Three-dimensional analysis of mandibular morphology asymmetry and temporomandibular joint position in patients with unilateral Brodie bite.

OBJECTIVE: Previous studies have shown unilateral posterior crossbite is associated with mandibular asymmetry in morphology and position. However, it remains unclear whether unilateral Brodie bite plays a similar role in mandibular development. Therefore, this study aims to investigate the morphological and positional symmetry of mandibles in patients with unilateral Brodie bite by three-dimensional anaylsis. METHODS: Fourteen patients with unilateral Brodie bite (mean age 18.43 ± 4.24 years) and fourteen sex- and age-matched patients with normal occlusion (mean age 18.07 ± 5.48 years) underwent cone-beam computed tomography (CBCT) scans. 3D surface mesh models of their mandibles were established using Mimics Research 19.0. The surface matching percentage was compared between the original and mirrored mandible by Geomagic Control X software. Furthermore, the dimension and position of the temporomandibular joint (TMJ) were determined for both groups using InVivoDental 5.0. RESULTS: For surface-to-surface deviation analysis, the percentage of mismatch in patients with unilateral Brodie bite was significantly higher than the control group at ±0.50 mm, ±0.75 mm, and ±1.00 mm tolerance (P < .001). In patients with unilateral Brodie syndrome, the condyles on the scissors-bite side showed a significantly more anterior position (P = .03), greater medial inclination (P < .01), and larger posterior TMJ space (P = .01) than the non-scissors-bite side. CONCLUSION: Patients with unilateral Brodie bite exhibit a more asymmetrical mandibular morphology, with a greater anterior condylar position and posterior joint space on the scissors-bite side, indicating that early diagnosis and treatment may be necessary for patients with unilateral Brodie bite.

A proposed protocol for correlation between bone density in hemimandibular hyperplasia radiography and histopathological findings - A retrospective study.

The role of low-dose computed tomography (LDCT) in surgical planning can be assessed based on the correlation among bone density (BD/HU), radiographic values, and the histopathological appearance of hyperplastic overgrowth in mandibular condyles (hemimandibular hyperplasia/osteochondroma). The aim of this study was to evaluate the correlation between LDCT indices of bone-density measurements in surgical planning and histopathological specimens. The patients incuded in this study underwent detailed radiological evaluation as preparation for further clinical procedures. Excised condyles were evaluated in terms of bone density index using LDCT, and then histopathologically to investigate the accuracy of surgical procedures and set the basis for future surgical planning. An index value between both condyles' bone densities represented the relative difference between the healthy condyle and the side with hemimandibular hyperplasia (HH). Patients with unilateral condylar hyperplasia (UCH) showed a statistical correlation between condyle heads with increased bone density (BD) and scintigraphic (SCI) values (p < 0.001). On the other hand, correlation between BD and histopathological studies alone was significant (p < 0.001). With the increase in BD measured in HU in UCH condyles, the overall value of fibrous cartilage layer thickness decreased (p < 0.001). Furthermore, histopathological evaluation indicated that increased bone density on the UCH side resulted in increased total thickness (p > 0.001). The proposed index measurements in the mandibular condyles based on LDCT/BD can be used to estimate the degree of required surgical resection. Results from LDCT radiographic studies correlate with histopathological specimens more than scintigraphy.

The Role of Digital Surgical Planning and Surgical Guides in the Treatment of Unilateral Condylar Hyperplasia.

Unilateral condylar hyperplasia (UCH) results in facial asymmetry, malocclusion, and temporomandibular joint dysfunction. Treatment consists of both surgical and orthodontic intervention. A review was performed for 4 patients with UCH who underwent digital surgical planning (DSP)-assisted condylectomy. All patients were female, aged 14 to 35 years at the time of operation with facial asymmetry and class III malocclusion. None of the patients had prior treatment and all had perioperative orthodontic appliances to provide fixation and postoperative elastic therapy. All patients underwent DSP-guided condylectomy, and intraoperative surgical cutting guides were used for 3 of the patients. All had significant improvement in facial symmetry and occlusion. None had recurrence, and additional intervention has not been required. If UCH is recognized before marked secondary changes in the maxilla, mandible, and occlusion, future orthognathic surgery may be potentially obviated. Craniomaxillofacial surgeons should consider using DSP and surgical guides in the treatment of UCH.

Mandibular condylar hyperplasia and its correlation with vascular endothelial growth factor.

