Artificial intelligence vs. semi-automated segmentation for assessment of dental periapical lesion volume index score: A cone-beam CT study.

INTRODUCTION: Cone beam computed tomography periapical volume index (CBCTPAVI) is a categorisation tool to assess periapical lesion size in three-dimensions and predict treatment outcomes. This index was determined using a time-consuming semi-automatic segmentation technique. This study compared artificial intelligence (AI) with semi-automated segmentation to determine AI's ability to accurately determine CBCTPAVI score. METHODS: CBCTPAVI scores for 500 tooth roots were determined using both the semi-automatic segmentation technique in three-dimensional imaging analysis software (Mimics Research™) and AI (Diagnocat™). A confusion matrix was created to compare the CBCTPAVI score by the AI with the semi-automatic segmentation technique. Evaluation metrics, precision, recall, F1-score (2×precision×recallprecision+recall), and overall accuracy were determined. RESULTS: In 84.4 % (n = 422) of cases the AI classified CBCTPAVI score the same as the semi-automated technique. AI was unable to classify any lesion as index 1 or 2, due to its limitation in small volume measurement. When lesions classified as index 1 and 2 by the semi-automatic segmentation technique were excluded, the AI demonstrated levels of precision, recall and F1-score, all above 0.85, for indices 0, 3-6; and accuracy over 90 %. CONCLUSIONS: Diagnocat™ with its ability to determine CBCTPAVI score in approximately 2 min following upload of the CBCT could be an excellent and efficient tool to facilitate better monitoring and assessment of periapical lesions in everyday clinical practice and/or radiographic reporting. However, to assess three-dimensional healing of smaller lesions (with scores 1 and 2), further advancements in AI technologies are needed.

Conservative management of double teeth in molar teeth with pulp or periapical disease: a report of five cases and literature review.

BACKGROUND: Double teeth are usually the result of an abnormality in the developing tooth germ. Double teeth can occur in either the primary or permanent dentition, with the majority of cases concerning permanent teeth reported in the anterior teeth and less frequently in the molar teeth. CASE PRESENTATION: This report illustrates five cases of double teeth in molars with pulp and periapical disease, including one case of geminated teeth and four cases of fused teeth. Radiographic findings revealed the presence of extra teeth on the buccal aspect of the molar in five cases, with or without communication between the two root canal systems. Root canal treatment was performed by using CBCT and a dental operating microscope. The treatment outcome was good in all five cases. CONCLUSION: The diagnosis and treatment of double teeth requires special attention. The root canal system should be carefully explored to obtain a full understanding of the anatomy, allowing it to be fully cleaned and obturated. Proper anatomical structure analysis prior to treatment facilitates the development of an appropriate treatment plan, thereby increasing the likelihood of successful treatment both aesthetically and functionally.

Magnetic resonance imaging in the diagnosis of periodontal and periapical disease.

OBJECTIVES: Early pre-clinical inflammatory changes in periodontal and/or periapical lesions, which typically precede bone loss, are challenging to diagnose using ionizing-radiation-based imaging modalities. MRI provides relevant additional diagnostic information of inflammatory processes in soft and hard tissues. The aim of the present study is to undertake a systematic review of the literature on MRI in the diagnosis of periodontal and/or periapical disease. METHODS AND MATERIALS: The PubMed/MEDLINE and Scopus bibliographic databases were searched (2000-2021) using the search string: ("MRI" or "magnetic resonance imaging") and ("periodontitis" or "periodontal" or "apical pathology" or "endodontic pathology" or "periapical" or "furcation" or "intrabony"). The search was limited to studies published in English. The studies were assessed independently by three reviewers, focusing on the MRI sequences, imaging modalities (radiographs, cone beam CT (CBCT), and MRI), disease definition, assessed parameters, and outcome measurements. RESULTS: The search strategy yielded 34 studies, from which 13 were included. Overall, the findings of MRI were in agreement with CBCT. The studies showed that MRI provided diagnostic information of the hard and soft tissue components affected by periodontal and/or periapical disease with a fairly high sensitivity and specificity. However, the assessed parameters (e.g. MRI acquisition protocols, and disease definition) differed substantially. CONCLUSIONS: The included studies indicate that the use of MRI in the diagnosis of periodontal and/or periapical disease is feasible and promising. More studies are needed to define the accuracy of this non-ionizing-radiation-based diagnostic modality, in the assessment of periodontal and/or periapical lesions.

