1) The document discusses facial asymmetry caused by condylar hyperplasia or hypoplasia. It presents several case examples and classifications of condylar hyperplasia.
2) Condylar hyperplasia is classified into 4 types based on etiology and growth pattern. Type 1 is further divided into unilateral or bilateral cases.
3) Treatment options depend on the type and severity of asymmetry. Mild cases may be observed, while high condylectomy is considered for active, asymmetric growth. Orthodontics can address dentoalveolar changes in growing patients.
2. Šsylvainchamberland.com
Biography
Sylvain Chamberland
â˘D.M.D. (Docteur en MĂŠdecine Dentaire), University Laval, 1983
â˘Private practice, general dentistry 1983-1988
â˘CertiďŹcate in Orthodontics, University of Montreal, 1990
â˘M.Sc. in dental science, University Laval, 2008
â˘Private practice in orthodontics since 1990
â˘Publications
⌠Closer look at SARPE, JOMS 2008
⌠Short-term and long-term stability of SARPE revisited, AJODO 2011
⌠Long-term dental and skeletal changes following SARPE, letter to editor, OOOO 2013
⌠Functional genioplasty in growing patients, AO 2015,
â˘Lecturer in several graduate program and scientiďŹc meeting in USA, Canada, Europe
5. In Memoriam
Capt. Vanessa Chamberland
June 25,1989 - November 14, 2016
Vanessa lived 10 000 days. â¨
It seemed like a moment.
The next 10 000 days that I, Carole,
Pier-Eric and Richard will live will be an
eternity.
6. Šsylvainchamberland.com
ConďŹict of Interest Declaration
â˘I declare that neither I nor any member of my family have a ďŹnancial
arrangement or afďŹliation with any corporate organization offering
ďŹnancial support or grant monies for this continuing education
presentation, nor do I have a ďŹnancial interest in any commercial
product(s) or services I will discuss in this presentation
8. Šsylvainchamberland.com
â˘Attrition of the left posterior teeth
â˘3rd molars extracted :~ 2 years
â˘Jaw opening amplitude : 55mm
â˘Right lat. excursion : 12mm; left : 7mm
9. Šsylvainchamberland.com
â˘2 years post ortho
â˘Md deviation to the right
â˘Right TMJ clicking
⌠Is it caused by the occlusion?
Final Follow up 2 y
14 y 3 m 16 y 2 m
14. ŠDr Sylvain Chamberland
Facial Asymmetry
1st & 2nd branchial arch syndromes
We want to exclude congenital deformities from this discussion.
15. ŠDr Sylvain Chamberland
Hemimandibular Hypoplasia with
condylar-coronoid collapse
⢠Usually not diagnose at birth
⢠â soft-tissue defects; normal ears
⢠â nerve deďŹcit, well-developed masseter
⢠Deviation of the chin on the affected side,
with fullness on the affected cheek
⢠SigniďŹcant deviation to the affected side
during opening
AJODO 2011;139:e435-e447
Courtesy Dr Dany Morais
16. ŠDr Sylvain Chamberland
Hemimandibular Hypoplasia with
condylar-coronoid collapse
⢠Condyle mandibular dysplasia "en bosse
de chameau" (camel hump look)
⢠Hypoplasia of the ascending ramus +
condyle + coronoid process
⢠Collapse of the condyle on the
coronoid process
⢠Temporal fossa is always present
AJODO 2011;139:e435-e447
Courtesy Dr Dany Morais
Maezzini et al,True hemifacial microsomia and hemimandibular hypoplasia with
condylar-coronoid collapse: Diagnostic and prognostic differences,
AJODO2011;139:e435-e447
17. ŠDr Sylvain Chamberland
Hemifacial Microsomia
⢠Diagnosed at birth. Prevalence 1 : 5600
⢠Muscular, soft-tissue and nerve defects, (1st & 2nd
arch)
⌠Ear defects, pre-auricular tags, masseter muscle hypoplasia, Facial
nerve (VII) asymmetries
⢠Deviation of the chin on the affected side + ďŹatness
on the affected cheek
⢠Deviation to the affected side during opening
Courtesy Dr Dany Morais
Semin Orthod 2011;17:235-245
18. ŠDr Sylvain Chamberland
Hemifacial Microsomia
⢠Hypoplasia of
⌠Ascending ramus
⌠Condyle
⌠Coronoid process
⌠Absence of condyle and
temporal fossa
Maezzini et al,True hemifacial microsomia and
hemimandibular hypoplasia with condylar-
coronoid collapse: Diagnostic and prognostic
differences,AJODO2011;139:e435-e447
Pedersen TK and Norholt SE, Early
Orthopedic Treatment and Mandibular
Growth of Children with
Temporomandibular Joint Abnormalities,
Semin Orthod 2011;17:235-245.)
