Temporomandibular joint bony ankylosis: comparison of treatment with transport distraction osteogenesis or the matthews device arthroplasty

Temporomandibular joint (TMJ) bony ankylosis with micrognathia is a rare congenital condition that is difficult to treat and may result in recurrence. In a series of affected patients, we compared two new methods of treatment: transport distraction osteogenesis and Matthews Device arthroplasty. All patients had computed tomography scan documented bilateral TMJ bony ankylosis. Group I (transport distraction osteogenesis) underwent distraction advancement of the mandible (for micrognathia) followed by resection of the condyles, recontouring of the glenoid fossas with interposition temporoparietal-fascial flaps, and transport distraction osteogenesis of mandibular rami segments. Group II (Matthews Device arthroplasty) underwent all of the above procedures except for transport distraction osteogenesis. Instead, the Matthews Devices were anchored to the temporal bone and mandibular rami. Hinged arms allowed for motion at the reconstructed TMJ. In both groups, patients underwent extensive postoperative therapy. Preoperative, postoperative, and follow-up lateral cephalograms were obtained, and incisor opening distances were recorded. All patients but one had severe micrognathia (n = 9). For group I (transport distraction osteogenesis), mean age was 6.8 years. and mean advancement was 28.5 mm. For group II (Matthews Device arthroplasty) mean age was 8.2 years, and mean advancement was 23.5 mm. In group I (transport distraction osteogenesis), mean incisor opening was 1 mm preoperatively and 27.5 mm postoperatively; however, it relapsed to 14.3 mm by 12.5 months follow-up (48% relapse). Mean incisor opening in group II (Matthews Device arthroplasty) was 3.9 mm preoperatively and 33.4 mm postoperatively and remained at 30.6 mm after 11.1 months follow-up (8% relapse). One patient in group I (transport distraction osteogenesis) underwent surgical revision because of relapse. Our data showed that for congenital TMJ bony ankylosis both transport distraction osteogenesis and Matthews Device arthroplasty techniques were successful initially; however, the Matthews Device arthroplasty avoided long-term relapse.     

The role of simultaneous gap arthroplasty and distraction osteogenesis in the management of temporo-mandibular joint ankylosis with mandibular deformity in children.

INTRODUCTION: Temporo-mandibular joint ankylosis is a common cause of acquired deformity in children. PURPOSE: Surgical correction of the ankylosis only leaves the patient with an uncorrected mandibular deformity. This study was to evaluate the use of distraction osteogenesis for simultaneous correction of the mandibular deformity. MATERIAL: This study was done on six children with temporo-mandibular joint ankylosis and mandibular deformity. Uniaxial double pin distractors with Schanz pins were used in this study. METHODS: The patients underwent simultaneous gap arthroplasty and mandibular osteotomy (retromolar) with distractor insertion. Distraction was started on the fifth post-operative day. The patients were put on dynamic temporo-mandibular joint exercises on the first post-operative day. RESULTS: All patients had a satisfactory mouth opening on follow-up. Satisfactory cosmetic correction of the mandibular deformity was also achieved in all these patients. Some degree of malocclusion resulted from treatment due to which the patients were placed on orthodontic treatment.CONCLUSIONS: Distraction osteogenesis can be used simultaneously with gap arthroplasty in patients with temporo-mandibular ankylosis, for the correction of the mandibular deformity.     

正颌外科治疗颞下颌关节强直伴阻塞性睡眠呼吸暂停综合征

目的 评价正颌外科手术治疗颞下颌关节强直伴阻塞性睡眠呼吸暂停综合征(OSAS)的效果。方法 12例颞下颌关节强直伴OSAS患者(男4例，女8例，年龄10～25岁，平均18．4岁；双侧颞下颌关节强直8例，单侧颞下颌关节强直4例)，采用颞下颌关节成形术、下颌矢状劈开前徙术、颏前徙成形术、舌骨悬吊术以及牵张成骨术移动下颌骨和舌骨。术后随访3～36个月。结果 12例患者张口度由术前的0～2mm增大到术后25～40mm；术后患者颜面形态明显改善；其连续血氧饱和度最低值由术前的42％提高至术后的90％以上，睡眠呼吸障碍解除和睡眠质量获得提高。结论 在颞下颌关节强直伴OSAS患者的治疗中，行颞下颌关节成形术的同时，辅助正颌外科手术，不仅可以增大患者的张口度，而且还能解决患者下颌后缩的畸形，同时解除上气道狭窄，从而缓解或纠正患者的低氧血症。     

