Severe Mandibular Prognathism Research Articles

Modified surgery-first approach for management of severe class III malocclusion with maxillary skeletal midline discrepancy

This case report describes orthosurgical case that used the recently introduced surgery-first approach to correct a severe skeletal class III malocclusion with severe maxillary midline discrepancy. A 23-year-old adult male presented with severe mandibular prognathism and midline discrepancy associated with upper jaw. Firstly partial orthodontic movement were facilitated to decrowd the lower teeth in order to avoid any hindrance while anterior tooth advancement. After which prediction of the postsurgical tooth movement and surgical simulation was done by using Nemoceph software than 2-jaw surgery that included maxillary advancement differentially initiated to correct midline followed by mandibular setback was performed using a surgery-first approach. Immediate facial improvement was achieved and postsurgical orthodontic treatment was efficiently carried out. The total treatment time was 11 months. The patient's facial appearance improved significantly and a stable surgical orthodontic outcome was obtained even after patient was followed for six years.

Personalized 3D-printed Titanium Cutting Guide and Prefabricated Osteosynthesis Plate for Mandibular Step Osteotomy to Treat Severe Mandibular Prognathism

Mandibular step osteotomy, performed for mandibular prognathism, is a difficult and time-consuming procedure. Virtual computer surgery and computer-aided design & computer-aided manufacturing have demonstrated accurate results in orthognathic surgery, though not used for mandibular step osteotomy yet. In this study, the authors report the case of a 21-year-old man with severe mandibular prognathism, with a reverse overjet of 12 mm. Step osteotomy, a modified method of body osteotomy, was planned virtually and performed using 3-dimensional (3D) printed titanium surgical guides and osteosynthesis plates, using computer-aided design & computer-aided manufacturing. At the 6-month postoperative follow-up, there were no notable complications, and normal healing was observed. Each segment was stably in place with the prefabricated plates. The proximal segments were not sagged medially or laterally. With 3D-printed surgical guides and osteosynthesis plates, intraoperative complications, such as injury to adjacent teeth and nerves, could be avoided. They also showed reasonable accuracy and helped reduce operative time and improve outcomes. Unlike surgical guides made of resin/polyamide, titanium surgical guides can be made thinner, which can reduce the extent of detachment. They also did not undergo any deterioration during the operation. Cutting guides and prefabricated plates using virtual surgical planning and 3D printing have many advantages, including reduced preoperative preparation time and operative time, reduced incidence of intraoperative complications, and improved outcomes. However, limitations still exist and further studies are required.

A severe skeletal Class III malocclusion treated with Le Fort I combined with sagittal split ramus osteotomy, mandibular body ostectomy and tongue reduction surgery. A case report

This case report describes the orthodontic-orthognathic management of a 17-year-old male patient with extremely severe skeletal Class III malocclusion due to a marked mandibular protrusion with a small and narrowed upper jaw which increased the remarkable concave facial profile. Dental articulation was entirely lacking, resulting in great difficulty in masticating food. A two-jaw surgery combined with mandibular body ostectomy was performed to correct mandibular asymmetry and the severe sagittal skeletal discrepancy (Wits appraisal –36.5 mm and ANB angle –14.3°). Bi-maxillary surgery was performed in two-stages; the first surgery consisted of maxillary advancement with Le Fort I osteotomy followed by a second surgery where a combination of sagittal split ramus osteotomy (SSRO) and mandibular body ostectomy was performed to correct the severe mandibular prognathism. A partial glossectomy was also carried out to address macroglossia. After a total treatment time of 32 months, a Class I occlusion with a favorable facial profile and lip competence were obtained. The occlusion was made approximately ideal, and mastication improved remarkably. Three years after retention, the occlusion was stable and no relapse was observed. The patient’s complaints and orthodontic problems were completely resolved. Therefore, a combination of two-jaw surgeries with Le Fort I maxillary osteotomy, mandibular SSRO, mandibular ostectomy, and glossectomy may be a viable option in the correction of extremely severe anteroposterior skeletal discrepancy.

