Skeletal Mandibular Protrusion Research Articles

Comparison of the skeletal stability after mandibular counter-clockwise rotation in three surgical procedures.

The treatment of mandibular deformities with an anterior open bite is challenging. In this study, skeletal stability after mandibular osteotomies was evaluated to determine the best treatment for mandibular prognathism with an anterior open bite in three procedures: intraoral vertical ramus osteotomy (IVRO), conventional sagittal split ramus osteotomy (conv-SSRO), and SSRO without bone fixation (nonfix-SSRO). Patients who underwent mandibular osteotomy to correct skeletal mandibular protrusion were included. Changes in skeletal and soft tissues were assessed using lateral cephalograms taken before (T1), 3 ± 2days (T2), and 12 ± 3months (T3) after surgery. Thirty-nine patients were included: nine in the IVRO group and 11 and 19 in the conv- and nonfix-SSRO groups, respectively. The mandibular plane angles (MPAs) of the T2-T1 were - 2.7 ± 2.0 (p = 0.0040), - 3.7 ± 1.7 (p < 0.0001), and - 2.3 ± 0.7 (p < 0.0001) in the IVRO, conv-SSRO, and nonfix-SSRO groups, respectively. The skeletal relapse of the MPAs was not related to the MPA at T2-T1, and it was approximately 1.3° in the conv-SSRO group. The skeletal relapse of the MAPs was significantly correlated with the MPA of T2-T1 in the IVRO (p = 0.0402) and non-fix-SSRO (p = 0.0173) groups. When the relapse of the MPAs was less than 1.3°, the MPA of T2-T1 was calculated as 2.5° in the nonfix-SSRO group. When the MPA of T2-T1 is less than 2.5°, non-fix SSRO may produce a reliable outcome, and when it is more than 2.5°, conv-SSRO may produce better outcomes.

Relation between masseter muscle volumes and mandibular body lengths in skeletal Class III adult female cases without severe mandibular asymmetry

ABSTRACT Objective As reported in our pilot study using skeletal Class III adult female cases without severe mandibular asymmetry (Kawajiri A, et al, Jpn J Jaw Deform. 2019;29:31-41), cranial vaults with unilateral posterior deformation had posteriorly positioned mandibular fossae on the same side, and the longer mandibular bodies were seen with more posteriorly-positioned mandibular fossae. These findings suggest that mandibular body length compensated the A-P position of the mandibular fossa to prevent facial asymmetry. However, the used subjects in our pilot study were selected by two-dimensional P-A cephalograms. Thus, as the first purpose, three-dimensional case selection was performed, and craniofacial structure was examined in subjects. As the second purpose, the relation between the mandibular body lengths and the masticatory muscle volume was examined. Materials and Methods CT images of 32 adult female patients with skeletal mandibular protrusion were used in this study. The lateral deviation of Pog was less than 3 mm in all cases. The 3D analysis was performed on CT images. The cranial vault shape, the position of the mandibular fossae and the length of the mandibular bodies were analyzed. The masseter and medial pterygoid muscles were reconstructed and analyzed. Results The present findings reproduced the results in our previous pilot study. The volume of the masseter muscles, but not the medial pterygoid muscles, had a significant positive correlation with the mandibular body lengths. Conclusion A novel mechanism for preventing mandibular asymmetry was proposed. Both hard and soft craniofacial tissues are likely to be involved in this mechanism.

Long-term Management of a Patient with Apert Syndrome

To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

Two Cases of Skeletal Mandibular Protrusion Who Underwent Orthognathic Treatment after Middle Age

Two Cases of Skeletal Mandibular Protrusion Who Underwent Orthognathic Treatment after Middle Age

Surgical Orthodontic Treatment of Skeletal Mandibular Protrusion with Multiple Impacted Ankylosed Teeth Treated with Alveolar Corticotomy

To present a case of skeletal mandibular protrusion with multiple impacted ankylosed teeth, which were treated with conventional orthognathic surgery and alveolar corticotomy, respectively. Tooth ankylosis is characterized by the fusion of a root surface with the surrounding alveolar bone. Various treatment modalities for tooth ankylosis have been developed and are used commonly in the clinic. Corticotomy is defined as the application of intentional surgical injury to the cortical bone to mobilize a tooth with the adjacent bone and soft tissues. The corticotomy technique has been improved in recent years to avoid possible risks such as periodontal damage, tooth devitalization, and osseous necrosis due to an inadequate blood supply. A female patient aged 16 years and 3 months was diagnosed with anterior crossbite and the impaction and ankylosis of multiple canines. After the confirmation of ankylosis, alveolar corticotomy was performed on the maxillary left and mandibular right canines. After 6 months of traction (patient age, 19 years and 7 months), both canines had extruded successfully. After the completion of preoperative treatment, bilateral intraoral vertical ramus osteotomy was performed to correct the anterior crossbite involving a skeletal mandibular protrusion. The amounts of mandibular setback on the right and left sides were approximately 7 and 5 mm, respectively. The total treatment period was 55 months. Acceptable occlusion with a balanced profile was maintained over a 5-year retention period, indicating the long-term stability and success of the treatment. Our results indicate that alveolar corticotomy should be considered to facilitate the treatment of multiple impacted ankylosed teeth. This report proposes an efficacy of alveolar corticotomy for extrusion of impacted ankylosed teeth.

