The International Journal of Periodontics & Restorative Dentistry

Mandibular Regional Anatomical Landmarks and Clinical Implications for Ridge Augmentation

Istvan A. Urban, DMD, MD, PhD1 Vertical and horizontal ridge aug- Alberto Monje, DDS2,3 mentation of the severely atrophic Hom-Lay Wang, DDS, MSD, PhD3/Jaime Lozada, DDS1 posterior and anterior mandible is Gabor Gerber, DMD, PhD4/Gabor Baksa, MD5 considered the most challenging scenario for implant-supported oral rehabilitation in implant dentistry. Mandibular ridge augmentation via guided bone regeneration in the atrophic Due to the presence of the inferior mandible is considered one of the most challenging scenarios for implant- alveolar neurovascular bundle and supported oral rehabilitation. Uneventful wound healing has clearly demonstrated the submandibular fossa, this region its impact on the final regenerative outcome. Soft tissue management must be is remarkable for its high risk dur- precise and adequate to attain flap-free wound closure. Accordingly, it demands 1–3 exhaustive insight and expertise to avoid damaging the neighboring structures. ing implant placement. Compli- The cadaver study described herein discusses the mandibular morphologic cations in this zone include but are landmarks (ie, musculature, vascularization, innervation, and salivary glands) not limited to sensory disturbances necessary to safely perform regenerative procedures in the atrophic mandibular or trauma of the sublingual and sub- ridge, such as vertical ridge augmentation and dental implant surgery. The mental arteries with consequential potential intraoperative complications are presented, as well as clinical implications hematoma in the submandibular of which the clinician must be aware to prevent adverse surgical events during 4 regenerative surgery and implant placement in this anatomical region. Int J and sublingual spaces. A compre- Periodontics Restorative Dent 2017;37:347–353. doi: 10.11607/prd.3199 hensive and precise understanding of such anatomical structures is necessary to avoid potential complications that could ultimately jeopar- dize the treatment outcome. Furthermore, ridge augmentation in the posterior mandibular region has been classified as an un-

1Assistant Professor, Graduate Implant Dentistry, Loma Linda University, Loma Linda, predictable therapy due to the com- California, USA; Director, Urban Regeneration Institute, Budapest, Hungary. plexity of the approach.5 A variety 2ITI Fellow, Department of Oral Surgery and Stomatology, School of Dental Medicine, of treatment modalities have been University of Bern, Bern, Switzerland. proposed, such as onlay/inlay block 3Professor, Graduate Periodontics, Department of Periodontics and Oral Medicine, 6,7 School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA. grafting and guided bone regen- 4Dean, Semmelweis University, School of Dentistry; Associate Professor, Department of eration (GBR) by means of a barrier Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary. membrane.8–12 Although early find- 5Research Assistant, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary. ings conceived of autogenous block grafts as the gold standard, recent Corresponding author: Dr Istvan A. Urban, Urban Regeneration Institute, data seem to demonstrate the fea- Sodras utca 9, Budapest, Hungary 1026. Fax: +36-1-2004447. sibility of combining biomaterials Email address: [email protected] with autogenous bone particles. ©2017 by Quintessence Publishing Co Inc. Combined with a nonresorbable

