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The double-headed mandibular condyle
The double-headed mandibular condyle Karsten K.H. Gundlach, M.D., D.D.S., M.S.D.,* Andreas Fuhrmann, D.D.S.,** Georg Beckmann-Van der Ven, D.D.S.,*** Hamburg, West Germany UNIVERSITY
HOSPITALS
and
EPPENDORF
The double-headed condylar process is rare. Radiographs of four patients with this type of anomaly and one skeletal specimen are described in this article. Histologic studies in rodents suggest a possible mode of pathogenesis: maldirected muscular pull may lead to the development of an extra mandibular capitulum. (ORAL
SURG.OW Mtm. O~\L PATHOL.1987;64:249-53)
I
n the past few years the temporomandibular joint has attracted the interest of many oral and maxillofacial surgeons. In particular, such problems as the
*Nordwestdeutsche Kieferklinik. **Department of Dento-maxilla-facial Radiology. ***Department of Orthodontics.
pain-dysfunction syndrome and internal derangements have been the subject of many articles in dental journals. Malformations of the TMJ and clinical findings related thereto, however, have only rarely been discussed.This may partly be due to the fact that malformations of the TMJ are rare. In the North German Center for Craniofacial Anomalies we often see patients with hypoplasia or
Fig. 1. Case 1. A, Lateral view of left and right condyles. B, Sagittal view of both condylar processes.C and D, Sagittal tomogram of same patient. Both heads are seen clearly on two different shifts.
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Gundlach, Fuhrmann, and Beckmann-Van der Ven
Fig. 2. Case 2. A, Left condyle shows small duplication on sagittal view of mandible. B, On lateral plane film small line shows indentation.
aplasia of the ascending ramus of the mandible; we treat many casesof hemifacial microsomia or Franceschetti’s syndrome.l Therefore, malformations of the TMJ are also frequently encountered. In addition, we tried to experimentally produce dysplasia of the posterior parts of the mandible in rats and micek2 The purpose of this article is to present five cases of unilateral bifid mandibular condyle and to compare these caseswith the findings of animal experiments in which we successfully produced doubleheaded condyloid processes.Finally, we will present our theory on the pathogenesis of this malformation.
CASE REPORTS CASE 1
In 1982 a 23-year-old man was referred to the Department of Orthodontics. The diagnosis was crowding in the maxillary and mandibular arches in a basal deep confrguration. No abnormal functions of the temporomandibular joints were detected. Wide opening of the mouth was possible, no deviation was noted, and protrusion and laterotrusion to either side were uninhibited. However, an opening click in the left joint had been noted before the patient underwent orthodontic treatment with fixed appliances. These noiseshad not changed during the ensuing two years. On a panoramic radiograph two mandibular heads were noticed on the left side. Plain films and tomograms
Double-headed
Volume 64 Number 2
mandibular
condyle
25 1
Fig. 4. Case 4. A, Sagittal tomogram showing fracture of condylar processand well-formed double head. B, Panoramic radiograph does not show the double head well.
revealed that the lateral one of these was smaller and more anteriorly located than the medial capitulum (Fig. 1). The fossae of both appeared to be communicating and were located posterior to the tuberculum articulare. There was no history of trauma or fracture of the mandible. CASE 2
An incidental finding detected on the radiographs of another patient was made in the Radiology Department. This patient was clinically free of any symptoms regarding the temporomandibular joint. However, an anteroposterior radiograph demonstrated a small indentation in the superior circumference of the left condyle, changing the overall appearance of the condyle to produce a microform duplication of the mandibular head (Fig. 2). CASE 3
A panoramic radiograph of a third person with unilateral duplication of the condylar head was also found (Fig. 3). However, we were not able to locate the patient and
therefore cannot present either clinical findings or other radiographic documentation. CASE 4
While undergoing an examination for a mandibular fracture, a fourth patient was found to have a doubleheaded condyle. This fracture was found to be located at the base of the neck of the mandible, without exhibiting any connection to the malformed capitulum (Fig. 4). CASE 5
Finally, in the museum of the School of Dentistry, a mandible with perfect duplication of the right capitulum was found (Fig. 5). The condyle appeared completely different from those specimensthat had malformed condyloid processesdue to trauma. Experimental
models
In our laboratory (Forschungsgruppe Experimentelle Biologie, Teratologie und Onkologie) colonies of
HOSPITALS
and
EPPENDORF
The double-headed condylar process is rare. Radiographs of four patients with this type of anomaly and one skeletal specimen are described in this article. Histologic studies in rodents suggest a possible mode of pathogenesis: maldirected muscular pull may lead to the development of an extra mandibular capitulum. (ORAL
SURG.OW Mtm. O~\L PATHOL.1987;64:249-53)
I
n the past few years the temporomandibular joint has attracted the interest of many oral and maxillofacial surgeons. In particular, such problems as the
*Nordwestdeutsche Kieferklinik. **Department of Dento-maxilla-facial Radiology. ***Department of Orthodontics.