上下顎無歯顎となった骨格性下顎前突症患者に対して上下顎移動術を施行した1例

上下顎無歯顎となった骨格性下顎前突症患者に対して上下顎移動術を施行した1例

Relationship between olfaction and maxillofacial morphology in children with malocclusion.

ObjectivesFunctional problems, including nasal flow problems, are associated with specific skeletal and dental features. Further, maxillary expansion has been associated with nasal airway resistance alterations. This study aimed to investigate whether there is a correlation between skeletal features and nasal airflow‐ and olfaction‐related problems.Materials and methodsThis prospective study included 68 patients (30 boys, 38 girls; mean age 9 ± 2 years) examined at the Ohu University Hospital. We classified patients into three skeletal Classes (Class I, II, and III) based on the ANB angle. Olfactory disorder history was collected from the guardians. Maxillofacial measurements, nasal airflow assessments, and olfactory tests were performed using cephalometric analysis, rhinomanometry, and T&T olfactometer, respectively.ResultsMalocclusion, resulting from skeletal mandibular protrusion and smaller maxilla, was associated with reduced olfaction in children. The detection and recognition thresholds of skeletal Class III were significantly higher than those of Classes I (p = .01) and II (p = .01). Significant correlations were observed between SNA and the detection threshold (r = −.50) as well as between nasion perpendicular‐point A and the recognition threshold (r = −.53). The detection and recognition thresholds were significantly higher in Class III than in Classes I (r = .3) and II (r = −.1).ConclusionsMaxillary growth and development may be associated with olfaction in children. Changing the maxillofacial morphology may improve olfactory function. In the future, we will investigate how malocclusion treatment affects olfactory function.

Postoperative Stability and Three-dimensional Evaluation of Medial Pterygoid Muscle in Skeletal Mandibular Protrusion Cases Undergone Short Lingual Osteotomy

Postoperative Stability and Three-dimensional Evaluation of Medial Pterygoid Muscle in Skeletal Mandibular Protrusion Cases Undergone Short Lingual Osteotomy

Morphologic Evaluation for Safe Le Fort I Osteotomy in Cleft Lip and Palate.

The present study aimed to determine the structure and morphology of the maxilla in patients with cleft lip and palate to ensure safe Le Fort I osteotomy. A total of 34 sides of 17 patients with unilateral cleft lip and palate (nonsyndromic cases) were included in this study. The control group included 10 sides of 5 patients who exhibited skeletal mandibular protrusion without malformation. Finite element analysis was performed to examine the distribution of occlusal force over the maxilla, and continuous 3-dimensional measurement was performed at the sites of stress concentration. In patients with cleft lip and palate, bones at the lateral border of the piriform aperture and the anterior wall of the maxillary sinus were significantly thicker than those in controls ( P < .05). Furthermore, the attachment of the pterygomaxillary junction was wider and thicker ( P < .05), and the anterior distance to the descending palatine artery was shorter ( P < .01) in patients with cleft lip and palate than in controls. Our results further indicated that alveolar bone grafting may significantly influence bone thickness and the attachment state of the pterygomaxillary junction. Our results suggest that the complications of LFI can be reduced in patients with cleft lip and palate by ensuring proper understanding of each patient's maxillary anatomy and bone thickness, as well as the location of the descending palatine artery and the attachment state of the pterygomaxillary junction.

Bloch-Sulzberger症候群（色素失調症）を有する顎形態異常患者を顎矯正手術により治療した1例

Bloch-Sulzberger syndrome (Incontinentia pigmenti) is a genetic disease that displays multiple forms of symptoms including those of the skin, teeth and eyes. Here, we report the case of a patient with Bloch-Sulzberger syndrome on whom we performed orthognathic surgery under general anesthesia. The patient was a 21-year-old female. Oral cavity findings were congenital defects in the right upper jaw 7542, left upper jaw 12578, right lower jaw 754, and left lower jaw 125. Late-stage residual E in the left upper jaw, and abnormal crown morphology of tooth 23 in the right lower jaw and tooth 3 in the left upper jaw were observed. Right cephalometric radiographic analysis revealed marked skeletal mandibular protrusion at SNA: 77.6°, SNB: 89.1°, and ANB: −11.5°. Mandibular protrusion with anomaly in the number of teeth was diagnosed; sagittal split ramus osteotomy and Le Fort 1 osteotomy were performed under general anesthesia. At 18 months postsurgery, the patient is wearing the final prosthesis and occlusion has been confirmed. The present status of occlusion is good and the patient is also satisfied.

