stabilize the osteomobilized fragments of maxilla and mandible.

Post surgical orthodontic settling
The postsurgical orthodontic treatment will be commenced after six month of surgery.Both arches will be coordinated and remaining space and rotation of teeth will be corrected.Patient will give upper and lower retainers.

Results:
Considering the skeletal pattern and the surgical approach that was chosen, excellent facial and occlusal results were achieved As there, so far only the orthognatic surgery was performed, so skeletal cephalometric points were corrected; the remaining dental cephalometric points will be corrected by post surgical orthodontic treatment [Table -I].

Discussion:
The first report of surgical repositioning of the mandible was written by VP Blair in 1907 10 Since then, the surgical correction dentofacial deformities has developed into not only a well defined science but also a fascinating art form.
The development of surgical repositioning of the mandible includes ingenious work by surgeons [11][12][13] described body osteotomy procedures.Procedures to reposition the mandible using various ramus oestotomies were described.
In 1955 Obwegeser and Trauner described a surgical procedure involving a saggitial splite osteotomoies through the ramus of the mandible.
After Le Fort described the natural planes of fracture of the midface in 1901, maxillary surgery developed through the work of Wassmud, Auxhauser, Obwegeser, willmar and others.It was not however until Bell 7 and his coworkers excellent research in mid 1970 on the biologic basic of hemodynamic and the vescular supply of maxilla during after maxillary dowen fracture surgery that the Le Fort I oesteotomy developed in to the refined science and art that it is today.
Maxillary abnormalities contribute too many facial deformities that should be recognized and treated successfully by adhering to basic biologic and technical principles.Numerous techniques for Le Fort I maxillary osteotomy have been described and reflect a strong tendency to operators preference.
The patient displayed typical characteristics of achondroplasia like midfacial deficiency, concave profile and retrognathic maxilla.The additional significant features were the Class III molar relation, upper and lower anterior proclination, anterior open bite, prognathic mandible, maxillary and mandibular vertical excess with macroglossia.
Considering above clinical and radiological findings, the treatment plan should be included pre-orthognathic correction followed by bimaxillary orthognathic surgery which is a combination of Le Fort I Osteotomy in maxilla, and Bilateral Saggital Splite Ramus Osteotomy in mandible followed by surgical correction of macroglossia.The residual occlusal irregularities will be corrected by post surgical orthodontic treatment.
Mock surgery was done on models to asses the position of the jaws after surgery.An occlusal splint was fabricated on these models [Figure-4(o)].

Fig.- 5 :
Fig.-5: Diagram illustrated the location of wedge shaped bone fragment that will be removed from maxilla.
[Fig-1(b), (d)] despite lack of pre-surgical orthodontic treatment.At the completion of treatment, the lips were slightly less protrusive with improved lip competence.