Reabsorción Condilar como Complicación Postoperatoria en Pacientes Sometidos a Cirugía Ortognática. Revisión Narrativa / Condylar Resorption as a Postoperative Complication in Patients Undergoing Orthognathic Surgery. Narrative Review

RESUMEN: La reabsorción condilar como complicación postoperatoria en cirugía ortognática es una causa frecuente de recidiva de anomalías dentomaxilares, existiendo diversos factores que se relacionan con su aparición. El objetivo de este estudio fue describir mediante una revisión narrativa la reabsorción condilar como complicación postoperatoria en cirugía ortognática. Se realizó una búsqueda electrónica de la literatura en las bases de datos electrónicas PubMed, EBSCO, TripDatabase y Epistemonikos sin límite de años, en idioma inglés y español, incluyendo revisiones sistemáticas, ensayos clínicos y estudios observacionales. Se excluyeron reportes de casos, estudios en animales y aquellos que no relacionaran la complicación con cirugía ortognática. Se evaluaron los estudios según grado de recomendación y calidad de reporte. Veintiún artículos fueron seleccionados según los criterios de selección establecidos en esta revisión. La literatura reportada sugiere que la reabsorción condilar es una patología de frecuencia relativa en pacientes postoperados de cirugía ortognática (1,4-32 % de los casos) y que está asociada a factores de riesgo preoperatorios tales como género, edad, tipo de anomalía dentomaxilar y técnica quirúrgica utilizada. La reabsorción condilar es una complicación postoperatoria a cirugía ortognática que debemos considerar en la planificación del tratamiento e identificar pacientes con factores de riesgo. Luego de la intervención quirúrgica es de vital importancia realizar un seguimiento estricto a este tipo de pacientes e identificar de forma temprana cambios clínicos y radiográficos. Finalmente, es importante seguir investigando sobre esta materia para establecer criterios de prevención y diagnóstico, con mayor claridad.

ABSTRACT: Condylar resorption as a complication following orthognathic surgery is considered to cause dento-facial anomalies, relating to different pre and intra-operative factors. The aim of the research was to describe condylar resorption as a postoperative complication after orthognathic surgery. A review of the literature was made in four databases: PubMed, EBSCO, Trip database and Epistemonikos. The search was carried out without year limiting, articles in English and Spanish, including systematic reviews, observational studies and clinical trials. Exclusion criteria were applied for report cases, animal studies and articles that do not relate condylar resorption with orthognathic surgery. Quality of evidence and strength of the recommendations were assessed for the chosen studies. For this study 21 articles were selected following the inclusion criteria. The literature found reported that condylar resorption is a relatively frequent complication following orthognathic surgery (1.4-32 % of frequency) and that it can be associated with several factors such as genre, age, dento-maxillary anomaly and surgical technique. Condylar resorption is a complication that we must consider in the planning of orthognathic surgery, in order to identify risk factors and patients who are more likely to present this post-surgical complication. Following surgery, strict follow-up is a key factor to determine early clinical and radiographic changes. Finally, further research is needed to establish stronger prevention and diagnostic criteria.

Design of a Randomized Controlled Clinical Study of tissue-engineered osteogenic materials using bone marrow-derived mesenchymal cells for Maxillomandibular bone defects in Japan: the TEOM study protocol.