Courtesy Dre A-CValcourt
CCC HF
21. Šsylvainchamberland.com
ClassiďŹcation system
â˘CH Type 1
⌠1A : Bilateral
â Bilateral symmetric or asymmetric growth; self-limiting; can grow into mid-20s; class III occlusion
⌠1B : Unilateral
â unilateral accelerated asymmetric growth; self-limiting; can grow into mid-20s; deviated mandibular
prognathism; ipsilateral class III, anterior and contralateral Xbite
â˘CH Type 2
⌠Unilateral vertical elongation of face and jaws; not self-limiting; ipsilateral posterior open bite
â Type 2 A: Osteochondroma
â Type 2 B: Osteome (horizontal exophytic tumor growth)
Wolford, Larry M, Reza Movahed, and Daniel E Perez. "A ClassiďŹcation System for Conditions Causing Condylar Hyperplasia. â¨
JOMS 72, no. 3 (2014): doi:10.1016/j.joms.2013.09.002
Rodrigues, DB, Castro V, Condylar hyperplasia of the temporomandibular joint. Types, treatment, and surgical implications, Oral Maxillofacial Surg Clin N Am
27. 155-167 (2015): dx.doi.org/10.1016/j.coms.2014.09.011
22. Šsylvainchamberland.com
ClassiďŹcation system
â˘CH Type 3
⌠Unilateral facial
â Benign tumors: osteoma, neuroďŹbroma, giant cell tumor, ďŹbrous dysplasia,
chondroma, chondroblastoma, arteriovenous malformation
â˘CH Type 4
⌠Unilateral vertical enlargement
â Malignant tumors: chondrosarcoma, multiple myeloma, osteosarcoma,
metastatic lesion, Ewing sarcoma
Wolford, Larry M, Reza Movahed, and Daniel E Perez. "A ClassiďŹcation System for Conditions Causing Condylar Hyperplasia. â¨
JOMS 72, no. 3 (2014): doi:10.1016/j.joms.2013.09.002
Rodrigues, DB, Castro V, Condylar hyperplasia of the temporomandibular joint. Types, treatment, and surgical implications, Oral Maxillofacial Surg Clin N Am
27. 155-167 (2015): dx.doi.org/10.1016/j.coms.2014.09.011
25. Šsylvainchamberland.com
Unilateral Condylar Hyperplasia
â˘Most frequent postnatal anomaly of growth of the TMJ
â˘Prevalence 2 F : 1 M
â˘Symmetry observed at birth, develops during 2nd decade
â˘Accelerated growth rate of condylar head & neck resulting in facial
asymmetry
â˘Difference to do with hypoplasia of the opposite side or a
generalized asymmetrical growth (hemimandibular hyperplasia)
28. Šsylvainchamberland.com
Therapeutic options
â˘Wait and see if
⌠Mild asymmetry
⌠Phasing out shown by serial Tc99 bone scan
â Asymmetry corrected by standard orthognatic surgery
â˘High condylectomy if
⌠SigniďŹcant asymmetry
⌠Active abnormal condyle
⌠Prevent worsening (How much more asymmetry are you willing to tolerate?)