Diagnóstico clínico, radiográfico e histológico de un caso de fibrosis periapical posendodóntica / Clinical, radiographic, and histologic diagnosis of a postendodontic periapical fibrosis case

Objetivo: La fibrosis periapical posendodóntica es un proceso reparativo asintomático, radiolúcido y no progresivo que se interpreta con frecuencia como una lesión patológica persistente. El diagnóstico de esta entidad suele ser dudoso y sólo puede definirse mediante la correlación de las obser- vaciones clínicas, radiográficas e histológicas. El objetivo de este informe es describir el caso de un paciente que presenta un área radiolúcida periapical persistente y asintomática en un incisivo lateral superior. Caso clínico: Luego de cuatro años y dos meses de ha- ber recibido un tratamiento endodóntico el paciente concurre a la consulta para un examen de rutina. El examen radiográfico del diente revela un área radiolúcida persistente y bien defini- da. A causa de una fractura radicular irreparable, se indicó la extracción de la pieza dentaria. Esto permitió realizar el estu- dio histológico del tejido blando que permanecía adherido en el ápice de la raíz, lo que confirmó y completó el diagnóstico de fibrosis periapical posendodóntica.(AU)

Aim: The postendodontic periapical fibrosis is an asymp- tomatic radiolucent and non-progressive healing process that is often interpreted as a persistent pathological lesion. The diagnosis of this entity is usually uncertain, and it is only de- fined by the correlation of clinical, radiographic and histo- logical observations.The aim of this report is to describe the case of a patient with a long-term persisting asymptomatic and radiolucent area in a upper lateral incisor. Clinical case: Four years and two months after receiv- ing an endodontic treatment the patient comes to our office for a routine control. Radiographic examination revealed the presence of a persistent well defined radiolucent area. Sur- gical tooth extraction was required due to the presence of a complicated root fracture.This allowed to perform a histolog- ical study of the soft tissue attached to the apex of the ex- tracted root, which confirmed and completed the diagnosis of postendodontic periapical fibrosis (AU)

Sphericity of Periapical Lesion and Its Relation to the Novel CBCT Periapical Volume Index.

BACKGROUND: The purpose of this study was to assess the sphericity of periapical lesions and its relation to the cone-beam computed tomography periapical volume index (CBCTPAVI). METHODS: A total of 261 periapical lesions were assessed using cone-beam computed tomography images from InteleViewer. Three-dimensional analysis of the lesions was conducted using analytical imaging software Mimics Research. Lesion volume and surface area measurements were determined using the semiautomatic segmentation technique, and these measurements were then used to determine lesion sphericity and CBCTPAVI score. One-way analysis of variance with post hoc Tukey test was used to assess for differences in sphericity among CBCTPAVI groups. RESULTS: The mean sphericity of periapical lesions was 62%. Periapical lesions with larger CBCTPAVI scores were significantly less spherical than lesions with smaller CBCTPAVI scores. CONCLUSIONS: Periapical lesions of endodontic origin are mostly semi-spherical in their spread, and as CBCTPAVI score increases, sphericity decreases, indicating that larger lesions expand less uniformly compared with smaller lesions. Clinicians should be aware that lesions of increased volume have less sphericity, and are thus elongated or stretched in 1 or more anatomic plane. This information will assist clinicians in planning and performing periapical surgery and may aid in differential diagnosis of radiolucent jaw lesions.

Automatic Detection of Periapical Osteolytic Lesions on Cone-beam Computed Tomography Using Deep Convolutional Neuronal Networks.

INTRODUCTION: Cone-beam computed tomography (CBCT) is an essential diagnostic tool in oral radiology. Radiolucent periapical lesions (PALs) represent the most frequent jaw lesions. However, the description, interpretation, and documentation of radiological findings, especially incidental findings, are time-consuming and resource-intensive, requiring a high degree of expertise. To improve quality, dentists may use artificial intelligence in the form of deep learning tools. This study was conducted to develop and validate a deep convolutional neuronal network for the automated detection of osteolytic PALs in CBCT data sets. METHODS: CBCT data sets from routine clinical operations (maxilla, mandible, or both) performed from January to October 2020 were retrospectively screened and selected. A 2-step approach was used for automatic PAL detection. First, tooth localization and identification were performed using the SpatialConfiguration-Net based on heatmap regression. Second, binary segmentation of lesions was performed using a modified U-Net architecture. A total of 144 CBCT images were used to train and test the networks. The method was evaluated using the 4-fold cross-validation technique. RESULTS: The success detection rate of the tooth localization network ranged between 72.6% and 97.3%, whereas the sensitivity and specificity values of lesion detection were 97.1% and 88.0%, respectively. CONCLUSIONS: Although PALs showed variations in appearance, size, and shape in the CBCT data set and a high imbalance existed between teeth with and without PALs, the proposed fully automated method provided excellent results compared with related literature.