Simultaneous arthroplasty and distraction osteogenesis for the treatment of ankylosis of the temporomandibular joint and secondary mandibular deformities in children

The purpose of this study was to explore the use of simultaneous arthroplasty and distraction osteogenesis in the treatment of children with ankylosis of the temporomandibular joint (TMJ) and secondary mandibular deformities. Between January 2012 and December 2016, 17 children (7 boys and 10 girls, mean (range) age 7 (4–12) years) were treated. Preoperatively, the mean (range) maximal incisal opening was 1.4 (0–5) mm. Distraction osteogenesis was used to elongate the mandibular body or ramus, or both, after the release of ankylosis. Distraction began after five to seven days at a rate of 0.5 mm twice daily, and the distractor was removed three to five months after the completion of distraction. The mean (range) follow-up time after removal was 29.6 (16–45) months, and the distance of distraction was 14.4 (10–18) mm. After treatment, all patients had satisfactory outcomes, a good facial profile, alignment of the midline lower incisor, and a level occlusal plane. The mean (range) maximum incisal opening reached 35.7 (31–41) mm. Bone formation across the distraction gap was good. The mean minimum axial area of the airway increased from 61.4 mm to 96.4 mm (p < 0.01). No patients had a recurrence of ankylosis during follow up. Our results suggest that simultaneous arthroplasty and distraction osteogenesis is feasible in this group.     

Simultaneous costochondral graft and distraction osteogenesis in unilateral TMJ ankylosis associated with mandibular retrognathia and asymmetry

The purpose of this study was to review the long-term effect of simultaneous costochondral graft (CCG) and distraction osteogenesis (DO) in the management of unilateral temporomandibular joint ankylosis associated with severe dentofacial deformities in our clinic. In addition, we sought to analyze the advantages and disadvantages of CCG and DO. Four patients were included in this clinical study during 2005 to 2007. The mean length of ankylosis history was 14.5 years. All patients had significant mandibular retrognathia and asymmetry histories and have been diagnosed with obstructive sleep apnea syndrome by a polysomnogram before surgery. A 1-stage surgery, with gap arthroplasty, CCG, and mandibular DO, was performed. The surgical plan and technique were reviewed. No severe complications were observed after surgery. Distraction was started on day 7 after surgery. The distance of distraction ranged from 20 to 25 mm (mean, 22.5 mm). Mouth opening was increased from 25 to 37 mm (mean, 33.5 mm) during the follow-up period (range of 3.5-5 y). No recurrence of joint ankylosis occurred based on the clinical and radiographic evaluations. All of the patients had significant improvement in obstructive sleep apnea syndrome after surgery. Mandibular asymmetry and retrognathia were well corrected in all of the patietns. In conclusion, a 1-stage surgical treatment with DO and CCG demonstrated its feasibility and effectiveness in management of temporomandibular joint ankylosis combined with severe dentofacial deformity. It is a safe and reliable method of treatment.     

Treatment of temporomandibular joint ankylosis and facial asymmetry with bidirectional transport distraction osteogenesis technique

Transport distraction technique is a good treatment modality for unilateral temporomandibular joint ankylosis. However, with a unidirectional distraction, it is not possible to correct facial asymmetry that results from mandibular hypoplasia associated with early-onset unilateral temporomandibular joint ankylosis. For this purpose, gap arthroplasty and simultaneous bidirectional transport distraction was used to correct these deformities. Although vertical distraction corrects vertical deficiency of the ramus and creates a neocondyle, the simultaneous anteroposterior distraction of the transport segment corrects facial asymmetry resulting from horizontal shortness of mandible. Three patients, whose mean mouth opening was 8.6 mm, were successfully treated with this technique. Mean advancements in vertical and anteroposterior direction were 14.7 and 7.7 mm, respectively. Mean maximal mouth opening was 29.7 mm postoperatively. The average follow-up period was 13 months (range, 12-15 mo). During this period, reankylosis was not observed, and the interincisal distance did not decrease. Gap arthroplasty and bidirectional transport distraction of the mandibular ramus is a good and effective therapeutic option in treatment.     

