Year : 2005 | Volume
: 9 | Issue : 1 | Page : 37--40
A case of right hemimandibular hypertrophy treated by high condylectomy of the right side followed by recontouring of the lower border with superior repositioning of inferior alveolar neurovascular bundle
Sanjiv Baveja, Suresh P Menon, GK Thapliyal
Department of Dental Surgery, Armed Forces Medical College, Pune 411 040, India
G K Thapliyal
Department of Dental Surgery, Armed Forces Medical College, Pune 411 040
Hemimandibular hypertrophy is a unilateral excessive growth of the mandible, which creates facial asymmetry. The condition can occur before or during the adolescent growth spurt but usually becomes apparent only after the adolescent growth spurt, when one side of the mandible continues to grow. The deformity in hemimandibular hypertrophy affects the body as well as the ramus of the mandible. In some patients, the head of the condyle remains approximately normal in size, but the length of the condylar neck increase; while in others, the condylar head enlarges.
If progressive deformity requires removing the condylar growth site, the surgical options for the affected side consists of excision of bone at the head of the condyle, then recon touring or repositioning the bony stump which was done in our case, removing the condyle and condylar process and reconstructing the area either with a costrochondral junction transplant or with a free graft. Typically, a downward bowing of the mandibular body exists that can be corrected by removing bone from the lower border on the affected side. In addition, a sagittal split osteotomy on the unaffected side will allow proper positioning of the mandible. In some cases in adults, if the maxilla is canted because of excessive vertical growth on the affected side, maxillary surgery may also be required.
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Baveja S, Menon SP, Thapliyal G K. A case of right hemimandibular hypertrophy treated by high condylectomy of the right side followed by recontouring of the lower border with superior repositioning of inferior alveolar neurovascular bundle.J Oral Maxillofac Pathol 2005;9:37-40
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Baveja S, Menon SP, Thapliyal G K. A case of right hemimandibular hypertrophy treated by high condylectomy of the right side followed by recontouring of the lower border with superior repositioning of inferior alveolar neurovascular bundle. J Oral Maxillofac Pathol [serial online] 2005 [cited 2022 Sep 29 ];9:37-40
Available from: https://www.jomfp.in/text.asp?2005/9/1/37/39060
True hemimandibular hyperplasia is an uncommon maxillolacial deformity. Patients with this affliction present clinically with varying degrees of asymmetry characterized by art increase in ramus height, a rotated facial appearance with kinking at the mandibular symphysis, and prominence of the lower border of the mandible. Hyperplasia of the mandibular condyle is an anomaly that usually occurs unilaterally and equally frequently in both inch and women. Hyperplasia of the condyle is differentiated into hemimandibular hyperplasia (HH), hemimandibular elongation (HE), and condylar hyperplasia (CH). The term condylar hyperplasia refers to hyperplasia of the condyle alone and should not be confused with HH or HE (Obwegeser and Makek, 1986). The goals of treatment off HH are to obtain proper Occlusion, good aesthetic appearance, and prevent recurrence. A case of a patient with (R) HH treated with high condylcetomy and recontouring of the lower border with superior repositioning of the inferior alveolar nerve is presented here.
A 29-year-old woman was referred for treatment of mandibular asymmetry. Mandibular deviation and overgrowth was noticed at 15 years of age and progressed slowly until she reached 21 years of age- The patient complained of discomfort in both temporomandibular joints (TMJ) and pain in the right masseter muscle. There was no history of trauma or inflammation in the jaw. A deviation of the mandible to the left side and a protruded position of the chin, combined with an elongation of the right mandibular ramus bowing of the (R) enlarged lower border of the mandible were evident in the patients appearance [Figure 1]. Occlusion showed displacement of the dental midline to the unaffected side with resulting cross bite on the unaffected side. The occlusal plane and lip fissure line were titled. Mouth opening and mandibular movements were normal in all excursions.