BACKGROUND: Maxillomandibular bone defects arise from maxillofacial injury or tumor/cyst removal. While the standard therapy for bone regeneration is transplantation with autologous bone or artificial bone, these therapies are still unsatisfactory. Autologous bone harvesting is invasive and occasionally absorbed at the implanted site. The artificial bone takes a long time to ossify and it often gets infected. Therefore, we have focused on regenerative therapy consisting of autologous bone marrow-derived mesenchymal cells (BM-MSCs), which decreases the burden on patients. Based on our previous research in patients with maxillomandibular bone defects or alveolar bone atrophy using a mixture of BM-MSCs, platelet-rich plasma (PRP), thrombin, and calcium, we confirmed the efficacy and acceptable safety profile of this treatment. In this investigator-initiated clinical study (the TEOM study), we intended to add ß-tricalcium phosphate (ß-TCP) owing to large defect with patients. The TEOM study aimed to evaluate the efficacy and safety of bone regeneration using mixtures of BM-MSCs in patients with bone defects resulting from maxillofacial injury, and tumor/cyst removal in the maxillomandibular region. METHODS: The TEOM study is an open-label, single-center, randomized controlled study involving a total of 83 segments by the Fédération Dentaire Internationale numbering system in maxillomandibular bone defects that comprise over 1/3 of the maxillomandibular area with a remaining bone height of ≤10 mm. The primary endpoint is rate of procedure sites with successful bone regeneration defined as a computed tomography (CT) value of more than 400 and a bone height of more than 10 mm. Our specific hypothesis is that the number of required regions was calculated assuming that the rate of procedure sites with successful bone regeneration is similar and the non-inferiority margin is 15.0%. DISCUSSION: The TEOM study is the first randomized controlled study of regenerative treatment using BM-MSCs for large maxillomandibular bone defects. We will evaluate the efficacy and safety in this study to provide an exploratory basis for the necessity of BM-MSCs for these patients. TRIAL REGISTRATION: This trial was registered at the University Hospital Medical information Network Clinical Trials Registry (UMIN-CTR Unique ID: UMIN000020398; Registration Date: Jan 15, 2016; URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000016543 ).

Tratamento cirúrgico da limitação de abertura bucal causada por hiperplasia do processo coronoide: relato de caso / Surgical treatment for mouth opening limitation caused by coronoid process hyperplasia: case report

A hiperplasia do processo coronoide é uma condiçãoincomum de etiologia desconhecida que se apresentaclinicamente por meio da limitação de abertura bucal enão possui sintomatologia dolorosa durante a aberturae o fechamento bucal. Objetivo: relatar e discutir, pormeio de um caso cirúrgico, o tratamento da limitaçãode abertura bucal causada por hiperplasia bilateral doprocesso coronoide. Relato de caso: paciente do sexofeminino, com 11 anos de idade, foi encaminhada paraatendimento devido à dificuldade de mastigação emfunção da limitação de abertura bucal, sem históricode trauma em face ou na região articular. O exame tomográficoevidenciou o alongamento bilateral do processocoronoide, fazendo com que ele colidisse com oarco zigomático durante a abertura bucal e causasse otravamento. O tratamento proposto foi a coronoidectomiabilateral com acesso cirúrgico intraoral, obtendono pós-cirúrgico imediato um ganho na abertura bucal.Considerações finais: a coronoidectomia é uma abordagemcirúrgica de fácil acesso por via intraoral, poucotraumática e eficaz no tratamento de pacientes com hiperplasiado processo coronoide. (AU)

The coronoid process hyperplasia is an unusual condition of unknown etiology that is presented clinically through mouth opening limitation, without painful symptoms during mouth opening and closure. Objective: to report and discuss, through a surgical case, the treatment of mouth opening limitation caused by bilateral coronoid process hyperplasia. Case report: female patient, 11 years old, referred due to chewing difficulty by mouth opening limitation. No history of trauma in the face or joint area. The tomographic examination showed the bilateral elongation of the coronoid process, causing it to collide with the zygomatic arch during mouth opening, which caused locking. The treatment proposed was bilateral coronoidectomy with intraoral surgical access, which enhanced mouth opening at the immediate postoperative period. Final considerations: coronoidectomy is a surgical approach with easy intraoral access, non-traumatic, and effective in the treatment of patients with coronoid process hyperplasia. (AU)

Assessment of spontaneous resolution of idiopathic bone cavity.