Management of temporomandibular joint ankylosis with temporalis fascia flap and fat graft

AimTemporomandibular joint (TMJ) ankylosis is a serious problem that restricts jaw mobility and causes disturbances in facial and mandibular growth. The purpose of this paper is to present an easy and versatile method for the treatment of TMJ ankylosis to decrease postoperative complications such as re-ankylosis.Material and methodEleven patients who presented with ankylosis of the TMJ underwent surgical release. After performing gap arthroplasty through a preauricular approach, the temporalis fascia flap was transposed to the gap. An autogenous fat graft was then obtained from the abdomen and used as interpositional material. The follow-up time was 3–5 years.ResultsRe-ankylosis did not occur in any of the patients, and all had satisfactory mouth opening.ConclusionSurgical treatment of TMJ ankylosis with gap arthroplasty, interposition of the temporalis fascia flap and fat grafting is an effective and easily procedure for preventing of re-ankylosis. The autogenous nature and close proximity to the joint are the main advantages of the temporalis fascia flap when compared with other interpositional materials, and the fat graft provides additional support by reducing pressure.     

Piezoelectric osteoarthrectomy for management of ankylosis of the temporomandibular joint

We describe the use of a piezoelectric osteotome for removal of bone in patients with ankylosis of the temporomandibular joint (TMJ) and its advantages over conventional techniques. We studied 35 patients with ankylosis of 62 TMJ (27 bilateral and 8 unilateral, 2 recurrent) who were treated by gap arthroplasty between 1 January 2011 and 31 December 2012. We used a preauricular, with extended temporal, incision in all cases. The ankylosis was released with a piezoelectric scalpel. There were 23 men and 12 women, mean (SD) age 16 (9) years. We noticed a substantial reduction in bleeding with the piezoelectric bone cutter compared with the dental drill, though the operating time was longer. We noticed no bleeding from the maxillary artery or pterygoid plexus. Mean (SD) bleeding/side was 43 (5) ml, and mean (SD) operating time was 77 (8) minutes for a single joint. At 6 months’ follow-up mean (SD) passive mouth opening was 35 (3) mm. Piezoelectric bone removal for the release of ankylosis of the TMJ is associated with minimal bleeding, few postoperative complications, and satisfactory mouth opening at 6 months’ follow up.     

自体喙突移植重建髁突对儿童颞下颌关节强直患者下颌骨生长的远期影响

目的 儿童期下颌骨髁突受损通常导致错颌畸形和面部生长不协调。本研究目的是评价自体喙突移植重建下颌骨髁突对儿童颞下颌关节强直患者面部生长发育的远期影响。方法 追踪评估2008年1月1日至2016年12月31日期间收治于四川大学华西口腔医院正颌及关节外科的10名单侧颞下颌关节强直的儿童患者,其中包括3名男性和7名女性,于5~12岁期间接受了关节间隙成形术、同侧喙突移植髁突重建术和带蒂颞筋膜瓣置入术。术后追踪3~8年,平均4.9年。术后拍摄曲面断层X线片,测定患侧下颌体长度和下颌支高度的生长量并与健侧相比较。结果 所有患者术后恢复良好,追踪结束时10名患者的最大开口度为32~41 mm,平均35.6 mm。自体喙突移植重建髁突解除强直后下颌支高度和下颌体长度均继续生长,但是依然存在生长不足的现象。与初始数据（术后）相比,患侧下颌支高度（随访结束）增加了25.3%（P<0.05）,患侧下颌体长度增加了26.1%（P<0.05）。对比患侧与健侧的下颌骨生长率,患侧下颌支高度增长量与健侧相比少47.1%（P<0.05）,患侧下颌体长度的增长量与健侧相比少27.2% （P<0.05）。结论 自体喙突移植重建下颌骨髁突治疗儿童颞下颌关节强直后,患侧下颌骨可继续生长,但依然会存在生长不足的现象。在颞下颌关节强直治疗完成后,相比于健侧,患侧的生长率是减小的。     