[Overview of technical advances in the diagnosis of pulp and periapical diseases].

Pulp and periapical diseases are common and frequently occurring diseases of which diagnosis and treatment must be dealt with by the dental clinicians. The diagnostic techniques of these diseases include evaluation of pulp vitality, measurement of pulp blood circulation and analysis and judgment of root canal anatomy. With the continuous emergence of digital and imaging technologies, the correct application of these technologies in clinic will help clinicians improve their abilities in diagnosis and treatment of related diseases. The present article summarizes and reviews the progress of assistant technology for diagnosing dental pulp and periapical diseases in recent years and puts forward some suggestions for its application.

[Application and prospect of static/dynamic guided endodontics for managing pulpal and periapical diseases].

Root canal therapy and endodontic surgery are conventional treatments for pulpal and periapical diseases. Compared with naked-eye operations, the application of dental operating microscope has enhanced the procedural accuracy and prognosis efficiently. However, root canals with pulp calcification/obliteration, apical lesions with thick cortical bone or adjacent to important anatomic structures are even challenging for experienced operators to achieve predictable clinical outcomes. Recently, with the advances in the field of digitalized information sciences, the above mentioned complicated endodontic cases can be solved under static and dynamic guidance. Before the treatment begins, virtual path is designed from data collected by cone-beam CT and oral image scanning using guidance software. Afterwards, root canal therapy and endodontic surgery can be performed precisely under the assistance of three-dimensional printed guide or dynamic guidance system. The present review describes the classification, features and clinical applications of the guided endodontics.

Pulpal and periapical disease in crowned vital teeth: A prospective matched cohort study.

This study aimed to determine the incidence and contributing factors to pulpal and periapical disease in crowned vital teeth. Seventy-three pairs of healthy teeth were included and divided into two groups; 'crowned' and 'untreated' groups. The crowned group was prepared for full coverage crown and no treatment was carried out on the untreated group. Both groups were subjected to clinical and radiographic examination to detect endodontic signs and symptoms pre-operatively and one-week after crown cementation. Electric pulp test was also subjected to both groups, pre-operatively, after tooth preparation and before crown cementation. The incidence of pulpal and periapical disease was 6.8% and 1.4%, respectively, after tooth preparation. Factors associated with pulpal and periapical disease were exposed pulp during tooth preparation and pre-operative bone level <35%. Despite the low incidence, the occurrence of pulpal and periapical disease within a short period is noteworthy.

Noninvasive Endodontic Periapical Biopsy of a Periapical Fibrous Scar: Case Report.

Postendodontic periapical fibrous scars (PFScs) comprise a type of radiolucent healing that is frequently misinterpreted as a pathological lesion. A combined clinical, radiologic, and histologic correlation is essential for a reliable diagnosis. This report presents a case of a patient with a long-term persistent asymptomatic postendodontic radiolucency that was misdiagnosed as endodontic failure and referred for endodontic retreatment and periapical surgery. To reach a definitive diagnosis, a core bone biopsy needle (CBBn) technique was performed on the area of the radiolucency. The material obtained was processed for histologic analysis and the lesion was determined to be a PFSc. In conclusion, the use of a CBBn before any invasive treatment allowed the clinician to distinguish between PFSc and other persisting pathosis, such as periapical granuloma or cystic lesions.

Overview of technical advances in the diagnosis of pulp and periapical diseases / 中华口腔医学杂志

Pulp and periapical diseases are common and frequently occurring diseases of which diagnosis and treatment must be dealt with by the dental clinicians. The diagnostic techniques of these diseases include evaluation of pulp vitality, measurement of pulp blood circulation and analysis and judgment of root canal anatomy. With the continuous emergence of digital and imaging technologies, the correct application of these technologies in clinic will help clinicians improve their abilities in diagnosis and treatment of related diseases. The present article summarizes and reviews the progress of assistant technology for diagnosing dental pulp and periapical diseases in recent years and puts forward some suggestions for its application.