Idiopathic Bone Cavity (IBC) or Simple Bone Cyst (SBC) is a non- epithelialized bone cavity with serosanguinous fluid content or empty. There is a literature debate regarding its pathogenesis that remains unclear. The main treatment option is the surgical exploration, although there are successful cases described in the literature in which just a follow-up with clinical and radiographic evaluation was performed. Objective This study aimed to assess the spontaneous resolution of idiopathic bone cavity untreated by surgery. Material and Methods Twenty-one patients diagnosed with surgically untreated IBC were submitted to a follow-up protocol modified from Damante, Guerra, and Ferreira5 (2002). A clinical and radiographic evaluation was performed in 13 patients (13/21), while eight patients (8/21) were only radiographically evaluated. Three observers evaluated the panoramic radiographs of 21 patients and the Kappa test was performed by intra and inter-examiners. Inductive and descriptive statistics were applied to the results. Results Only one patient had a positive response to palpation and percussion of the teeth in the cyst area. Most of the cysts evaluated were rated as 3 (lesion "in involution"), 4 (lesion "almost completely resolved"), or 5 ("completely resolved"). Conclusions We observed progressive spontaneous resolution of IBC. Most cysts were found in the recovery process in different follow-up periods. Patient's follow-up, without surgery, may be considered after the diagnosis based on epidemiological, clinical, and radiographic features of the lesion.

Impact of Bone Volume Upon Condylar Activity in Patients With Unilateral Condylar Hyperplasia.

PURPOSE: Unilateral condylar hyperplasia or hyperactivity (UCH) is a bone overgrowth disorder affecting the mandible. The purpose of this study was to determine the relations among age, condylar bone structure, condylar bone volume, and condylar bone activity on single-photon emission computed tomographic (SPECT) scans in patients with UCH. MATERIALS AND METHODS: This study included 20 patients with a clinical presentation of progressive mandibular asymmetry and a positive bone SPECT scan. A bone SPECT-derived standardized uptake value (bSUV) for the condylar region was determined. All patients underwent condylectomy to arrest further progression of the disease. The resected condyles were scanned with a micro-computed tomographic scanner (18-µm resolution). Bone architectural parameters were calculated with routine morphometric software. RESULTS: The mean bSUV of the condyle on the affected side was 15.32 (standard deviation [SD], 8.98) compared with 9.85 (SD, 4.40) on the nonaffected side (P = .0007). For trabecular bone structure, there was a nonsignificant correlation between the SUV of the affected condyle and the measured bone volume fraction (r = 0.13; P = .58) and trabecular thickness (r = 0.03; P = .90). CONCLUSION: No meaningful relation was found between condylar bone volume fraction and condylar activity on bone scan; therefore, the impact of bone volume fraction on the results of bone scans is limited. The measured condylar activity on SPECT scan seems to be primarily a reflection of the remodeling rate of bone.

Comparative study of biomechanical stability of resorbable and titanium fixation systems after sagittal split ramus osteotomy with a novel designed in-vitro testing unit.

INTRODUCTION: Sagittal split ramus osteotomy (SSRO) is one of the most popular surgical procedures for correction of mandibular deformities. Several clinical and biomechanical studies exist in the literature which, comparing the stability of different osteosynthesis materials and techniques, were performed using two or three-point biomechanical test models. The aim of this study was to compare the stability of biodegradable and titanium materials for SSRO on one-piece polyurethane mandible samples which were fixed in a novel designed 6-point testing unit. MATERIALS AND METHODS: 16 polyurethane one piece replicas of human mandibles were used and bilateral SSRO were performed by the manufacturer according to Dal Pont modification. Mandibles were fixed with titanium and PLLA/PGA fixation materials. Displacement amounts were measured under loading forces using a non-contact extensometer, and strain values at the screws were recorded by strain gauges. RESULTS: Bicortical titanium screws (Group 2) showed significantly lower displacement values, while bicortical PLLA/PGA screws (group 4) showed significantly higher displacement values at 40-360 N forces. (p < 0.05). The highest strain value was measured on screws that were inserted upright in a proximal segment near the osteotomy line. CONCLUSION: To achieve more realistic results in biomechanical studies, test models should imitate jaw movements and test environments should be as similar as possible to physiological conditions. Newly designed six-point testing units will contribute to future biomechanical studies.

Mandibular kinematics and maximum voluntary bite force following segmental resection of the mandible without or with reconstruction.