内置式下颌骨牵引成骨术的早期并发症及防治

目的 总结内置式下颌骨牵引成骨术(DO)术中和术后早期并发症，探讨其有效防治方法。方法 对1997年11月～2002年12月间应用DO治疗的48例(83侧)下颌骨畸形或缺损患者进行分析。其中颞下颌关节强直伴小颌畸形双侧13例、单侧9例，下颌骨发育不足或小颌畸形14例，第一、二鳃弓综合征单侧5例、双侧1例，爆炸伤或肿瘤术后缺损畸形5例，Treacher Colins综合征1例，伴睡眠呼吸暂停综合征(OSAHS)者19例。所有病例均采用口内或(联合)口外切口并应用内置式牵引器。总结自施行手术开始至牵引完成期间的并发症及处理措施。结果 6例患者出现术中或术后早期并发症，发生率为12．5％，其中牵引机械装置故障2例，骨皮质切开术不彻底1例，早期感染1例，前牙严重开He1例，牵引早期疼痛剧烈1例，积极处理后均达到预期治疗目的。结论 减少DO术中及术后早期并发症的关键在于充分理解下颌骨牵引成骨术的机理，熟悉掌握下颌骨及邻近解剖结构，熟练操作规范，充分的术前准备和术后护理尤为重要。     

Is dermis fat arthroplasty better than plain gap arthroplasty? A prospective randomised controlled trial

The aim of the study was to compare interpositional arthroplasty using a dermis fat graft with gap arthroplasty in the management of ankylosis of the temporomandibular joint (TMJ). We organised a prospective randomised study of 22 patients who presented with ankylosis of the TMJ. They were randomised to be treated with either plain gap arthroplasty or dermis fat arthroplasty, and the predictor variable was the method of treatment. The primary outcome variables were mouth opening and pain on jaw exercises. Pain and interincisal opening were measured on day 5, day 14, at the end of one month, and at six months, one year, two years, and three years. There was a significant difference between the two groups on two occasions: postoperative day 5 (p = 0.013) and at one year (p = 0.018). The mean (SD) scores for mouth-opening were higher in the dermis fat group at all times (41.20 (4.69) mm compared with 39.50 (2.46) mm in gap arthroplasty at two years, and 41.40 (3.60) mm compared with 38.9 (2.02) mm at three years). The visual analogue pain scores were also lower in the dermis fat graft group. The groups showed similar results at the end of three years follow up, with no significant difference in mouth opening. We conclude therefore that the two techniques have similar outcomes in the management of ankylosis of the TMJ.     

A clinical study on ankylosis of the temporomandibular joint.

INTRODUCTION: Restoration of normal function and jaw movement in patients with temporomandibular joint (TMJ) ankylosis is difficult. Various techniques have been defined for the treatment of the condition. PATIENTS: This study is based on the pre-, intra- and post-operative evaluation of 78 TMJ operations in 59 patients who were treated for TMJ ankylosis between 1985 and 2002. METHODS: The patients in this study were evaluated with regard to age, gender, aetiology of ankylosis, ankylosis type/classification, existing facial asymmetry, maximal pre- and post-operative mouth opening, the arthroplasty methods (gap and interpositional arthroplasty) including complications and recurrence of ankylosis. RESULTS: Falls represented the most widespread aetiological factor (85%), and women constituted the group with the highest incidence of ankylosis (61%). Forty cases were unilateral (68%) and 19 bilateral (32%); 82% (64 joints) were of the bony type. Gap arthroplasty was applied in 34 of the 59 cases (58%) and interpositional arthroplasty in the remaining 25 (42%). Pre- and post-operative mean mouth opening were 3.5+/-1.7 and 30.7+/-3.0mm, respectively. Re-ankylosis was noted in 5%. CONCLUSION: In addition to radical and sufficient resection of the ankylosed bone, early post-operative exercises, appropriate physiotherapy and close follow-up of the patient play an important role in the prevention of post-operative adhesions and re-ankylosis.     