Control of the occlusal plane in orthognathic surgery

• Diagnostic considerations of occlusal plane can make a treatment plan for better results. • Presurgical control of occlusal plane can contribute in reducing the need for double-jaw surgery. • Functional occlusal plane should be controlled to improve stability with better esthetics. • Adequate planning of occlusal plane orientation is of high significance in orthognathic surgery. The orientation of the occlusal plane (OP) influences the functional and esthetic balance of the face. We report on two patients for which the careful consideration of OP angulation from diagnosis to treatment planning aided in achieving a superior esthetic correction and improved stability. In both surgical patients, adequate presurgical control of the OP facilitated the surgical correction with a rotation of the OP. The results showed a better esthetic outcome and improved orientation of the musculoskeletal relation. Therefore, in severe mandibular prognathism or retrognathism, adequate planning of the OP orientation is of high significance.

重度の骨格性下顎前突症患者に対して二段階の顎矯正手術を施行した1例

In cases of jaw deformity, bimaxillary surgery combining Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO) is one of the standard operations. However, this operation can be difficult to use in cases of severe mandibular prognathism because of the large amount of setback. We report herein a case of severe mandibular prognathism treated with a two-stage surgical procedure. At the first stage, we performed mandibular body ostectomy, followed at the second stage by maxillary advancement by Le Fort I osteotomy and mandibular set-back by sagittal split ramus osteotomy. This unique two-stage surgical treatment improved and kept the patient's overall facial aesthetics and occlusion for one year postoperatively.

Stability of Obwegeser II osteotomy (transoral angle ostetomy) for severe mandibular proganthism or openbite

This study evaluated the postoperative stability after Obwegeser II osteotomy (transoral angle osteotomy, first reported by Obwegeser 1973) for severe prognathism or open bite. The 43 patients who underwent Obwegeser II osteotomy for mandibular setback had been evaluated with frontal & lateral cephalogram. The patients were divided into the three groups; Group 1, bilateral Obwegeser II osteotomy for severe prognathism (n = 18), Group 2, unilateral Obwegeser II & contralateral Sagital spit ramus osteotomy (SSRO) for severe asymmetric prognathism (n = 16), Group 3, bilateral Obwegeser II for severe open-bite (n = 9). Posterior or superior movement at B point [B(x) or B(y)] was 14.1 mm and 2.7 mm in Group 1, 13.4 mm and 1.5 mm in Group 2 and 5.1 mm and 5.5 mm in Group 3, respectively (all p < 0.05). There was no statistically significant vertical relapse in all groups. The horizontal relapse was 0.9 mm in Group 1, 1.6 mm in group 2, and 0.8 mm in Group 3 (all p < 0.05). In frontal view, the horizontal relapse was within 1° in all groups (p > 0.05). Obwegeser II osteotomy showed similar stability compared to the former results with SSRO that had been performed at our department. Therefore, this method can be considered as a reliable option for severe mandibular prognathism or open bite.

Seven Years of Retention of Severe Mandibular Prognathism Treated With Bimaxillary Surgery: Two Case Reports

ABSTRACT These case reports describe the surgical treatment of 2 male adult patients with severe mandibular prognathism. For both patients, anterior repositioning of the maxilla by Le Fort I osteotomies with and without impaction and mandibular posterior repositioning by sagittal split ramus osteotomies were performed. The aim of this case report is to identify successfully treated surgical cases maintaining the results throughout the follow-up period of 7 years.

Class III malocclusion with severe anteroposterior discrepancy

This study aims at reporting the clinical case of a patient with Class III skeletal malocclusion with severe maxillary deficiency, producing a reduced midface associated with severe mandibular prognathism. The pre-surgical orthodontic preparation was composed mainly by dentoalveolar expansion and repositioning of the incisors in the lower arch. Then, a combined maxillary and mandibular orthognathic surgery was performed. The treatment objectives were achieved, with significant improvement in facial esthetics and occlusion, followed by post-treatment stability. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO), as part of the requirements for obtaining the title of Diplomate by BBO.

Rectangular Body Ostectomy for the Treatment of Severe Mandibular Prognathism

The aim of this article was to present the surgical technique and the outcomes of rectangular body ostectomy in the treatment of severe mandibular prognathism. Mandibular setback by bilateral rectangular body ostectomies combined with Le Fort I level maxillary advancement was performed. The deep bony concavity of paranasal area was grafted with bone blocks harvested from the ostectomized segments of the mandible. Satisfactory functional and aesthetic outcomes were obtained by rectangular body ostectomy combined with Le Fort I level maxillary advancement and an acceptable profile was provided for the patient. The mandibular rectangular ostectomy remains a safe and versatile procedure with predictable results in well-selected cases.