OBJECTIVES: The purpose was to analyze mandibular kinematics and maximum voluntary bite force in patients following segmental resection of the mandible without and with reconstruction (autologous bone, alloplastic total temporomandibular joint replacement (TMJ TJR)). MATERIALS AND METHODS: Subjects operated from April 2002 to August 2014 were enrolled in the study. Condylar (CRoM) and incisal (InRoM) range of motion and deflection during opening, condylar retrusion, incisal lateral excursion, mandibular rotation angle during opening, and maximum voluntary bite force were determined on the non-affected site and compared between groups. Influence of co-factors (defect size, soft tissue deficit, neck dissection, radiotherapy, occlusal contact zones (OCZ), and time) was determined. RESULTS: Twelve non-reconstructed and 26 reconstructed patients (13 autologous, 13 TMJ TJR) were included in the study. InRoM opening and bite force were significantly higher (P ≤ .024), and both condylar and incisal deflection during opening significantly lower (P ≤ .027) in reconstructed patients compared with non-reconstructed. Differences between the autologous and the TMJ TJR group were statistically not significant. Co-factors defect size, soft tissue deficit, and neck dissection had the greatest impact on kinematics and number of OCZs on bite force. CONCLUSIONS: Reconstructed patients (both autologous and TMJ TJR) have better overall function than non-reconstructed patients. CLINICAL RELEVANCE: Reconstruction of segmental mandibular resection has positive effects on mandibular function. TMJ TJR seems to be a suitable technique for the reconstruction of mandibular defects including the TMJ complex.

Assessment of spontaneous resolution of idiopathic bone cavity

Abstract Idiopathic Bone Cavity (IBC) or Simple Bone Cyst (SBC) is a non- epithelialized bone cavity with serosanguinous fluid content or empty. There is a literature debate regarding its pathogenesis that remains unclear. The main treatment option is the surgical exploration, although there are successful cases described in the literature in which just a follow-up with clinical and radiographic evaluation was performed. Objective This study aimed to assess the spontaneous resolution of idiopathic bone cavity untreated by surgery. Material and Methods Twenty-one patients diagnosed with surgically untreated IBC were submitted to a follow-up protocol modified from Damante, Guerra, and Ferreira5 (2002). A clinical and radiographic evaluation was performed in 13 patients (13/21), while eight patients (8/21) were only radiographically evaluated. Three observers evaluated the panoramic radiographs of 21 patients and the Kappa test was performed by intra and inter-examiners. Inductive and descriptive statistics were applied to the results. Results Only one patient had a positive response to palpation and percussion of the teeth in the cyst area. Most of the cysts evaluated were rated as 3 (lesion "in involution"), 4 (lesion "almost completely resolved"), or 5 ("completely resolved"). Conclusions We observed progressive spontaneous resolution of IBC. Most cysts were found in the recovery process in different follow-up periods. Patient's follow-up, without surgery, may be considered after the diagnosis based on epidemiological, clinical, and radiographic features of the lesion.

Mandibular Gorham-Stout disease: A case report and literature review.

RATIONALE: Gorham-Stout disease (GSD) is characterized by aggressive bone resorption, proliferation of vascular or lymphatic vessels, and soft-tissue swelling. Bones that initially appear normal start to resorb, partially or completely. However, the etiology of GSD is unknown. PATIENT CONCERNS: A 29-year-old man with a chief complaint of toothache and mobility in the lower right mandible for the previous 1 year. DIAGNOSES: Gorham-Stout disease (GSD). INTERVENTIONS: The RANK-ligand inhibitor denosumab was suggested to use to inhibit the development of osteoclasts and slow mandibular resorption. In addition, we proposed resection of the remaining mandible and reconstruction via vascularized bone graft, after resorption of the mandible had become stationary. OUTCOMES: Regular follow-ups were advised to this patient to monitor the stability of bone resorption prior to any surgical intervention. LESSONS: We strongly recommend that every attempt should be made for early diagnosis and prompt effective medical and surgical management. The failure to do so results in further complications and poor prognosis.

The Status of Affected Infraorbital Nerve and Inferior Alveolar Nerve in Patients With Jaw Fibrous Dysplasia: A Clinical and Radiographic Evaluation.