同期关节重建及下颌体牵张成骨治疗颞下颌关节强直3例报道

目的:对伴有严重牙颌面畸形的颞下颌关节强直患者,采用自体肋骨软骨移植重建关节,同期运用牵张成骨术行下颌骨牵张成骨延长下颌体长度,治疗下颌后缩和阻塞性睡眠呼吸暂停低通气综合征(OSAHS),评价治疗计划的可行性及短期效果。方法:3例颞下颌关节强直患者,平均年龄17.5岁,发生关节强直的平均年龄为3.6岁,病程平均为13.9a,开口度均为0,均伴有严重牙颌面畸形和OSAHS。根据头影测量结果,预先设计患侧下颌支下降的长度和下颌体延长长度;采用关节成形术加双侧冠突切除,术中取模制备板,进行同期自体肋骨软骨移植重建颞下颌关节和双侧下颌体牵张成骨术。术后第7天开始牵引,每天2次,牵引速率为0.8mm/d。结果:3例患者均顺利完成手术,术后未出现感染等严重并发症。顺利完成牵张成骨。下颌骨牵引长度平均为22.5mm(20.5～25mm)。术后3个月开口度平均为28mm(26～32mm),患者面形及OSAHS获得良好改善。结论:肋骨软骨移植关节重建同期进行下颌体牵张成骨具有良好的稳定性,该设计有利于缩短治疗周期和治疗费用,在短期内可同时解决开口、面形和OSAHS等问题,为后续矫正咬合关系奠定了基础。     

Intraoral distraction osteogenesis for the correction of facial deformities following temporomandibular joint ankylosis: a modified technique

The aim of this study was to evaluate the feasibility of transoral bimaxillary distraction osteogenesis before releasing temporomandibular joint (TMJ) ankylosis using intraoral mandibular distractors. Nine patients (5 males, 4 females) aged 14-35 (mean 19) years were included. A bilateral Le Fort I osteotomy was performed together with a mandibular osteotomy on the affected side(s). An intraoral distractor(s) was inserted in the lower jaw, followed by an intermaxillary fixation (IMF) to maintain preoperative dental occlusion. The distractor was activated, after a latency period of 5-7 days, 2 times daily by 0.5 mm. There followed a consolidation period of 6-8 weeks. TMJ ankylosis was then released via a peri-auricular incision, a gap arthroplasty was performed, and mandibular movement was established after removal of the IMF and distractor. Optimal results were achieved clinically and radiologically with minimal relapse and complications. Apart from minor complaints, the distraction process was smooth and tolerable in all cases. Total mandibular elongation ranged from 17 to 25 mm (20.7 mm). Occlusal canting decreased to 0 degrees in 7 patients and to 1 degree in 2 patients (mean 0.2 degrees). After a mean follow-up period of 17 months, a mean postoperative mouth opening of 34.7 mm was achieved (0.6 mm preoperatively) and no re-ankylosis was detected. Intraoral distraction of a deformed mandible and maxilla before releasing TMJ ankylosis is a feasible and perhaps advantageous technique.     

Treatment of temporomandibular joint ankylosis with temporalis muscle and fascia flap.

This study sought to determine the efficacy of interpositional arthroplasty with temporalis muscle and fascia flap in the treatment of unilateral temporomandibular joint (TMJ) ankylosis in adults. This retrospective study of seven cases evaluated the postoperative results of interpositional arthroplasty on temporalis muscle and fascia flap in adults. The operative protocol for unilateral TMJ ankylosis entailed, (1) resection of ankylotic mass, (2) intraoral ipsilateral coronoidectomy, (3) contralateral coronoidectomy when necessary, (4) interpositional tissue transfer to the TMJ with temporalis muscle and fascia flap, (5) maxillomandibular fixation (MMF), and (6) early mobilization and aggressive physiotherapy. The results of this protocol were encouraging, while the functional results of interpositional arthroplasty on temporalis muscle and fascia flap were satisfactory. The findings of this study support the use of temporalis muscle and fascia flap in adult patients with unilateral TMJ ankylosis. Early postoperative initial exercise, physiotherapy, and strict follow-up play an important role in preventing postoperative adhesions.     