Volume 37, Number 3, 2017

© 2017 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. 348 membrane, these may offer compa- tures of the posterior mandibular Musculature of the Floor of the rable bone gain with less morbidity, region (ie, musculature, vasculariza- Mouth and the Tongue fewer postsurgical complications, tion, innervation, and salivary glands) and better stability of the peri-implant necessary to safely perform regen- The key muscle of this region is the bone level in the long term.8 Never- erative procedures such as vertical mylohyoid, which creates the dia- theless, adequate hard and soft tis- ridge augmentation and dental im- phragm of the mouth—diaphragma sue management and fulfillment of plant surgery in the atrophic man- oris. This muscle originates from the biologic principles (ie, primary dibular ridges are included here. the mylohyoid line of the inner sur- wound closure, angiogenesis, stabil- face of the mandible, and its line is ity of the clot, and space creation)13 oblique, running more superior at are the most relevant factors for suc- Materials and Methods the molar region and starting deep- cessful GBR.9,14,15 In this sense, it is er at the first premolar and anterior. worth noting that wound dehiscence A total of 10 embalmed cadaver The muscle inserts into the body of may be detrimental to the bone aug- heads including mandibles with as- the hyoid bone and anteriorly into mentation outcome as flap tension sociated intact soft tissue were used a connective tissue raphe located plays a primary role in postopera- for this study. The cadaver heads in the middle (Fig 1). It functions in tive closure, and thus in undisturbed were provided by the Department swallowing and mouth opening and wound healing. As such, closing of Anatomy, Histology, and Embry- creates a separation for the floor of forces of > 0.1 N may substantially in- ology, Semmelweis University, Bu- the mouth. crease the rate of wound dehiscence dapest, Hungary. Postmortem time Several muscles are involved in (≥ 40%).16 To coronally advance and ranged from 0 to 5 days. In 5 of the movement of the tongue, including achieve tension-free flap closure, cadaver heads, both common carot- the genioglossus muscle, the hyo- vertical and periosteal releasing inci- id and vertebral arteries were can- glossus and styloglossus muscles, sions combined with flap reposition- nulated and irrigated with cold saline and the palatoglossus muscle (Fig ing are recommended. (500–1,000 mL), followed by perfu- 2). The groove between the mylo Management of soft tissues in sion with Thiel solution.19 After a sec- hyoid and the hyoglossus muscles this region demands exhaustive in- ond irrigation of the vessels with cold is called the lateral lingual groove— sight and expertise to avoid damag- saline (50 mL) they were injected sulcus lateralis linguae. ing the neighboring structures. For with red-colored Creato Latexmilch The digastric muscle has an instance, the first step in releasing (Zitzmann Zentrale). Specimens were anterior and a posterior belly con- the lingual flap to obtain elastic- then immersed in Thiel solution for nected by an intermediate tendon, ity is to raise the mylohyoid muscle at least 1 year. which is held to the hyoid bone. that extends toward the origin of the The remaining 5 cadavers were The stylohyoideus muscle originates hyoglossus muscle.14 It is important fixed in a 10% neutral formalin so- from the styloid process and inserts to protect this anatomical area since lution. The heads were sectioned into the hyoid bone, usually with a the lingual nerve, the branches of such that the mandibular alveolar lateral and medial tendon that sur- the lingual artery, and the sublingual arches were preserved along with rounds the posterior belly and the gland could be damaged, requiring the surrounding soft tissue. An intermediate tendon of the digastric emergency care to stop bleeding.17 experienced surgeon and dissec- muscle. The posterior belly arises These unfortunate events could re- tion assistant reflected the soft tis- from the mastoid notch of the tem- sult in hematoma followed by swell- sues, vessels, nerves, and glands poral bone, and the anterior belly ing, which has occasionally been to display the regional anatomical arises from the digastric notch at reported as life-threatening due to features carefully. Experienced anat- the mandibular symphysis. The di- respiratory obstruction.18 Therefore, omists assisted with the interpreta- gastric muscle and the body of the descriptions of the anatomical fea- tion and allocation of the structures. mandible form the submandibular