The affected infraorbital nerve (IFBN) and inferior alveolar nerve (IFAN) status in patients with jaw fibrous dysplasia has not been definitely depicted. In this study, the authors try to explore the status of affected IFBN and IFAN in patients with jaw fibrous dysplasia. Ten patients with jaw fibrous dysplasia were included in this study. The complaints of numbness in the IFBA and IFAN innervated area were asked and recorded, and careful clinical examination was performed to evaluate the touch sense, pain sense, pressure sense, and temperature sense in the IFBA and IFAN innervated areas. Computed tomography scans also were performed to evaluate the imaging characteristics of affected IFBA and IFAN. The results showed that 1 patient with maxillary lesion showed complaints of slight numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense. In addition, 1 patient with mandibular lesion showed relative obvious complaints of numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense and temperature sense, but not serious. All other patients exhibited no numbness in the IFBA and IFAN innervated area. Although the position and morphology changed in some patients, all neural canal of affected IFBA or IFAN existed and showed no invasion of lesion. Taking these findings together, it further confirmed that evaluation of the function of IFBAN and IFAN is necessary for patients with jaw fibrous dysplasia, and the affected IFBAN and IFAN may should be reserved in most patients with jaw fibrous dysplasia when resecting or recontouring the lesion.

Restricted Mandibular Movement Attributed to Ossification of Mandibular Depressors and Medial Pterygoid Muscles in Patients With Fibrodysplasia Ossificans Progressiva: A Report of 3 Cases.

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare genetic condition characterized by congenital malformation and progressive heterotopic ossification (HO) caused by a recurrent single nucleotide substitution at position 617 in the ACVR1 gene. As the condition progresses, HO leads to joint ankylosis, breathing difficulties, and mouth-opening restriction, and it can shorten the patient's lifespan. This report describes 3 cases of FOP confirmed by genetic testing in patients with restricted mouth opening. Each patient presented a different onset and degree of jaw movement restriction. The anatomic ossification site of the mandibular joint was examined in each patient using reconstructed computed tomographic (CT) images and 3-dimensional reconstructed CT (3D-CT) images. A 29-year-old woman complained of jaw movement restriction since 13 years of age. 3D-CT image of the mandibular joint showed an osseous bridge, formed by the mandibular depressors that open the mouth, between the hyoid bone and the mentum of the mandible. A 39-year-old man presented with jaw movement restriction that developed at 3 years of age after a mouth injury. 3D-CT image of the jaw showed ankylosis of the jaw from ossification of the mandibular depressors that was worse than in patient 1. CT images showed no HO findings of the masticatory muscles. To the authors' knowledge, these are the first 2 case descriptions of the anatomic site of ankylosis involving HO of the mandibular depressors in the jaw resulting from FOP. In contrast, a 62-year-old bedridden woman with an interincisal distance longer than 10 mm (onset, 39 years of age) had no HO of the mandibular depressors and slight HO of the medial pterygoid muscle on the right and left sides. These findings suggest that restricted mouth opening varies according to the presence or absence of HO of the mandibular depressors.

Spontaneous bone formation after mandible segmental resection in "krokodil" drug-related jaw osteonecrosis patient: case report.

We report a case of a 48-year-old male patient with "krokodil" drug-related osteonecrosis of both jaws. Patient history included 1.5 years of "krokodil" use, with 8-month drug withdrawal prior to surgery. The patient was HCV positive. On the maxilla, sequestrectomy was performed. On the mandible, sequestrectomy was combined with bone resection. From ramus to ramus, segmental defect was formed, which was not reconstructed with any method. Post-operative follow-up period was 3 years and no disease recurrence was noted. On 3-year post-operative orthopantomogram, newly formed mandibular bone was found. This phenomenon shows that spontaneous bone formation is possible after mandible segmental resection in osteonecrosis patients.

The histological and histomorphometric changes in the mandible after radiotherapy: An animal model.