Is aggressive gap arthroplasty essential in the management of temporomandibular joint ankylosis?—a prospective clinical study of 15 cases

The purpose of this three-year, prospective, follow-up study was to evaluate whether aggressive gap arthroplasty is essential in the management of ankylosis of the temporomandibular joint (TMJ). Fifteen patients were treated by the creation of a minimal gap of 5–8 mm and insertion of an interpositional gap arthroplasty using the temporalis fascia. Eleven patients had unilateral coronoidectomy and 4 bilateral coronoidectomy based on Kaban's protocol. Preoperative assessment included recording of history, clinical and radiological examinations, personal variables, the aetiology of the ankylosis, the side affected, and any other relevant findings. Patients were assessed postoperatively by a surgeon unaware of the treatment given for a minimum of 3 years, which included measurement of the maximal incisal opening, presence of facial nerve paralysis, recurrence, and any other relevant findings. Of the 15 patients (17 joints), 12 had unilateral and three had bilateral involvement, with trauma being the most common cause. The patients were aged between 7 and 29 years (mean (SD) age 20 (8) years). Preoperative maximal incisal opening was 0–2 mm in 8 cases and 2–9 mm in 9. Postoperatively adequate mouth opening of 30–40 mm was achieved in all cases, with no recurrence or relevant malocclusion during 3-year follow up. However, patients will be followed up for 10 years. Aggressive gap arthroplasty is not essential in the management of ankylosis of the TMJ. Minimal gap interpositional arthroplasty with complete removal of the mediolateral ankylotic mass is a feasible and effective method of preventing recurrence.     

Modified internal mandibular distraction osteogenesis in the treatment of micrognathia secondary to temporomandibular joint ankylosis: 4-Year follow-up of a case

Micrognathia and obstructive sleep apnoea syndrome (OSAS) are problems subsequent to temporomandibular joint ankylosis (TMJa) in growing patients. For patients with micrognathia and OSAS secondary to TMJa, it is important to restore proper mandibular form and dimension, achieve occlusal stability and recover satisfactory joint movement.We report a 4-year follow-up of a patient with micrognathia and OSAS secondary to bilateral TMJa. The treatment of this patient involved (1) a modified internal mandibular distraction osteogenesis without altering the pre-existing occlusion; (2) TMJ arthroplasty in which the dislocated disc was found and repositioned and the shape of the glenoid fossa and articular head was formed without removing bone in vertical dimension; (3) passive mouth-opening exercise with an individualized occlusal pad postoperatively for one month; and (4) orthodontic treatment for the occlusal disturbance and active mouth-opening exercise for one year. After the treatment the micrognathia was corrected; the oropharyngeal airway was increased significantly; mouth-opening increased to 40 mm intraoperatively was maintained at 36.66 mm 4 years after surgery. Satisfactory occlusion was achieved after orthodontic treatment. Through the 4-year follow-up, no signs of reankylosis were found. In conclusion, this new clinical protocol is a safe, effective and quick way to treat micrognathia and OSAS secondary to TMJa.     

Severe proliferative congenital temporomandibular joint ankylosis: a proposed treatment protocol utilizing distraction osteogenesis