29. Šsylvainchamberland.com
High Condylectomy
â˘Removal of the top 3-5 mm of the condylar head including the
lateral and medial poles
â˘In most cases, pathologic portion is difďŹcult to identify making
bone resection arbitrary
Wolford LM et al, Surgical management of mandibular condylar hyperplasia type 1, Proc (Bayl Univ Med Cent) 2009;22(4):321â329
Bouchard C, Paris M, and Villemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of Condylar Hyperplasia: Description of a New
Technique. J Oral Maxillofac Surg. 2013, Feb 2;
32. Šsylvainchamberland.com
Condylar Hyperplasia Type 2B
â˘Unilateral vertical elongation of face and jaws
⌠Vertical growth vector (Prevalence 15:1)
⌠Elongation + enlargement : Condylar head & neck
+ mandibular ramus and body
⌠Ipsilateral posterior open bite
⌠Progressive laterodeviation to the unaffected side
⌠Mandibular midline inclined to the affected side
Courtesy Dr Dany Morais
Condyle & neck:
bigger & longer
34. Šsylvainchamberland.com
â˘Splitting of inferior border â
⌠Flattening of the antegonial notch
â˘Scintigraphy Tc99
⌠Discreet increase of the uptake of the right condyle â¨
compatible with a right hypercondyle (condylar hyperplasia)
DifďŹcult to evaluate
â at the condyle
KaPaVa 29-03-11; 12 aKaPaVa 02-03-10; 11 a
38. Šsylvainchamberland.com
Condylar Hyperplasia Type 1B
â˘Horizontal type (CH type 1B)
⌠Horizontal growth vector;
⌠Growth is self-limiting
⌠Usually begin at the adolescence and stop at mid-20s
⌠Elongation of condylar head & neck
⌠Laterodeviation to the unaffected side & midline deviation
⌠Loss of the antegonial notch
39. Šsylvainchamberland.com
Condylar Hyperplasia Type 1B
⌠Laterodeviation to the controlateral side
⌠Ipsilateral class III
⌠Posterior crossbite in the unaffected side or dentoalveolar
compensation
PA Le 19-05-11
40. ŠDr Sylvain Chamberland
PA Le 15-10-09; 14a 1mPA Le 11-02-04; 8a 5mPA Le 03-12-01; 6a 4m PA Le 19-05-11; 15a 8m
41. Šsylvainchamberland.com
â˘Scintigraphie Tc99
â˘Scinti Tc99 = Positive (increased uptake) in spring 2011
â˘Left TMJ clicking at maximum jaw opening
PA Le 19-05-11; 15a 8mPA Le 15-10-09; 14a 1m PA Le 19-05-11; 15a 8m PA Le 15-10-09; 14a 1m
Compare the height
of sigmoid notch
42. Šsylvainchamberland.com
â˘Frontal view
⌠Slight vertical compensation causing a cant of the occlusal plane
â˘Lateral view
⌠Splitting of the occlusal plane and inferior mandibular border
PA Le 19-05-11; 15a 8mPA Le 15-10-09; 14a 1m
Display of
13 â 23
Pearl: distal angulation /5s
43. Šsylvainchamberland.com
Scintigraphy
â˘In July ratio 3,2/1,93 = 1,66
â˘In January: ratio 2,13/1,97 = 1,08
â˘Diminution of the activity
â˘Decision:
⌠No condylectomy
⌠Initiate comprehensive ortho treatment at appropriate
timing (around 17 y)
⌠Scinti presurgery if midline â
P.-A. Le.
Mean Maximum
Right 1,98 3,2
July 2011
Left 1,65 1,93
Right 1,58 2,13
January
2012
Left 1,25 1,97
44. Šsylvainchamberland.com
Tx
â˘Goal : avoid the progression of the facial asymmetry
â˘Orthosurgical tx
⌠Dentoalveolar decompensation
⌠Bimaxillary surgery
⌠High condylectomy could be possible if still actively
overgrowing
58. Šsylvainchamberland.com
â˘Tx
⌠RPE + facial mask
â˘Slight improvement of the
deviation
â˘Persistence of the right
class III relationship
MĂŠPo 16-08-06; 11a 5 m
MĂŠPo 11-04-07; 12a 1 m
60. Šsylvainchamberland.com
⢠Evolution of the
asymmetry
⢠Slanting of inferior teeth
(oblique)