BACKGROUND: Condylar hyperplasia (CH) is a rare condition characterised by excessive unilateral growth of the mandibular condyle after cessation of growth on the contralateral side causing facial asymmetry, being more prevalent in the second and third decades. OBJECTIVE: The aim of this study was to determine the utility of vascular endothelial growth factor (VEGF-A) as a diagnostic and prognostic factor in condylar hyperplasia, and to determine its potential viability as a therapeutic target. METHODS: This is a case-control study, where 17 mandibular condyles specimens were collected from 17 patients treated for active mandibular condyle hyperplasia and three unaffected human mandibular condyles from cadavers will serve as the control group. The samples were immunostained with VEGF-A antibody and evaluated on both quantity and intensity of staining. RESULTS: VEGF-A was qualitatively found to be greatly upregulated in patients with condylar hyperplasia. CONCLUSION: VEGF-A was qualitatively found to be upregulated in patients affected by CH, validating VEGF-A as a potential diagnostic, prognostic and therapeutic target.

Can Condylectomy Alone Achieve Facial Symmetry in Patients With Hemimandibular Hyperplasia (Condylar Hyperplasia Type 2)?

The purpose of the present study was to evaluate the 3-dimensional orofacial changes occurring after proportional condylectomy in patients with unilateral condylar hyperplasia type 2 (hemimandibular hyperplasia). Eight patients underwent proportional condylectomy that was not followed by orthognathic surgery or orthodontic treatment for at least 1 year. The precondylectomy and postcondylectomy photographs and radiographs were analyzed cephalometrically and compared. The average length of the condylar segment removed was 13 mm and this resulted in almost equal heights of the ramus-condyle units of both sides. Evaluations in the vertical plane improved after surgery; however, when the preoperative asymmetry was significant, the residual asymmetry continued to be notable after condylectomy. Transverse plane evaluations improved after condylectomy, and chin position was satisfactorily centralized in all patients. In the horizontal plane, mandibular setback occurred, and this was considered favorable when the preoperative skeletal profile was class III, whereas the opposite was when the patient was class I before surgery. The occlusion improved gradually over the postoperative months by the intrusion on the affected side and extrusion on the unaffected side into a bilaterally balanced posterior contacts with residual anterior open bite. In conclusion, condylar hyperplasia type 2 patients with mild asymmetry and low esthetic demands can benefit from proportional condylectomy as the sole treatment to both stop the hyperplastic condylar growth and improve the asymmetry to some extent. Surgeons should be able to predict the change that is expected to occur after proportional condylectomy and discuss this with the patient before surgery.

Discrepancy in Mandibular Medullary Cavity on Different Sides: More Hints Towards Understanding Hemifacial Microsomia.

The authors attempt to approach hemifacial microsomia with macroscopic techniques and look for a link between clinical manifestations with pathogenesis. In this study, for the first time mandibular medullary cavities as essential parts of the mandible were intravitally measured based on the 3-dimensional models. A total of 153 patients were included. The 3-dimensional models of patients' mandibles were reconstructed and medullary cavity volumes (mm 3 ) were measured. The ratio of medullary cavity volume to mandible volume was calculated to determine the proportion of the marrow in the bone. Statistical significance was found in mandible volumes ( P <0.001) and medullary cavity volumes ( P <0.001) on different sides. Medullary cavity volumes were significantly related to mandible volumes on both sides (both P <0.001). Medullary cavity volumes on the nonaffected and affected side were both in correlation with age but in different degrees ( r =0.214, P =0.008 versus r =0.170, P =0.036). The ratios of medullary cavity volume and the mandible were significantly different ( P <0.001) on 2 sides. The volume ratio on the nonaffected side correlated to age while this correlation did not exist on the affected side ( r =0.195, P =0.016 versus r =0.129, P =0.112). A smaller medullary cavity found on the affected side could lead to a reduced amount of bone marrow cells and consequently reduced osteogenic and hematopoietic potential. This could result in abnormal bone formation on the affected side of mandible. Proportions of marrow in bone on the affected side irrelevant to patients' ages signify a poorer potential of expansion. This may explain a higher reluctancy of growth in affected mandibular sides.

A systematic review and meta-analysis of the surgical outcomes in patients with osteochondroma of mandibular condyle.