Orthodontics-surgical combination therapy for Class III skeletal malocclusion

The correction of skeletal Class III malocclusion with severe mandibular prognathism in an adult individual requires surgical and Othodontic combination therapy. The inter disciplinary approach is the treatment of choice in most of the skeletal malocclusions. A case report of an adult individual with Class III malocclusion, having mandibular excess in sagittal and vertical plane and treated with orthodontics,, bilateral sagittal split osteotomy and Le – Forte I osteotomy for the correction of skeletal, dental and soft tissue discrepancies is herewith presented. The surgical–orthodontic combination therapy has resulted in near–normal skeletal, dental and soft tissue relationship, with marked improvement in the facial esthetics in turn, has helped the patient to improve the self-confidence level.

Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism

IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism. Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22months (mean 17.8months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6months postoperatively. ResultsThe average setback was 6.9mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance. ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.

Miniscrew-assisted nonsurgical palatal expansion before orthognathic surgery for a patient with severe mandibular prognathism

A transverse maxillary deficiency in an adult is a challenging problem, especially when it is combined with a severe anteroposterior jaw discrepancy. The demand for nonsurgical maxillary expansion might increase as patients and clinicians try to avoid a 2-stage surgical procedure-surgically assisted rapid palatal expansion followed by orthognathic surgery-and detrimental periodontal effects and relapse. In this regard, a miniscrew-assisted rapid palatal expansion was devised and used to treat a 20-year-old patient who had severe transverse discrepancy and mandibular prognathism. Sufficient maxillary orthopedic expansion with minimal tipping of the buccal segment was achieved preoperatively, and orthognathic surgery corrected the anteroposterior discrepancy. The periodontal soundness and short-term stability of the maxillary expansion were confirmed both clinically and radiologically. Effective incorporation of orthodontic miniscrews for transverse correction might help eliminate the need for some surgical procedures in patients with complex craniofacial discrepancies by securing the safety and stability of the treatment, assuming that the suture is still patent.

Incomplete mobilization of the maxilla resulting in failed maxillary distraction: a case report

Maxillary distraction osteogenesis has become an accepted alternative method in the treatment of patients with severe maxillary hypoplasia in craniofacial syndromes and cleft-related deformities. Insufficient distraction, undesirable soft tissue changes, and occurrence of defective distraction vectors are among the potential complications of intraoral maxillary distraction osteogenesis. A 2-stage procedure combining maxillary advancement by distraction technique with genioplasty and mandibular setback surgery was planned to correct jaw deformities in a 22-year-old patient with severe maxillary retrusion, mandibular prognathism, and excessive lower facial height. In the first stage, osteotomies were performed and maxilla was lightly mobilized after down-fracture. Distractors were placed to the maxilla intraorally. During activation period, the maxilla rotated in a clockwise direction, producing a discrepancy between the planned and the actual vectors. Complete distraction was unsatisfactory and the complication was due to surgical technique. This case report presents the failure of maxillary distraction due to incomplete mobilization of the maxilla. Treatment of the case was achieved by the conventional osteotomy techniques at final operation. The maxilla was successfully advanced to the desired position producing good occlusion and an improved facial profile.

Skeletal changes after modified intraoral vertical ramus osteotomy for correction of mandibular prognathism

Orthognathic surgery is widely used to correct congenital and acquired dentofacial discrepancies. Various surgical procedures have been advocated for correction of mandibular prognathism. In this study, a modified intraoral vertical ramus osteotomy has been developed for surgical correction of mandibular prognathism. The aim of this study is to identify contributing factors to skeletal change by analysing cephalometric changes after modified intraoral vertical ramus osteotomy. Forty-one patients, treated for absolute mandibular prognathism by bilateral modified intraoral vertical ramus osteotomy, were evaluated cephalometrically with reference to the menton point. A set of four standardised lateral cephalograms were obtained from each subject preoperatively (T1) and immediately postoperatively (T2), prior to removal of maxillomandibular fixation (T3), and at 1-year postoperatively (T4). The mean setback of the menton was 12.4 mm in the horizontal direction. Relapse was defined as forward movement of the menton during the 1-year follow-up. The highly significant backward movements in a horizontal direction were observed during the maxillomandibular fixation period (T3-T2). Moreover, highly significant forward movement was observed following the maxillomandibular fixation period (T4-T3). After 1-year follow-up (T4-T2), the mean changes of the menton were 0.1 mm backward in the horizontal direction. In this series, the mean skeletal change compared with the amount of setback was less than 1% (0.1/12.4 mm) in backward movement. The results suggest that the modified intraoral vertical ramus osteotomy technique is useful and the more stable approach for correction of severe mandibular prognathism.