pain-dysfunction syndrome and internal derangements have been the subject of many articles in dental journals. Malformations of the TMJ and clinical findings related thereto, however, have only rarely been discussed.This may partly be due to the fact that malformations of the TMJ are rare. In the North German Center for Craniofacial Anomalies we often see patients with hypoplasia or
Fig. 1. Case 1. A, Lateral view of left and right condyles. B, Sagittal view of both condylar processes.C and D, Sagittal tomogram of same patient. Both heads are seen clearly on two different shifts.
250
Gundlach, Fuhrmann, and Beckmann-Van der Ven
Fig. 2. Case 2. A, Left condyle shows small duplication on sagittal view of mandible. B, On lateral plane film small line shows indentation.
aplasia of the ascending ramus of the mandible; we treat many casesof hemifacial microsomia or Franceschetti’s syndrome.l Therefore, malformations of the TMJ are also frequently encountered. In addition, we tried to experimentally produce dysplasia of the posterior parts of the mandible in rats and micek2 The purpose of this article is to present five cases of unilateral bifid mandibular condyle and to compare these caseswith the findings of animal experiments in which we successfully produced doubleheaded condyloid processes.Finally, we will present our theory on the pathogenesis of this malformation.
CASE REPORTS CASE 1
In 1982 a 23-year-old man was referred to the Department of Orthodontics. The diagnosis was crowding in the maxillary and mandibular arches in a basal deep confrguration. No abnormal functions of the temporomandibular joints were detected. Wide opening of the mouth was possible, no deviation was noted, and protrusion and laterotrusion to either side were uninhibited. However, an opening click in the left joint had been noted before the patient underwent orthodontic treatment with fixed appliances. These noiseshad not changed during the ensuing two years. On a panoramic radiograph two mandibular heads were noticed on the left side. Plain films and tomograms
Double-headed
Volume 64 Number 2
mandibular
condyle
25 1
Fig. 4. Case 4. A, Sagittal tomogram showing fracture of condylar processand well-formed double head. B, Panoramic radiograph does not show the double head well.
revealed that the lateral one of these was smaller and more anteriorly located than the medial capitulum (Fig. 1). The fossae of both appeared to be communicating and were located posterior to the tuberculum articulare. There was no history of trauma or fracture of the mandible. CASE 2
An incidental finding detected on the radiographs of another patient was made in the Radiology Department. This patient was clinically free of any symptoms regarding the temporomandibular joint. However, an anteroposterior radiograph demonstrated a small indentation in the superior circumference of the left condyle, changing the overall appearance of the condyle to produce a microform duplication of the mandibular head (Fig. 2). CASE 3
A panoramic radiograph of a third person with unilateral duplication of the condylar head was also found (Fig. 3). However, we were not able to locate the patient and
therefore cannot present either clinical findings or other radiographic documentation. CASE 4
While undergoing an examination for a mandibular fracture, a fourth patient was found to have a doubleheaded condyle. This fracture was found to be located at the base of the neck of the mandible, without exhibiting any connection to the malformed capitulum (Fig. 4). CASE 5
Finally, in the museum of the School of Dentistry, a mandible with perfect duplication of the right capitulum was found (Fig. 5). The condyle appeared completely different from those specimensthat had malformed condyloid processesdue to trauma. Experimental
models
In our laboratory (Forschungsgruppe Experimentelle Biologie, Teratologie und Onkologie) colonies of