The classical treatment for temporomandibular joint (TMJ) ankylosis in children: 1) joint release; 2) arthroplasty; 3) reconstruction; and 4) postoperative physical therapy (PT), is often unsuccessful. Postoperative physical therapy is difficult in the young patient due to poor cooperation. Moreover, there is a subgroup of patients who have a refractory congenital proliferative bony process that is the cause of their disease. In these patients, a role for distraction osteogenesis (DO) has been defined. We present a series of young patients with congenital proliferative TMJ ankylosis. Some have failed classic treatment. In such cases, DO is used to expand the mandibular size and soft tissue matrix. This creates a static open bite, facilitates mid-facial growth, and avoids compromise of the airway, speech, nutrition, and oral hygiene. To maintain these objectives, mandibular DO may be repeated as the child matures. Once skeletal maturity is reached, DO is used to normalize occlusion and further expand the soft tissue envelope prior to definitive reconstruction and aggressive post-op PT. In seven patients, this protocol has been used. Five patients are currently in the active phase of growth and undergoing interim treatment with mandibular DO. Two patients have reached skeletal maturity and have completed the protocol of DO with definitive arthroplasty and reconstruction. DO is a valuable aid in the treatment of the problematic child with congenital proliferative TMJ ankylosis. Interim DO, prior to definitive arthroplasty and reconstruction, can provide a static open bite that prevents progressive deformity and its associated functional disturbances.     

Gap arthroplasty of temporomandibular joint ankylosis by transoral access: a case series

This article describes a technique of gap arthroplasty in temporomandibular joint (TMJ) ankylosis performed by transoral access. The treatment of TMJ ankylosis by creating an adequate gap is of paramount importance in preventing any future recurrence and this can be achieved only when good access is gained to this complex anatomical joint. Five patients with TMJ ankylosis (eight TMJ) were treated by gap arthroplasty using an intraoral approach. The average mouth opening before surgery was 8.6 mm and the average mouth opening achieved postsurgery was 37.9 mm. The average follow-up time was 13 months and none of the patients had any recurrence or significant complications during or after surgery. Our technique relies on the use of a stable landmark to trace the superior-most extent of the ankylotic mass thereby facilitating the removal of the entire mass including the medial extent. We found that even though transoral access is technically challenging and took an average time of 84 min, it has many advantages over conventional extraoral approaches in terms of facial scars and facial nerve injury. The authors also emphasize the importance of good postoperative physiotherapy and presurgical patient counselling to prevent future recurrences.     

Distraction osteogenesis in the management of mandibular hypoplasia secondary to temporomandibular joint ankylosis. Long term follow up

PurposeThe aim of this retrospective study was to evaluate the short-term and long-term skeletal and soft-tissue stability after MDO with or without genioplasty, as well as the stability of the achieved maximum inter-incisal opening (MIO) in patients with mandibular hypoplasia secondary to TMJ ankylosis.Patients and methodsTwenty patients with mandibular hypoplasia secondary to TMJ ankylosis were managed by a two-stage surgical protocol, gap arthroplasty as the first stage, followed by MDO. The patients were analyzed for skeletal and soft-tissue stability as well as the maintenance of the achieved MIO. Lateral cephalograms were evaluated at four time intervals: pre-distraction (T1), after a consolidation period with or without genioplasty (T2), after one year following consolidation (T3), and at the longest follow-up (T4). Statistical analyses compared the skeletal and soft-tissue changes at different intervals in every group.ResultsAll the ankylosed joints except three were treated with gap arthroplasty without costochondral graft. The MIO was increased from 8.2 ± 2.1 mm preoperatively to 40.2 ± 1.7 mm postoperatively. After the consolidation period, MIO decreased to 23 ± 6.5 mm. The patients were instructed to restart active physiotherapy after removal of the distractors to regain the pre-distraction MIO, which was maintained during the short-term follow-up. The mean follow-up period was 8.5 ± 1.5 years. At the end of the follow-up, two patients showed recurrence of ankylosis. Cephalometric analysis revealed great improvements in the hard- and soft-tissue structures after MDO with or without genioplasty. Several significant long-term relapses could be observed in all groups; however, they did not reach their pre-operative values.ConclusionTMJ ankylosis leads to severe, multidirectional mandibular hypoplasia, which is significantly corrected with the MDO. The MDO provides a stable short-term improvement in the facial esthetics at the first postoperative year, but a significant relapse occurs during the long term follow-up. Nevertheless, a satisfied facial esthetic is maintained for up to seven to 12 years postoperatively. During the activation period, the MDO minimizes the gained MIO after release of ankylosis, but the MIO is successfully restored with physiotherapy.