Application and prospect of static/dynamic guided endodontics for managing pulpal and periapical diseases / 中华口腔医学杂志

Root canal therapy and endodontic surgery are conventional treatments for pulpal and periapical diseases. Compared with naked-eye operations, the application of dental operating microscope has enhanced the procedural accuracy and prognosis efficiently. However, root canals with pulp calcification/obliteration, apical lesions with thick cortical bone or adjacent to important anatomic structures are even challenging for experienced operators to achieve predictable clinical outcomes. Recently, with the advances in the field of digitalized information sciences, the above mentioned complicated endodontic cases can be solved under static and dynamic guidance. Before the treatment begins, virtual path is designed from data collected by cone-beam CT and oral image scanning using guidance software. Afterwards, root canal therapy and endodontic surgery can be performed precisely under the assistance of three-dimensional printed guide or dynamic guidance system. The present review describes the classification, features and clinical applications of the guided endodontics.

Is periapical surgery follow-up with only two-dimensional radiographs reliable? A retrospective cohort type sensitivity study / ¿El seguimiento de la cirugía periapical se realiza únicamente con radiografías bidimensionales confiable? Un estudio retrospectivo de sensibilidad de tipo cohorte

Background: Two-dimensional (2D) radiographic techniques are commonly used for assessing lesion prognosisafter endodontic surgery. The present retrospective cohort study analyzes the sensitivity and ability of differentradiographic techniques in obtaining area and volume measurements of periapical lesions.Material and Methods: Preoperative and follow-up (6-48 months) periapical and panoramic radiographs (indextest) and cone-beam computed tomography (CBCT) images (reference standard) were selected from an endodonticmicrosurgery database. Sensitivity was analyzed independently by two examiners. The areas of the 2D radio-graphic images and CBCT volumes were studied using Itk-Snap software and Romexis viewer.Results: The sample comprised 105 patients and 105 teeth, with a mean follow-up of 21 months (range 6-48). Preop-eratively, CBCT detected all the periapical areas, periapical radiography detected 67, and panoramic radiographydetected 60. Postoperatively, of the 52 cases in which CBCT detected remains of the periapical area, periapical ra-diography detected 22, and panoramic radiography detected 17. The measurements of the areas obtained by the 2Dmethods, and the volumes obtained by CBCT, had to be transformed into linear measures for comparison purpos-es. The measurements were found to be significantly different in both the preoperative and the follow-up images. Conclusions: Periapical radiography showed greater sensitivity than panoramic radiography, both preoperatively andat follow-up. The lesions measured with CBCT were larger, with significant differences than as evidenced by theperiapical and panoramic radiographs.(AU)

Conservative approach in a patient with multiple radiolucent periapical lesions using endodontics and surgery

Case report of a 43- year old male patient with multiple periapical radiolucent lesions caused by endodontic failure in teeth supporting a metalloceramic prosthetic rehabilitation, who came to the clinic to assess the possibility of keeping his teeth. After clinical and radiological examination with periapical x-rays and cone beam computer tomography (CBCT), we decided to use a combined endodontic-surgical approach. Clinical evolution was favourable, and the radiographic and tomographic controls showed complete healing of the periapical radiolucent lesions. Endodontic retreatment combined with periapical microsurgery are effective tools for conservative treatment of teeth with periapical lesions caused by endodontic failures. (AU)

Actitud terapéutica frente a una reabsorción interna perforante / Therapeutic attitude against a perforating internal resorption

Atendiendo a la localización de la reabsorción radicular, ésta puede ser clasificada en externa o interna. La reabsorción interna es relativamente poco frecuente, y su etiología y patogénesis no está todavía del todo clara. Este artículo muestra la complejidad de un incisivo central superior con una reabsorción interna inflamatoria perforante. El diagnóstico definitivo lo hallamos a través del examen tridimensional, que confirmó la extensión y comunicación con la superficie externa radicular. Aunque como podremos ver a lo largo de la exposición del caso clínico, la ayuda del microscopio nos permitió abordar el caso con mayor seguridad. En todo momento pudimos eliminar el tejido inflamatorio y preparar el conducto de manera adecuada. La obturación en este tipo de casos supone un reto para el endodoncista, siendo éste, mayor cuando se realiza únicamente de manera ortógrada. Para la obturación realizamos una técnica descrita en la literatura, sellando la zona apical a la reabsorción con gutapercha adaptada mediante condensación vertical; la zona reabsortiva con material biocerámico y, por último, la zona coronal con guta-percha inyectada. Se realizó un 3D a los 26 meses para una nueva evaluación de la zona reabsortiva, y así evaluar el estado óseo alrededor de la misma. La paciente se presenta totalmente asintomática sin signos clínicos y con buena salud de los tejidos periapicales