PURPOSE: Approximately 5% of irradiated head and neck cancer patients develop osteoradionecrosis of the mandible. The current non-surgical treatment options for osteoradionecrosis have limited effects and are based on a small number of studies. Therefore, we aimed to enhance the understanding of the pathophysiology of osteoradionecrosis by investigating changes induced by external irradiation in mini-pigs. METHODS: Sixteen Göttingen mini-pigs were divided into four groups for the application in two fractions with total equivalent radiation dosages of 25, 50, 70 Gray, and one group served as control. Thirteen weeks after irradiation, the left lateral teeth the mandible were removed and implants were placed. The pigs were sacrificed twenty-six weeks after irradiation, and the bone samples were stained with Masson's trichrome. RESULTS: The amount of fibrosis, resorption lacunae, necrosis, and the woven/lamellar bone ratios were increased after higher radiation dosages. The diameter of the lumen of the inferior alveolar artery was reduced depending on the irradiation dosages. The rate of bone remodeling decreased after irradiation. CONCLUSION: Both surgery and increasing irradiation dosages cause architectural bone changes and damage the vascularization. This might result in a chronic hypoxic state of the mandibular bone. In general, the bone formation rate was markedly decreased after radiotherapy.

Functional Outcome of CAD/CAM-Assisted versus Conventional Microvascular, Fibular Free Flap Reconstruction of the Mandible: A Retrospective Study of 30 Cases.

Background Different advantages of virtually planned and guided mandibular reconstructions have been described. Functional analyses and comparisons with conventionally reconstructed patients. Methods We retrospectively analyzed 30 cases of mandibular reconstructions that involved virtually planned or conventional microvascular, fibular free flaps that occurred between April 2011 and December 2014 at a single center. The results were also compared with a healthy cohort of 30 participants. Axiographic measurements were performed postoperatively, and uni- and multivariate regressions analyses were performed to determine the association between possible predictor variables on functional outcome. Results Operation time, hospital stay, number of osteotomies, incidence of postoperative temporomandibular joint pain, noise, and tension did not differ significantly between the conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) groups (each p > 0.05). Mouth opening and protrusion and laterotrusion also did not differ significantly (each p > 0.05) but were significantly reduced compared with the healthy group. Univariate analysis showed a significant influence of postoperative irradiation on mouth opening and laterotrusion in the conventional group (p = 0.047 and p = 0.028). In addition, multivariate analysis showed a significant influence of indication and number of osteotomies on laterotrusion (p = 0.005 and p = 0.043). Uni and multivariate analyses revealed a significant influence of indication, preoperative irradiation, and number of osteotomies on protrusion and mouth opening in the CAD/CAM group (p = 0.016, p = 0.044, and p = 0.028). Conclusion CAD/CAM-assisted reconstructions of the mandible give comparable functional results with those of the conventional technique, but no functional superiority has been established. Nevertheless, the integration of virtual planning and guided surgery is definitely of significant value but should be indicated individually case by case.

Ameliorative effect of black grape juice on systemic alterations and mandibular osteoradionecrosis induced by whole brain irradiation in rats.

PURPOSE: Whole brain irradiation (WBI) causes a variety of secondary side-effects including anorexia and bone necrosis. We evaluated the radiomodifying effect of black grape juice (BGJ) on WBI alterations in rats measuring food and water intake, body weight, hemogram, and morphological and histological mandibular parameters. MATERIALS AND METHODS: Forty male rats (200-250 g) were exposed to eight sessions of cranial X-ray irradiation. The total dose absorbed was 32 Gy delivered over 2 weeks. Four groups were defined: (i) NG: non-irradiated, glucose and fructose solution-supplemented (GFS); (ii) NJ: non-irradiated, BGJ-supplemented; (iii) RG: irradiated, GFS-supplemented; and (iv) RJ: irradiated, BGJ-supplemented. Rats received daily BGJ or GFS dosing by gavage starting 4 days before, continuing during, and ending 4 days after WBI. RESULTS: RJ rats ingested more food and water and showed less body weight loss than RG rats during the irradiation period. Forty days after WBI, irradiated animals started losing weight again compared with controls as a consequence of masticatory hypofunction by mandibular osteoradionecrosis (ORN). Osteoclastic activity and inflammation were apparent in RG rat mandibles. BGJ was able to attenuate the severity of ORN as well as to improve white and red blood cell counts. CONCLUSIONS: Fractionated whole brain irradiation induces mandibular changes that interfere with normal feeding. BGJ can be used to mitigate systemic side-effects of brain irradiation and ORN.