Many options exist in the diagnosis and management of condylar osteochondroma. The purpose of this study was to provide a congregate information concerning treatment of the osteochondroma involving the mandibular condyle. The search was conducted in PubMed, Google Scholar, Semantic Scholar, and Cochrane database until February 2022. Twenty-seven studies were included for the final review. The review included 439 patients who underwent surgical management for mandibular condylar osteochondroma. The position of osteochondroma was mentioned in 13 studies. Preauricular, retromandibular, endaural, submandibular, transzygomatic, and intraoral approaches were used for approaching the tumor. Surgical techniques included resection, conservative condylectomy, and total condylectomy. Concomitant orthognathic surgery was performed along with tumor resection in 19 studies. In the entire review, the recurrence rate was 0.22% (1/439). The results of the meta-analysis showed that 2 studies reported significant malocclusion events after surgical therapy. Total joint replacement after tumor resection has a higher improvement in maximal mouth opening (8 mm) compared with vertical ramus osteotomy and no reconstruction groups, which have similar improvements (6 mm). The mainstay of treatment of osteochondroma is surgical excision either as condylectomy or conservative condylectomy. Among the various reconstruction modalities, total joint replacement showed better improvement in mouth opening. Adjunct procedures like orthodontic and orthognathic surgery have an important role in holistic management of severe cases. The treating surgeon must choose the surgical procedures in a pragmatic way.

"Proportional Condylectomy" for Vertical Condylar Hyperplasia Without Intermaxillary Elastics: Clinical Results and Patient Satisfaction.

OBJECTIVES: First, to investigate the clinical outcome of 'proportional condylectomy' for patients with active unilateral condylar hyperplasia without complementary treatment by intermaxillary elastics and, second, to examine their level of satisfaction regarding function and esthetics. STUDY DESIGN: A retrospective observational descriptive study was conducted. All patients included in the study suffered from active unilateral condylar hyperplasia with a vertical component. The length of the condylar-ramus unit was measured on both sides by an multidetector computed tomography scan. The difference was calculated and resected from the hyperplastic condyle during the operation. Facial, occlusal, and skeletal changes were evaluated using photographic and radiologic records, and a satisfaction questionnaire regarding function and esthetics was completed. P <0.05 was considered significant. RESULTS: Fifteen patients were included in the study. The mean participants' age was 27.93±13.06 years, and the mean follow-up duration was 12.40±6.55 months. The mean chin deviation improved by 58.47% ( P =0.001). Mean lip commissure plane tilt was improved by 61.31% ( P =0.001). Six months postoperatively, all patients exhibited centered dental midlines ( P =0.001). Occlusal plane tilt was significantly improved by 70.02% ( P =0.001), and high patient satisfaction was recorded. Twenty-six percent (4/15) of patients did not require the complementary orthodontic treatment, and none of them required complementary orthognathic surgery. CONCLUSIONS: 'Proportional condylectomy' for patients with active unilateral vertical condylar hyperplasia without complementary treatment by intermaxillary elastics is a predictable procedure in terms of function and esthetics.

Active Unilateral Condylar Hyperplasia Treated With Simultaneous Condylectomy and Orthognathic Surgery: A Clinical Report.

PURPOSE: To review and report the demographic and diagnostic data in a population with active unilateral condylar hyperplasia. The surgical intervention, sequencing of surgery, and treatment outcomes, including a quality-of-life survey, are described. MATERIALS AND METHODS: Eighty patients were diagnosed with active disease. Demographic, treatment, and treatment outcomes were assessed. Quality of life was assessed by a 21-question questionnaire. RESULTS: Women were affected more frequently than men (W - 52; 65%; P = .008). Hemimandibular elongation (HE) (49; 61%; P - .004) occurred more frequently than hemimandibular hyperplasia (HH) (24; 30%) and HH-HE (7; 9%). Right side was affected more than left (R - 49; 61%; P - .003) overall, and when stratified. All racial groups were represented. Of the 80 patients in the sample, 80 (100%) underwent condylectomy on the side of active growth, 70 (87%) underwent bimaxillary osteotomies, 53 patients (66%) had single-piece maxillary osteotomies, 17 (21%) underwent segmental maxillary osteotomies, and 38 (48%) genioplasties were performed. Four patients (5%) underwent a second operation within a year of the first surgery to adjust the position of the mandible. Four (5%) facial nerve deficits were recorded. Class I cuspid occlusion was achieved with coincident maxillary and mandibular midlines and resolution of crossbite in 70 (88%) patients. Twenty three of the 24 respondents (96%) reported that they were satisfied with the treatment. CONCLUSIONS: Both HH and HE are diagnosed through clinical and radiographic examinations. Our results showed that HE occurs more frequently, all deformity subclassifications occur more frequently in females, the majority present in adolescence, and all racial groups are affected. The right side predominated. This study suggests that simultaneous condylectomy and orthognathic surgery provides predictable and stable outcomes for patients with active unilateral condylar hyperplasia and associated dentofacial deformities with an improvement in quality of living.