A Case of Skeletal Mandibular Protrusion Treated with Implant Prostheses after Orthodontic Treatment Using Definitive Implants as Anchors

A Case of Skeletal Mandibular Protrusion Treated with Implant Prostheses after Orthodontic Treatment Using Definitive Implants as Anchors

Morphological Changes in the Temporomandibular Joint Before and After Sagittal Splitting Ramus Osteotomy of the Mandible for Skeletal Mandibular Protrusion

Changes of temporomandibular joint (TMJ) morphology were analyzed in 21 patients with mandibular protrusion corrected using bilateral sagittal split ramus osteotomy (SSRO) and mini-plate fixation with TMJ cephalometric laminographs. The condylar pass angle, eminence to the FH plane angle, and total height of fossa and lower height of fossa in both left and right sides, significantly decreased after surgery. The width of the condyle, in both left and right sides, significantly increased after treatment. However, in the joint spaces, there were no significant differences before and after treatment. The amount of change in the eminence to the FH plane angle, total height of fossa and lower height of fossa, before and after surgery, showed significant positive correlations with that of SNB, before and after surgery. These results suggest that adaptive bone remodeling of the TMJ might occur due to the correction of occlusion and craniofacial morphology by SSRO in patients with mandibular protrusion.

長期的観察を行っている著しい下顎偏位および多数歯補綴治療を伴った骨格性下顎前突外科症例

骨格が不正であることにより，口腔内に不適切な補綴物が装着されることがしばしばみうけられる．これらの場合予期せぬ咬合圧の負担が認められ，早期に咬合の崩壊を招くおそれが懸念される．そこで外科矯正で骨格の不正を是正し，良好な補綴物を装着することは，咬合および歯周病の観点において重要なことである．また，正しい歯の位置と緊密な咬合を獲得することは，咬合機能や審美性の獲得に重要であるとともに，外科矯正の後戻り防止において不可欠である．本症例は初診時年齢32歳3か月の女性で，下顎の前突感および非対称を主訴に矯正科を来院した．多数歯にわたり補綴処置が施され，前歯部のoverjet が－7.0 mmであり，下顎左側前下方への過成長を伴う long face type の骨格性下顎前突と診断した．レントゲン分析によりANB-3°, Ul-SNplanell2°, 下顎前歯歯軸角（以下 IMPA）86.1°, Gonialangle130.9°を示し，下顎角が大きく前歯部には骨格性下顎前突症特有の dental compensation が認められた．治療はマルチブラケットを装着し，術前矯正を1年4か月行った後，下顎枝矢状分割術を施行した．その後detailing を行い1 年後に術後矯正を終了した．術後において被蓋関係は overjet＋2.0 mm, oveerbite＋l. 5 mm に，上顎前歯歯軸角は Ul-SN108°に，IMPAは90.5°に改善した．骨格の不正および咬合が是正された後，ただちに適正な補綴物に換装することで，安定的な咬合が得られた．現在は保定開始後約10年を経過するが，安定した予後経過をたどっている．

Class III malocclusion with complex problems of lateral open bite and severe crowding successfully treated with miniscrew anchorage and lingual orthodontic brackets

In this article, we report the successful use of miniscrews in a patient with an Angle Class III malocclusion, lateral open bite, midline deviation, and severe crowding. Simultaneously resolving such problems with conventional Class III treatment is difficult. In this case, the treatment procedure was even more challenging because the patient preferred to have lingual brackets on the maxillary teeth. As a result, miniscrews were used to facilitate significant asymmetric tooth movement in the posterior and downward directions; this contributed to the camouflage of the skeletal mandibular protrusion together with complete resolution of the severe crowding and lateral open bite. Analysis of the jaw motion showed that irregularities in chewing movement were also resolved, and a stable occlusion was achieved. Improvements in the facial profile and dental arches remained stable at the 18-month follow-up.