The International Journal of Periodontics & Restorative Dentistry

i a b c g f h g e

d f c b h d j i a e

Fig 1 Inferior view of a deeper layer of the musculature of the floor Fig 2 Schematic drawing of the suprahyoid musculature: of the mouth after removal of the anterior belly of the digastric and (a) Geniohyoid muscle. (b) Genioglossus muscle. (c) Hyoglossus resection of the left side of the mylohyoid muscle and the body of muscle. (d) Posterior belly of the digastric muscle. (e) Intermediate the mandible. The submandibular glands have also been removed. tendon of the digastric muscle. (f) Stylohyoid muscle. (a) Mylohyoid muscle. (b) Mylohyoid raphe. (c) Geniohyoid muscle. (g) Styloglossus muscle. (h) Inferior longitudinal muscle of the (d) Hyoid bone. (e) Facial artery. (f) Submental artery. (g) Sublingual tongue. (i) Palatoglossus muscle. branch of the submental artery. Note that it perforates the mylohyoid muscle. (h) Carotid bifurcation. (i) Sternohyoid muscle. (j) Upper belly of the omohyoid muscle. triangle. The digastric muscle func- arteries, which are the second and artery runs between the mylohyoid tions in mouth opening and lower- third branches arising from the ca- and the genioglossus muscle, which ing the mandible. When the lower rotid. It is not uncommon for these is the anterior part of the lateral jaw is stabilized, it elevates the hyoid arteries to arise from the common lingual groove (Fig 5). It provides bone. Other muscles of the neck are lingual-facial trunk. branches to the sublingual gland, not of clinical relevance for mandib- muscles, and gingiva, and in most ular bone graft surgery and are not Lingual Artery cases creates an anastomosis with described in detail herein. The lingual artery commonly arises the submental artery anteriorly. Ad- from the carotid artery slightly supe- ditionally, some terminal branches rior to the hyoid bone, as the second penetrate the cortical bone. Vascular Supply anterior branch of the external carotid. It then runs anteriorly between Facial Artery Severe bleeding and hematoma the space of hyoglossus and middle The facial artery arises as the third have been reported related to pharyngeal constrictor, and anterior anterior branch of the external ca- implant surgery in the mandible. to genioglossus muscles. This is also rotid (Fig 3). It runs anteriorly and Anatomical knowledge of the vascu- called the medial lingual groove. curves superiorly, medial to the di- larization of the floor of the mouth Passing the body of the hyoid gastric and stylohyoideus muscles, is critical when the clinician is per- bone anteriorly, the lingual artery and reaches the base of the man- forming regenerative therapy in the starts to run superiorly, branching dible superior to the submandibular posterior and anterior mandible. into the hyoid and the dorsal lin- gland. Before reaching the man- Branches of the external carotid gual arteries. Running anteriorly, it dible, it branches into the submen- artery provide the arterial supply. bifurcates and becomes the deep tal artery, which runs toward the The two main anterior branches of lingual artery and the sublingual ar- chin and, in 29% of the cases, gives the artery are the lingual and facial tery (Figs 3 and 4). The sublingual rise to a branch that perforates the

Volume 37, Number 3, 2017

Fig 3 (left) Oblique view of the submandibular region: (a) External carotid artery. (b) Digastric muscle. (c) Facial artery. (d) Submental f artery. (e) Submandibular gland. (f) Masseter muscle. (g) Hypoglossal nerve.

Fig 4 (below left) Lateral view of the lingual artery entering the c medial lingual groove: (a) External carotid artery. (b) Linguofacial trunk. (c) Lingual artery. (d) Facial artery. (e) Hyoglossus muscle. (f) g d Hyoid bone. (g) Hyoid branch of the facial artery. (h) Hypoglossus e b nerve. (i) Posterior belly of the digastric muscle.

Fig 5 (below right) Anterior view of the lateral lingual groove. The a sublingual artery is clearly visible arising from the lingual artery. This anatomical variation is the most typical, existing in about 63% of cases: (a) Mylohyoid muscle. (b) Genioglossus muscle. (c) Lingual artery. (d) Sublingual artery. (e) Deep lingual artery. (f) Lingual nerve. (g) Sublingual gland. (h) Wharton duct.

h f d b e c a e g d c g f h a

mylohyoid muscle and anastomo- (63%) is the sublingual artery supply- the sublingual and the deep lingual ses with the sublingual artery (Figs ing the sublingual space (Figs 5 to artery are missing from the lingual 6 and 7).20 The facial artery then 7).20 In 29.6% of the cases, the sub- artery and the floor of the mouth, curves up to the face in front of the lingual artery did not exist and the and the tongue is supplied by the masseter muscle, running toward sublingual space was supplied by a submental artery arising from the the medial corner of the eye. It pro- branch of the submental artery.20 In facial artery.20 vides branches to the face through- this situation, a branch of the sub- out its course. mental artery perforates the mylohyoid muscle and enters the lingual Innervation Anatomical Variations in space. The lingual artery supplies Mandibular Vascularization the tongue, and the submental ar- There are two major nerves to be Studies investigating the anatomical tery supplies the floor of the mouth. aware of when performing these variations of the floor of the mouth These are the two main variations. surgeries: the lingual and the hypo- have recently been published. In a In 5.6% of the cases, the sublingual glossal. Surgically, the most remark- study investigating 27 cadavers, four and submental artery anastomoses, able is the lingual nerve, a branch types of variations were found.20 The supplying together the floor of the of the mandibular nerve (cranial most common anatomical variation mouth. Rarely (in 1.8% of the cases), nerve V/III). The lingual nerve starts