Innovation of new clinical concepts in the correction of facial deformity of patients with post-traumatic condylar hyperplasia condition.

Post traumatic condylar hyperplasia condition is an increase in the total number of cells due to increased activity, which exist only as long as the activity or the stimulus is applied. When it is removed, the tissue returns to the normal state; however, a secondary structural alteration in the general architecture due to accompanying degeneration may render a complete return to the normal state impossible. Mandibular asymmetry following condylar injury is poorly documented as a cause of facial asymmetry. leFort1 (low-level fracture) osteotomies and bilateral sagittal mandibular osteotomies, which are comprehensive surgical plans, correct the facial deformity together with the occlusion. An innovation of new clinical concepts has been used in the correction of facial deformity in 11 patients with post-traumatic condylar hyperplasia condition (syndrome) by applying a new modified allo plastic material (subperiosteal acrylic implant).

Precise Intraoral Condylectomy With the Guide of Three-Dimensional Printed Template in a Mandibular Condylar Hyperplasia Patient.

PURPOSE: This study aimed to introduce an innovative method for mandibular condylectomy. A customized three-dimensional (3D) printed template is used to perform precise condylectomy in an intraoral approach. METHODS: Condylectomy combined with orthognathic surgery was used for the treatment of facial asymmetry secondary to unilateral condylar hyperplasia. The customized 3D printed osteotomy guide was placed with an intraoral approach under endoscopy, in order to perform a precise condylectomy. RESULT: With the customized 3D printed template, the condylectomy was performed more precisely, and the conventional extraoral incision was avoided. The osteotomy line was accurately transferred from the virtual surgical plan to the real surgery, which assured the precise resection. CONCLUSIONS: The intraoral approach combined with a 3D printed template provides a novel solution to perform the condylectomy precisely.

Can cystic lesions of the jaws be considered as the cause of mandibular asymmetry?

Background: The aim of this study is to investigate the presence of condylar and ramal asymmetry in patients with a cyst larger than 10 mm in the maxilla or mandible. Material and Methods: Condylar and ramal asymmetry index measurements of 47 patients (mean age: 28.85 ± 15.348) in the study group and 40 patients in the control group (mean age: 33.73 ± 13.095) were performed using panoramic radiographs. The study group consists of patients with cysts larger than 10 mm in diameter in the maxilla or mandible. The control group consisted of patients with no radiolucent lesions and no history of trauma. The possible statistical difference between the groups was evaluated by the Mann-Whitney U test. Results: No statistically significant difference was observed in asymmetry indices according to gender and the jaw (maxilla or mandible) in which the cyst was located. However, it was determined that CAI and RAI values were statistically significantly different between the study and control groups (p = 0.047 and p = 0.016, respectively). Conclusions: The presence of intraosseous cysts larger than 10 mm in the jaws was found to be associated with condylar and ramal asymmetry.(AU)

Can cystic lesions of the jaws be considered as the cause of mandibular asymmetry?

BACKGROUND: The aim of this study is to investigate the presence of condylar and ramal asymmetry in patients with a cyst larger than 10 mm in the maxilla or mandible. MATERIAL AND METHODS: Condylar and ramal asymmetry index measurements of 47 patients (mean age: 28.85 ± 15.348) in the study group and 40 patients in the control group (mean age: 33.73 ± 13.095) were performed using panoramic radiographs. The study group consists of patients with cysts larger than 10 mm in diameter in the maxilla or mandible. The control group consisted of patients with no radiolucent lesions and no history of trauma. The possible statistical difference between the groups was evaluated by the Mann-Whitney U test. RESULTS: No statistically significant difference was observed in asymmetry indices according to gender and the jaw (maxilla or mandible) in which the cyst was located. However, it was determined that CAI and RAI values were statistically significantly different between the study and control groups (p = 0.047 and p = 0.016, respectively). CONCLUSIONS: The presence of intraosseous cysts larger than 10 mm in the jaws was found to be associated with condylar and ramal asymmetry.

Surgery First and Clear Aligners on Relapsed Condylar Hyperplasia.