Radiographic examination revealed enlargement of the right condyle, elongation of the right ascending ramus and mandibular body, and tilted occlusal plane. The position of the inferior alveolar nerve was determined preoperatively using the orthopantomogram. Three-dimensional computed tomography apparently showed difference in the size of both condylar heads as well as elongation of the ascending ramus and mandibular body on the right side [Figure 2].
After 8 months of presurgical orthodontic treatment in June 2004, the patient was operated under general anesthesia. Alkayat and Bramely's preauricular approach was used to expose the (R) TMJ region. Approximately 12 mm length of the condylar neck was resected using a round bur and osteotome and the proximal segment was stabilized via overlap. Stump of the condylar process was rounded off using vulcanite bur.
lntermaxillary fixation was done. Submandibular incision was placed to expose the right lower border and body of mandible from angle to symphysis region. Mental neurovascular bundle was identified and isolated. Bony fenestration was created along the course of the inferior alveolar neurovasular bundle to expose it [Figure 3]. Contouring of the lower mandibular margin with repositioning of the inferior alveolar nerve was performed by making a groove cut into the contoured lower border of the resected mandible [Figure 4]. A 3-month follow tip examination revealed a dramatic improvement in the full face appearance and occlusion [Figure 5]. Guiding elastics was placed post operatively for a month. The patient showed no relapse, recurrence, deviation, or TMJ disorders. All complaints regarding mastication were fully resolved.
CH with mandibular asymmetry was first described in 1436 as a complication of rheumatoid arthritis. There is considerable speculation and controversy with regard to the etiology of this ailment. Trauma, infection (particularly in the TMJ), heredity, and intrauterine influences have been advanced as possible etiologic factors. Hyperplasia of the condyle can be differentiated into the following categories. HH, enlargement of the condyle, condylar neck, ramus, and body with tilting of the occlusal plane: HE, condylar neck enlargement, and variable displacement of the ramus and bodywithout tilting of the occlusal plane; and CH, hyperplasia of the condyle alone. Chen et al (1996) suggested that the term CH should not be used to refer to either HH or HE but should be used before mandibular deformity occurs because progression of CH to HH or HE, although difficult to prove, was possible.
Removed of the condyle is indicated in patients in whom joint function is disturbed. An accurate pathological and anatomical diagnosis is required or abnormally high growth activity can be demonstrated. In such cases, removal should be carried out as early as possible to avoid further Facial asymmetry. However, whether the active pathological condyle should be resected is a clinically difficult problem. The speed of condylar overgrowth can be estimated by history and comparing serial orthopantomographs and cephalograms. Technetium 99m Phosphate studies can detect condylar activity. The scintigram is highly sensitive but nonspecific and should therefore not be used as the single determinant of the need of condylar resection because the activity level of the scintigram does not necessarily correlate with the histological signs of active growth.
When an early diagnosis of unilateral CH is made, high condylectomy should be performed in concert with the related mandibular surgery. Orthodontic treatment is essential afterward in patients treated by early condylar resection. However, if the surgery to remove the condylar head is excessively traumatic, with damage to the meniscus or failure to re-establish normal jaw function postoperatively, deficient secondary growth and even TMJ ankylosis are possible. Cases with nonactive enlargement and acceptable movement of the condylec should be preserved and the joint capsule should not he violated.
There have been a few reports of complications in the condylectomy: anterior open bite, lateral precontact treated by cup grinding, deviation to the operated side when opening the mouth, and loss of lateral excursion on the operated side because of the failure or reinsertion of the lateral pterygoid muscle to the neocondyle. Therefore patients with unilateral CH of the mandible and deviation can be treated favorably by unilateral ramus osteotomy of the affected side. However, bilateral ramus osteotomy was required in prognathic cases and in cases in which a unilateral procedure would cause excessive rotation of the contra lateral condyle. In cases where mandibular osteotomy is combined with Le Fort I osteotomy, especially in cases with occlusal canting, it would be quite difficult to project how much the contra lateral condyle would rotate postoperatively. Bilateral osteotomies should be preformed to avoid postoperative TMJ pain and dysfunction.