⢠Cant of the mouth
commissure
⢠Vertical asymmetry of
inferior border of the
chin
MĂŠPo 16-08-06; 11a 5 m
MĂŠPo 11-04-07; 12a 1 m
MĂŠPo 16-04-08; 13a 1 m
MĂŠPo 11-04-07; 12a 1 m
MĂŠPo 17-10-11; 16a 7 m
61. Šsylvainchamberland.com
â˘Cant of the occlusal plane in frontal view
â˘Splitting of the occlusal plane in the lateral view
â˘Elongation of the right condylar neck
â˘Slanting of the lower midline to the affected side
Display of â¨
13 â 23
MĂŠPo 17-10-11; 16a 7 m
62. Šsylvainchamberland.com
Scinti Report
â˘Metabolism augmentation in the right condyle
⌠Mean asymmetry index right / left = 1,49
⌠Maximum asymmetry index right / left = 1,97
â˘Right intense uptake
M. Po.
Mean Maximum
Right 2,51 3,07
January
2012
Left 1,68 1,56
64. Šsylvainchamberland.com
â˘Post condylectomy
⌠Persistence of the facial asymmetry
⌠&
⌠Class III relationship
⌠A more agressive cut of the condyle could â¨
have caused an anterior openbite
MĂŠPo 17-10-11; 16a 7 m
MĂŠPo 27-04-12; 17a 1 m
66. Šsylvainchamberland.com
â˘Condylar growth seem to have
stopped
â˘Facial asymmetry persist
â˘Patient declined any further treatment
MĂŠPo 21-05-2013; 18a 2 m
Recall 13 months post
condylectomy
69. Šsylvainchamberland.com
â˘2 years post ortho
â˘Md deviation to the right
â˘Right TMJ clicking
⌠What happened between the
removal of the appliances and
monitoring 2 years post
treatment?
Final Suivi 2 ans
14 a 3 m 16 a 2 m
70. Šsylvainchamberland.com
Scintigraphy
â˘She had clicking in the right TMJ near the end of ortho
treatment (2012)
⌠Discrete increase uptake in the left joint
â Decision to observe
â˘New scinti July 2014
⌠Decrease of maximum ratio
â Follow up December 2014: no change
â˘Follow up September 2015
⌠No worsening of the deviation. Persistence of a right click.
FĂŠvrier 2012
Juillet 2014
71. Šsylvainchamberland.com
Conclusion
â˘Do not confuse a joint clicking problem with a problem of condylar
hyperplasia
â˘Clicking is rather a consequence of the condylar hyperplasia
causing torsion of the contralateral condyle in the glenoid fossa
72. Šsylvainchamberland.com
Common clinical and radiographic characteristics
observed in asymmetrically growing condylar hyperplasia
type 1 patients
â˘Characteristics in asymmetric cases:
⌠1. TMJ articular disc displacement and arthritis on the contralateral side as a result
of increased loading of that joint caused by the condylar hyperplasia on the
opposite side
⌠2. Worsening facial and occlusal asymmetry, with the mandible progressively
shifting toward the contralateral side
⌠3. Unilateral posterior cross-bite on the contralateral side
⌠4. Transverse bowing of the mandibular body on the ipsilateral side
⌠5. Transverse ďŹattening of the mandibular body on the contralateral side
Wolford LM et al, Surgical management of mandibular condylar hyperplasia type 1, Proc (Bayl Univ Med Cent) 2009;22(4):321â329
78. Šsylvainchamberland.com
2 y into txâŚ!
â˘Progression of asymmetry to the right
â˘Left Cl III molar; right cl II molar
â˘Md midline deviated to right
â˘This is illogical!