ABSTRACT: Condylar hyperplasia is (CH) a mandibular malformation that involves a change in the size and morphology of the condylar neck and head. The CH is an abnormality that usually occurs unilaterally and affects equally both men and women. Its etiology is controversial in its own right. Under this condition, mandibular growth occurs in all the 3 planes of space, but more predominantly in one of them. Treatment protocols are variable, but one of the best treatment choices is high condylectomy. Compared to the past, the change in the treatment protocol, as well as the innovations in both surgical and orthodontic technology, allowed a simplification of the therapeutic path, reduced patient discomfort and ensured more stable long-term postsurgical results.The authors present a case of a 40-year-old female patient with relapsed of unilateral CH, treated surgically for the second time and with orthodontic treatment with clear aligners. The clear aligners orthodontic treatment is now considered one the best treatment orthodontic options. In this case, considering the relapse of the hyperplasia and the need of a new orthodontic treatment we decide to use this technique to reduce patient discomfort and teeth force appliance.

The need for secondary orthognathic surgery after high condylectomy in patients with active unilateral condylar hyperplasia.

The need for secondary orthognathic surgery (OS) after a high condylectomy (HC) in patients with active unilateral condylar hyperplasia was assessed in 25 patients, reviewing patient characteristics and treatment planning. At 6-12 months after HC, 13 patients (52%) required secondary OS. The amount of mandibular dental midline shift before the HC (P=0.037), and a dental crossbite that was present before the HC (P=0.017) were significantly associated with the need for secondary OS. Overall, the mandibular dental midline coincided with the facial midline in eight patients (32%) at 2 weeks after HC. In 16% of the patients, no additional OS was needed despite this being the initial treatment plan. Additionally, the initially planned type of secondary OS was modified in six other patients. Early HC in skeletally immature patients provided very good results, both aesthetic and functional, with only two of them needing supplementary OS at 6-12 months after HC. The HC remains a valuable treatment in patients with active unilateral condylar hyperplasia, as it can eliminate the need for secondary OS and is very well tolerated by most patients.

Mandibular condylar remodeling characteristics after simultaneous condylectomy and orthognathic surgery.

INTRODUCTION: The objectives of this study were to evaluate postsurgical condylar remodeling using a radiographical interpretation, quantify condylar volumetric asymmetry, and assess soft tissue symmetry after simultaneous unilateral high condylectomy and bimaxillary osteotomies. METHODS: Sixteen patients diagnosed with unilateral condylar hyperplasia underwent unilateral high condylectomy and orthognathic surgery to correct skeletal and facial asymmetries. Cone-beam computed tomography scans were acquired before and 1-year after surgery. A radiographic consensus was evaluated for signs of reparative or degenerative changes. The condyles were mirrored and registered for assessment of volumetric and morphologic asymmetry. Soft tissue symmetry was evaluated by measurement of the distance of soft tissue pogonion from the skeletal midsagittal plane. RESULTS: Patients who undergo unilateral high condylectomy and orthognathic surgery present radiographic signs suggestive of degenerative changes, including sclerosis, osteophytes, flattening, and erosion in both the surgical and nonsurgical condyles (P ≤0.01). There was an average volumetric improvement of 531.9 ± 662.3 mm3 1-year postsurgery (P = 0.006). Soft tissue symmetry improved in all patients, with an average improvement of 65.8% (4.0 mm ± 2.6 mm, P ≤ 0.01). There was no correlation between the change in condylar volumetric asymmetry and the stability of the soft tissue correction. CONCLUSIONS: High condylectomy for the correction of a skeletal asymmetry in patients with condylar hyperplasia successfully reduces the volumetric asymmetry between the condyles. Postsurgical dysmorphic remodeling and degenerative changes were noted in both the surgical and nonsurgical condyles. Despite remarkable changes and remaining joint asymmetry, the soft tissue correction is stable 1-year postsurgery.

Case Report: unilateral condylar hyperplasia.

Case: This report describes a clinical case of unilateral condylar hyperplasia (CH) with unique, atypical morphology. An important feature of this report is the documentation of a series of clinical photographs of the patient, showing a gradual increase in facial asymmetry associated with the CH. The main symptom reported in this case was facial asymmetry. The main intraoral clinical features observed in the patient were contralateral crossbite and ipsilateral open bite associated with CH. Surgical reshaping of the condyle was the treatment plan for this case. Conclusions: The main take away point from this case is the importance of obtaining previous photographs of the patient at different ages during case diagnosis, which helps the clinician to determine the approximate time of commencement of CH. This case also highlights the imaging features of rarely observed atypical shape of the hyperplastic condyle.