Hemimandibular hyperplasia (HH) is characterized by a generalized increase in size of the mandible. The chin deviates away from the affected side; there is bowing of the lower border, a symphyseal kink, canting of the occlusal plane, and varying degrees of malocclusion. The first reports using various terminologies and classifications have appeared in the literature, with most mandibular overgrowth syndromes classified into the condylar hyperplasia category. Obgwegeser and Makek further differentiated condylar hyperplasia into the following categories; hemimandibular hypertrophy (HH), hemimandibular elongation (HE), and condylar hyperplasia (CH). Both HH and HE have an asymmetrical effect on mandibular anatomy. In HE, the mandibular body is slender and elongated on the involved side without an increase in body height, whereas HH has a marked increased ramus and body height which stop abruptly at the symphysis, where a kink is evident.
The dysfunctional condylar growth usually occurs early in the second decade, and results in a downward and forward mandibular overgrowth and an open bite between the ipsilateral maxilla and mandible. This leads to a subsequent reactive overgrowth of the ipsilateral maxillary and mandibular alveolar bone with tilting of the anterior teeth to the affected side. Failure of the contra lateral (normal) side to match this growth results in a tilting of the occulusal plane.
Hemimandibular hyperplasia is thought of as a generalized enlargement of the hemi mandible, whose greatest disturbance is an increased vertical height. The incidence of hemimandibular hyperplasia and its hybrid forms is not known. Previous reports in the literature have made reference to a caudal displacement of the mandibular canal in hemimandibular hyperplasia. Only the upper horizontal ramus height is significantly changed, resulting in a relative decrease in the position of the mandibular canal when compared with overall horizontal ramus height. The importance of this Carding allows for safer correction of the bowed lower mandibular angle in masseter muscle hypertrophy. 'The orthopantomograrn and lateral cephalogrann are used preoperatively to determine the amount of bony resection required to correct the downward bowing of the horizontal ramus. This in turn allows us to predict which cases will require repositioning of the inferior alveolar nerve.
The cause of hemimandibular hyperplasia remains obscure. Egyedi outlined the possible causes of condylar hyperplasia neutropenic disturbances, local circulatory disturbances, previous trauma, partial hemi hypertrophy, arthrosis, multiple osteochondromatosis, hormonal disturbances, and true neoplasia. Trauma may be the cause in sonic patients but most cases after condylar fracture present with hypoplasia. Obwegeser and Makek suggested that different growth factors individually controlling generalized hypertrophy and elongation might he responsible for the deformities.
The speed of condylar overgrowth can be estimated by history and by comparing serial cephalometric roentgenograms. Technetium 99 m phosphate studies can detect condylar activity. These studies are highly sensitive but nonspecific and do not necessarily correlate with active growth, therefore, should not be used as the sole determinant of the need for condylar resection. Active treatment should begin once malocclusion or facial asymmetry become evident. Before adolescence should begin once malocclusion or facial asymmetry become evident. Before adolescence the abnormally active condyle (as assessed clinically, by 99 mtc, and on serial cephalogram) should be resected. Proper follow tip, which includes splinting and orthodontic care, is essential in patients treated by early condylar resection or intracapsular reshaping. If the process is insidious, i.e., occlusal function has been maintained and asymmetry is mild, total correction can be deferred until after adolescence. The importance of the nature of the deformity should be of little importance if early detection and treatment regimen is successful, then the incidence of HE, HH, and its hybrid forms should decrease because these deformities cannot grow to become recognizable. The result would be an increase in the diagnosing of condylar hyperplasia in patients with asymmetric mandibular deformities.
Condylar hyperplasia consists of condylar overgrowth with elongation of the condylar neck, which causes variable displacement of the normal sized and shaped mandibular ramus and body without an associated tilting of the occlusal plane. It presents with varying degree of severity and influence on maxillofacial growth, and involves only the condylar region, which is homogeneously enlarged. It the disease process is arrested in it is early stage. The term condylar hyperplasia is used before the mandibular deformity occurs. Whether CH will progress to HE if left untreated has not been established. Total correction of the established deformities can usual ve performed in one operation with care being taken to re level the occlusal plane and to reestablish the facial midline.
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