CrBo041103; 15a 2m
86. Šsylvainchamberland.com
Facial Asymmetry
⌠Rigth laterodeviation & Absence of shift
⌠Reciprocal click of right TMJ, slight click in the left
⌠Pain on palpation ext. pterygoid muscle
⌠Left posterior openbite > right
⌠Attrition of posterior teeth
â˘The deformation would have gradually appeared
ErBĂŠ.12-12-00; 22 ans
Patient initial
93. Šsylvainchamberland.com
High Condylectomy
Description of a New Technique
â˘Radioguided high
condylectomy using a Îł-probe
â˘Injection of technetium-99m methylene
diphosphate, â¨
25 mCi, 2 hours pre op
Bouchard C, Paris M, andVillemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of
Condylar Hyperplasia: Description of a New Technique. J Oral Maxillofac Surg. 2013, Feb 2; [In press]
94. ŠSylvain Chamberland
â˘Condylar neck elongated
â˘No clear demarcation of
hyperplastic portion vs
normal bone
Îł-probe
Malleable retracor (shield)
â˘Malleable retractor inserted
at the medial aspect of the
condyle to provide
appropriate shielding
â˘Prevent reading of Îł-
emission of the cranial base
â˘1st reading: right mandibular
parasymphysis = 2965 CPS
â˘2nd reading: right condyle =
4197 CPS
â˘Marking the section to be
resected
â˘Îł-probe was used until
normal reading was obtain
Bouchard C, Paris M, andVillemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of Condylar Hyperplasia: Description of a
New Technique. J Oral Maxillofac Surg. 2013, Feb 2; [In press]
95. ŠSylvain Chamberland
â˘Intraoperative view of the
residual condylar head
â˘No adjunct procedure of the
articular disk were
performed because it
appeared normal and free of
any pathologic process
â˘7 mm of bone removed
â˘3 cuts were necessary
to obtain normal
reading
â˘Patient is placed on
soft diet for 7 days
â˘Postoperative period in
uneventful
â˘No sign of relapse
were noticed 9 months
post surgery
Bouchard C, Paris M, andVillemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of Condylar Hyperplasia: Description of a
New Technique. J Oral Maxillofac Surg. 2013, Feb 2; [In press]
96. Šsylvainchamberland.com
Radio-guided surgery
â˘Sentinel lymph node surgery for breast cancer
â˘Minimally invasive parathyroid surgery
⌠Other described applications in cutaneous, gastrointestinal,
urologic, gynecologic, thoracic, neuroendocrine and head
and neck malignancies
Bouchard C, Paris M, andVillemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of Condylar Hyperplasia: Description of a
New Technique. J Oral Maxillofac Surg. 2013, Feb 2; [In press]
97. Šsylvainchamberland.com
Radio-guided surgery
â˘Îł-emission are easily detected
â˘Making bone resection easier and limited to the affected area
â˘Surgery is less invasive
â˘May decrease postoperative discomfort and complications
such as arthalgia and osteoarthrosis
Bouchard C, Paris M, andVillemaire JM. Intraoperative Use of a Gamma Probe for the Treatment of Condylar Hyperplasia: Description of a
New Technique. J Oral Maxillofac Surg. 2013, Feb 2; [In press]
100. Šsylvainchamberland.com
Differential Diagnosis
â˘Absence of shift
â˘Transverse asymmetry
â˘Laterodeviated to left
â˘Right condyle longer than left
â˘Most likely explanation could be
⌠Left condylar hypoplasia
â Lack of vertical alveolar development on the left side
MP.Ro-Ja.0404; 15a
101. Šsylvainchamberland.com
Follow up 2 years
â˘Stable occlusion
â˘Persistence of chin asymmetry
â˘Note hypodevelopment â¨
of left md corpus
â˘Increased left antegonial notch
MP.Ro-Ja.0707
MP.Ro-Ja.0707
MP.Ro-Ja.0106
106. Šsylvainchamberland.com
â˘2nd phase surgery
⌠Le Fort 1 differential impaction
⌠BSSO
â˘Implant position 12
â˘A genio of vertical reduction â¨
& right deviation would have â¨
been beneďŹcialâŚ
DoVo 28-11-11
DoVo 05-4-12
Note: â¨
1st phase surgery: SARPE
108. Osteochondroma
35% of all benign bone tumors
Average age at presentation: 40 y (range 11-69)
Ratio 1,8 â: 1â
No cases of malignant transformation of TMJ yet reported
â˘Chapter 82- Mandibular asymmetry: temporomandibular joint degeneration,Wolford L. In Current therapy in Oral and maxillofacial surgery,W.B.Saunders, 2012
â˘Osteochondroma of the temporomandibular joint: a case report. Utumi ER, Pedron IG, Perrella A, Zambon CE, Ceccheti MM, Cavalcanti MG. Braz Dent J. 2010;21(3):253-8. PMID: 21203710
⢠Shintaku WH,Venturin JS, Langlais RP, and Clark GT. Imaging modalities to access bony tumors and hyperplasic reactions of the temporomandibular joint. J Oral Maxillofac Surg. 2010,Aug 68(8):
1911-21.