Based on the location of the root resorption, it can be classified as external or internal. Internal resorption is relatively rare, and its etiology and pathogenesis is not yet entirely clear. This article shows the complexity of a superior central incisor with a perforating inflammatory internal resorption. The definitive diagnosis is found through the three-dimensional examination, which confirmed the extension and communication with the external root surface. Although as we can see throughout the presentation of the clinical case, the help of the microscope allowed us to address the case with greater certainty. At all times we were able to remove the inflammatory tissue and prepare the duct properly. The obturation in this type of cases supposes a challenge for the endodontist, being this one, greater when it is done only in an ortograde way. For the filling, we performed a technique described in the literature, filling the apical area with resorption with gutta-percha adapted by vertical condensation; the resorptive zone with bioceramic material and finally the coronal zone with injected gutta-percha. A 3D was performed at 26 months for a new evaluation of the resorptive zone, and thus evaluate the bone state around it. The patient presents totally asymptomatic without clinical signs and with good health of the periapical tissues

Hallazgo incidental en tomografía computada de haz cónico / Incidenal finding in cone beam computed tomography

El creciente número de técnicas radiográficas realizadas por paciente para diagnóstico y planificación provoca un aumento en el número de hallazgos incidentales. La descripción de un hallazgo incidental puede desencadenar atención médica adicional, que incluye otros procedimientos y tratamientos de diagnóstico, con lo cual, en muchas ocasiones es necesario derivar al paciente para tratar la patología descubierta en forma incidental. La CBCT puede ayudar a detectar la presencia de lesión periapical no diagnosticada previamente, donde la evaluación clínica previa y las radiografías convencionales no han revelado la patología. La patología asintomática u oculta puede conducir a un diagnóstico tardío, lo que puede afectar negativamente las posibles estrategias de tratamiento y los resultados. La detección temprana y la precisión diagnóstica son esenciales. La CBCT es una técnica que proporciona vistas de zonas anatómicas con las cuales la mayoría de los odontólogos no están familiarizados y que pueden revelar patología oculta, permitiendo diagnósticos más precisos y confiables, y reduciendo así la posibilidad de perder la patología clínicamente relevante. Este articulo trata de sintetizar las ventajas del uso de la tomografía para diagnosticar el hallazgo incidental (AU)

The increasing number of radiographic techniques performed by the patient for diagnosis and planning causes an increase the number of incidental findings. The description of an unexpected finding can trigger additional medical care including, other diagnostic procedures and treatments, therefore, in many occasions it is necessary to refer the patient to treat the pathology discovered incidentally. CBCT may aid in detecting the presence of previously undiagnosed periapical disease, where prior clinical evaluation and conventional radiographs have failed to reveal pathology. Asymptomatic or occult pathology may lead to delayed diagnosis, which may adversely affect eventual treatment strategies and outcomes. Early detection and improved diagnostic accuracy are essential, also, provide views of anatomy that most dentists have never before seen; in addition, they may reveal occult pathology, enabling more accurate and reliable diagnoses thereby reducing the possibility of missing clinically relevant disease (AU)

Clinicopathological and ultrastructural characterization of periapical actinomycosis

BACKGROUND: The aim of the present study was to analyze the clinicopathological and the ultrastructural features of periapical actinomycosis (PA) cases. MATERIAL AND METHODS: Data from the files of an oral pathology laboratory were retrieved and the findings of histopathological analysis were evaluated. Hematoxylin-eosin (HE), a modified Brown & Brenn, and Grocott stains as well as ultrastructural analysis using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were utilized. RESULTS: Six cases were obtained, 4 females and 2 males, with a mean age of 34 year-old. Two cases were symptomatic, lower teeth and the anterior region were more commonly affected, and all cases were characterized by periapical radiolucencies. All cases presented sulfur granules with a ray-fungus or club-shaped pattern of the Splendore-Hoeppli phenomenon in HE-stained sections, with filamentous gram-positive bacteria aggregates highlighted by the modified Brown & Brenn stain. SEM analysis revealed abundant packed rod-like and filamentous bacteria associated with an extracellular amorphous material. EDX analysis showed predominant picks of calcium and sulfur in actinomycotic colonies. CONCLUSIONS: Our findings suggest that PA manifests either clinically and radiologically as a non-specific and heterogeneous condition and that the actinomycotic colonies consist in a calcium- and sulfur-rich matrix. Furthermore, the results highlight the importance of submitting periapical specimens after surgical removal to histopathological análisis

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Assessment of conformity between clinical (radiological) and histopathological diagnoses of chronic inflammatory periapical lesions treated with apicoectomy. Clinical and histopathological diagnoses of periapical lesions. Research article.