Mandibular prognathism in Japanese families ascertained through orthognathically treated patients

Patients with severe mandibular prognathism frequently require orthognathic surgery to correct skeletal disharmony. Genetic and environmental factors are suggested in the etiology of mandibular prognathism, but the precise contribution of these factors is unknown. To clarify the impact of genetic factors on mandibular prognathism, we gave a questionnaire to 105 subjects with severe skeletal Class III mandibular prognathism who planned to undergo or had undergone orthognathic surgery. The questionnaire assessed mandibular prognathism in 3 generations of each subject's family. All answers were confirmed in a careful interview that included differentiation of "maxillary deficiency" and "mandibular excess." This is the first 3-generation family study of mandibular prognathism in orthognathically treated patients. The average ANB, SNA, and SNB angles in the probands were -3.7 degrees , 80.9 degrees , and 84.6 degrees, respectively. A total of 1480 family members were examined, and 11.2% had mandibular prognathism. Men were slightly more affected than women; 68.6% of families had at least 1 member other than the proband with mandibular prognathism. The affected ratio of first-degree relatives was more than twice that of second-degree relatives (17.5% and 7.6%, respectively). There was no difference in the occurrence between fathers and mothers of probands, and siblings showed a high affected ratio of 25.0%. Falconer's heritability was calculated as 84.3% in first-degree relatives. A high occurrence of mandibular prognathism was seen in families of orthognathically treated skeletal Class III patients, suggesting a profound genetic influence.

Treatment in Bimaxillary Prognathism with Anterior Open Bite: A Case Report

In general, the skeletal class III has the characteristics of mandibular overgrowth with a normal maxillary growth or maxillary undergrowth with a normal mandibular growth And clinical and radiographic evaluations of the patient are needed. However, the treatment plan is not dependent on these evaluations alone, because patient's general condition and hope for aesthetics varies. The aim of this report is to consider the treatment of a medically compromised patient with an anterior open bite and skeletal class III, which showed a severe mandibular overgrowth. In 2003, a 17-year-old boy with epilepsy, mental retardation presented at our clinic complaining of concave profile. A clinical examination showed severe mandibular prognathism with an anterior open bite. The radiographic examination revealed a short cranial base, a moderate maxillary overgrowth, severe mandibular overgrowth and skeletal open bite tendency. In 2004, he was verified to have no potential of growth by hand-and-wrist radiographs and an endocrine examination. He completed the preoperative orthodontic treatment and orthognathic surgery (sagittal split ramus osteotomy, genioplasty). He was evaluated on the first visit, the preoperative period and the postoperative period with a clinical and radiographic examination. At the first visit, the patient showed moderate overgrowth of the maxilla, severe overgrowth of the mandible, and a subsequential skeletal open bite. After the preoperative orthodontic treatment (preoperative period), the patient showed the same skeletal problem as before and a decompensated dentition for orthognathic surgery. After orthognathic surgery, his profile had improved, but he had still a skeletal openbite tendency because the maxillary orthognathic surgery was not performed. Severe mandibular prognathism with a maxillary overgrowth and anterior open bite should be treated by bimaxillary orthognathic surgery. However, one-jaw orthognathic surgery on the remaining the skeletal open bite tendency was performed for his medical problem and facial esthetics. This subsequential open bite should be resolved with a postoperative orthodontic treatment.

上顎劣成長を伴った骨格性下顎前突症に対し上顎骨延長術と下顎枝矢状分割術を施行した１例

In cases of severe mandibular prognathism, hypergrowth of the mandible is frequently complicated by maxillary undergrowth. Recently, two-jaw surgery has been performed in such cases, in which gradual advancement of the maxilla by distraction osteogenesis, and then posterior shift of the mandible by sagittal split ramus osteotomy are carried out. To treat mandibular prognathism complicated with maxillary undergrowth, we performed gradual advancement of maxilla by using an internal distraction device, and then carried out sagittal split ramus osteotomy approximately 5 months after.The patient was an 18-year and 4 month-old male with malocclusion, and was diagnosed as having skeletal class III deformities with maxillary undergrowth and open bite. After preoperative orthodontic treatment, the maxilla was advanced approximately 10mm by distraction osteogenesis. About 5 months after, the mandible was posteriorly shifted by 10mm on the left side, and 12mm on the right side by sagittal split ramus osteotomy.As a result, the concavity of the middle face and the mandibular prognathism were improved. Good and stable occlusion was obtained. Furthermore, improvement in speech function by this treatment was also confirmed.