The International Journal of Periodontics & Restorative Dentistry

a d e g b e c c b

d a f

Fig 6 Inferior view of the vascularization of the floor of the mouth. Fig 7 Superior view of the lateral lingual groove after the body of (a) Facial artery. (b) Submental artery. (c) Sublingual branch of the the mandible has been rotated facially. This region is of key interest submental artery. Note that it perforates the mylohyoid muscle. when posterior mandibular ridge augmentation is performed. In (d) Submandibular gland. (e) Mylohyoid muscle. (f) Anterior belly of about 30% of cases, the main blood supply to the floor of the the digastric after detachment of its insertion. mouth comes from the perforating branch of the submental artery as seen in this specimen: (a) Mylohyoid muscle. (b) Geniohyoid muscle. (c) Sublingual branch of the submental artery. (d) Sublingual gland. (e) Uncinate process of the submandibular gland. (f) Lingual nerve. (g) Wharton duct.

just after the mandibular nerve ex- the facial nerve (cranial nerve VII) Salivary Glands its the foramen ovale of the skull. connects to the lingual nerve. This Running downward between the nerve is responsible for taste sensa- There are two salivary glands in medial and lateral pterygoid mus- tion in the anterior two-thirds of the this area: the submandibular and cles, it reaches the ramus of the tongue and the salivary production the sublingual. The submandibular mandible. Around the wisdom of the sublingual and submandibu- gland is the major component of the tooth area, it turns anteriorly and lar glands. posterior part of the submandibular runs into the lateral lingual groove. The hypoglossal nerve (cranial trigone. It protrudes into the lateral It has been reported that 75% turn nerve XII) is responsible for the mo- lingual groove with its uncinate pro- toward the lingual site at the first tor function of the tongue. Exiting cess and occasionally merges with and second molar. The distances the skull, it runs between the inter- the sublingual gland (Figs 3, 5, 6, are 9.6 mm, 13 mm, and 14.8 mm nal carotid artery and the internal and 7). at the second molar, first molar, and jugular vein. Running anteriorly and The excretory duct of the sub- second premolar, respectively.1 The downward, it enters deep into the mandibular gland is the submandib- lingual nerve innervates the anteri- lateral lingual groove and reaches ular duct, also known as Wharton or two-thirds of the tongue. Before the lateral border of the hyoglossus duct. This runs into the lateral lin- entering the lateral lingual groove, muscle, where it breaks up into its gual groove, is crossed by the lin- the chorda tympani, a branch of terminal branches. gual nerve inferiorly from outside,

Volume 37, Number 3, 2017

© 2017 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. 352 and opens into the sublingual car- tial complications resulting from mography), lingual nerve damage uncle. The sublingual gland is lo- anatomical variations should be ex- can occur when the lingual flap is cated in the anterior portion of the plored presurgically to foresee any raised carelessly in ridge augmenta- lateral lingual groove. It is covered potential risk. Due to the proximity tion procedures. Trauma may also directly by the oral mucosa and to nerves and blood vessels in the occur from the injection needle. protrudes laterally from the lingual mandible, especially the posterior When anesthetizing the inferior al- frenulum into the oral cavity as the region, this area must be thorough- veolar nerve, the lingual nerve is sublingual fold. The posterior lobes ly understood. At implant drilling/ held within the interpterygoid fas- open with numerous short ducts placement, due to the morphology cia; the lingual nerve fibers might (ductus sublinguales minores), and of the posterior mandible (ie, pres- be damaged, causing transient par- the anterior lobe opens with the ma- ence of concavity—U type ridge ~ esthesia.25 Moreover, the anterior jor sublingual duct (of Bartholin) into 70%),22 lingual cortical plate per- mandible is not exempt from neuro- the Wharton duct. foration is possible (occurrence ~ sensory and vascular complications 1%). 23 Knowing that the vascular- originating from the end portion of ization to the inner aspect of the the lingual, sublingual, and submen- Connective Tissue mandible is supplied by the facial tal arteries.26 artery and its branch, the submen- It was noted throughout this inves- tal artery, and the lingual artery and tigation that all the key anatomical its branch, the sublingual artery, Clinical Implications for landmarks, such as the lingual nerve, is critical as penetrating the man- Ridge Augmentation sublingual artery, sublingual gland, dibular lingual plate may trigger and Wharton duct, were imbedded excessive hemorrhage that, if not Several methods have been pro- in a dense, thick, supportive con- controlled by compression or liga- posed for advancing the lingual flap nective tissue (CT) layer. The fibers tion, may result in a life-threatening without injuring the surrounding vi- forming such a dense CT are thick episode.24 It has been reported that tal structures. Blunt dissection with and more numerous than those the most common presentation a dull instrument (ie, 90-degree ro- found in loose CT—for instance, (92%) is the artery running medial to tated blade or dull periosteotome in- in adipose CT—with ground sub- the sublingual gland, while in 45% struments) or application of manual/ stance that occupies relatively little of cases the artery lies further from compression forces to detach the space. Collagen fibers dominate this the lingual plate.20 Since anatomical mylohyoid muscle from the mandible dense, irregular CT beside the fibro- variations occur, caution must be or the mucosa overlaying the floor of blasts and ground substance.21 exercised when placing implants in the mouth have been advocated.12,27 the posterior mandible or reflecting In the anterior atrophic mandible, the lingual flap for ridge augmenta- when the lingual flap is reflected to Potential Intraoperative tion procedures. access/advance, nerves and ves- Complications In addition, neurosensory dis- sels (branches of the lingual artery turbances could manifest during the and nerve) that approach the genial The most common surgical com- immediate postoperative period as spinal foramina might be injured. To plications are hemorrhage, nerve hypoesthesia, paresthesia, or dyes- prevent hemorrhagic/neurosensory damage, and accidental injury to thesia. Disregarding damage to the alteration events, cautious and gen- neighboring anatomical structures. inferior alveolar nerve due to inad- tle reflection assisted by a dull el- While these may result from inad- equate implant selection or poor evator must be performed and must equate implant therapy planning, presurgical planning (ie, assisted by never extend beyond the genial fo- the clinician must be prepared for three-dimensional diagnostic tools ramina. However, as was found in the any adverse complication. Poten- such as cone beam computed to- present morphologic study, dense/