111. Šsylvainchamberland.com
Osteochondroma
â˘Possible etiology
⌠Peripheral displacement of undifferentiated cells from growth
cartilage or neoplastic cells arising from the periosteum form
metaplastic cartilage
⌠Residues from the cartilaginous cranium and Meckel cartilage
that have not been replaced by mandibular bone
⌠Possible trauma, but there is inadequate data to support this
hypothesis
112. Šsylvainchamberland.com
â˘Hyperplasy of right condyle +++
â˘Laterodeviation to the left
â˘Indication of a condylectomy : osteochondroma or osteoma
⢠>20 years ago : Jigli osteotomy + genioplasty
116. Šsylvainchamberland.com
Wisdom Thoughts
â˘"A patient with an elongated condylar process is more likely to
stop growing spontaneously than one with an enlarged condyle
â but I don't have enough cases to prove it".
Dr William ProfďŹtâ¨
Personal communication. January 2012
122. Šsylvainchamberland.com
Early fracture of the mandibular condyles: Frequently an
unsuspected cause of growth disturbance
ProďŹt W., Vig K., Turvey T., AJODO 1980, 78, #1, 1-24
â˘If unilateral : deviation + openbite + xbite + distal occlusion ipsilaterally
â˘If bilateral : distoclusion + anterior openbite
â˘Recommandation post trauma
⌠Observation + exercices to maintain normal fonction & occlusion
â˘Compensatory growth occur but will not necessarily compensate for the
loss of condylar lenght
â˘Compensatory overgrowth is also possible
5 to 10% of
asymmetries or
severe md
deďŹciencies
127. Šsylvainchamberland.com
â˘Healing of condylar stumps
â˘SigniďŹcant shortening of the right ascending ramus
â˘Anterior posturing permits conterclockwise md rotation to close
the openbite
JuLe. 30 janvier 2008; 7 ans
133. Šsylvainchamberland.com
â˘At 2 years:
⌠Fall & dentoalveolar trauma: intrusion of primary incisor (51)
â˘Laterodeviation to the left
â˘Constriction of left hemimaxilla
â˘Ipsilateral Class II (class II subdivision left)
OlLa080914
134. Šsylvainchamberland.com
â˘Hypoplasia of left TMJ. (Condylar-coronoĂŻd collapse??)
â˘Increased left antegonial notch
⌠Compensatory growth at gonial angle
â˘Splitting of mandibular border and occlusal plane
Maezzini et al,True hemifacial microsomia and hemimandibular hypoplasia with condylar-
coronoid collapse: Diagnostic and prognostic differences,AJODO2011;139:e435-e447
OlLa080914
136. Šsylvainchamberland.com
Follow up +2 y
â˘Right: normal condylar growth
â˘Left: hypoplasia or normal growth followed the
loss of the stump
OlLa080217
139. Šsylvainchamberland.com
Follow up 1 y into Retention
â˘Left condylar hypoplasia, likely sequella of the fall at 5-6y
â˘Deepened antegonial notch, compensatory growth at the
gonial angle
140. Šsylvainchamberland.com
Non Growing
â˘Motor bike accident
â˘Open reductionâ¨
But the condylar head moved
forward
⌠Could be because
inadequate immobilization
or the fragment were not
realigned at surgery
142. Šsylvainchamberland.com
Follow up 4 Years
â˘Compensatory growth
⌠Right condyle reshaped normally
⌠R : Overgrowth vertically?
⌠L : Overgrowth horizontally?
PACl.160309; 14 years 9 months
PACl.27022013; 18 y 11 m
143. Šsylvainchamberland.com
Follow up 8
Years
â˘Overgrowth right
condyle
⌠Right post Xbite
⌠Cant of lower
occlusal plane
â˘CH type 2 vertical
PACl.160309; 14 years 9 months
PACl.27022013; 18 y 11 m
PACl09052017; 22 y 10 m
PACl09052017; 22 y 10 m
PACl16032009
PACl.27022013; 18 y 11 m
PACl30102007
144. Šsylvainchamberland.com
Conclusion
â˘Facial asymmetries are sometimes difďŹcult to diagnose
â˘An asymmetric growth can express itself in the adolescence without having
been present during childhood
â˘Articular clicking can be a confounding factor in the diagnosis, but should
be considered as a clue.
â˘The treatment often implies a surgical approach
â˘5 to10 % of the facial asymmetries are due to an undiagnosed early
condylar fracture or a traumatic impact in period of growth