Six-year Follow-up in Skeletal Class III Patient Aged over 40 Receiving Orthognathic Surgery and Autotransplantation: A Case Report

This paper describes the post-operative course of care in a patient requiring orthognathic surgery for skeletal mandibular protrusion in whom autotransplantation of a third molar was performed. A lower third molar that had to be removed for sagittal split ramus osteotomy (SSRO) was transplanted to replace the missing right second molar during pre-surgical orthodontic treatment, contributing to post-treatment occlusal stability. A 44-year-old woman presented with mandibular protrusion. The upper left second molar was congenitally missing and the lower right second molar had been extracted. She was diagnosed as having skeletal mandibular protrusion with excess vertical growth of the mandible and anterior open bite. Correction of the skeletal problem required orthognathic surgery by SSRO and Le Fort I osteotomy without orthodontic tooth extraction. At month 5 during 18 months of pre-surgical orthodontic treatment, the lower left third molar was transplanted to the lower right second molar site. Active treatment was completed after 7 months of post-surgical orthodontic treatment. The patient wore upper and lower Begg-type removable retainers for approximately 2 years. She returned for a recall checkup at 6 years post-treatment. Although radiographic examination revealed root resorption and ankylosis of the autotransplanted tooth at 8 years after transplantation, occlusion has remained stable with no clinically significant complications. The autotransplanted tooth helped stabilize her occlusion and acted as a kind of temporary tooth prior to the final decision on treatment to be given such a dental implant.

成長に伴い再治療を要した下顎非対称を伴う下顎前突症の一例

成長期における矯正治療は, 成長予測が重要となってくる. 本症例は成長期である11歳5か月時に骨格性上顎前突傾向を呈していたため, 他院にて上顎両側第一小臼歯抜去を行い, マルチブラケット装置にて矯正治療を開始した. 13歳10か月で動的治療終了 (動的治療期間2年5か月) となり保定装置による経過観察を行っていた. しかし経過観察中に, 成長に伴い顎位の変化が認められたため当科を紹介され受診した. 当科初診時における診断は, 骨格性下顎前突症傾向を示す下顎左方偏位であり, 左側下顎頸部の下顎骨内側内面方向への変形および下顎頭の変形を伴っていた. 治療方針は外科的矯正治療を前提とし, 顎の成長終了まで経過観察を行った. 成長の経過観察終了後に, 上顎は既に抜歯されていたことと下顎両側犬歯が先天性欠如であることから, 上下顎非抜歯にて外科的矯正治療併用した咬合の改善を行った.我々は, 本症例の成長期および動的治療における変化の様相と保定期間中の咬合の維持についての考察を報告する.

統合失調症を伴う骨格性下顎前突症に対し外科的矯正治療を行った１例

Schizophrenia is an inherent disease that causes disruption of thinking patterns, sensing, self-esteem, will and emotions, resulting in mental disorder involving hallucinations and other mental symptoms.The major complaint of this 21-year-old female patient with skeletal mandibular protrusion was thought to be pain of the temporomandibular region. However, upon careful analysis based on Narrative Based Medicine, the primary concern was the mandibular protrusion with asymmetry inducing multiple psychological symptoms. Combined ortho-surgical intervention was performed to resolve this patient's problem. Although increased antidepressant intake was noted prior to the surgery, once the treatment had been performed, resulting in major improvements of the profile and appearance, dramatic mental and psychological changes for the better were noted, allowing this patient's return to a healthy and normal social life along with decreased dependency on anti-depressant drugs.

Stomatognathic function and image evaluation for skeletal mandibular protrusion case with remarkable remodeling on the condyle

Stomatognathic function and image evaluation for skeletal mandibular protrusion case with remarkable remodeling on the condyle

吸収性プレートを用いて上下顎移動術を施行した骨格性下顎前突症例―上顎前方移動時の位置決めにフェイスボウを用いて―

We present a case report of remarkable skeletal mandibular protrusion operated with Le Fort I osteotomy and sagittal splitting ramus osteotomy, the so-called twojaw surgery. In Le Fort I osteotomy, positioning of the maxillary bone was performed using a face bow transfer method. As a result of the osteotomy, the maxillary bone segment was fixed at the planned position. The surgical procedures achieved an improvement in the facial form and the occlusion. In this case, an absorbable bone fixation plate, FIXSORB®MX, was employed and it could be as useful for two-jaw surgery as a titanium plate under equal conditions. The progress after the operation was evaluated. Although skeletal changes were merely observed at one year after operation, the dental and skeletal stability was well maintained for three years after the operation.

Changes in Frontal Facial Appearance after Surgical Orthodontic Treatment in Skeletal Mandibular Protrusion Cases : The Usefulness of Standardized

Changes in Frontal Facial Appearance after Surgical Orthodontic Treatment in Skeletal Mandibular Protrusion Cases : The Usefulness of Standardized