A Delayed Complication of Temporal Craniotomy Leading to a Potentially Difficult Airway.

Pseudoankylosis of the temporomandibular joint may occur as a complication of frontotemporal craniotomy. We report a patient who presented for surgery with a restricted mouth opening resulting from an infectious complication after frontotemporal craniotomy. Early identification of the potentially difficult airway helped manage this patient. We explain the mechanism of this late complication that may result in a difficult airway. If this is not identified preoperatively when a patient presents for emergency surgery or when the patient is in altered sensorium, it may lead to an unanticipated difficult airway.

Management of dentoskeletal deformity due to condylar resorption: literature review.

OBJECTIVES: The aim of this review was to examine all publicly available literature on the current treatments of the dentoskeletal deformity due to condylar resorption and their outcomes and to suggest management guidelines. STUDY DESIGN: A systematic review was performed of all literature located on the electronic PubMed database from 1970 to 2012. RESULTS: The search resulted in 21 papers and 210 cases treated from 1991 to 2012. Orthognathic surgery was the most commonly used option (42%) and was sometimes combined with open joint surgery (19%). Stability was observed, respectively, in 57% and 100% of the orthognathic surgery and open joint surgery cases. Condylectomy and reconstruction with chondrocostal graft or temporomandibular joint total joint prosthesis were used in 19% and 10% of all cases of orthognathic surgery and open joint surgery with good results (95% and 100%, respectively). Osteogenic distraction was anecdotic (1%). Nine percent of all cases received conservative treatment. CONCLUSIONS: Larger comparative studies are necessary to obtain evidence-based recommendations.

Numb Chin Syndrome.

"Numb chin syndrome" (NCS) refers to new-onset numbness of the lower lip and chin within the distribution of the mental or inferior alveolar nerves. While this focal numbness may be downplayed or even overlooked by patients and clinicians, in the right clinical scenario this may be the presenting symptom of an underlying malignancy. In the absence of any obvious, temporally related dental cause, there are certain conditions that clinicians should consider including orofacial and systemic malignancies as well as several inflammatory disorders. Thorough diagnostic evaluation should always be performed when no clear cause is evident. This paper will discuss the differential, recommended evaluations, and the prognosis, for a patient presenting with NCS.

An Animal Model for Inducing Deviation of the Mandible.

PURPOSE: Altering the occlusal surface is still a common choice for inducing a deviated mandible in an animal model. Botulinum neurotoxin type A (BoTx/A) can block the action potential transmission in neuromuscular junctions by inhibiting acetylcholine release without damaging the nerves and muscle structures. Our present study was aimed at developing an easy-to-reproduce animal model of asymmetric mandibles in which injection of BoTx/A was applied. MATERIALS AND METHODS: A total of 96 healthy 4-week-old male Sprague-Dawley rats were divided into 2 groups: an experimental group (n = 48) with BoTx/A injection and a control group (n = 48) with sterile saline injection at 4 sites of the right masseter muscle. Twelve rats from each group were humanely euthanized at weeks 1, 2, 3, and 4 for morphometric analysis using the micro-computed tomography (CT) findings. RESULTS: The micro-CT scans revealed facial asymmetry in the experimental group, with no facial asymmetry in the control group after injection. Significant differences were found between the experimental and control groups regarding the indexes containing the mandibular length (length from condyle to menton, length from coronoid to menton, and length of mandibular corpus from gonion to menton) and ramus height (posterior border and middle region near coronoid, and height of anterior mandible at vertical distance from menton). CONCLUSION: Our data have indicated that this deviated mandible animal model induced by injection of BoTx/A is highly reproducible and might be proved suitable for future studies of the asymmetric mandible.