OBJECTIVES: Periapical inflammation is one of the most common pathologies within the jaws, leading to the destruction of periodontal ligaments, bone resorption and the formation of periapical granulomas or radicular cysts. The final diagnosis can be made only on the basis of histopathological examination. The aim of the study was to assess the conformity between clinical and histopathological diagnosis of inflammatory periapical lesions treated with apicoectomy. MATERIALS AND METHODS: The case histories of 52 patients subjected to surgical treatment at the Clinic of Conservative Dentistry with Endodontics between 2008 and 2018 were analyzed. Demographic data (age, gender), clinical (radiological) diagnosis, and data on the presence of sinus tracts and causal tooth were obtained from patients' records. RESULTS: In the light of clinical and radiological examination, 32 (61.5%) periapical granulomas, 18 (34.6%) radicular cysts and 2 (3.9%) periapical scars were diagnosed, whereas the result of histopathological examination revealed granuloma in 34 (65.4%) cases and in 18 (34.6%) - radicular cyst. For clinical diagnosis of granuloma, the result coincided with the result of the histopathological examination in 28 cases, and in the case of cysts in 14. The analysis showed a significant relationship between the clinical and histopathological diagnoses (p <0.05). CONCLUSIONS: The study emphasizes the importance of histopathological assessment for the proper diagnosis of periapical lesions. CLINICAL RELEVANCE: The article emphasizes the high importance of histopathological examination for the correct diagnosis of chronic inflammatory periapical lesions.

Effect of Periapical Diseases in Development of MRONJ in Immunocompromised Mouse Model.

OBJECTIVES: This study aimed to assess the effect of zoledronic acid on an immunocompromised mice model with periapical disease. MATERIALS AND METHODS: Thirty C57BL/6N mice were randomly divided into three groups (N = 10). All animals were subjected to bilateral ovariectomy (OVX) and then treated with saline (Veh), zoledronic acid (ZA), or concomitant zoledronic acid and dexamethasone (ZA/Dx) for 12 weeks. Eight weeks after starting drug administration, pulpal exposure was conducted on the lower left first molar. Four weeks after pulpal exposure, all mice were sacrificed and the mandibles were collected for radiological and histological examinations. RESULTS: Microcomputed tomography (µ-CT) examination showed significantly reduced periapical bone resorption in the ZA/Dx group and decreased periodontal bone resorption in both ZA and ZA/Dx groups. Higher bone mineral density (BMD) and strengthened microstructure were found in ZA and ZA/Dx groups. More empty lacunae were found in ZA and ZA/Dx groups. CONCLUSIONS: Apical periodontitis aggravates MRONJ under immunocompromised circumstances. Concurrent use of ZA and steroids inhibits alveolar bone resorption but increases the risk of developing MRONJ.

Periapical Microsurgery: A 4-dimensional Analysis of Healing Patterns.

INTRODUCTION: Currently, the success of periapical microsurgery is determined by the restoration of the lamina dura and the elimination of symptoms. However, inadequate site preservation may prevent later implant placement. Although not possible before, the advent of cone-beam computed tomographic imaging and computer-aided registration allows for indirect and accurate 3-dimensional analysis of the surgical site over time. This study analyzed the volumetric healing pattern of the buccal plate after periapical microsurgery, with a specific focus on the buccolingual thickness of bone and the regression of the surface contour of the cortical plate. METHODS: Thirty-seven patients were scheduled for follow-up at least 1 year after periapical microsurgery (median = 25 months, total range = 12-31 months). Volumetric healing was analyzed by converting preoperative and postoperative cone-beam computed tomographic images into digital 3-dimensional models. The models were then registered to be able to analyze the changes in volume over time. Analysis was completed using Geomagic software (3D Systems, Rock Hill, SC), which allowed for registration of the volumes, calculation of volume change, and calculation of the margin of error. RESULTS: Twelve cases qualified for volumetric analysis. The median volumetric reduction of the cortical plate was -24.9 mm3 (interquartile range = -8.94 to -67 mm3), with an average linear error of 0.7 mm. This corresponded to an average loss in buccolingual dimension of 0.1-0.25 mm. Regression of the cortical plate was within the margin of error in all cases. CONCLUSIONS: After periapical microsurgery, and in the absence of grafting materials or membranes, healing occurs with little to no regression of the buccal cortical plate.