The International Journal of Periodontics & Restorative Dentistry

thick, supportive fibrous connective 4. Camargo IB, Van Sickels JE. Surgical 15. Tinti C, Parma-Benfenati S, Polizzi G. tissue forms a protective compart- complications after implant placement. Vertical ridge augmentation: What is the Dent Clin North Am 2015;59:57–72. limit? Int J Periodontics Restorative Dent ment around such anatomical struc- 5. Milinkovic I, Cordaro L. Are there specific 1996;16:220–229. tures that may prevent irreversible indications for the different alveolar bone 16. Burkhardt R, Lang NP. Role of flap tension augmentation procedures for implant in primary wound closure of mucoperi- deep injury. placement? A systematic review. Int J osteal flaps: A prospective cohort study. Oral Maxillofac Surg 2014;43:606–625. Clin Oral Implants Res 2010;21:50–54. 6. Chiapasco M, Giammattei M, Carmag- 17. Kalpidis CD, Setayesh RM. Hemorrhag- nola D, Autelitano L, Rabbiosi D, Dellavia ing associated with endosseous implant Conclusions C. Iliac crest fresh-frozen allografts and placement in the anterior mandible: A re- autografts in maxillary and mandibular review of the literature. J Periodontol 2004; construction: A histologic and histomor- 75:631–645. An understanding of and knowl- phometric evaluation. Minerva Stomatol 18. Niamtu J 3rd. Near-fatal airway obstruc- 2013;62:3–16. tion after routine implant placement. edge about the key anatomical 7. Esposito M, Pistilli R, Barausse C, Felice Oral Surg Oral Med Oral Pathol Oral Ra- landmarks of the mandibular region P. Three-year results from a randomised diol Endod 2001;92:597–600. controlled trial comparing prostheses 19. Thiel W. [Supplement to the conserva- is imperative to safely perform ridge supported by 5-mm long implants or by tion of an entire cadaver according to augmentation when releasing the longer implants in augmented bone in W. Thiel] [in German]. Ann Anat 2002; posterior atrophic edentulous jaws. Eur 184:267–269. lingual flap to attain tension-free clo- J Oral Implantol 2014;7:383–395. 20. Katsumi Y, Tanaka R, Hayashi T, Koga T, sure and consequently undisturbed 8. Urban IA, Monje A, Lozada JL, Wang HL. Takagi R, Ohshima H. Variation in arterial Long-term evaluation of peri-implant supply to the floor of the mouth and as- wound healing. Dense connective bone level after reconstruction of severe- sessment of relative hemorrhage risk in tissue may play an important role in ly atrophic edentulous maxilla via vertical implant surgery. Clin Oral Implants Res and horizontal guided bone regenera- 2013;24:434–440. protecting the key elements of the tion in combination with sinus augmen- 21. Omelyanenko NP, Slutsky LI, Mironov sublingual space during lingual flap tation: A case series with 1 to 15 years SP. Peculiarities of connective tissue. In: management. of loading. Clin Implant Dent Relat Res Omelyanenko NP, Slutsky LI, Mironov SP 2017;19:46–55. (eds). Connective Tissue: Histophysiol- 9. Urban IA, Monje A, Nevins M, Nevins ogy, Biochemistry, Molecular Biology. ML, Lozada JL, Wang HL. Surgical man- Boca Raton: CRC Press, 2014:2–15. agement of significant maxillary anterior 22. Chan HL, Brooks