Treatment measures of hemimandibular hyperplasia and associated facial deformities.

This study aims to show our institute's experience in the treatment of HH and its associated facial deformities in adults and growing adolescents and to investigate condylar remodeling and volumetric changes and long-term stability of orthognathic surgery in adults. The study included consecutive patients with clinical and radiological features of HH who underwent high condylectomy with or without simultaneous orthognathic surgery from 2013 to 2018. The clinical outcomes were assessed based on functional activities, TMJ pain, and recurrence. Postoperative 3D condylar remodeling and orthognathic stability were evaluated with the use of ITK-Snap and 3D Slicer. Thirteen patients (8 females and 5 males) with a mean age of 26.3 ± 5.79 years (range; 13-34 years) were included with facial asymmetry as the chief complaint. The patients were followed up for a minimum of 12 months and a maximum of 4 years (mean; 16.85 ± 10.04). There were no postoperative complications, and all patients achieved a satisfactory functional and aesthetic outcome using a one-stage surgical procedure. There was no incidence of recurrence or further asymmetries, with long-term stability at the selected points showing a mean difference of less than ±1 mm. The affected condylar volume was significantly reduced following high condylectomy, with mean changes between T1 and T2 of -144. 80 mm3 (p = .012). However, the contralateral condylar volume remained stable, with a mean change of 2.54 mm3 (p = .881). One-stage high condylectomy and orthognathic surgery is a viable measure for the treatment of HH and associated deformities in adults. High condylectomy in early adolescence could result in termination of the disease, and aesthetic improvement with further constant orthodontist-surgeon follow-up is required.

A Better Understanding of Unilateral Condylar Hyperplasia of the Mandible.

PURPOSE: Our current understanding of unilateral condylar hyperplasia (UCH) was put forth by Obwegeser. He hypothesized that UCH is 2 separate conditions: hemimandibular hyperplasia and hemimandibular elongation. This hypothesis was based on the following 3 assumptions: 1) the direction of overgrowth, in UCH, is bimodal-vertical or horizontal, with rare cases growing obliquely; 2) UCH can expand a hemimandible with and without significant condylar enlargement; and 3) there is an association between the condylar expansion and the direction of overgrowth-minimal expansion resulting in horizontal growth and significant enlargement causing vertical displacement. The purpose of this study was to test these assumptions. PATIENTS AND METHODS: We analyzed the computed tomography scans of 40 patients with UCH. First, we used a Silverman Cluster analysis to determine how the direction of overgrowth is distributed in the UCH population. Next, we evaluated the relationship between hemimandibular overgrowth and condylar enlargement to confirm that overgrowth can occur independently of condylar expansion. Finally, we assessed the relationship between the degree of condylar enlargement and the direction of overgrowth to ascertain if condylar expansion determines the direction of growth. RESULTS: Our first investigation demonstrates that the general impression that UCH is bimodal is wrong. The growth vectors in UCH are unimodally distributed, with the vast majority of cases growing diagonally. Our second investigation confirms the observation that UCH can expand a hemimandible with and without significant condylar enlargement. Our last investigation determined that in UCH, there is no association between the degree of condylar expansion and the direction of the overgrowth. CONCLUSIONS: The results of this study disprove the idea that UCH is 2 different conditions: hemimandibular hyperplasia and hemimandibular elongation. It also provides new insights about the pathophysiology of UCH.

Hemifacial hyperplasia: a case series and review of the literature.

Condylar hyperplasia is known to result in facial asymmetries and constitutes a well-recognized group of unilateral mandibular enlargements. Condylar hyperplasia has been sub-classified into hemimandibular hyperplasia and hemimandibular elongation. A much rarer disorder, hemifacial hyperplasia (or hemifacial hypertrophy) is a congenital malformation characterized by prominent unilateral overdevelopment of the hard and soft tissues of the face. The affected side grows at a faster rate than the non-affected side, creating a marked asymmetry that potentially involves the skeleton and teeth, as well as all components of the associated soft tissues. Hemifacial hyperplasia is usually identified at birth and progresses towards puberty, but is not thought to alter throughout the lifetime of affected individuals. A case series of five patients clinically diagnosed with hemifacial hyperplasia is presented, with the aim of reviewing the clinical features, discussing their individual surgical management, and summarizing the more recent identification of possible genetic mutations that may be responsible for hemifacial hyperplasia and related overgrowth disorders. It is speculated that depending on the genetic factors, the disorder may be progressive in specific cases.