Treatment of severe mandibular prognathism in combination with maxillary hypoplasia: case report

We performed a Le Fort I osteotomy and sagittal split ramus osteotomy (Obwegeser-Dal Pont) combined with mandibular anterior segmental osteotomy without tooth extraction for a patient with severe mandibular prognathism accompanied by a hypoplastic maxilla, anterior open bite and normal anterior mandibular vertical dimension. The results of facial appearance and occlusion were excellent. This combined surgical method appears to be satisfactory for treating severe mandibular prognathism with hypoplastic maxilla. Copyright 2002 European Association for Cranio-Maxillofacial Surgery. Published by Elsevier Science Ltd. All rights reserved.

Long-term application of chincup force alters the morphology of the dolichofacial Class III mandible

The conventional orthopedic Milwaukee brace exerts a large and continuous force that induces malocclusion and a significant deformation of the mandible. Our previous chincup study examined its use in moderately severe mandibular prognathism without retrusion of the maxilla. The orthopedic force was approximately 500 g at the center of chin and was applied during sleep for 6 to 24 months. For mandibular prognathism subjects (means, 1.0° and –1.3° of ANB angle in the prepubertal and pubertal subjects), the resultant changes were maintained after retention. However, research reported that the changes obtained during chincup treatment (average, 4½ years’ use) were often not maintained in severe skeletal Class III malocclusion. The aim of this clinical study was to investigate the immediate and long-term effects of prolonged use (mean, 7 years 2 months) of chincup appliances in subjects with dolichofacial Class III mandibles. Thirty-six female subjects with severe skeletal Class III malocclusions, associated with large gonial angles, were selected from the dental records of a private clinic. At posttreatment (T1, 65 months’ duration) and postretention (T2, 56 months after T1), Ar-Me and Wits appraisal cephalometric parameters were significantly different ( P < .01) between patients and control subjects (n = 230). Furthermore, the Go-Me parameter in treated subjects was longer than that of the controls at T0 but became significantly shorter at T2 ( P < .01). Treatment was associated with a finding that the Ar-Go parameter increased less than the controls at T2. Our results indicate that long-term use of the chincup appliance (>5 years) is effective in subjects with severe skeletal Class III abnormality. (Am J Orthod Dentofacial Orthop 1999;116:610-5)

Surgical correction of facial asymmetry with mandibular prognathism by Le Fort I osteotomy and obwegeser II method: Report of a case

Orthognathic surgery is widely used to correct congenital and acquired dentofacial discrepancies. Various surgical procedures have been advocated for correction of mandibular prognathism. In this study, a modified intraoral vertical ramus osteotomy has been developed for surgical correction of mandibular prognathism. The aim of this study is to identify contributing factors to skeletal change by analysing cephalometric changes after modified intraoral vertical ramus osteotomy.Forty-one patients, treated for absolute mandibular prognathism by bilateral modified intraoral vertical ramus osteotomy, were evaluated cephalometrically with reference to the menton point. A set of four standardised lateral cephalograms were obtained from each subject preoperatively (T1) and immediately postoperatively (T2), prior to removal of maxillomandibular fixation (T3), and at 1-year postoperatively (T4). The mean setback of the menton was 12.4 mm in the horizontal direction. Relapse was defined as forward movement of the menton during the 1-year follow-up.The highly significant backward movements in a horizontal direction were observed during the maxillomandibular fixation period (T3–T2). Moreover, highly significant forward movement was observed following the maxillomandibular fixation period (T4–T3). After 1-year follow-up (T4–T2), the mean changes of the menton were 0.1 mm backward in the horizontal direction.In this series, the mean skeletal change compared with the amount of setback was less than 1% (0.1/12.4 mm) in backward movement. The results suggest that the modified intraoral vertical ramus osteotomy technique is useful and the more stable approach for correction of severe mandibular prognathism.