SL, Fu JH, Yeh CY, Acknowledgments vertical ridge defects. Int J Periodontics Rudek I, Wang HL. Cross-sectional analy- Restorative Dent 2016;36:329–337. sis of the mandibular lingual concavity us- 10. Urban IA, Monje A, Wang HL. Verti- ing cone beam computed tomography. The authors would like to thank Viktor Pan- cal ridge augmentation and soft tissue Clin Oral Implants Res 2011;22:201–206. kovics for his assistance in the preparation reconstruction of the anterior atrophic 23. Chan HL, Benavides E, Yeh CY, Fu JH, of the specimens shown in this manuscript. maxillae: A case series. Int J Periodontics Rudek IE, Wang HL. Risk assessment Restorative Dent 2015;35:613–623. of lingual plate perforation in poste- The authors reported no conflicts of interest 11. Sanz M, Simion M. Surgical techniques rior mandibular region: A virtual implant related to this study. on periodontal plastic surgery and soft placement study using cone-beam com- tissue regeneration: Consensus report of puted tomography. J Periodontol 2011; Group 3 of the 10th European Workshop 82:129–135. on Periodontology. J Clin Periodontol 24. Mordenfeld A, Andersson L, Bergström References 2014;41(suppl 15):S92–S97. B. Hemorrhage in the floor of the mouth 12. Urban IA, Lozada JL, Jovanovic SA, Na- during implant placement in the edentu- gursky H, Nagy K. Vertical ridge aug- lous mandible: A case report. Int J Oral . 1 Chan HL, Leong DJ, Fu JH, Yeh CY, Tata- mentation with titanium-reinforced, Maxillofac Implants 1997;12:558–561. rakis N, Wang HL. The significance of the dense-PTFE membranes and a combi- 25. Pogrel MA, Bryan J, Regezi J. Nerve lingual nerve during periodontal/implant nation of particulated autogenous bone damage associated with inferior alveo- surgery. J Periodontol 2010;81:372–377. and anorganic bovine bone-derived lar nerve blocks. J Am Dent Assoc 1995; 2. Froum S, Casanova L, Byrne S, Cho SC. mineral: A prospective case series in 19 126:1150 –1155. Risk assessment before extraction for patients. Int J Oral Maxillofac Implants 26. Flanagan D. Important arterial supply of immediate implant placement in the 2014;29:185–193. the mandible, control of an arterial hem- posterior mandible: A computerized to- 13. Wang HL, Boyapati L. “PASS” principles orrhage, and report of a hemorrhagic in- mographic scan study. J Periodontol 2011; for predictable bone regeneration. Im- cident. J Oral Implantol 2003;29:165–173. 82:395–402. plant Dent 2006;15:8–17. 27. Misch CM, Jensen OT, Pikos MA, 3. Ritter L, Neugebauer J, Mischkowski RA, 14. Tinti C, Parma-Benfenati S. Vertical ridge Malmquist JP. Vertical bone augmenta- et al. Evaluation of the course of the infe- augmentation: Surgical protocol and tion using recombinant bone morphoge- rior alveolar nerve in the mental foramen retrospective evaluation of 48 consecu- netic protein, mineralized bone allograft, by cone beam computed tomography. tively inserted implants. Int J Peridontics and titanium mesh: A retrospective cone Int J Oral Maxillofac Implants 2012;27: Restorative Dent 1998;18:434–443. beam computed tomography study. 1014–1021. Int J Oral Maxillofac Implants 2015;30: 202–207.

Volume 37, Number 3, 2017